update verson numbers to v8.0.1

To cover widgets on the top layer too

.editorconfig

@@ -0,0 +1,6 @@
+[*.{c,h,ino}]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true

.github/FUNDING.yml

@@ -0,0 +1 @@
+open_collective: lvgl

.github/ISSUE_TEMPLATE/bug-report.md

@@ -0,0 +1,43 @@
+---
+name: Bug report
+about: Create a bug report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+<!--
+IMPORTANT
+Issues that don't use this template will be ignored and closed.
+-->
+
+### Perform all steps below and tick them with [x]
+- [ ] Check the related part of the [Documentation](https://docs.lvgl.io/)
+- [ ] Update lvgl to the latest version
+- [ ] Reproduce the issue in a [Simulator](https://docs.lvgl.io/latest/en/html/get-started/pc-simulator.html)
+
+### Describe the bug
+<!--
+A clear and concise description of what the bug is.
+-->
+
+### To Reproduce
+<!--
+Provide a small, independent code sample that can be used to reproduce the issue.
+Ideally this should work in the PC simulator unless the problem is specific to a platform.
+Format the code like this:
+```c
+your code here
+```
+-->
+
+### Expected behavior
+<!--
+A clear and concise description of what you expected to happen.
+-->
+
+### Screenshots or video
+<!--
+If applicable, add screenshots to help explain your problem.
+-->

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,14 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Documentation
+    url: https://docs.lvgl.io
+    about: Be sure to read to documentation first
+  - name: Forum
+    url: https://forum.lvgl.io
+    about: For topics like How-to, Getting started, Feature request
+  - name: CONTIBUTING.md
+    url: https://github.com/lvgl/lvgl/blob/master/docs/CONTRIBUTING.md#faq-about-contributing
+    about: The basic rules of contributing
+  - name: CODING_STYLE.md
+    url: https://github.com/lvgl/lvgl/blob/master/docs/CODING_STYLE.md
+    about: Quick summary of LVGL's code style

.github/ISSUE_TEMPLATE/dev-discussion.md

@@ -0,0 +1,29 @@
+---
+name: Development discussion
+about: Discussion strictly related to the development of the LVGL.
+title: ''
+labels: ''
+assignees: ''
+
+---
+<!--
+IMPORTANT
+Issues that don't use this template will be ignored and closed.
+
+Normal Feature requests should go to the Forum: https://forum.lvgl.io/c/feature-request/9
+-->
+
+### Introduce the problem
+<!--
+A clear and concise description of the problem.
+-->
+
+### Examples and cases
+<!--
+Mention some examples and cases where the problem or the missing feature is relevant
+-->
+
+### Suggested solution
+<!--
+If you already have an idea about the solution share it here
+-->

.github/auto-comment.yml

@@ -0,0 +1,12 @@
+# Comment to a new issue.
+pullRequestOpened: |
+  Thank you for raising your pull request.
+
+  To ensure that all licensing criteria is met all repositories of the LVGL project apply a process called DCO (Developer's Certificate of Origin).
+
+  The text of DCO can be read here: https://developercertificate.org/
+  For a more detailed description see the [Documentation](https://docs.lvgl.io/latest/en/html/contributing/index.html#developer-certification-of-origin-dco) site.
+
+  By contributing to any repositories of the LVGL project you state that your contribution corresponds with the DCO.
+
+  No further action is required if your contribution fulfills the DCO. If you are not sure about it feel free to ask us in a comment.

.github/pull_request_template.md

@@ -0,0 +1,8 @@
+### Description of the feature or fix
+
+A clear and concise description of what the bug or new feature is.
+
+### Checkpoints
+- [ ] Follow the [styling guide](https://github.com/lvgl/lvgl/blob/master/docs/CODING_STYLE.md)
+- [ ] Update [CHANGELOG.md](https://github.com/lvgl/lvgl/blob/master/docs/CHANGELOG.md)
+- [ ] Update the documentation

.github/workflows/build_micropython.yml

@@ -0,0 +1,43 @@
+name: Build Micropython with LVGL submodule
+
+on:
+  push:
+    branches: [ master, dev ]
+  pull_request:
+    branches: [ master, dev ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Install SDL
+      run: |
+        sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu `lsb_release -sc` main universe restricted multiverse"
+        sudo apt-get update -y -qq
+        sudo apt-get install libsdl2-dev
+    - name: Clone lv_micropython
+      run: |
+        git clone https://github.com/lvgl/lv_micropython.git .
+        git checkout dev-8.0
+    - name: Update submodules
+      run: git submodule update --init --recursive
+    - name: Checkout LVGL submodule
+      working-directory: ./lib/lv_bindings/lvgl
+      run: |
+        git fetch --force ${{ github.event.repository.git_url }} "+refs/heads/*:refs/remotes/origin/*"
+        git fetch --force ${{ github.event.repository.git_url }} "+refs/pull/*:refs/remotes/origin/pr/*"
+        git checkout ${{ github.sha }} || git checkout ${{ github.event.pull_request.head.sha }}
+        git submodule update --init --recursive
+    - name: Build mpy-cross
+      run: make -j $(nproc) -C mpy-cross
+    - name: Build the unix port
+      run: make -j $(nproc) -C ports/unix
+    - name: Run advanced_demo
+      run: >
+        echo "import gc,utime;
+        utime.sleep(5);
+        gc.collect();
+        utime.sleep(5)" |
+        ports/unix/micropython -i lib/lv_bindings/examples/advanced_demo.py

.github/workflows/ccpp.yml

@@ -0,0 +1,18 @@
+name: C/C++ CI
+
+on:
+  push:
+    branches: [ master, dev ]
+  pull_request:
+    branches: [master, dev ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ammaraskar/gcc-problem-matcher@master
+    - name: Run tests
+      run: sudo apt-get install libpng-dev; cd tests; python ./build.py

.github/workflows/close_old_issues.yml

@@ -0,0 +1,20 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+  workflow_dispatch:
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v3
+        with:
+          repo-token: ${{ secrets.LVGL_BOT_TOKEN }}
+          stale-issue-message: 'This issue is stale because it has been open 14 days with no activity. Remove stale label or comment or this will be closed in 7 days.'
+          stale-pr-message: 'This PR is stale because it has been open 14 days with no activity. Remove stale label or comment or this will be closed in 7 days.'
+          close-issue-message: 'This issue was closed because it has been stalled for 7 days with no activity.'
+          days-before-stale: 14
+          days-before-close: 7
+          exempt-issue-labels: 'pinned'
+          exempt-pr-labels: 'pinned'

.github/workflows/compile_docs.yml

@@ -0,0 +1,75 @@
+name: Build docs
+on:
+  push:
+    branches:
+    - master
+    - 'release/*'
+env:
+  EM_VERSION: 2.0.4
+  EM_CACHE_FOLDER: 'emsdk-cache'
+jobs:
+  build-and-deploy:
+    if: github.repository == 'lvgl/lvgl'
+    runs-on: ubuntu-latest
+    concurrency: docs-build-and-deploy
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+      - name: Setup Python
+        uses: actions/setup-python@v1
+        with:
+          python-version: 3.7
+      - name: Cache Python packages
+        uses: actions/cache@v2
+        with:
+          # Cache the Python package environment, excluding pip and setuptools installed by setup-python
+          path: |
+            ~/.cache/pip
+            ${{ env.pythonLocation }}/bin/*
+            ${{ env.pythonLocation }}/include
+            ${{ env.pythonLocation }}/lib/python*/site-packages/*
+            !${{ env.pythonLocation }}/bin/pip*
+            !${{ env.pythonLocation }}/lib/python*/site-packages/pip*
+            !${{ env.pythonLocation }}/lib/python*/site-packages/setuptools*
+          key: ${{ env.pythonLocation }}-${{ hashFiles('docs/requirements.txt') }}
+      - name: Install Doxygen and Latex dependencies
+        run: sudo apt-get install doxygen texlive-xetex texlive-binaries texlive-lang-english latexmk fonts-freefont-otf
+      - name: Install requirements
+        run: |
+          pip install -r docs/requirements.txt
+      - name: Setup Emscripten cache
+        id: cache-system-libraries
+        uses: actions/cache@v2
+        with:
+          path: ${{env.EM_CACHE_FOLDER}}
+          key: ${{env.EM_VERSION}}-${{ runner.os }}
+      - uses: mymindstorm/setup-emsdk@v9
+        with:
+          version: ${{env.EM_VERSION}}
+          actions-cache-folder: ${{env.EM_CACHE_FOLDER}}
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1
+      - name: Build examples (with cache)
+        run: scripts/build_html_examples.sh
+      - name: Build docs
+        run: docs/build.py
+      - name: Remove .doctrees
+        run: rm -rf out_html/.doctrees
+      - name: Retrieve version
+        run: |
+          echo "::set-output name=VERSION_NAME::$(scripts/find_version.sh)"
+        id: version
+      - name: Deploy
+        uses: JamesIves/github-pages-deploy-action@3.7.1
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ACCESS_TOKEN: ${{ secrets.LVGL_BOT_TOKEN }}
+          REPOSITORY_NAME: lvgl/docs
+          BRANCH: gh-pages # The branch the action should deploy to.
+          FOLDER: out_html  # The folder the action should deploy.
+          TARGET_FOLDER: ${{ steps.version.outputs.VERSION_NAME }}
+          PRESERVE: true
+          SINGLE_COMMIT: true

.github/workflows/main.yml

@@ -0,0 +1,16 @@
+on:
+  issues:
+    types: [opened, edited]
+
+jobs:
+  auto_close_issues:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - name: Automatically close issues that don't follow the issue template
+        uses: lucasbento/auto-close-issues@v1.0.2
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          issue-close-message: "@${issue.user.login}: hello! :wave:\n\nThis issue is being automatically closed because it does not follow the issue template." # optional property
+          closed-issues-label: "not-template"

.github/workflows/release.yml

@@ -0,0 +1,27 @@
+on:
+  push:
+    # Sequence of patterns matched against refs/tags
+    tags:
+      - 'v*' # Push events to matching v*, i.e. v1.0, v20.15.10
+
+name: Create Release
+
+jobs:
+  build:
+    name: Create Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # This token is provided by Actions, you do not need to create your own token
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: Release ${{ github.ref }}
+          body: |
+            See the [CHANGELOG](https://github.com/lvgl/lvgl/blob/master/docs/CHANGELOG.md)
+          draft: false
+          prerelease: false

.gitignore

@@ -1 +1,17 @@
-**/*.o
+**/*.o
+**/*bin
+**/*.swp
+**/*.swo
+tags
+docs/api_doc
+scripts/cppcheck_res.txt
+scripts/built_in_font/lv_font_*
+docs/doxygen_html
+docs/xml
+docs/out_latex
+docs/_static/built_lv_examples
+docs/LVGL.pdf
+docs/env
+out_html
+__pycache__
+/emscripten_builder

CMakeLists.txt

@@ -0,0 +1,67 @@
+if(ESP_PLATFORM)
+
+file(GLOB_RECURSE SOURCES src/*.c)
+
+idf_component_register(SRCS ${SOURCES}
+                       INCLUDE_DIRS . src ../
+                       REQUIRES main)
+
+target_compile_definitions(${COMPONENT_LIB} PUBLIC "-DLV_CONF_INCLUDE_SIMPLE")
+
+if (CONFIG_LV_MEM_CUSTOM)
+    if (CONFIG_LV_MEM_CUSTOM_ALLOC)
+        target_compile_definitions(${COMPONENT_LIB} PUBLIC "-DLV_MEM_CUSTOM_ALLOC=${CONFIG_LV_MEM_CUSTOM_ALLOC}")
+    endif()
+
+    if (CONFIG_LV_MEM_CUSTOM_FREE)
+        target_compile_definitions(${COMPONENT_LIB} PUBLIC "-DLV_MEM_CUSTOM_FREE=${CONFIG_LV_MEM_CUSTOM_FREE}")
+    endif()
+endif()
+
+if (CONFIG_LV_TICK_CUSTOM)
+    if (CONFIG_LV_TICK_CUSTOM_SYS_TIME_EXPR)
+        target_compile_definitions(${COMPONENT_LIB} PUBLIC "-DLV_TICK_CUSTOM_SYS_TIME_EXPR=${CONFIG_LV_TICK_CUSTOM_SYS_TIME_EXPR}")
+    endif()
+endif()
+
+if (CONFIG_LV_USER_DATA_FREE)
+    target_compile_definitions(${COMPONENT_LIB} PUBLIC "-DLV_USER_DATA_FREE=${CONFIG_LV_USER_DATA_FREE}")
+endif()
+
+if (CONFIG_LV_ATTRIBUTE_FAST_MEM_USE_IRAM)
+    target_compile_definitions(${COMPONENT_LIB} PUBLIC "-DLV_ATTRIBUTE_FAST_MEM=IRAM_ATTR")
+endif()
+
+elseif(ZEPHYR_BASE)
+
+if(CONFIG_LVGL)
+
+zephyr_include_directories(${ZEPHYR_BASE}/lib/gui/lvgl)
+
+target_include_directories(lvgl INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
+
+zephyr_compile_definitions(LV_CONF_KCONFIG_EXTERNAL_INCLUDE=<autoconf.h>)
+
+zephyr_compile_definitions_ifdef(CONFIG_LV_MEM_CUSTOM
+    LV_MEM_CUSTOM_ALLOC=${CONFIG_LV_MEM_CUSTOM_ALLOC}
+    )
+zephyr_compile_definitions_ifdef(CONFIG_LV_MEM_CUSTOM
+    LV_MEM_CUSTOM_FREE=${CONFIG_LV_MEM_CUSTOM_FREE}
+    )
+zephyr_compile_definitions_ifdef(CONFIG_LV_TICK_CUSTOM
+    LV_TICK_CUSTOM_SYS_TIME_EXPR=${CONFIG_LV_TICK_CUSTOM_SYS_TIME_EXPR}
+    )
+
+zephyr_library()
+
+file(GLOB_RECURSE SOURCES src/*.c)
+zephyr_library_sources(${SOURCES})
+
+endif() # CONFIG_LVGL
+
+else()
+
+file(GLOB_RECURSE SOURCES src/*.c)
+add_library(lvgl STATIC ${SOURCES})
+
+endif()

Kconfig

@@ -0,0 +1,714 @@
+# Kconfig file for LVGL v8.0
+
+menu "LVGL configuration"
+
+    config LV_ATTRIBUTE_FAST_MEM_USE_IRAM
+        bool "Set IRAM as LV_ATTRIBUTE_FAST_MEM"
+        help
+            Set this option to configure IRAM as LV_ATTRIBUTE_FAST_MEM
+
+    config LV_CONF_MINIMAL
+        bool "LVGL minimal configuration."
+
+    # Define CONFIG_LV_CONF_SKIP so we can use LVGL
+    # without lv_conf.h file, the lv_conf_internal.h and
+    # lv_conf_kconfig.h files are used instead.
+    config LV_CONF_SKIP
+        bool
+        default y
+
+    menu "Color settings"
+        choice
+            prompt "Color depth."
+            default LV_COLOR_DEPTH_16
+            help
+                Color depth to be used.
+
+            config LV_COLOR_DEPTH_32
+                bool "32: ARGB8888"
+            config LV_COLOR_DEPTH_16
+                bool "16: RGB565"
+            config LV_COLOR_DEPTH_8
+                bool "8: RGB232"
+            config LV_COLOR_DEPTH_1
+                bool "1: 1 byte per pixel"
+        endchoice
+
+        config LV_COLOR_DEPTH
+            int
+            default 1 if LV_COLOR_DEPTH_1
+            default 8 if LV_COLOR_DEPTH_8
+            default 16 if LV_COLOR_DEPTH_16
+            default 32 if LV_COLOR_DEPTH_32
+
+        config LV_COLOR_16_SWAP
+            bool "Swap the 2 bytes of RGB565 color. Useful if the display has a 8 bit interface (e.g. SPI)."
+            depends on LV_COLOR_DEPTH_16
+
+        config LV_COLOR_SCREEN_TRANSP
+            bool "Enable more complex drawing routines to manage screens transparency."
+            depends on LV_COLOR_DEPTH_32
+            help
+                Can be used if the UI is above another layer, e.g. an OSD menu or video player.
+                Requires `LV_COLOR_DEPTH = 32` colors and the screen's `bg_opa` should be set to
+                non LV_OPA_COVER value
+    
+        config LV_COLOR_CHROMA_KEY_HEX
+            hex "Images pixels with this color will not be drawn (if they are chroma keyed)."
+            range 0x000000 0xFFFFFF
+            default 0x00FF00
+            help
+                See misc/lv_color.h for some color values examples.
+    endmenu
+
+    menu "Memory settings"
+        config LV_MEM_CUSTOM
+            bool "If true use custom malloc/free, otherwise use the built-in `lv_mem_alloc()` and `lv_mem_free()`"
+
+        config LV_MEM_SIZE_KILOBYTES
+            int "Size of the memory used by `lv_mem_alloc` in kilobytes (>= 2kB)"
+            range 2 128
+            default 32
+            depends on !LV_MEM_CUSTOM
+
+        config LV_MEM_CUSTOM_INCLUDE
+            string "Header to include for the custom memory function"
+            default "stdlib.h"
+            depends on LV_MEM_CUSTOM
+
+        config LV_MEMCPY_MEMSET_STD
+            bool "Use the standard memcpy and memset instead of LVGL's own functions"
+    endmenu
+
+    menu "HAL Settings"
+        config LV_DISP_DEF_REFR_PERIOD
+            int "Default display refresh period (ms)."
+            default 30
+            help
+                Can be changed in the display driver (`lv_disp_drv_t`).
+
+        config LV_INDEV_DEF_READ_PERIOD
+            int "Input device read period [ms]."
+            default 30
+
+        config LV_TICK_CUSTOM
+            bool
+            prompt "Use a custom tick source"
+
+        config LV_TICK_CUSTOM_INCLUDE
+            string
+            prompt "Header for the system time function"
+            default "Arduino.h"
+            depends on LV_TICK_CUSTOM
+
+        config LV_DPI_DEF
+            int "Default Dots Per Inch (in px)."
+            default 130
+            help
+                Used to initialize default sizes such as widgets sized, style paddings.
+                (Not so important, you can adjust it to modify default sizes and spaces)
+    endmenu
+
+    menu "Feature configuration"
+
+        menu "Drawing"
+            config LV_DRAW_COMPLEX
+                bool "Enable complex draw engine"
+                default y
+                help
+                    Required to draw shadow, gradient, rounded corners, circles, arc, skew lines,
+                    image transformations or any masks.
+
+            config LV_SHADOW_CACHE_SIZE
+                int "Allow buffering some shadow calculation"
+                depends on LV_DRAW_COMPLEX
+                default 0
+                help
+                    LV_SHADOW_CACHE_SIZE is the max shadow size to buffer, where
+                    shadow size is `shadow_width + radius`.
+                    Caching has LV_SHADOW_CACHE_SIZE^2 RAM cost.
+
+            config LV_IMG_CACHE_DEF_SIZE
+                int "Default image cache size. 0 to disable caching."
+                default 0
+                help
+                    If only the built-in image formats are used there is no real advantage of caching.
+                    (I.e. no new image decoder is added).
+
+                    With complex image decoders (e.g. PNG or JPG) caching can
+                    save the continuous open/decode of images.
+                    However the opened images might consume additional RAM.
+
+            config LV_DISP_ROT_MAX_BUF
+                int "Maximum buffer size to allocate for rotation"
+                default 10240
+                help
+                    Only used if software rotation is enabled in the display driver.
+        endmenu
+        
+        menu "GPU"
+            config LV_USE_GPU_STM32_DMA2D
+                bool "Enable STM32 DMA2D (aka Chrom Art) GPU."
+            config LV_GPU_DMA2D_CMSIS_INCLUDE
+                string "include path of CMSIS header of target processor"
+                depends on LV_USE_GPU_STM32_DMA2D
+                default ""
+                help
+                    Must be defined to include path of CMSIS header of target processor
+                    e.g. "stm32f769xx.h" or "stm32f429xx.h"
+
+            config LV_USE_GPU_NXP_PXP
+                bool "Use NXP's PXP GPU iMX RTxxx platforms."
+            config LV_USE_GPU_NXP_PXP_AUTO_INIT
+                bool "Call lv_gpu_nxp_pxp_init() automatically or manually."
+                depends on LV_USE_GPU_NXP_PXP
+                help
+                    1: Add default bare metal and FreeRTOS interrupt handling
+                    routines for PXP (lv_gpu_nxp_pxp_osa.c) and call
+                    lv_gpu_nxp_pxp_init() automatically during lv_init().
+                    Note that symbol FSL_RTOS_FREE_RTOS has to be defined in order
+                    to use FreeRTOS OSA, otherwise bare-metal implementation is
+                    selected.
+                    0: lv_gpu_nxp_pxp_init() has to be called manually before
+                    lv_init().
+            config LV_USE_GPU_NXP_VG_LITE
+                bool "Use NXP's VG-Lite GPU iMX RTxxx platforms."
+        endmenu
+
+        menu "Logging"
+            config LV_USE_LOG
+                bool "Enable the log module"
+
+            choice
+                bool "Default log verbosity" if LV_USE_LOG
+                default LV_LOG_LEVEL_WARN
+                help
+                    Specify how important log should be added.
+
+                config LV_LOG_LEVEL_TRACE
+                    bool "A lot of logs to give detailed information"
+                config LV_LOG_LEVEL_INFO
+                    bool "Log important events"
+                config LV_LOG_LEVEL_WARN
+                    bool "Log if something unwanted happened but didn't cause a problem"
+                config LV_LOG_LEVEL_ERROR
+                    bool "Only critical issues, when the system may fail"
+                config LV_LOG_LEVEL_USER
+                    bool "Only logs added by the user"
+                config LV_LOG_LEVEL_NONE
+                    bool "Do not log anything"
+            endchoice
+
+            config LV_LOG_LEVEL
+                int
+                default 0 if LV_LOG_LEVEL_TRACE
+                default 1 if LV_LOG_LEVEL_INFO
+                default 2 if LV_LOG_LEVEL_WARN
+                default 3 if LV_LOG_LEVEL_ERROR
+                default 4 if LV_LOG_LEVEL_USER
+                default 5 if LV_LOG_LEVEL_NONE
+
+            config LV_LOG_PRINTF
+                bool "Print the log with 'printf'" if LV_USE_LOG
+                help
+                    Use printf for log output.
+                    If not set the user needs to register a callback with `lv_log_register_print_cb`.
+
+            config LV_LOG_TRACE_MEM
+                bool "Enable/Disable LV_LOG_TRACE in mem module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_TIMER
+                bool "Enable/Disable LV_LOG_TRACE in timer module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_INDEV
+                bool "Enable/Disable LV_LOG_TRACE in indev module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_DISP_REFR
+                bool "Enable/Disable LV_LOG_TRACE in disp refr module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_EVENT
+                bool "Enable/Disable LV_LOG_TRACE in event module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_OBJ_CREATE
+                bool "Enable/Disable LV_LOG_TRACE in obj create module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_LAYOUT
+                bool "Enable/Disable LV_LOG_TRACE in layout module"
+                default y
+                depends on LV_USE_LOG
+
+            config LV_LOG_TRACE_ANIM
+                bool "Enable/Disable LV_LOG_TRACE in anim module"
+                default y
+                depends on LV_USE_LOG
+        endmenu
+
+        menu "Asserts"
+            config LV_USE_ASSERT_NULL
+                bool "Check if the parameter is NULL. (Very fast, recommended)"
+                default y if !LV_CONF_MINIMAL
+
+            config LV_USE_ASSERT_MALLOC
+                bool "Checks if the memory is successfully allocated or no. (Very fast, recommended)"
+                default y if !LV_CONF_MINIMAL
+
+            config LV_USE_ASSERT_STYLE
+                bool "Check if the styles are properly initialized. (Very fast, recommended)"
+
+            config LV_USE_ASSERT_MEM_INTEGRITY
+                bool "Check the integrity of `lv_mem` after critical operations. (Slow)"
+
+            config LV_USE_ASSERT_OBJ
+                bool "Check NULL, the object's type and existence (e.g. not deleted). (Slow)."
+        endmenu
+
+        menu "Others"
+            config LV_USE_PERF_MONITOR
+                bool "Show CPU usage and FPS count in the right bottom corner."
+
+            config LV_USE_MEM_MONITOR
+                bool "Show the used memory and the memory fragmentation in the left bottom corner. Requires LV_MEM_CUSTOM = 0"
+
+            config LV_USE_REFR_DEBUG
+                bool "Draw random colored rectangles over the redrawn areas."
+
+            config LV_SPRINTF_CUSTOM
+                bool "Change the built-in (v)snprintf functions"
+
+            config LV_SPRINTF_USE_FLOAT
+                bool "Enable float in built-in (v)snprintf functions"
+                depends on !LV_SPRINTF_CUSTOM
+
+            config LV_USE_USER_DATA
+                bool "Add a 'user_data' to drivers and objects."
+                default y
+        endmenu
+
+        menu "Compiler settings"
+            config LV_BIG_ENDIAN_SYSTEM
+                bool "For big endian systems set to 1"
+
+            config LV_USE_LARGE_COORD
+                bool "Extend the default -32k..32k coordinate range to -4M..4M by using int32_t for coordinates instead of int16_t"
+        endmenu
+
+        config LV_USE_USER_DATA_FREE
+            bool "Free the user data field upon object deletion"
+            depends on LV_USE_USER_DATA
+        config LV_USER_DATA_FREE_INCLUDE
+            string "Header for user data free function"
+            default "something.h"
+            depends on LV_USE_USER_DATA_FREE
+        config LV_USER_DATA_FREE
+            string "Invoking for user data free function. It has the lv_obj_t pointer as single parameter."
+            default "(user_data_free)"
+            depends on LV_USE_USER_DATA_FREE
+        config LV_USE_API_EXTENSION_V6
+            bool "Use the functions and types from the older (v6) API if possible."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_API_EXTENSION_V7
+            bool "Use the functions and types from the older (v7) API if possible."
+            default y if !LV_CONF_MINIMAL
+    endmenu
+
+    menu "Font usage"
+        menu "Enable built-in fonts"
+            config LV_FONT_MONTSERRAT_8
+                bool "Enable Montserrat 8"
+            config LV_FONT_MONTSERRAT_10
+                bool "Enable Montserrat 10"
+            config LV_FONT_MONTSERRAT_12
+                bool "Enable Montserrat 12"
+            config LV_FONT_MONTSERRAT_14
+                bool "Enable Montserrat 14"
+                default y if !LV_CONF_MINIMAL
+            config LV_FONT_MONTSERRAT_16
+                bool "Enable Montserrat 16"
+            config LV_FONT_MONTSERRAT_18
+                bool "Enable Montserrat 18"
+            config LV_FONT_MONTSERRAT_20
+                bool "Enable Montserrat 20"
+            config LV_FONT_MONTSERRAT_22
+                bool "Enable Montserrat 22"
+            config LV_FONT_MONTSERRAT_24
+                bool "Enable Montserrat 24"
+            config LV_FONT_MONTSERRAT_26
+                bool "Enable Montserrat 26"
+            config LV_FONT_MONTSERRAT_28
+                bool "Enable Montserrat 28"
+            config LV_FONT_MONTSERRAT_30
+                bool "Enable Montserrat 30"
+            config LV_FONT_MONTSERRAT_32
+                bool "Enable Montserrat 32"
+            config LV_FONT_MONTSERRAT_34
+                bool "Enable Montserrat 34"
+            config LV_FONT_MONTSERRAT_36
+                bool "Enable Montserrat 36"
+            config LV_FONT_MONTSERRAT_38
+                bool "Enable Montserrat 38"
+            config LV_FONT_MONTSERRAT_40
+                bool "Enable Montserrat 40"
+            config LV_FONT_MONTSERRAT_42
+                bool "Enable Montserrat 42"
+            config LV_FONT_MONTSERRAT_44
+                bool "Enable Montserrat 44"
+            config LV_FONT_MONTSERRAT_46
+                bool "Enable Montserrat 46"
+            config LV_FONT_MONTSERRAT_48
+                bool "Enable Montserrat 48"
+
+            config LV_FONT_UNSCII_8
+                bool "Enable UNSCII 8 (Perfect monospace font)"
+                default y if LV_CONF_MINIMAL
+            config LV_FONT_UNSCII_16
+                bool "Enable UNSCII 16 (Perfect monospace font)"
+
+            config LV_FONT_MONTSERRAT12SUBPX
+                bool "Enable Montserrat 12 sub-pixel"
+            config LV_FONT_MONTSERRAT28COMPRESSED
+                bool "Enable Montserrat 28 compressed"
+            config LV_FONT_DEJAVU_16_PERSIAN_HEBREW
+                bool "Enable Dejavu 16 Persian, Hebrew, Arabic letters"
+            config LV_FONT_SIMSUN_16_CJK
+                bool "Enable Simsun 16 CJK"
+        endmenu
+
+        config LV_FONT_FMT_TXT_LARGE
+            bool "Enable it if you have fonts with a lot of characters."
+            help
+                The limit depends on the font size, font face and bpp
+                but with > 10,000 characters if you see issues probably you
+                need to enable it.
+
+        config LV_USE_FONT_COMPRESSED
+            bool "Sets support for compressed fonts."
+
+        config LV_USE_FONT_SUBPX
+            bool "Enable subpixel rendering."
+
+        config LV_FONT_SUBPX_BGR
+            bool "Use BGR instead RGB for sub-pixel rendering."
+            depends on LV_USE_FONT_SUBPX
+            help
+                Set the pixel order of the display.
+                Important only if "subpx fonts" are used.
+                With "normal" font it doesn't matter.
+
+        choice LV_FONT_DEFAULT
+            prompt "Select theme default title font"
+            default LV_FONT_DEFAULT_MONTSERRAT_16 if !LV_CONF_MINIMAL
+            default LV_FONT_DEFAULT_UNSCII_8 if LV_CONF_MINIMAL
+            help
+                Select theme default title font
+
+            config LV_FONT_DEFAULT_MONTSERRAT_8
+                bool "Montserrat 8"
+                select LV_FONT_MONTSERRAT_8
+            config LV_FONT_DEFAULT_MONTSERRAT_12
+                bool "Montserrat 12"
+                select LV_FONT_MONTSERRAT_12
+            config LV_FONT_DEFAULT_MONTSERRAT_14
+                bool "Montserrat 14"
+                select LV_FONT_MONTSERRAT_14
+            config LV_FONT_DEFAULT_MONTSERRAT_16
+                bool "Montserrat 16"
+                select LV_FONT_MONTSERRAT_16
+            config LV_FONT_DEFAULT_MONTSERRAT_18
+                bool "Montserrat 18"
+                select LV_FONT_MONTSERRAT_18
+            config LV_FONT_DEFAULT_MONTSERRAT_20
+                bool "Montserrat 20"
+                select LV_FONT_MONTSERRAT_20
+            config LV_FONT_DEFAULT_MONTSERRAT_22
+                bool "Montserrat 22"
+                select LV_FONT_MONTSERRAT_22
+            config LV_FONT_DEFAULT_MONTSERRAT_24
+                bool "Montserrat 24"
+                select LV_FONT_MONTSERRAT_24
+            config LV_FONT_DEFAULT_MONTSERRAT_26
+                bool "Montserrat 26"
+                select LV_FONT_MONTSERRAT_26
+            config LV_FONT_DEFAULT_MONTSERRAT_28
+                bool "Montserrat 28"
+                select LV_FONT_MONTSERRAT_28
+            config LV_FONT_DEFAULT_MONTSERRAT_30
+                bool "Montserrat 30"
+                select LV_FONT_MONTSERRAT_30
+            config LV_FONT_DEFAULT_MONTSERRAT_32
+                bool "Montserrat 32"
+                select LV_FONT_MONTSERRAT_32
+            config LV_FONT_DEFAULT_MONTSERRAT_34
+                bool "Montserrat 34"
+                select LV_FONT_MONTSERRAT_34
+            config LV_FONT_DEFAULT_MONTSERRAT_36
+                bool "Montserrat 36"
+                select LV_FONT_MONTSERRAT_36
+            config LV_FONT_DEFAULT_MONTSERRAT_38
+                bool "Montserrat 38"
+                select LV_FONT_MONTSERRAT_38
+            config LV_FONT_DEFAULT_MONTSERRAT_40
+                bool "Montserrat 40"
+                select LV_FONT_MONTSERRAT_40
+            config LV_FONT_DEFAULT_MONTSERRAT_42
+                bool "Montserrat 42"
+                select LV_FONT_MONTSERRAT_42
+            config LV_FONT_DEFAULT_MONTSERRAT_44
+                bool "Montserrat 44"
+                select LV_FONT_MONTSERRAT_44
+            config LV_FONT_DEFAULT_MONTSERRAT_46
+                bool "Montserrat 46"
+                select LV_FONT_MONTSERRAT_46
+            config LV_FONT_DEFAULT_MONTSERRAT_48
+                bool "Montserrat 48"
+                select LV_FONT_MONTSERRAT_48
+            config LV_FONT_DEFAULT_UNSCII_8
+                bool "UNSCII 8 (Perfect monospace font)"
+                select LV_FONT_UNSCII_8
+            config LV_FONT_DEFAULT_UNSCII_16
+                bool "UNSCII 16 (Perfect monospace font)"
+                select LV_FONT_UNSCII_16
+            config LV_FONT_DEFAULT_MONTSERRAT12SUBPX
+                bool "Montserrat 12 sub-pixel"
+                select LV_FONT_MONTSERRAT12SUBPX
+            config LV_FONT_DEFAULT_MONTSERRAT28COMPRESSED
+                bool "Montserrat 28 compressed"
+                select LV_FONT_MONTSERRAT28COMPRESSED
+            config LV_FONT_DEFAULT_DEJAVU_16_PERSIAN_HEBREW
+                bool "Dejavu 16 Persian, Hebrew, Arabic letters"
+                select LV_FONT_DEJAVU_16_PERSIAN_HEBREW
+            config LV_FONT_DEFAULT_SIMSUN_16_CJK
+                bool "Simsun 16 CJK"
+                select LV_FONT_SIMSUN_16_CJK
+        endchoice
+    endmenu
+
+    menu "Themes"
+        config LV_USE_THEME_DEFAULT
+            bool "A simple, impressive and very complete theme"
+            default y
+        config LV_THEME_DEFAULT_PALETTE_LIGHT
+            bool "Yes to set light mode, No to set dark mode"
+            default y
+            depends on LV_USE_THEME_DEFAULT
+        config LV_THEME_DEFAULT_GROW
+            bool "Enable grow on press"
+            default y
+            depends on LV_USE_THEME_DEFAULT
+        config LV_THEME_DEFAULT_TRANSITION_TIME
+            int "Default transition time in [ms]"
+            default 80
+            depends on LV_USE_THEME_DEFAULT
+        config LV_USE_THEME_BASIC
+            bool "A very simple theme that is a good starting point for a custom theme"
+            default y
+    endmenu
+
+    menu "Text Settings"
+        choice LV_TXT_ENC
+            prompt "Select a character encoding for strings"
+            help
+                Select a character encoding for strings. Your IDE or editor should have the same character encoding.
+            default LV_TXT_ENC_UTF8 if !LV_CONF_MINIMAL
+            default LV_TXT_ENC_ASCII if LV_CONF_MINIMAL
+
+            config LV_TXT_ENC_UTF8
+                bool "UTF8"
+            config LV_TXT_ENC_ASCII
+                bool "ASCII"
+        endchoice
+
+        config LV_TXT_BREAK_CHARS
+            string "Can break (wrap) texts on these chars"
+            default " ,.;:-_"
+
+        config LV_TXT_LINE_BREAK_LONG_LEN
+            int "Line break long length"
+            default 0
+            help
+                If a word is at least this long, will break wherever 'prettiest'.
+                To disable, set to a value <= 0.
+
+        config LV_TXT_LINE_BREAK_LONG_PRE_MIN_LEN
+            int "Min num chars before break"
+            default 3
+            depends on LV_TXT_LINE_BREAK_LONG_LEN > 0
+            help
+                Minimum number of characters in a long word to put on a line before a break.
+
+        config LV_TXT_LINE_BREAK_LONG_POST_MIN_LEN
+            int "Min num chars after break"
+            default 3
+            depends on LV_TXT_LINE_BREAK_LONG_LEN > 0
+            help
+                Minimum number of characters in a long word to put on a line after a break.
+
+        config LV_TXT_COLOR_CMD
+            string "The control character to use for signalling text recoloring"
+            default "#"
+
+        config LV_USE_BIDI
+            bool "Support bidirectional texts"
+            help
+                Allows mixing Left-to-Right and Right-to-Left texts.
+                The direction will be processed according to the Unicode Bidirectional Algorithm:
+                https://www.w3.org/International/articles/inline-bidi-markup/uba-basics
+
+        choice
+            prompt "Set the default BIDI direction"
+            default LV_BIDI_DIR_AUTO
+            depends on LV_USE_BIDI
+
+            config LV_BIDI_DIR_LTR
+                bool "Left-to-Right"
+            config LV_BIDI_DIR_RTL
+                bool "Right-to-Left"
+            config LV_BIDI_DIR_AUTO
+                bool "Detect texts base direction"
+        endchoice
+
+        config LV_USE_ARABIC_PERSIAN_CHARS
+            bool "Enable Arabic/Persian processing"
+            help
+                In these languages characters should be replaced with
+                an other form based on their position in the text.
+    endmenu
+
+    menu "Widget usage"
+        config LV_USE_ARC
+            bool "Arc."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_BAR
+            bool "Bar."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_BTN
+            bool "Button."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_BTNMATRIX
+            bool "Button matrix."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_CANVAS
+            bool "Canvas. Dependencies: lv_img."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_CHECKBOX
+            bool "Check Box"
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_CHART
+            bool "Chart."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_DROPDOWN
+            bool "Drop down list. Requires: lv_label."
+            select LV_USE_LABEL
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_IMG
+            bool "Image. Requires: lv_label."
+            select LV_USE_LABEL
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_LABEL
+            bool "Label."
+            default y if !LV_CONF_MINIMAL
+        config LV_LABEL_TEXT_SEL
+            bool "Enable selecting text of the label."
+            depends on LV_USE_LABEL
+        config LV_LABEL_LONG_TXT_HINT
+            bool "Store extra some info in labels (12 bytes) to speed up drawing of very long texts."
+            depends on LV_USE_LABEL
+        config LV_USE_LINE
+            bool "Line."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_METER
+            bool "Meter."
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_ROLLER
+            bool "Roller. Requires: lv_label."
+            select LV_USE_LABEL
+            default y if !LV_CONF_MINIMAL
+        config LV_ROLLER_INF_PAGES
+            int "Number of extra 'pages' when the controller is infinite."
+            default 7
+            depends on LV_USE_ROLLER
+        config LV_USE_SLIDER
+            bool "Slider. Requires: lv_bar."
+            select LV_USE_BAR
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_SWITCH
+            bool "Switch. Dependencies: lv_slider."
+            select LV_USE_SLIDER
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_TEXTAREA
+            bool "Text area. Requires: lv_label."
+            select LV_USE_LABEL
+            default y if !LV_CONF_MINIMAL
+        config LV_TEXTAREA_DEF_PWN_SHOW_TIME
+            int "Text area def. pwn show time [ms]."
+            default 1500
+            depends on LV_USE_TEXTAREA
+        config LV_USE_TABLE
+            bool "Table."
+            default y if !LV_CONF_MINIMAL
+    endmenu
+
+    menu "Extra components"
+	config LV_USE_ANIMIMG
+            bool "Anim image."
+            select LV_USE_IMG
+            default y if !LV_CONF_MINIMAL
+        config LV_USE_CALENDAR
+            bool "Calendar."
+            default y if !LV_CONF_MINIMAL
+        config LV_CALENDAR_WEEK_STARTS_MONDAY
+            bool "Calendar week starts monday."
+            depends on LV_USE_CALENDAR
+        config LV_USE_CALENDAR_HEADER_ARROW
+            bool "Use calendar header arrow"
+            default y
+        config LV_USE_CALENDAR_HEADER_DROPDOWN
+            bool "Use calendar header dropdown"
+            default y
+        config LV_USE_COLORWHEEL
+            bool "Colorwheel."
+        config LV_USE_IMGBTN
+            bool "Imgbtn."
+        config LV_USE_KEYBOARD
+            bool "Keyboard."
+        config LV_USE_LED
+            bool "LED."
+        config LV_USE_LIST
+            bool "List."
+        config LV_USE_MSGBOX
+            bool "Msgbox."
+        config LV_USE_SPINBOX
+            bool "Spinbox."
+        config LV_USE_SPINNER
+            bool "Spinner."
+        config LV_USE_TABVIEW
+            bool "Tabview."
+        config LV_USE_TILEVIEW
+            bool "Tileview"
+        config LV_USE_WIN
+            bool "Win"
+        config LV_USE_SPAN
+            bool "span"
+    endmenu
+
+    menu "Layouts"
+        config LV_USE_FLEX
+            bool "A layout similar to Flexbox in CSS."
+            default y
+        config LV_USE_GRID
+            bool "A layout similar to Grid in CSS."
+            default y
+    endmenu
+
+endmenu

LICENCE.txt

@@ -1,5 +1,5 @@
 MIT licence
-Copyright (c) 2016 Gábor Kiss-Vámosi
+Copyright (c) 2020 LVGL LLC
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -1,69 +1,165 @@
-# Littlev Graphics Library
+**The master branch now contains the test version of v8. For the last v7 version use the release/v7 branch.** 
 
-![LittlevGL cover](https://littlevgl.com/docs/themes/lv_theme_intro.png)
 
-**LittlevGL provides everything you need to create a Graphical User Interface (GUI) on embedded systems with easy-to-use graphical elements, beautiful visual effects and low memory footprint.**  
-https://littlevgl.com
+<h1 align="center"> LVGL - Light and Versatile Graphics Library</h1>
 
-## Key features
-* **Powerful building blocks** buttons, charts, lists, sliders, images, etc.
-* **Advanced graphics** with animations, anti-aliasing, opacity, smooth scrolling
-* **Various input devices** touch pad, mouse, keyboard, encoder, buttons, etc.
-* **Multi-language support** with UTF-8 encoding
-* **Fully customizable** graphical elements
-* **Hardware independent** to use with any microcontroller or display
-* **Scalable** to operate with little memory (50 kB Flash, 10 kB RAM)
-* **OS, External memory and GPU** supported but not required
-* **Single frame buffer** operation even with advances graphical effects
-* **Written in C** for maximal compatibility
-* **Simulator** to develop on PC without embedded hardware
-* **Tutorials, examples, themes** for rapid development
-* **Documentation** and API references online
+<p align="center">
+<img src="https://lvgl.io/assets/images/img_1.png">
+</p>
 
-## Porting
-In the simplest case you need 5 things:
-1. Call `lv_tick_inc(x)` every `x` milliseconds in a Timer or Task (`x` should be between 1 and 10)
-2. Register a function which can **copy a pixel array** to an area of the screen.
-3. Register a function which can **read an input device**. (E.g. touch pad)
-4. Copy `lv_conf_templ.h` as `lv_conf.h` and set at least `LV_HOR_RES`, `LV_VER_RES` and `LV_COLOR_DEPTH`. 
-5. Call `lv_task_handler()` periodically every few milliseconds.
-For a detailed description visit https://littlevgl.com/porting
-Or check the [Porting tutorial](https://github.com/littlevgl/lv_examples/blob/master/lv_tutorial/0_porting/lv_tutorial_porting.c)
- 
-## Project set-up
-1. **Clone** or [Download](https://littlevgl.com/download) the lvgl repository: `git clone  https://github.com/littlevgl/lvgl.git`
-2. **Create project** with your preferred IDE and add the *lvgl* folder
-3. Copy **lvgl/lv_conf_templ.h** as **lv_conf.h** next to the *lvgl* folder
-4. In the lv_conf.h delete the first `#if 0` and its `#endif`. Leave the default configuration for the first try.
-5. In your *main.c*: #include "lvgl/lvgl.h"   
-6. In your *main function*:
-   * lvgl_init();
-   * tick, display and input device initialization (see above)
-7. To **test** create a label: `lv_obj_t * label = lv_label_create(lv_scr_act(), NULL);`  
-8. In the main *while(1)* call `lv_task_handler();` and make a few milliseconds delay (e.g. `my_delay_ms(5);`) 
-9. Compile the code and load it to your embedded hardware
+<p align="center">
+LVGL provides everything you need to create embedded GUI with easy-to-use graphical elements, beautiful visual effects and low memory footprint.
+</p>
 
-## PC Simulator
-You can test the graphics library in a PC simulator, if you don't have an embedded hardware. The simulator uses [SDL2](https://www.libsdl.org/) library to emulate a display on your monitor and a touch pad with your mouse.
+<h4 align="center">
+<a href="https://lvgl.io">Website </a> &middot;
+<a href="https://lvgl.io/demos">Online demo</a> &middot;
+<a href="https://lvgl.github.io/lv_examples/">Nightly demos</a> &middot;
+<a href="https://docs.lvgl.io/">Docs</a> &middot;
+<a href="https://forum.lvgl.io">Forum</a>
+</h4>
 
-There is a pre-configured PC project for **Eclipse CDT** in this repository: https://github.com/littlevgl/pc_simulator
+---
 
-## Related repositories
-* PC simulator: https://github.com/littlevgl/pc_simulator
-* Projects: https://github.com/littlevgl/lv_projects
-* Examples: https://github.com/littlevgl/lv_examples
-* Drivers: https://github.com/littlevgl/lv_drivers
+## Features
+* Powerful [building blocks](https://docs.lvgl.io/latest/en/html/widgets/index.html): buttons, charts, lists, sliders, images, etc.
+* Advanced graphics: animations, anti-aliasing, opacity, smooth scrolling
+* Use [various input devices](https://docs.lvgl.io/latest/en/html/overview/indev.html): touchscreen, mouse, keyboard, encoder, buttons, etc.
+* Use [multiple displays](https://docs.lvgl.io/latest/en/html/overview/display.html): e.g. monochrome and color display
+* Hardware independent to use with any microcontroller or display
+* Scalable to operate with little memory (64 kB Flash, 10 kB RAM)
+* Multi-language support with UTF-8 handling, Bidirectional and Arabic script support
+* Fully customizable graphical elements via [CSS-like styles](https://docs.lvgl.io/latest/en/html/overview/style.html)
+* OS, External memory and GPU are supported but not required
+* Smooth rendering even with a [single frame buffer](https://docs.lvgl.io/latest/en/html/porting/display.html)
+* Written in C for maximal compatibility (C++ compatible)
+* Micropython Binding exposes [LVGL API in Micropython](https://blog.lvgl.io/2019-02-20/micropython-bindings)
+* [Simulator](https://docs.lvgl.io/latest/en/html/get-started/pc-simulator.html) to develop on PC without embedded hardware
+* [Examples](lv_examples) and tutorials for rapid development
+* [Documentation](http://docs.lvgl.io/) and API references
 
-## Screenshots
-![TFT material](http://www.gl.littlev.hu/github_res/tft_material.png)
-![TFT zen](http://www.gl.littlev.hu/github_res/tft_zen.png)
-![TFT alien](http://www.gl.littlev.hu/github_res/tft_alien.png)
-![TFT night](http://www.gl.littlev.hu/github_res/tft_night.png)
+## Requirements
+Basically, every modern controller (which is able to drive a display) is suitable to run LVGL. The minimal requirements are:
+
+<table>
+  <tr>
+    <td> <strong>Name</strong> </td>
+    <td><strong>Minimal</strong></td>
+    <td><strong>Recommended</strong></td>
+  </tr>
+  <tr>
+    <td><strong>Architecture</strong></td>
+    <td colspan="2">16, 32 or 64 bit microcontroller or processor</td>
+  </tr>
+  <tr>
+    <td> <strong>Clock</strong></td>
+    <td> &gt; 16 MHz </td>
+    <td> &gt; 48 MHz</td>
+  </tr>
+
+  <tr>
+    <td> <strong>Flash/ROM</strong></td>
+    <td> &gt; 64 kB </td>
+    <td> &gt; 180 kB</td>
+  </tr>
+
+  <tr>
+    <td> <strong>Static RAM</strong></td>
+    <td> &gt; 2 kB </td>
+    <td> &gt; 4 kB</td>
+  </tr>
+
+  <tr>
+    <td> <strong>Stack</strong></td>
+    <td> &gt; 2 kB </td>
+    <td> &gt; 8 kB</td>
+  </tr>
+
+  <tr>
+    <td> <strong>Heap</strong></td>
+    <td> &gt; 2 kB </td>
+    <td> &gt; 8 kB</td>
+  </tr>
+
+  <tr>
+    <td> <strong>Display buffer</strong></td>
+    <td> &gt; 1 &times; <em>hor. res.</em> pixels </td>
+    <td> &gt; 10 &times; <em>hor. res.</em> pixels </td>
+  </tr>
+
+  <tr>
+    <td> <strong>Compiler</strong></td>
+    <td colspan="2"> C99 or newer </td>
+  </tr>
+</table>
+
+*Note that the memory usage might vary depending on the architecture, compiler and build options.*
+
+Just to mention some platforms:
+- STM32F1, STM32F3, STM32F4, STM32F7, STM32L4, STM32L5, STM32H7
+- Microchip dsPIC33, PIC24, PIC32MX, PIC32MZ
+- NXP: Kinetis, LPC, iMX, iMX RT
+- [Linux frame buffer](https://blog.lvgl.io/2018-01-03/linux_fb) (/dev/fb)
+- [Raspberry Pi](http://www.vk3erw.com/index.php/16-software/63-raspberry-pi-official-7-touchscreen-and-littlevgl)
+- [Espressif ESP32](https://github.com/lvgl/lv_port_esp32)
+- [Infineon Aurix](https://github.com/lvgl/lv_port_aurix)
+- Nordic NRF52 Bluetooth modules
+- Quectel modems
+
+## Get started
+This list shows the recommended way of learning the library:
+1. Check the [Online demos](https://lvgl.io/demos) to see LVGL in action (3 minutes)
+2. Read the [Introduction](https://docs.lvgl.io/latest/en/html/intro/index.html) page of the documentation (5 minutes)
+3. Get familiar with the basics on the [Quick overview](https://docs.lvgl.io/latest/en/html/get-started/quick-overview.html) page (15 minutes)
+4. Set up a [Simulator](https://docs.lvgl.io/latest/en/html/get-started/pc-simulator.html) (10 minutes)
+5. Try out some [Examples](https://github.com/lvgl/lv_examples/)
+6. Port LVGL to a board. See the [Porting](https://docs.lvgl.io/latest/en/html/porting/index.html) guide or check the ready to use [Projects](https://github.com/lvgl?q=lv_port_&type=&language=)
+7. Read the [Overview](https://docs.lvgl.io/latest/en/html/overview/index.html) page to get a better understanding of the library (2-3 hours)
+8. Check the documentation of the [Widgets](https://docs.lvgl.io/latest/en/html/widgets/index.html) to see their features and usage
+9. If you have questions go to the [Forum](http://forum.lvgl.io/)
+10. Read the [Contributing](https://docs.lvgl.io/latest/en/html/contributing/index.html) guide to see how you can help to improve LVGL (15 minutes)
+
+## Examples
+
+For more examples see the [lv_examples](https://github.com/lvgl/lv_examples) repository.
+
+### Button with label
+```c
+lv_obj_t * btn = lv_btn_create(lv_scr_act(), NULL);     /*Add a button to the current screen*/
+lv_obj_set_pos(btn, 10, 10);                            /*Set its position*/
+lv_obj_set_size(btn, 100, 50);                          /*Set its size*/
+lv_obj_set_event_cb(btn, btn_event_cb);                 /*Assign a callback to the button*/
+
+lv_obj_t * label = lv_label_create(btn, NULL);          /*Add a label to the button*/
+lv_label_set_text(label, "Button");                     /*Set the labels text*/
+
+...
+
+void btn_event_cb(lv_obj_t * btn, lv_event_t event)
+{
+    if(event == LV_EVENT_CLICKED) {
+        printf("Clicked\n");
+    }
+}
+```
+![LVGL button with label example](https://raw.githubusercontent.com/lvgl/docs/latest/misc/simple_button_example.gif)
+
+### LVGL from Micropython
+Learn more about [Micropython](https://docs.lvgl.io/latest/en/html/get-started/micropython.html).
+```python
+# Create a Button and a Label
+scr = lv.obj()
+btn = lv.btn(scr)
+btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
+label = lv.label(btn)
+label.set_text("Button")
+
+# Load the screen
+lv.scr_load(scr)
+```
 
 ## Contributing
-See [CONTRIBUTING.md](https://github.com/littlevgl/lvgl/blob/master/docs/CONTRIBUTING.md)
+LVGL is an open project and contribution is very welcome. There are many ways to contribute from simply speaking about your project, through writing examples, improving the documentation, fixing bugs to hosing your own project under in LVGL.
 
-## Donate
-If you are pleased with this graphics library, found it useful, or are happy with the support you got, please help its further development:
-
-[![Donate](https://littlevgl.com/donate_dir/donate_btn.png)](https://littlevgl.com/donate)
+For a detailed description of contribution opportunities visit the [Contributing](https://docs.lvgl.io/latest/en/html/contributing/index.html) section of the documentation.
+ 

component.mk

@@ -0,0 +1,34 @@
+# ESP-IDF component file for make based commands
+
+COMPONENT_SRCDIRS := . \
+                  src \
+                  src/core \
+                  src/draw \
+                  src/extra \
+                  src/font \
+                  src/gpu \
+                  src/hal \
+                  src/misc \
+                  src/widgets \
+                  src/extra/layouts \
+                  src/extra/layouts/flex \
+                  src/extra/layouts/grid \
+                  src/extra/themes \
+                  src/extra/themes/basic \
+                  src/extra/themes/default \
+                  src/extra/widgets/calendar \
+                  src/extra/widgets/colorwheel \
+                  src/extra/widgets \
+                  src/extra/widgets/imgbtn \
+                  src/extra/widgets/keyboard \
+                  src/extra/widgets/led \
+                  src/extra/widgets/list \
+                  src/extra/widgets/msgbox \
+                  src/extra/widgets/spinbox \
+                  src/extra/widgets/spinner \
+                  src/extra/widgets/tabview \
+                  src/extra/widgets/tileview \
+                  src/extra/widgets/win
+
+
+COMPONENT_ADD_INCLUDEDIRS := $(COMPONENT_SRCDIRS) .

docs/CHANGELOG.md

@@ -0,0 +1,496 @@
+# Changelog
+
+## v8.0.0 (01.06.2021)
+
+v8.0 brings many new features like simplified and more powerful scrolling, new layouts inspired by CSS Flexbox and Grid, simplified and improved widgets, more powerful events, hookable drawing, and more.
+
+v8 is a major change and therefore it's not backward compatible with v7. 
+
+### Directory structure
+- The `lv_` prefix is removed from the folder names
+- The `docs` is moved to the `lvgl` repository
+- The `examples` are moved to the `lvgl` repository
+- Create an `src/extra` folder for complex widgets:
+   - It makes the core LVGL leaner
+   - In `extra` we can have a lot and specific widgets
+   - Good place for contributions
+
+### Widget changes
+- `lv_cont` removed, layout features are moved to `lv_obj`
+- `lv_page` removed, scroll features are moved to `lv_obj`
+- `lv_objmask` the same can be achieved by events
+- `lv_meter` added as the unioin of `lv_linemeter` and `lv_gauge`
+- `lv_span` new widget mimicing HTML `<span>`
+- `lv_animing` new widget for simple slideshow animations
+- \+ many minor changes and improvements
+
+### New scrolling
+- Support "elastic" scrolling when scrolled in
+- Support scroll chaining among any objects types (not only `lv_pages`s)
+- Remove `lv_drag`. Similar effect can be achieved by setting the position in `LV_EVENT_PRESSING`
+- Add snapping
+- Add snap stop to scroll max 1 snap point
+
+### New layouts
+- [CSS Grid](https://css-tricks.com/snippets/css/a-guide-to-grid/)-like layout support
+- [CSS Flexbox](https://css-tricks.com/snippets/css/a-guide-to-flexbox/)-like layout support
+
+### Styles
+- Optimize and simplify styles
+- State is saved in the object instead of the style property
+- Object size and position can be set in styles too
+
+### Events
+- Allow adding multiple events to an object
+- A `user_data` can be attached to the added events
+
+### Driver changes
+- `lv_disp_drv_t`, `lv_indev_drv_t`, `lv_fs_drv_t` needs to be `static`
+- `...disp_buf...` is renamed to `draw_buf`. See an initialization example [here](https://github.com/lvgl/lv_sim_eclipse_sdl/blob/e164e3591c3e1e3bf3464d19e0dcdc67b2e6a791/main.c#L87-L97).
+- No partial update if two screen sized buffers are set
+- `disp_drv->full_refresh = 1` makes always the whole display redraw. 
+- `hor_res` and `ver_res` need to be set in `disp_drv`
+- `indev_read_cb` returns `void`. To indicate that there is more that to read set `data->continue_reading = 1` in the `read_cb`
+
+### Other changes
+- Remove the copy parameter from create functions
+- Simplified File system interface API
+- Use a more generic inheritance
+- The built-in themes are reworked
+- `lv_obj_align` now saved the alignment and realigns the object automatically but can't be used to align to other than the parent
+- `lv_obj_align_to` can align to an object but doesn't save the alignment
+- `lv_pct(x)` can be used to set the size and position in percentage
+- There are many other changes in widgets that are not detailed here. Please refer to the documentation of the widgets.
+
+### New release policy
+- We will follow [Release branches with GitLab flow](https://docs.gitlab.com/ee/topics/gitlab_flow.html#release-branches-with-gitlab-flow)
+- Minor releases are expected in every 3-4 month
+- `master` will always contain the latest changes
+
+### Migrating from v7 to v8
+- First and foremost, create a new `lv_conf.h` based on `lv_conf_template.h`.
+- To try the new version it's recommended to use a simulator project and see the examples.
+- When migrating your project to v8
+  - Update the drivers are described above
+  - Update the styles
+  - Update the events
+  - Use the new layouts instead of `lv_cont` features
+  - Use `lv_obj` instead of `lv_page`
+  - The other parts are mainly minor renames and refactoring. See the functions' documentation for descriptions. 
+
+## v7.11.0 (16.03.2021)
+
+### New features
+- Add better screen orientation management with software rotation support
+- Decide text animation's direction based on base_dir (when using LV_USE_BIDI)
+
+### Bugfixes
+- fix(gauge) fix needle invalidation
+- fix(bar) correct symmetric handling for vertical sliders
+
+## v7.10.1 (16.02.2021)
+
+### Bugfixes 
+- fix(draw) overlap outline with background to prevent aliasing artifacts
+- fix(indev) clear the indev's `act_obj` in `lv_indev_reset`
+- fix(text) fix out of bounds read in `_lv_txt_get_width`
+- fix(list) scroll list when button is focused using LV_KEY_NEXT/PREV
+- fix(text) improve Arabic contextual analysis by adding hyphen processing and proper handling of lam-alef sequence
+- fix(delete) delete animation after the children are deleted
+- fix(gauge) consider paddings for needle images
+
+## v7.10.0 (02.02.2021)
+
+### New features
+- feat(indev) allow input events to be passed to disabled objects
+- feat(spinbox) add inline get_step function for MicroPython support
+
+### Bugfixes
+- fix(btnmatrix) fix lv_btnmatrix_get_active_btn_text() when used in a group
+
+## v7.9.1 (19.01.2021)
+
+### Bugfixes
+- fix(cpicker) fix division by zero
+- fix(dropdown) fix selecting options after the last one
+- fix(msgbox) use the animation time provided
+- fix(gpu_nxp_pxp) fix incorrect define name
+- fix(indev) don't leave edit mode if there is only one object in the group
+- fix(draw_rect) fix draw pattern stack-use-after-scope error
+
+
+## v7.9.0 (05.01.2021)
+
+### New features
+- feat(chart) add lv_chart_remove_series and lv_chart_hide_series
+- feat(img_cahce) allow disabling image caching
+- calendar: make get_day_of_week() public
+- Added support for Zephyr integration
+ 
+### Bugfixes
+- fix(draw_rect) free buffer used for arabic processing
+- fix(win) arabic process the title of the window
+- fix(dropdown) arabic process the option in lv_dropdown_add_option
+- fix(textarea) buffer overflow in password mode with UTF-8 characters
+- fix(textarea) cursor position after hiding character in password mode
+- fix(linemeter) draw critical lines with correct color
+- fix(lv_conf_internal) be sure Kconfig defines are always uppercase
+- fix(kconfig) handle disable sprintf float correctly.
+- fix(layout) stop layout after recursion threshold is reached
+- fix(gauge) fix redraw with image needle
+
+## v7.8.1 (15.12.2020)
+
+### Bugfixes
+- fix(lv_scr_load_anim) fix when multiple screen are loaded at tsame time with delay
+- fix(page) fix LV_SCOLLBAR_MODE_DRAG
+
+## v7.8.0 (01.12.2020)
+
+### New features
+- make DMA2D non blocking 
+- add unscii-16 built-in font
+- add KConfig
+- add lv_refr_get_fps_avg()
+
+### Bugfixes
+- fix(btnmatrix) handle arabic texts in button matrices
+- fix(indev) disabled object shouldn't absorb clicks but let the parent to be clicked
+- fix(arabic) support processing again already processed texts with _lv_txt_ap_proc
+- fix(textarea) support Arabic letter connections
+- fix(dropdown) support Arabic letter connections
+- fix(value_str) support Arabic letter connections in value string property
+- fix(indev) in LV_INDEV_TYPE_BUTTON recognize 1 cycle long presses too
+- fix(arc) make arc work with encoder
+- fix(slider) adjusting the left knob too with encoder
+- fix reference to LV_DRAW_BUF_MAX_NUM in lv_mem.c
+- fix(polygon draw) join adjacent points if they are on the same coordinate
+- fix(linemeter) fix invalidation when setting new value 
+- fix(table) add missing invalidation when changing cell type
+- refactor(roller) rename LV_ROLLER_MODE_INIFINITE -> LV_ROLLER_MODE_INFINITE
+
+## v7.7.2 (17.11.2020)
+### Bugfixes
+- fix(draw_triangle): fix polygon/triangle drawing when the order of points is counter-clockwise
+- fix(btnmatrix): fix setting the same map with modified pointers
+- fix(arc) fix and improve arc dragging
+- label: Repair calculate back `dot` character logical error which cause infinite loop.
+- fix(theme_material): remove the bottom border from tabview header
+- fix(imgbtn) guess a the closest available state with valid src
+- fix(spinbox) update cursor position in lv_spinbox_set_step 
+
+## v7.7.1 (03.11.2020)
+### Bugfixes
+- Respect btnmatrix's `one_check` in `lv_btnmatrix_set_btn_ctrl`
+- Gauge: make the needle images to use the styles from `LV_GAUGE_PART_PART`
+- Group: fix in `lv_group_remove_obj` to handle deleting hidden obejcts correctly
+
+## v7.7.0 (20.10.2020)
+
+### New features
+- Add PXP GPU support (for NXP MCUs)
+- Add VG-Lite GPU support (for NXP MCUs)
+- Allow max. 16 cell types for table
+- Add `lv_table_set_text_fmt()`
+- Use margin on calendar header to set distances and padding to the size of the header
+- Add `text_sel_bg` style property
+
+### Bugfixes
+- Theme update to support text selection background
+- Fix imgbtn state change
+- Support RTL in table (draw columns right to left)
+- Support RTL in pretty layout (draw columns right to left)
+- Skip objects in groups if they are in disabled state
+- Fix dropdown selection with RTL basedirection
+- Fix rectangle border drawing with large width
+- Fix `lv_win_clean()`
+
+## v7.6.1 (06.10.2020)
+
+### Bugfixes
+- Fix BIDI support in dropdown list
+- Fix copying base dir in `lv_obj_create`
+- Handle sub pixel rendering in font loader
+- Fix transitions with style caching
+- Fix click focus
+- Fix imgbtn image switching with empty style
+- Material theme: do not set the text font to allow easy global font change
+
+## v7.6.0 (22.09.2020)
+
+### New features
+- Check whether any style property has changed on a state change to decide if any redraw is required
+
+### Bugfixes
+- Fix selection of options with non-ASCII letters in dropdown list 
+- Fix font loader to support LV_FONT_FMT_TXT_LARGE
+
+## v7.5.0 (15.09.2020)
+
+### New features
+- Add `clean_dcache_cb` and `lv_disp_clean_dcache` to enable users to use their own cache management function
+- Add `gpu_wait_cb` to wait until the GPU is working. It allows to run CPU a wait only when the rendered data is needed.
+- Add 10px and 8ox built in fonts
+
+### Bugfixes
+- Fix unexpected DEFOCUS on lv_page when clicking to bg after the scrollable
+- Fix `lv_obj_del` and `lv_obj_clean` if the children list changed during deletion.
+- Adjust button matrix button width to include padding when spanning multiple units.
+- Add rounding to btnmatrix line height calculation
+- Add `decmopr_buf` to GC roots
+- Fix divisioin by zero in draw_pattern (lv_draw_rect.c) if the image or letter is not found
+- Fix drawing images with 1 px height or width
+
+## v7.4.0 (01.09.2020)
+
+The main new features of v7.4 are run-time font loading, style caching and arc knob with value setting by click.
+
+### New features
+- Add `lv_font_load()` function - Loads a `lv_font_t` object from a binary font file
+- Add `lv_font_free()` function - Frees the memory allocated by the `lv_font_load()` function
+- Add style caching to reduce access time of properties with default value
+- arc: add set value by click feature
+- arc: add `LV_ARC_PART_KNOB` similarly to slider
+- send gestures event if the object was dragged. User can check dragging with `lv_indev_is_dragging(lv_indev_act())` in the event function.
+
+### Bugfixes
+- Fix color bleeding on border drawing
+- Fix using 'LV_SCROLLBAR_UNHIDE' after 'LV_SCROLLBAR_ON'
+- Fix croping of last column/row if an image is zoomed
+- Fix zooming and rotateing mosaic images
+- Fix deleting tabview with LEFT/RIGHT tab position
+- Fix btnmatrix to not send event when CLICK_TRIG = true and the cursor slid from a pressed button
+- Fix roller width if selected text is larger than the normal
+
+## v7.3.1 (18.08.2020)
+
+### Bugfixes
+- Fix drawing value string twice
+- Rename  `lv_chart_clear_serie` to `lv_chart_clear_series` and `lv_obj_align_origo` to `lv_obj_align_mid`
+- Add linemeter's mirror feature again
+- Fix text decor (udnerline strikethrough) with older versions of font converter
+- Fix setting local style property multiple times 
+- Add missing background drawing and radius handling to image button
+- Allow adding extra label to list buttons
+- Fix crash if `lv_table_set_col_cnt` is called before `lv_table_set_row_cnt` for the first time
+- Fix overflow in large image transformations
+- Limit extra button click area of button matrix's buttons. With large paddings it was counter intuitive. (Gaps are mapped to button when clicked).
+- Fix `lv_btnmatrix_set_one_check` not forcing exactly one button to be checked
+- Fix color picker invalidation in rectangle mode
+- Init disabled days to gray color in calendar
+
+## v7.3.0 (04.08.2020)
+
+### New features
+- Add `lv_task_get_next`
+- Add `lv_event_send_refresh`, `lv_event_send_refresh_recursive` to easily send `LV_EVENT_REFRESH` to object
+- Add `lv_tabview_set_tab_name()` function - used to change a tab's name
+- Add `LV_THEME_MATERIAL_FLAG_NO_TRANSITION` and `LV_THEME_MATERIAL_FLAG_NO_FOCUS` flags
+- Reduce code size by adding: `LV_USE_FONT_COMPRESSED` and `LV_FONT_USE_SUBPX` and applying some optimization
+- Add `LV_MEMCPY_MEMSET_STD` to use standard `memcpy` and `memset`
+
+### Bugfixes
+- Do not print warning for missing glyph if its height OR width is zero.
+- Prevent duplicated sending of `LV_EVENT_INSERT` from text area
+- Tidy outer edges of cpicker widget.
+- Remove duplicated lines from `lv_tabview_add_tab`
+- btnmatrix: hadle combined states of buttons (e.g. chacked + disabled)
+- textarea: fix typo in lv_textarea_set_sscrollbar_mode
+- gauge: fix image needle drawing
+- fix using freed memory in _lv_style_list_remove_style
+
+## v7.2.0 (21.07.2020)
+
+### New features
+- Add screen transitions with `lv_scr_load_anim()`
+- Add display background color, wallpaper and opacity. Shown when the screen is transparent. Can be used with `lv_disp_set_bg_opa/color/image()`.
+- Add `LV_CALENDAR_WEEK_STARTS_MONDAY`
+- Add `lv_chart_set_x_start_point()` function - Set the index of the x-axis start point in the data array
+- Add `lv_chart_set_ext_array()` function - Set an external array of data points to use for the chart
+- Add `lv_chart_set_point_id()` function - Set an individual point value in the chart series directly based on index
+- Add `lv_chart_get_x_start_point()` function - Get the current index of the x-axis start point in the data array
+- Add `lv_chart_get_point_id()` function - Get an individual point value in the chart series directly based on index
+- Add `ext_buf_assigned` bit field to `lv_chart_series_t` structure - it's true if external buffer is assigned to series
+- Add `lv_chart_set_series_axis()` to assign series to primary or secondary axis
+- Add `lv_chart_set_y_range()` to allow setting range of secondary y axis (based on `lv_chart_set_range` but extended with an axis parameter)
+- Allow setting different font for the selected text in `lv_roller`
+- Add `theme->apply_cb` to replace `theme->apply_xcb` to make it compatible with the MicroPython binding
+- Add `lv_theme_set_base()` to allow easy extension of built-in (or any) themes
+- Add `lv_obj_align_x()` and `lv_obj_align_y()` functions
+- Add `lv_obj_align_origo_x()` and `lv_obj_align_origo_y()` functions
+
+### Bugfixes
+- `tileview` fix navigation when not screen sized
+- Use 14px font by default to for better compatibility with smaller displays 
+- `linemeter` fix conversation of current value to "level"
+- Fix drawing on right border
+- Set the cursor image non clickable by default
+- Improve mono theme when used with keyboard or encoder
+
+## v7.1.0 (07.07.2020)
+
+### New features
+- Add `focus_parent` attribute to `lv_obj`
+- Allow using buttons in encoder input device
+- Add lv_btnmatrix_set/get_align capability
+- DMA2D: Remove dependency on ST CubeMX HAL
+- Added `max_used` propriety to `lv_mem_monitor_t` struct
+- In `lv_init` test if the strings are UTF-8 encoded.
+- Add `user_data` to themes
+- Add LV_BIG_ENDIAN_SYSTEM flag to lv_conf.h in order to fix displaying images on big endian systems.
+- Add inline function lv_checkbox_get_state(const lv_obj_t * cb) to extend the checkbox functionality.
+- Add inline function lv_checkbox_set_state(const lv_obj_t * cb, lv_btn_state_t state ) to extend the checkbox functionality.
+
+### Bugfixes
+- `lv_img` fix invalidation area when angle or zoom changes
+- Update the style handling to support Big endian MCUs
+- Change some methods to support big endian hardware.
+- remove use of c++ keyword 'new' in parameter of function lv_theme_set_base().
+- Add LV_BIG_ENDIAN_SYSTEM flag to lv_conf.h in order to fix displaying images on big endian systems.
+- Fix inserting chars in text area in big endian hardware.
+
+## v7.0.2 (16.06.2020)
+
+### Bugfixes
+- `lv_textarea` fix wrong cursor position when clicked after the last character
+- Change all text related indices from 16-bit to 32-bit integers throughout whole library. #1545
+- Fix gestures
+- Do not call `set_px_cb` for transparent pixel
+- Fix list button focus in material theme
+- Fix crash when the a text area is cleared with the backspace of a keyboard
+- Add version number to `lv_conf_template.h`
+- Add log in true double buffering mode with `set_px_cb`
+- `lv_dropdown`: fix missing `LV_EVENT_VALUE_CHANGED` event when used with encoder
+- `lv_tileview`: fix if not the {0;0} tile is created first
+- `lv_debug`: restructure to allow asserting in from `lv_misc` too
+- add assert if `_lv_mem_buf_get()` fails
+- `lv_textarea`: fix character delete in password mode
+- Update `LV_OPA_MIN` and `LV_OPA_MAX` to widen the opacity processed range
+- `lv_btnm` fix sending events for hidden buttons
+- `lv_gaguge` make `lv_gauge_set_angle_offset` offset the labels and needles too
+- Fix typo in the API `scrllable` -> `scrollable`
+- `tabview` by default allow auto expanding the page only to right and bottom (#1573)
+- fix crash when drawing gradient to the same color
+- chart: fix memory leak
+- `img`: improve hit test for transformed images
+
+## v7.0.1 (01.06.2020)
+
+### Bugfixes
+- Make the Microptyhon working by adding the required variables as GC_ROOT
+- Prefix some internal API functions with `_` to reduce the API of LVGL 
+- Fix built-in SimSun CJK font
+- Fix UTF-8 encoding when `LV_USE_ARABIC_PERSIAN_CHARS` is enabled
+- Fix DMA2D usage when 32 bit images directly blended
+- Fix lv_roller in infinite mode when used with encoder
+- Add `lv_theme_get_color_secondary()`
+- Add `LV_COLOR_MIX_ROUND_OFS` to adjust color mixing to make it compatible with the GPU
+- Improve DMA2D blending
+- Remove memcpy from `lv_ll` (caused issues with some optimization settings)
+- `lv_chart` fix X tick drawing
+- Fix vertical dashed line drawing
+- Some additional minor fixes and formattings
+
+## v7.0.0 (18.05.2020)
+
+### Documentation
+The docs for v7 is available at https://docs.littlevgl.com/v7/en/html/index.html
+
+### Legal changes
+
+The name of the project is changed to LVGL and the new website is on https://lvgl.io
+
+LVGL remains free under the same conditions (MIT license) and a company is created to manage LVGL and offer services.
+
+### New drawing system
+Complete rework of LVGL's draw engine to use "masks" for more advanced and higher quality graphical effects. 
+A possible use-case of this system is to remove the overflowing content from the rounded edges.
+It also allows drawing perfectly anti-aliased circles, lines, and arcs.
+Internally, the drawings happen by defining masks (such as rounded rectangle, line, angle). 
+When something is drawn the currently active masks can make some pixels transparent. 
+For example, rectangle borders are drawn by using 2 rectangle masks: one mask removes the inner part and another the outer part. 
+
+The API in this regard remained the same but some new functions were added:
+- `lv_img_set_zoom`: set image object's zoom factor
+- `lv_img_set_angle`: set image object's angle without using canvas
+- `lv_img_set_pivot`: set the pivot point of rotation
+
+The new drawing engine brought new drawing features too. They are highlighted in the "style" section.
+
+### New style system
+The old style system is replaced with a new more flexible and lightweighted one. 
+It uses an approach similar to CSS: support cascading styles, inheriting properties and local style properties per object. 
+As part of these updates, a lot of objects were reworked and the APIs have been changed. 
+
+- more shadows options: *offset* and *spread*
+- gradient stop position to shift the gradient area and horizontal gradient 
+- `LV_BLEND_MODE_NORMAL/ADDITIVE/SUBTRACTIVE` blending modes
+- *clip corner*: crop the content on the rounded corners
+- *text underline* and *strikethrough*
+- dashed vertical and horizontal lines (*dash gap*, *dash_width*)
+- *outline*: a border-like part drawn out of the background. Can have spacing to the background.
+- *pattern*: display and image in the middle of the background or repeat it
+- *value* display a text which is stored in the style. It can be used e.g. as a lighweighted text on buttons too.
+- *margin*: similar to *padding* but used to keep space outside of the object
+
+Read the [Style](https://docs.littlevgl.com/v7/en/html/overview/style.html) section of the documentation to learn how the new styles system works.
+
+### GPU integration
+To better utilize GPUs, from this version GPU usage can be integrated into LVGL. In `lv_conf.h` any supported GPUs can be enabled with a single configuration option.
+
+Right now, only ST's DMA2D (Chrom-ART) is integrated. More will in the upcoming releases.
+
+### Renames
+The following object types are renamed:
+- sw -> switch
+- ta -> textarea
+- cb -> checkbox
+- lmeter -> linemeter
+- mbox -> msgbox
+- ddlist -> dropdown
+- btnm -> btnmatrix
+- kb -> keyboard
+- preload -> spinner
+- lv_objx folder -> lv_widgets
+- LV_FIT_FILL -> LV_FIT_PARENT
+- LV_FIT_FLOOD -> LV_FLOOD_MAX
+- LV_LAYOUT_COL_L/M/R -> LV_LAYOUT_COLUMN_LEFT/MID/RIGHT
+- LV_LAYOUT_ROW_T/M/B -> LV_LAYOUT_ROW_TOP/MID/BOTTOM
+
+### Reworked and improved object
+- `dropdown`: Completely reworked. Now creates a separate list when opened and can be dropped to down/up/left/right.
+- `label`: `body_draw` is removed, instead, if its style has a visible background/border/shadow etc it will be drawn. Padding really makes the object larger (not just virtually as before)
+- `arc`: can draw bacground too.
+- `btn`: doesn't store styles for each state because it's done naturally in the new style system.
+- `calendar`: highlight the pressed datum. The used styles are changed: use `LV_CALENDAR_PART_DATE` normal for normal dates, checked for highlighted, focused for today, pressed for the being pressed. (checked+pressed, focused+pressed also work)
+- `chart`: only has `LINE` and `COLUMN` types because with new styles all the others can be described. LV_CHART_PART_SERIES sets the style of the series. bg_opa > 0 draws an area in LINE mode. `LV_CHART_PART_SERIES_BG` also added to set a different style for the series area. Padding in `LV_CHART_PART_BG` makes the series area smaller, and it ensures space for axis labels/numbers.
+- `linemeter`, `gauge`: can have background if the related style properties are set. Padding makes the scale/lines smaller. scale_border_width and scale_end_border_width allow to draw an arc on the outer part of the scale lines.
+- `gauge`: `lv_gauge_set_needle_img` allows use image as needle
+- `canvas`: allow drawing to true color alpha and alpha only canvas, add `lv_canvas_blur_hor/ver` and rename `lv_canvas_rotate` to `lv_canvas_transform`
+- `textarea`: If available in the font use bullet (`U+2022`) character in text area password 
+
+### New object types
+- `lv_objmask`: masks can be added to it. The children will be masked accordingly. 
+
+### Others
+- Change the built-in fonts to [Montserrat](https://fonts.google.com/specimen/Montserrat) and add built-in fonts from 12 px to 48 px for every 2nd size.
+- Add example CJK and Arabic/Persian/Hebrew built-in font
+- Add ° and "bullet" to the built-in fonts
+- Add Arabic/Persian script support: change the character according to its position in the text. 
+- Add `playback_time` to animations.
+- Add `repeat_count` to animations instead of the current "repeat forever".
+- Replace `LV_LAYOUT_PRETTY` with `LV_LAYOUT_PRETTY_TOP/MID/BOTTOM`
+
+### Demos
+- [lv_examples](https://github.com/littlevgl/lv_examples) was reworked and new examples and demos were added
+
+### New release policy
+- Maintain this Changelog for every release
+- Save old major version in new branches. E.g. `release/v6`
+- Merge new features and fixes directly into `master` and release a patch or minor releases every 2 weeks.
+
+### Migrating from v6 to v7
+- First and foremost, create a new `lv_conf.h` based on `lv_conf_template.h`.
+- To try the new version it suggested using a simulator project and see the examples.
+- If you have a running project, the most difficult part of the migration is updating to the new style system. Unfortunately, there is no better way than manually updating to the new format.
+- The other parts are mainly minor renames and refactoring as described above. 

docs/CODE_OF_CONDUCT.md

@@ -34,7 +34,7 @@ This Code of Conduct applies both within project spaces and in public spaces whe
 
 ## Enforcement
 
-Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at [atom@github.com](mailto:atom@github.com). All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team using the [contact form](https://lvgl.io/about). All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
 
 Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
 

docs/CODING_STYLE.md

@@ -0,0 +1,89 @@
+# Coding style
+
+## File format
+Use [misc/lv_templ.c](https://github.com/lvgl/lvgl/blob/master/src/misc/lv_templ.c) and [misc/lv_templ.h](https://github.com/lvgl/lvgl/blob/master/src/misc/lv_templ.h)
+
+## Naming conventions
+* Words are separated by '_'
+* In variable and function names use only lower case letters (e.g. *height_tmp*)
+* In enums and defines use only upper case letters (e.g. *e.g. MAX_LINE_NUM*)
+* Global names (API):
+  * start with *lv*
+  * followed by module name: *btn*, *label*, *style* etc.
+  * followed by the action (for functions): *set*, *get*, *refr* etc.
+  * closed with the subject: *name*, *size*, *state* etc.
+* Typedefs
+  * prefer `typedef struct` and `typedef enum` instead of  `struct name` and `enum name`
+  * always end `typedef struct` and `typedef enum` type names with `_t`
+* Abbreviations:
+  * Only words longer or equal than 6 characters can be abbreviated.
+  * Abbreviate only if it makes the word at least half as long
+  * Use only very straightforward and well-known abbreviations (e.g. pos: position, def: default, btn: button)
+
+## Coding guide
+* Functions:
+  * Try to write function shorter than is 50 lines
+  * Always shorter than 200 lines (except very straightforwards)
+* Variables:
+  * One line, one declaration (BAD: char x, y;)
+  * Use `<stdint.h>` (*uint8_t*, *int32_t* etc)
+  * Declare variables where needed (not all at function start)
+  * Use the smallest required scope
+  * Variables in a file (outside functions) are always *static*
+  * Do not use global variables (use functions to set/get static variables)
+
+## Comments
+Before every function have a comment like this:
+
+```c
+/**
+ * Return with the screen of an object
+ * @param obj pointer to an object
+ * @return pointer to a screen
+ */
+lv_obj_t * lv_obj_get_scr(lv_obj_t * obj);
+```
+
+Always use `/*Something*/` format and NOT `//Something`
+
+Write readable code to avoid descriptive comments like:
+`x++; /*Add 1 to x*/`.
+The code should show clearly what you are doing.
+
+You should write **why** have you done this:
+`x++; /*Because of closing '\0' of the string*/`
+
+Short "code summaries" of a few lines are accepted. E.g. `/*Calculate the new coordinates*/`
+
+In comments use \` \` when referring to a variable. E.g. ``/*Update the value of `x_act`*/``
+
+### Formatting
+Here is example to show bracket placing and using of white spaces:
+```c
+/**
+ * Set a new text for a label. Memory will be allocated to store the text by the label.
+ * @param label pointer to a label object
+ * @param text '\0' terminated character string. NULL to refresh with the current text.
+ */
+void lv_label_set_text(lv_obj_t * label, const char * text)
+{   /*Main brackets of functions in new line*/
+
+    if(label == NULL) return; /*No bracket only if the command is inline with the if statement*/
+
+    lv_obj_inv(label);
+
+    lv_label_ext_t * ext = lv_obj_get_ext(label);
+
+    /*Comment before a section*/
+    if(text == ext->txt || text == NULL) {  /*Bracket of statements start inline*/
+        lv_label_refr_text(label);
+        return;
+    }
+
+    ...
+}
+```
+
+Use 4 spaces indentation instead of tab.
+
+You can use **astyle** to format the code. Run `code-formatter.sh` from the `scrips` folder.

docs/CONTRIBUTING.md

@@ -1,181 +1,236 @@
-# Contributing to Littlev Graphics Library
-It's glad to see that you are interested in Contributing to LittlevGL! 
-
-In this guide you can learn how can you help to develop  LittlevGL. 
-
-### Table Of Content
-* [Who can contribute?](#who-can-contribute)
-* [How to report an issue?](#how-to-report-a-bug)
-* [How to suggest a feature?](#how-to-suggest-a-feature)
-* [How to implement a feature?](#how-to-implement-a-feature)
-* [Styling guide](#styling-guide)
-
-## Who can contribute?
-As graphical interfaces for embedded systems has an increasing relevance today you also might find important to work with a good graphics library. Now - independently from skills, programming level or any personal attributes - you can influence and help the development of Littlev Graphics Library with:
-* Report an issue
-* Suggest feature
-* Fix an issue
-* Implement a feature
-* Help with testing bugfixes and new features
-
-Please, take a look at [CODE_OF_CONDUCT](https://github.com/littlevgl/lvgl/blob/master/docs/CODE_OF_CONDUCT.md)
-
-There are few **general rules**
-* We use [GitHub's issue tracker](https://github.com/littlevgl/lvgl/issues)
-* Be kind and respectful. Starting with "Hi" is always a good idea :)
-* If somebody helped you give a feedback.
-* One issue should be about one topic. If you have other questions please open a new issue.
-* Always create an issue before creating a [Pull request](https://help.github.com/articles/about-pull-requests/) to discuss the idea first
-* Create small, "digestible" Pull requests.  
-* Tell your remarks in a structured way. Use paragraphs and the [Markdown](https://guides.github.com/features/mastering-markdown/) support of GitHub.
-* Be sure you are using the latest version (from `master` branch)
-* Keep in mind LittlevGL should be and should remain:
-  - usable on small MCUs as well (think about memory footprint)
-  - compilable with "non-standard" tools like Arduino (no gcc specific options) 
-  - C compatible (no C++ specific code and features)
-  - all configuration should be in `lv_conf.h`. (Instead of modifying the library)
-  - the API clean and easiy to understand
-  
-## How to report a bug?
-If you found a **simple and straightforward bug** like:
-* misspelling (in comments function/variable names or grammatical issues in comments)
-* not handled error cases (negative array index, overflow etc)
-* anything else which can be fixed locally with a few lines of code
-* or defective documentation
-
-then tell:
-* where you found the bug (which file/function/variable)
-* how can it cause problem
-* what is your suggested solution if you have 
-
-If you faced with **something more complex** like:
-* might be simple but you don't know its origin
-* affects a whole file, module or even the architecture
-* needs deeper discussion
-
-then please
-* tell what do you experience
-* tell what do you expect to happen
-* tell how to reproduce the issue 
-* provide a simplified code example (better if can be tested with copy-paste)
-* attache your lv_conf.h (if you feel it's important)
-* logs and long codes should be attached in a file (instead of copying into a comment)
-
-## How to suggest a feature?
-If you have a good and useful idea open issue to tell it! Please note the followings on suggesting new features:
-* What the new feature is about?
-* Why/Where/In which case is it useful/helpful/relevant?
-* Can you mention real life usecases/examples for the use this feature?
-* Can you help in implementing it?
-
-Your suggestion can have 4 possible outcomes:
-1. This feature is already exists. In this case you will learn how to achieve your goal.
-2. You can simply realize it with the current functionality.
-3. Although it's a new feature but it would break LittlevGL's platform independent and/or resource minimalist nature.
-4. It's really a new feature which would be good to be in LittlevGL. Hurray! In a discussion we figure out the technical details and implementation options. With the knowledge of how to do it somebody can implement the new feature.
-
-Keep in mind if you wouldn't like to do the implementation there is no guarantee that it will be ready in the near future. 
-However, if you would like to force it, take a look at this page: [Feature request service](http://www.gl.littlev.hu/services#feature)
-
-## How to implement a feature?
-In [docs/TODO_MINOR.md](https://github.com/littlevgl/lvgl/blob/master/docs/TODO_MINOR.md) and [docs/TODO_PATCH.md](https://github.com/littlevgl/lvgl/blob/master/docs/TODO_PATCH.md) you can see some ideas which are waiting for somebody to realize them! If want to deal with a feature from these files, please start an issue and discuss the details.
-
-The new feature should be in a new branch.
-
-## Styling guide
-
-### File format
-Use [lv_misc/lv_templ.c](https://github.com/littlevgl/lvgl/blob/master/lv_misc/lv_templ.c) and [lv_misc/lv_templ.h](https://github.com/littlevgl/lvgl/blob/master/lv_misc/lv_templ.h)
-
-### Naming conventions
-* Words are separated by '_'
-* In variable and function names use only lower case letters (e.g. *height_tmp*)
-* In enums and defines use only upper case letters (e.g. *e.g. MAX_LINE_NUM*)
-* Global names (API):
-  * starts with *lv*
-  * followed by module name: *btn*, *label*, *style* etc.
-  * followed by the action (for functions): *set*, *get*, *refr* etc.
-  * closed with the subject: *name*, *size*, *state* etc. 
-* Typedefs
-  * prefer `typedef struct` and `typedef enum` instead of  `struct name` and `enum name`
-  * always add a closing *..._t*
-* Abbreviations:
-  * Use abbreviations on public names only if they become longer than 32 characters 
-  * Use only very straightforward (e.g. pos: position) or well-established (e.g. pr: press) abbreviations 
-
-### Coding guide
-* Functions:
-  * Try to write function shorter than is 50 lines 
-  * Always shorter than 100 lines (except very straightforwards) 
-* Variables:
-  * One line, one declaration (BAD: char x, y;)
-  * Use `<stdint.h>` (*uint8_t*, *int32_t* etc)
-  * Declare variables when needed (not all at function start)
-  * Use the smallest required scope
-  * Variables in a file (outside functions) are always *static*
-  * Do not use global variables (use functions to set/get static variables)
-
-### Comments
-Before every function have a comment like this:
-
-```c
-/**
- * Return with the screen of an object
- * @param obj pointer to an object
- * @return pointer to a screen
- */
-lv_obj_t * lv_obj_get_scr(lv_obj_t * obj); 
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/CONTRIBUTING.md
 ```
 
-Always use `/* Something */` format and NOT `//Something`
+# Contributing
 
-Write readable code to avoid descriptive comments like: 
-`x++; /* Add 1 to x */`. 
-The code should show clearly what you are doing.
+## Introduction
 
-You should write **why** have you done this: 
-`x++; /*Because of closing '\0' of the string */`
+Join LVGL's community and leave your footprint in the library!
 
-Short "code summaries" of a few lines are accepted. E.g. `/*Calculate the new coordinates*/`
+There are a lot of ways to contribute to LVGL even if you are are new to the library or even new to programming. 
 
-In comments use \` \` when referring to a variable. E.g. ``/*Update the value of `x_act`*/``
+It might be scary to make the first step but you have nothing to be afraid of. 
+A friendly and helpful community is waiting for you. Get to know like-minded people and make something great together.
 
-### Formatting
-Here is example to show bracket placing and using of white spaces:
-```c
-/**
- * Set a new text for a label. Memory will be allocated to store the text by the label.
- * @param label pointer to a label object
- * @param text '\0' terminated character string. NULL to refresh with the current text.
+So let's find which contribution option fits you the best and help you join the development of LVGL!
+
+Before getting started here are some guidelines to make contribution smoother:
+- Be kind and friendly. 
+- Be sure to read the relevant part of the documentation before posting a question.
+- Ask questions in the [Forum](https://forum.lvgl.io/) and use [GitHub](https://github.com/lvgl/) for development-related discussions.
+- Always fill out the post or issue templates in the Forum or GitHub (or at least provide equivalent information). It makes understanding your contribution or issue easier and you will get a useful response faster.
+- If possible send an absolute minimal but buildable code example in order to reproduce the issue. Be sure it contains all the required variable declarations, constants, and assets (images, fonts).
+- Use [Markdown](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet) to format your posts. You can learn it in 10 minutes.
+- Speak about one thing in one issue or topic. It makes your post easier to find later for someone with the same question.
+- Give feedback and close the issue or mark the topic as solved if your question is answered. 
+- For non-trivial fixes and features, it's better to open an issue first to discuss the details instead of sending a pull request directly.
+- Please read and follow the <a href="https://github.com/lvgl/lvgl/blob/master/docs/CODING_STYLE.md">Coding style</a> guide.
+
+## Pull request
+
+Merging new code into the lvgl, documentation, blog, examples, and other repositories happen via *Pull requests* (PR for short).
+A PR is a notification like "Hey, I made some updates to your project. Here are the changes, you can add them if you want."
+To do this you need a copy (called fork) of the original project under your account, make some changes there, and notify the original repository about your updates. 
+You can see what it looks like on GitHub for LVGL here: [https://github.com/lvgl/lvgl/pulls](https://github.com/lvgl/lvgl/pulls).
+
+To add your changes you can edit files online on GitHub and send a new Pull request from there (recommended for small changes) or
+ add the updates in your favorite editor/IDE and use git to publish the changes (recommended for more complex updates).
+
+### From GitHub
+1. Navigate to the file you want to edit.
+2. Click the Edit button in the top right-hand corner.
+3. Add your changes to the file.
+4. Add a commit message on the bottom of the page.
+5. Click the *Propose changes* button.
+
+### From command line
+
+The instructions describe the main `lvgl` repository but it works the same way for the other repositories.
+1. Fork the [lvgl repository](https://github.com/lvgl/lvgl). To do this click the "Fork" button in the top right corner. 
+It will "copy" the `lvgl` repository to your GitHub account (`https://github.com/<YOUR_NAME>?tab=repositories`)
+2. Clone your forked repository.
+3. Add your changes. You can create a *feature branch* from *master* for the updates: `git checkout -b the-new-feature` 
+4. Commit and push your changes to the forked `lvgl` repository.
+5. Create a PR on GitHub from the page of your `lvgl` repository (`https://github.com/<YOUR_NAME>/lvgl`) by clicking the *"New pull request"* button. Don't forget to select the branch where you added your changes.
+7. Set the base branch. It means where you want to merge your update. In the `lvgl` repo fixes go to `master`, new features to `dev` branch. 
+8. Describe what is in the update. An example code is welcome if applicable.
+9. If you need to make more changes, just update your forked `lvgl` repo with new commits. They will automatically appear in the PR.
+
+## Developer Certification of Origin (DCO)
+
+### Overview
+
+To ensure all licensing criteria are met for every repository of the LVGL project, we apply a process called DCO (Developer's Certificate of Origin).
+
+The text of DCO can be read here: [https://developercertificate.org/](https://developercertificate.org/).
+
+By contributing to any repositories of the LVGL project you agree that your contribution complies with the DCO.
+
+If your contribution fulfills the requirements of the DCO no further action is needed. If you are unsure feel free to ask us in a comment.
+
+### Accepted licenses and copyright notices
+
+To make the DCO easier to digest, here are some practical guides about specific cases:
+
+#### Your own work
+
+The simplest case is when the contribution is solely your own work. 
+In this case you can just send a Pull Request without worrying about any licensing issues.
+
+#### Use code from online source
+
+If the code you would like to add is based on an article, post or comment on a website (e.g. StackOverflow) the license and/or rules of that site should be followed.
+
+For example in case of StackOwerflow a notice like this can be used:
+```
+/* The original version of this code-snippet was published on StackOverflow.
+ * Post: http://stackoverflow.com/questions/12345
+ * Author: http://stackoverflow.com/users/12345/username
+ * The following parts of the snippet were changed:
+ * - Check this or that
+ * - Optimize performance here and there
  */
-void lv_label_set_text(lv_obj_t * label, const char * text)
-{   /* Main brackets of functions in new line*/
-    
-    if(label == NULL) return; /*No bracket only if the command is inline with the if statement*/
-    
-    lv_obj_inv(label);
-    
-    lv_label_ext_t * ext = lv_obj_get_ext(label);
-
-    /*Comment before a section */
-    if(text == ext->txt || text == NULL) {  /*Bracket of statements start inline*/
-        lv_label_refr_text(label);
-        return;   
-    }
-    
-    ...
-}
+ ... code snippet here ...
 ```
 
-Use 4 spaces indentation instead of tab.
+#### Use MIT licensed code
+As LVGL is MIT licensed, other MIT licensed code can be integrated without issues.
+The MIT license requires a copyright notice be added to the derived work. Any derivative work based on MIT licensed code must copy the original work's license file or text.
 
-You can use **astyle** to format the code. The required config flies are: `docs/astyle_c` and `docs/astyle_h`.
-To format the source files: 
- `$ find . -type f -name "*.c" | xargs astyle --options=docs/astyle_c`
+#### Use GPL licensed code
+The GPL license is not compatible with the MIT license. Therefore, LVGL can not accept GPL licensed code. 
  
-To format the header files:
- `$ find . -type f -name "*.h" | xargs astyle --options=docs/astyle_h`
+## Ways to contribute
+
+Even if you're just getting started with LVGL there are plenty of ways to get your feet wet. 
+Most of these options don't even require knowing a single line of LVGL code. 
+
+Below we have collected some opportunities about the ways you can contribute to LVGL.  
+
+### Give LVGL a Star
+
+Show that you like LVGL by giving it star on GitHub!
+<!-- Place this tag in your head or just before your close body tag. -->
+<script async defer src="https://buttons.github.io/buttons.js"></script>
+<!-- Place this tag where you want the button to render. -->
+<a class="github-button" href="https://github.com/lvgl/lvgl" data-icon="octicon-star" data-size="large" data-show-count="true" aria-label="Star lvgl/lvgl on GitHub">Star</a>
+
+This simple click makes LVGL more visible on GitHub and makes it more attractive to other people. 
+So with this, you already helped a lot! 
+
+### Tell what you have achieved
+
+Have you already started using LVGL in a [Simulator](/get-started/pc-simulator), a development board, or on your custom hardware? 
+Was it easy or were there some obstacles? Are you happy with the result? 
+Showing your project to others is a win-win situation because it increases your and LVGL's reputation at the same time.
+
+You can post about your project on Twitter, Facebook, LinkedIn, create a YouTube video, and so on. 
+Only one thing: On social media don't forget to add a link to `https://lvgl.io` or `https://github.com/lvgl` and use the hashtag `#lvgl`. Thank you! :) 
+
+You can also open a new topic in the [My projects](https://forum.lvgl.io/c/my-projects/10) category of the Forum.
+
+The [LVGL Blog](https://blog.lvgl.io) welcomes posts from anyone. 
+It's a good place to talk about a project you created with LVGL, write a tutorial, or share some nice tricks.
+The latest blog posts are shown on the [homepage of LVGL](https://lvgl.io) to make your work more visible.
+
+The blog is hosted on GitHub. If you add a post GitHub automatically turns it into a website. 
+See the [README](https://github.com/lvgl/blog) of the blog repo to see how to add your post.
  
-Append `-n` to the end to skip creation of backup file OR use `$ find . -type f -name "*.bak"  -delete` (for source file's backups) and `find . -type f -name "*.orig" -delete` (for header file's backups)
+Any of these help to spread the word and familiarize new developers with LVGL.
+
+If you don't want to speak about your project publicly, feel free to use [Contact form](https://lvgl.io/#contact) on lvgl.io to private message to us. 
+
+### Write examples
+As you learn LVGL you will probably play with the features of widgets. Why not publish your experiments?
+
+Each widgets' documentation contains examples. For instance, here are the examples of the [Drop-down list](/widgets/core/dropdown#examples) widget. 
+The examples are directly loaded from the [lvgl/examples](https://github.com/lvgl/lvgl/tree/master/examples) folder. 
+
+So all you need to do is send a [Pull request](#pull-request) to the [lvgl](https://github.com/lvgl/lvgl) repository and follow some conventions:
+- Name the examples like `lv_example_<widget_name>_<index>`.
+- Make the example as short and simple as possible.
+- Add comments to explain what the example does.
+- Use 320x240 resolution.
+- Update `index.rst` in the example's folder with your new example. To see how other examples are added, look in the [lvgl/examples/widgets](https://github.com/lvgl/lvgl/tree/master/examples/widgets) folder.
+
+### Improve the docs
+
+As you read the documentation you might see some typos or unclear sentences. All the documentation is located in the [lvgl/docs](https://github.com/lvgl/lvgl/tree/master/docs) folder.
+For typos and straightforward fixes, you can simply edit the file on GitHub. 
+
+Note that the documentation is also formatted in [Markdown](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet). 
+
+### Report bugs
+As you use LVGL you might find bugs. Before reporting them be sure to check the relevant parts of the documentation.
+
+If it really seems like a bug feel free to open an [issue on GitHub](https://github.com/lvgl/lvgl/issues). 
+
+When filing the issue be sure to fill out the template. It helps find the root of the problem while avoiding extensive questions and exchanges with other developers.
+
+### Send fixes
+The beauty of open-source software is you can easily dig in to it to understand how it works. You can also fix or adjust it as you wish.
+
+If you found and fixed a bug don't hesitate to send a [Pull request](#pull-request) with the fix.
+
+In your Pull request please also add a line to [`CHANGELOG.md`](https://github.com/lvgl/lvgl/blob/master/CHANGELOG.md).
+
+### Join the conversations in the Forum
+It feels great to know you are not alone if something is not working. It's even better to help others when they struggle with something.
+
+While you were learning LVGL you might have had questions and used the Forum to get answers. As a result, you probably have more knowledge about how LVGL works.
+
+One of the best ways to give back is to use the Forum and answer the questions of newcomers - like you were once.
+
+Just read the titles and if you are familiar with the topic don't hesitate to share your thoughts and suggestions.
+
+Participating in the discussions is one of the best ways to become part of the project and get to know like-minded people!
+
+### Add features
+We collect the planned features in GitHub on the [Roadmap](/ROADMAP) page. If you are interested in any of them feel free to share your opinion and/or participate in the the implementation.
+
+Other features which are (still) not on the road map are listed in the [Feature request](https://forum.lvgl.io/c/feature-request/9) category of the Forum. 
+If you have a feature idea for LVGL please use the Forum to share it! 
+Make sure to check that there isn't an existing post; if there is, you should comment on it to show that there is increased interest in an existing request.
+
+When adding a new features the followings also needs to be updated:
+- Add a line to [CHANGELOG.md](https://github.com/lvgl/lvgl/blob/master/CHANGELOG.md).
+- Update the documentation. 
+- Add an example if applicable.  See this [guide](#write-examples).
+
+### Become a maintainer
+
+If you want to become part of the core development team, you can become a maintainer of a repository.
+
+By becoming a maintainer:
+- You get write access to that repo:
+  - Add code directly without sending a pull request
+  - Accept pull requests
+  - Close/reopen/edit issues
+- Your input has higher impact when we are making decisions
+
+You can become a maintainer by invitation, however the following conditions need to met
+1. Have > 50 replies in the Forum. You can look at your stats [here](https://forum.lvgl.io/u?period=all)
+2. Send > 5 non-trivial pull requests to the repo where you would like to be a maintainer
 
 
+If you are interested, just send a message (e.g. from the Forum) to the current maintainers of the repository. They will check if the prerequisites are met. 
+Note that meeting the prerequisites is not a guarantee of acceptance, i.e. if the conditions are met you won't automatically become a maintainer. 
+It's up to the current maintainers to make the decision.
+
+### Move your project repository under LVGL organization
+Besides the core `lvgl` repository there are other repos for ports to development boards, IDEs or other environment. 
+If you ported LVGL to a new platform we can host it under the LVGL organization among the other repos.
+
+This way your project will become part of the whole LVGL project and can get more visibility. 
+If you are interested in this opportunity just open an [issue in lvgl repo](https://github.com/lvgl/lvgl/issues) and tell what you have! 
+
+If we agree that your port fit well into the LVGL organization, we will open a repository for your project where you will have admin rights.  
+
+To make this concept sustainable there a few rules to follow:
+- You need to add a README to your repo.
+- We expect to maintain the repo to some extent:
+  - Follow at least the major versions of LVGL 
+  - Respond to the issues (in a reasonable time)
+- If there is no activity in a repo for 1 year it will be archived

docs/ROADMAP.md

@@ -0,0 +1,63 @@
+# Roadmap
+
+This is a summary for planned new features and a collection of ideas.
+This list indicates only the current intention and it can be changed.
+
+## v8.X
+- `lv_snapshot`: buffer a widget and all of its children into an image. he source widget can be on a different screen too. The result image can be transformed.
+- Add radio button support
+- Unit testing (gtest?). See [#1658](https://github.com/lvgl/lvgl/issues/1658)
+- Benchmarking (gem5?). See [#1660](https://github.com/lvgl/lvgl/issues/1660)
+- chart: pre-delete `X` pint after the lastly set
+- chart: autoscroll to the right
+- 9-patch support for `lv_imgbtn`.
+- Handle stride. See [#1858](https://github.com/lvgl/lvgl/issues/1858)
+- Optimize line and circle drawing and masking 
+
+## Ideas
+- Reconsider color format management for run time color format setting, and custom color format usage. (Also [RGB888](https://github.com/lvgl/lvgl/issues/1722))
+- Make gradients more versatile
+- Make image transformations more versatile
+- Switch to RGBA colors in styles
+- Consider direct binary font format support
+- Simplify `group`s. Discussion is [here](https://forum.lvgl.io/t/lv-group-tabindex/2927/3).
+- Use [generate-changelog](https://github.com/lob/generate-changelog) to automatically generate changelog
+- lv_mem_alloc_aligned(size, align)
+- Text node. See [#1701](https://github.com/lvgl/lvgl/issues/1701#issuecomment-699479408)
+- CPP binding. See [Forum](https://forum.lvgl.io/t/is-it-possible-to-officially-support-optional-cpp-api/2736)
+- Optimize font decompression
+- Need coverage report for tests
+- Need static analyze (via coverity.io or somehing else)
+- Support dot_begin and dot_middle long modes for labels
+- Add new label alignment modes. [#1656](https://github.com/lvgl/lvgl/issues/1656)
+- Support larger images: [#1892](https://github.com/lvgl/lvgl/issues/1892)
+
+--- 
+
+## v8
+- Create an `extra` folder for complex widgets
+   - It makes the core LVGL leaner
+   - In `extra` we can have a lot and specific widgets
+   - Good place for contributions
+- New scrolling:
+  - See [feat/new-scroll](https://github.com/lvgl/lvgl/tree/feat/new-scroll) branch and  [#1614](https://github.com/lvgl/lvgl/issues/1614)) issue.
+  - Remove `lv_page` and support scrolling on `lv_obj`
+  - Support "elastic" scrolling when scrolled in
+  - Support scroll chaining among any objects types (not only `lv_pages`s)
+  - Remove `lv_drag`. Similar effect can be achieved by setting the position in `LV_EVENT_PRESSING`
+  - Add snapping
+  - Add snap stop to scroll max 1 snap point
+  - Already working
+- New layouts:
+  - See [#1615](https://github.com/lvgl/lvgl/issues/1615) issue
+  - [CSS Grid](https://css-tricks.com/snippets/css/a-guide-to-grid/)-like layout support
+  - [CSS Flexbox](https://css-tricks.com/snippets/css/a-guide-to-flexbox/)-like layout support
+  - Remove `lv_cont` and support layouts on `lv_obj`
+- Simplified File system interface ([feat/new_fs_api](https://github.com/lvgl/lvgl/tree/feat/new-fs-api) branch) to make porting easier
+  - Work in progress
+- Remove the align parameter from `lv_canvas_draw_text`
+- Remove the copy parameter from create functions
+- Optimize and simplifie styles [#1832](https://github.com/lvgl/lvgl/issues/1832)
+- Use a more generic inheritenace [#1919](https://github.com/lvgl/lvgl/issues/1919)
+- Allow adding multiple events to an obejct
+

docs/_ext/lv_example.py

@@ -0,0 +1,50 @@
+import os
+
+from docutils import nodes
+from docutils.parsers.rst import Directive
+from docutils.parsers.rst.directives.images import Image
+from sphinx.directives.code import LiteralInclude
+
+
+class LvExample(Directive):
+    required_arguments = 3
+    def run(self):
+        example_path = self.arguments[0]
+        example_name = os.path.split(example_path)[1]
+        language = self.arguments[2]
+        node_list = []
+
+        env = self.state.document.settings.env
+
+        if self.arguments[2] == 'py':
+            paragraph_node = nodes.raw(text=f"Click to try in the simulator!<br/><a target='_blank' href='https://sim.lvgl.io/v7/micropython/ports/javascript/bundle_out/index.html?script_startup=https://raw.githubusercontent.com/lvgl/lv_examples/{env.config.example_commit_hash}/src/header.py&script=https://raw.githubusercontent.com/lvgl/lv_examples/{env.config.built_example_commit_hash}/{example_name}/{example_name}.py'><img alt='{example_name}' src='https://raw.githubusercontent.com/lvgl/lv_examples/{env.config.built_example_commit_hash}/{example_name}/{example_name}.png'/></a>", format='html')
+        else:
+            paragraph_node = nodes.raw(text=f"<iframe class='lv-example' src='/{env.config.version}/_static/built_lv_examples?example={example_name}&w=320&h=240'></iframe>", format='html')
+        toggle = nodes.container('', literal_block=False, classes=['toggle'])
+        header = nodes.container('', literal_block=False, classes=['header'])
+        toggle.append(header)
+        example_file = os.path.abspath("../examples/" + example_path + "." + self.arguments[2])
+
+        try:
+            with open(example_file) as f:
+                contents = f.read()
+        except FileNotFoundError:
+            contents = 'Error encountered while trying to open ' + example_file
+        literal_list = nodes.literal_block(contents, contents)
+        literal_list['language'] = language
+        toggle.append(literal_list)
+        header.append(nodes.raw(text=f"<p>code &nbsp; <a class='fa fa-github' href='https://github.com/lvgl/lvgl/blob/{env.config.repo_commit_hash}/examples/{example_path}.{language}'>&nbsp; view on GitHub</a></p>", format='html'))
+        if env.app.tags.has('html'):
+            node_list.append(paragraph_node)
+        node_list.append(toggle)
+        return node_list
+
+def setup(app):
+    app.add_directive("lv_example", LvExample)
+    app.add_config_value("repo_commit_hash", "", "env")
+
+    return {
+        'version': '0.1',
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }

docs/_static/css/custom.css

@@ -0,0 +1,74 @@
+table, th, td {
+  border: 1px solid #bbb;
+  padding: 10px;
+}
+
+td {
+  text-align:center;
+}
+span.pre
+{  
+  padding-right:8px;
+}
+
+span.pre:first-child
+{  
+  padding-right:0px;
+}
+
+
+code.sig-name
+{
+  //margin-left:8px;
+}
+
+.toggle .header {
+    display: block;
+    clear: both;
+    cursor: pointer;
+    font-weight: bold; 
+}
+
+.toggle .header:before {
+   font-family: FontAwesome, "Lato","proxima-nova","Helvetica Neue",Arial,sans-serif;
+   content: "\f0da \00a0 Show "; 
+   display: inline-block;
+   font-size: 1.1em;
+}
+
+.toggle .header.open:before {
+   content: "\f0d7 \00a0 Hide "; 
+}
+
+.header p {
+    display: inline-block;
+    font-size: 1.1em;
+    margin-bottom: 8px;
+}
+
+.wy-side-nav-search {
+  background-color: #f5f5f5;
+}
+.wy-side-nav-search>div.version {
+  color: #333;
+  display: none; /*replaced by dropdown*/
+}
+
+
+.home-img {
+  width:32%; 
+  transition: transform .3s ease-out;
+}
+
+.home-img:hover {
+  transform: translate(0, -10px);
+}
+
+.lv-example {
+  border: none;
+  outline: none;
+  padding: none;
+  display: block;
+  width: 320px;
+  height: 240px;
+}

docs/_templates/layout.html

@@ -0,0 +1,31 @@
+{% extends "!layout.html" %}
+
+{%- block extrahead %}
+{{ super() }}
+<!-- Global site tag (gtag.js) - Google Analytics -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=UA-78811084-3"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+	gtag('config', 'UA-78811084-3', { 'anonymize_ip': true });
+</script>
+{% endblock %}
+
+{% block footer %}
+{{ super() }}
+<div class="footer">This page uses <a href="https://analytics.google.com/">
+Google Analytics</a> to collect statistics. You can disable it by blocking
+the JavaScript coming from www.google-analytics.com.
+<script type="text/javascript">
+  (function() {
+    var ga = document.createElement('script');
+    ga.src = ('https:' == document.location.protocol ?
+              'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
+    ga.setAttribute('async', 'true');
+    document.documentElement.firstChild.appendChild(ga);
+  })();
+</script>
+</div>
+{% endblock %}

docs/_templates/page.html

@@ -0,0 +1,53 @@
+{% extends "!page.html" %}
+
+{% block footer %}
+
+<style>
+  .wy-side-nav-search > div[role="search"] {
+    color: black;
+  }
+</style>
+ <script type="text/javascript">
+    $(document).ready(function() {
+        $(".toggle > *").hide();
+        $(".toggle .header").show();
+        $(".toggle .header").click(function() {
+            $(this).parent().children().not(".header").toggle(400);
+            $(this).parent().children(".header").toggleClass("open");
+        })
+    });
+</script>
+
+<script type="text/javascript">
+function add_version_selector()
+{
+    return fetch("https://raw.githubusercontent.com/lvgl/docs_compiled/gh-pages/versionlist.txt")
+        .then(res => res.text())
+        .then(text => {
+            const versions = text.split("\n").filter(version => version.trim().length > 0);
+            let p = document.getElementById("rtd-search-form").parentElement;
+            p.innerHTML = `
+            <select name="versions" id="versions" onchange="ver_sel()" style="border-radius:5px; margin-bottom:15px">
+            ${versions.map(version => {
+                const versionName = "v" + ((version.indexOf(".") != -1) ? version : (version + " (latest minor)"));
+                return `<option value="${version}">${versionName}</option>`;
+            })}
+            </select>` + p.innerHTML;
+        });
+}
+
+function ver_sel()
+{
+  var x = document.getElementById("versions").value;
+  window.location.href = window.location.protocol + "//" + window.location.host + "/" + x + "/";
+}
+
+document.addEventListener('DOMContentLoaded', (event) => {
+    add_version_selector().then(() => {
+        var value = window.location.pathname.split('/')[1];
+        document.getElementById("versions").value = value;
+    });
+    
+})
+</script>
+{% endblock %}

docs/astyle_c

@@ -1 +0,0 @@
---style=kr --convert-tabs --indent=spaces=4 --indent-switches   --pad-oper --unpad-paren  --align-pointer=middle --suffix=.bak --lineend=linux --min-conditional-indent=

docs/astyle_h

@@ -1 +0,0 @@
---convert-tabs --indent=spaces=4

docs/build.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import subprocess
+import re
+
+langs = ['en']
+
+# Change to script directory for consistency
+abspath = os.path.abspath(__file__)
+dname = os.path.dirname(abspath)
+os.chdir(dname)
+
+def cmd(s):
+  print("")
+  print(s)
+  print("-------------------------------------")
+  r = os.system(s)
+  if r != 0: 
+    print("Exit build due to previous error")
+    exit(-1)
+
+# Get the current branch name
+status, br = subprocess.getstatusoutput("git branch | grep '*'")
+_, gitcommit = subprocess.getstatusoutput("git rev-parse HEAD")
+br = re.sub('\* ', '', br)
+urlpath = re.sub('release/', '', br)
+ 
+# Be sure the github links point to the right branch
+f = open("header.rst", "w")
+f.write(".. |github_link_base| replace:: https://github.com/lvgl/lvgl/blob/" + gitcommit + "/docs")
+f.close()
+
+base_html = "html_baseurl = 'https://docs.lvgl.io/" + urlpath + "/en/html/'"
+
+os.system("sed -i \"s|html_baseurl = .*|" + base_html +"|\" conf.py")
+
+clean = 0
+trans = 0
+skip_latex = False
+args = sys.argv[1:]
+if len(args) >= 1:
+  if "clean" in args: clean = 1
+  if "skip_latex" in args: skip_latex = True
+  
+lang = "en"
+print("")
+print("****************")
+print("Building")
+print("****************")
+if clean:
+  cmd("rm -rf " + lang)
+  cmd("mkdir " + lang)
+
+
+print("Running doxygen")
+cmd("cd ../scripts && doxygen Doxyfile")
+# BUILD PDF
+
+if not skip_latex:
+  # Silly workarond to include the more or less correct PDF download link in the PDF
+  #cmd("cp -f " + lang +"/latex/LVGL.pdf LVGL.pdf | true")
+  cmd("sphinx-build -b latex . out_latex")
+
+  # Generate PDF
+  cmd("cd out_latex && latexmk -pdf 'LVGL.tex'")
+  # Copy the result PDF to the main directory to make it avaiable for the HTML build
+  cmd("cd out_latex && cp -f LVGL.pdf ../LVGL.pdf")
+else:
+  print("skipping latex build as requested")
+
+# BULD HTML
+cmd("sphinx-build -b html . ../out_html")
+

docs/conf.py

@@ -0,0 +1,239 @@
+#!/usr/bin/env python3.7
+# -*- coding: utf-8 -*-
+#
+# LVGL documentation build configuration file, created by
+# sphinx-quickstart on Wed Jun 12 16:38:40 2019.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+import os
+import sys
+import subprocess
+sys.path.insert(0, os.path.abspath('./_ext'))
+
+import recommonmark
+from recommonmark.transform import AutoStructify
+from sphinx.builders.html import StandaloneHTMLBuilder
+from subprocess import Popen, PIPE
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#
+# needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = ['sphinx.ext.autodoc',
+    'sphinx.ext.intersphinx',
+    'sphinx.ext.todo',
+    'recommonmark',
+    'sphinx_markdown_tables',
+    'breathe',
+    'sphinx_sitemap',
+    'lv_example'
+    ]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The default language to highlight source code in. The default is 'python'. 
+# The value should be a valid Pygments lexer name, see Showing code examples for more details.
+
+
+highlight_language = 'c'
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+#
+source_suffix = ['.rst', '.md']
+
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = 'LVGL'
+copyright = '2020, LVGL LLC'
+author = 'LVGL community'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+# embeddedt: extract using scripts/find_version.sh
+
+version = subprocess.run(["../scripts/find_version.sh"], capture_output=True).stdout.decode("utf-8").strip()
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This patterns also effect to html_static_path and html_extra_path
+exclude_patterns = ['_build', 'doxygen_html', 'Thumbs.db', '.DS_Store', 
+                    'README.md', 'lv_examples', 'out_html' ]
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = True
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'sphinx_rtd_theme'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#
+html_theme_options = {
+    'collapse_navigation' : False,
+    'logo_only': True,
+}
+# For site map generation
+html_baseurl = 'https://docs.lvgl.io/' + version + "/"
+sitemap_url_scheme = "{link}"
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# Custom sidebar templates, must be a dictionary that maps document names
+# to template names.
+#
+# This is required for the alabaster theme
+# refs: http://alabaster.readthedocs.io/en/latest/installation.html#sidebars
+html_sidebars = {
+    '**': [
+        'relations.html',  # needs 'show_related': True theme option to display
+        'searchbox.html',
+    ]
+}
+
+html_favicon = 'favicon.png'
+html_logo = 'logo_lvgl.png'
+
+# -- Options for HTMLHelp output ------------------------------------------
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'LVGLdoc'
+
+html_last_updated_fmt = ''
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_engine = 'xelatex'
+latex_use_xindy = False
+latex_elements = {
+    # The paper size ('letterpaper' or 'a4paper').
+    #
+    # 'papersize': 'letterpaper',
+
+    # The font size ('10pt', '11pt' or '12pt').
+    #
+    # 'pointsize': '10pt',
+
+    # Additional stuff for the LaTeX preamble.
+    #
+    # 'preamble': '',
+
+    # Latex figure (float) alignment
+    #
+    # 'figure_align': 'htbp',
+    
+    'inputenc': '',
+    'utf8extra': '',
+    'classoptions': ',openany,oneside',
+    'babel': '\\usepackage{babel}',
+    'passoptionstopackages': r'''
+\PassOptionsToPackage{bookmarksdepth=5}{hyperref}% depth of pdf bookmarks
+''',
+    'preamble': r'''
+\usepackage{fontspec}
+\setmonofont{DejaVu Sans Mono}
+\usepackage{silence}
+\WarningsOff*
+''',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+    (master_doc, 'LVGL.tex', 'LVGL Documentation ' + version,
+     'LVGL community', 'manual'),
+]
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'lvgl', 'LVGL Documentation ' + version,
+     [author], 1)
+]
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    (master_doc, 'LVGL', 'LVGL Documentation ' + version,
+     author, 'Contributors of LVGL', 'One line description of project.',
+     'Miscellaneous'),
+]
+
+
+breathe_projects = {
+  "lvgl":"xml/",
+}
+
+StandaloneHTMLBuilder.supported_image_types = [
+    'image/svg+xml',
+    'image/gif',  #prefer gif over png
+    'image/png',
+    'image/jpeg'
+]
+
+smartquotes = False
+
+_, repo_commit_hash = subprocess.getstatusoutput("git rev-parse HEAD")
+
+
+# Example configuration for intersphinx: refer to the Python standard library.
+
+def setup(app):
+    app.add_config_value('recommonmark_config', {
+            'enable_eval_rst': True,
+            'enable_auto_toc_tree': 'True',
+            }, True)
+    app.add_transform(AutoStructify)
+    app.add_css_file('css/custom.css')
+    app.add_css_file('css/fontawesome.min.css')

docs/get-started/arduino.md

@@ -0,0 +1,77 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/arduino.md
+```
+
+# Arduino
+
+The [core LVGL library](https://github.com/lvgl/lvgl) and the [examples](https://github.com/lvgl/lv_examples) are directly available as Arduino libraries.
+
+Note that you need to choose a powerful enough board to run LVGL and your GUI.  See the [requirements of LVGL](https://docs.lvgl.io/latest/en/html/intro/index.html#requirements). 
+
+For example ESP32 is a good candidate to create your UI with LVGL.
+
+
+## Get the LVGL Ardunio library
+
+LVGL can be installed via the Arduino IDE Library Manager or as a .ZIP library.
+It will also install [lv_exmaples](https://github.com/lvgl/lv_examples) which contains a lot of examples and demos to try LVGL.
+
+## Set up drivers
+
+To get started it's recommended to use [TFT_eSPI](https://github.com/Bodmer/TFT_eSPI) library as a TFT driver to simplify testing. 
+To make it work setup `TFT_eSPI` according to your TFT display type via editing either
+- `User_Setup.h` 
+- or by selecting a configuration in the `User_Setup_Select.h`
+
+Both files are located in `TFT_eSPI` library's folder.
+
+## Configure LVGL
+
+LVGL has its own configuration file called `lv_conf.h`. When LVGL is installed the followings needs to be done to configure it:
+1. Go to directory of the installed Arduino libraries
+2. Go to `lvgl` and copy `lv_conf_template.h` as `lv_conf.h` into the Arduino Libraries directory next to the `lvgl` library folder.
+3. Open `lv_conf.h` and change the first `#if 0` to `#if 1`
+4. Set the resolution of your display in `LV_HOR_RES_MAX` and `LV_VER_RES_MAX`
+5. Set the color depth of you display in `LV_COLOR_DEPTH`
+6. Set `LV_TICK_CUSTOM 1`
+
+## Configure the examples
+`lv_examples` can be configures similarly to LVGL but it's configuration file is called `lv_ex_conf.h`. 
+1. Go to directory of the installed Arduino libraries
+2. Go to `lv_examples` and copy `lv_ex_template.h` as `lv_ex_conf.h` next to the `lv_examples` folder.
+3. Open `lv_ex_conf.h` and change the first `#if 0` to `#if 1`
+4. Enable the demos you want to use. (The small examples starting with `lv_ex_...()` are always enabled.)
+
+## Initialize LVGL and run an example
+
+Take a look at [LVGL_Arduino.ino](https://github.com/lvgl/lvgl/blob/master/examples/LVGL_Arduino.ino) to see how to initialize LVGL.
+TFT_eSPI is used as the display driver.
+
+In the INO file you can see how to register a display and a touch pad for LVGL and call an example.
+
+Note that, there is no dedicated INO file for every example but you can call functions like `lv_ex_btn1()` or `lv_ex_slider1()` to run an example.
+For the full list of examples see the [README of lv_examples](https://github.com/lvgl/lv_examples/blob/master/README.md).
+
+## Debugging and logging
+
+In case of trouble LVGL can display debug information. 
+In the `LVGL_Arduino.ino` example there is `my_print` method, which allow to send this debug information to the serial interface. 
+To enable this feature you have to edit `lv_conf.h` file and enable logging in the section `log settings`:
+
+```c
+/*Log settings*/
+#define USE_LV_LOG      1   /*Enable/disable the log module*/
+#if LV_USE_LOG
+/* How important log should be added:
+ * LV_LOG_LEVEL_TRACE       A lot of logs to give detailed information
+ * LV_LOG_LEVEL_INFO        Log important events
+ * LV_LOG_LEVEL_WARN        Log if something unwanted happened but didn't cause a problem
+ * LV_LOG_LEVEL_ERROR       Only critical issue, when the system may fail
+ * LV_LOG_LEVEL_NONE        Do not log anything
+ */
+#  define LV_LOG_LEVEL    LV_LOG_LEVEL_WARN
+```
+
+After enabling the log module and setting LV_LOG_LEVEL accordingly the output log is sent to the `Serial` port @ 115200 bps.
+

docs/get-started/espressif.md

@@ -0,0 +1,47 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/espressif.md
+```
+
+# Espressif (ESP32)
+Since v7.7.1 LVGL includes a Kconfig file, so LVGL can be used as an ESP-IDF v4 component.
+
+## Get the LVGL demo project for ESP32
+
+We've created [lv_port_esp32](https://github.com/lvgl/lv_port_esp32), a project using ESP-IDF and LVGL to show one of the demos from [lv_examples](https://github.com/lvgl/lv_examples).
+You are able to configure the project to use one of the many supported display controllers, see [lvgl_esp32_drivers](https://github.com/lvgl/lvgl_esp32_drivers) for a complete list
+of supported display and indev (touch) controllers.
+
+## Use LVGL in your ESP32 project
+
+### Prerequisites
+
+ESP-IDF v4 framework is the suggested version to use.
+
+### Get LVGL
+
+You are suggested to add LVGL as a "component". This component can be located inside a directory named "components" on your project root directory.
+
+When your project is a git repository you can include LVGL as a git submodule:
+
+```c
+git submodule add https://github.com/lvgl/lvgl.git components/lvgl
+```
+
+The above command will clone LVGL's main repository into the `components/lvgl` directory. LVGL includes a `CMakeLists.txt` file that sets some configuration options so you can use LVGL right away.
+
+When you are ready to configure LVGL launch the configuration menu with `idf.py menuconfig` on your project root directory, go to `Component config` and then `LVGL configuration`.
+
+## Use lvgl_esp32_drivers in your project
+
+You are suggested to add `lvgl_esp32_drivers` as a "component". This component can be located inside a directory named "components" on your project root directory.
+
+When your project is a git repository you can include `lvgl_esp32_drivers` as a git submodule:
+
+```c
+git submodule add https://github.com/lvgl/lvgl_esp32_drivers.git components/lvgl_esp32_drivers
+```
+
+### Support for ESP32-S2
+
+Basic support for ESP32-S2 has been added into the `lvgl_esp32_drivers` repository.

docs/get-started/index.md

@@ -0,0 +1,34 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/index.md
+```
+# Get started
+
+There are several ways to get your feet wet with LVGL. Here is one recommended order of documents to read and things to play with when you are learning to use LVGL:
+1. Check the [Online demos](https://lvgl.io/demos) to see LVGL in action (3 minutes)
+2. Read the [Introduction](https://docs.lvgl.io/latest/en/html/intro/index.html) page of the documentation (5 minutes)
+3. Read the [Quick overview](https://docs.lvgl.io/latest/en/html/get-started/quick-overview.html) page of the documentation (15 minutes)
+4. Set up a [Simulator](https://docs.lvgl.io/latest/en/html/get-started/pc-simulator.html) (10 minutes)
+5. Try out some [Examples](https://github.com/lvgl/lv_examples/)
+6. Port LVGL to a board. See the [Porting](https://docs.lvgl.io/latest/en/html/porting/index.html) guide or check the ready to use [Projects](https://github.com/lvgl?q=lv_port_&type=&language=)
+7. Read the [Overview](https://docs.lvgl.io/latest/en/html/overview/index.html) page to get a better understanding of the library. (2-3 hours)
+8. Check the documentation of the [Widgets](https://docs.lvgl.io/latest/en/html/widgets/index.html) to see their features and usage
+9. If you have questions got to the [Forum](http://forum.lvgl.io/)
+10. Read the [Contributing](https://docs.lvgl.io/latest/en/html/contributing/index.html) guide to see how you can help to improve LVGL (15 minutes) 
+
+```eval_rst
+
+.. toctree::
+   :maxdepth: 2
+   :hidden:
+
+   quick-overview
+   pc-simulator
+   stm32
+   nxp
+   espressif
+   arduino
+   micropython
+   nuttx
+```
+

docs/get-started/micropython.md

@@ -0,0 +1,96 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/micropython.md
+```
+# Micropython
+
+## What is Micropython?
+
+[Micropython](http://micropython.org/) is Python for microcontrollers.  
+Using Micropython, you can write Python3 code and run it even on a bare metal architecture with limited resources.
+
+### Highlights of Micropython
+
+- **Compact** - Fits and runs within just 256k of code space and 16k of RAM. No OS is needed, although you can also run it with an OS, if you want.
+- **Compatible** - Strives to be as compatible as possible with normal Python (known as CPython).
+- **Versatile** - Supports many architectures (x86, x86-64, ARM, ARM Thumb, Xtensa).
+- **Interactive** - No need for the compile-flash-boot cycle. With the REPL (interactive prompt) you can type commands and execute them immediately, run scripts etc.
+- **Popular** - Many platforms are supported. The user base is growing bigger. Notable forks: [MicroPython](https://github.com/micropython/micropython), [CircuitPython](https://github.com/adafruit/circuitpython), [MicroPython_ESP32_psRAM_LoBo](https://github.com/loboris/MicroPython_ESP32_psRAM_LoBo)
+- **Embedded Oriented** - Comes with modules specifically for embedded systems, such as the [machine module](https://docs.micropython.org/en/latest/library/machine.html#classes) for accessing low-level hardware (I/O pins, ADC, UART, SPI, I2C, RTC, Timers etc.)
+
+---
+
+## Why Micropython + LVGL?
+
+Currently, Micropython [does not have a good high-level GUI library](https://forum.micropython.org/viewtopic.php?f=18&t=5543) by default. LVGL is an [Object Oriented Component Based](https://blog.lvgl.io/2018-12-13/extend-lvgl-objects) high-level GUI library, which seems to be a natural candidate to map into a higher level language, such as Python. LVGL is implemented in C and its APIs are in C.
+
+### Here are some advantages of using LVGL in Micropython:
+
+- Develop GUI in Python, a very popular high level language. Use paradigms such as Object Oriented Programming.
+- Usually, GUI development requires multiple iterations to get things right. With C, each iteration consists of **`Change code` > `Build` > `Flash` > `Run`**.  
+In Micropython it's just **`Change code` > `Run`** ! You can even run commands interactively using the [REPL](https://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop) (the interactive prompt)
+
+### Micropython + LVGL could be used for:
+
+- Fast prototyping GUI.  
+- Shortening the cycle of changing and fine-tuning the GUI.
+- Modelling the GUI in a more abstract way by defining reusable composite objects, taking advantage of Python's language features such as Inheritance, Closures, List Comprehension, Generators, Exception Handling, Arbitrary Precision Integers and others.
+- Make LVGL accessible to a larger audience. No need to know C in order to create a nice GUI on an embedded system.  
+This goes well with [CircuitPython vision](https://learn.adafruit.com/welcome-to-circuitpython/what-is-circuitpython). CircuitPython was designed with education in mind, to make it easier for new or unexperienced users to get started with embedded development.
+- Creating tools to work with LVGL at a higher level (e.g. drag-and-drop designer).
+
+---
+
+## So what does it look like?
+
+> TL;DR:
+> It's very much like the C API, but Object Oriented for LVGL components.
+
+Let's dive right into an example!  
+
+### A simple example
+
+```python
+import lvgl as lv
+lv.init()
+scr = lv.obj()
+btn = lv.btn(scr)
+btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
+label = lv.label(btn)
+label.set_text("Button")
+lv.scr_load(scr)
+```
+
+## How can I use it?
+
+### Online Simulator
+
+If you want to experiment with LVGL + Micropython without downloading anything - you can use our online simulator!  
+It's a fully functional LVGL + Micropython that runs entirely in the browser and allows you to edit a python script and run it.
+
+[Click here to experiment on the online simulator](https://sim.lvgl.io/)
+
+[Hello World](https://sim.lvgl.io/v7/micropython/ports/javascript/bundle_out/index.html?script=https://gist.githubusercontent.com/amirgon/51299ce9b6448328a855826149482ae6/raw/0f235c6d40462fd2f0e55364b874f14fe3fd613c/lvgl_hello_world.py&script_startup=https://gist.githubusercontent.com/amirgon/7bf15a66ba6d959bbf90d10f3da571be/raw/8684b5fa55318c184b1310663b187aaab5c65be6/init_lv_mp_js.py)
+
+Note: the online simulator is available for lvgl v6 and v7.
+
+### PC Simulator
+
+Micropython is ported to many platforms. One notable port is "unix", which allows you to build and run Micropython (+LVGL) on a Linux machine. (On a Windows machine you might need Virtual Box or WSL or MinGW or Cygwin etc.)  
+
+[Click here to know more information about building and running the unix port](https://github.com/lvgl/lv_micropython)
+
+### Embedded platform
+
+In the end, the goal is to run it all on an embedded platform.  
+Both Micropython and LVGL can be used on many embedded architectures, such as stm32, ESP32 etc.  
+You would also need display and input drivers. We have some sample drivers (ESP32+ILI9341, as well as some other examples), but chances are you would want to create your own input/display drivers for your specific hardware.
+Drivers can be implemented either in C as a Micropython module, or in pure Micropython!
+
+## Where can I find more information?
+
+- In this [Blog Post](https://blog.lvgl.io/2019-02-20/micropython-bindings)
+- `lv_micropython` [README](https://github.com/lvgl/lv_micropython)
+- `lv_binding_micropython` [README](https://github.com/lvgl/lv_binding_micropython)
+- The [LVGL micropython forum](https://forum.lvgl.io/c/micropython) (Feel free to ask anything!)
+- At Micropython: [docs](http://docs.micropython.org/en/latest/) and [forum](https://forum.micropython.org/)

docs/get-started/nuttx.md

@@ -0,0 +1,101 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/nuttx.md
+```
+# NuttX RTOS
+
+## What is NuttX?
+
+[NuttX](https://nuttx.apache.org/) is a mature and secure real-time operating system (RTOS) with an emphasis on technical standards compliance and small size. 
+It is scalable from 8-bit to 64-bit microcontrollers and microprocessors and compliant with the Portable Operating System Interface (POSIX) and the American National Standards Institute (ANSI) standards and with many Linux-like subsystems.
+The best way to think about NuttX is to think of it as a small Unix/Linux for microcontrollers.
+
+### Highlights of NuttX
+
+- **Small** - Fits and runs in microcontrollers as small as 32KB Flash and 8KB of RAM.
+- **Compliant** - Strives to be as compatible as possible with POSIX and Linux.
+- **Versatile** - Supports many architectures (ARM, ARM Thumb, AVR, MIPS, OpenRISC, RISC-V 32-bit and 64-bit, RX65N, x86-64, Xtensa, Z80/Z180, etc).
+- **Modular** - Its modular design allows developers to select only what really matters and use modules to include new features.
+- **Popular** - NuttX is used by many companies around the world. Probably you already used a product with NuttX without knowing it was running NuttX.
+- **Predictable** - NuttX is a preemptible Realtime kernel, so you can use it to create predictable applications for realtime control.
+
+---
+
+## Why NuttX + LVGL?
+
+Although NuttX has its own graphic library called [NX](https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=139629474), LVGL is a good alternative because users could find more eye-candy demos and they can reuse code from previous projects. 
+LVGL is an [Object Oriented Component Based](https://blog.lvgl.io/2018-12-13/extend-lvgl-objects) high-level GUI library, that could fit very well for a RTOS with advanced features like NuttX. 
+LVGL is implemented in C and its APIs are in C.
+
+### Here are some advantages of using LVGL in NuttX
+
+- Develop GUI in Linux first and when it is done just compile it for NuttX. Nothing more, no wasting of time.
+- Usually, GUI development for low level RTOS requires multiple iterations to get things right, where each iteration consists of **`Change code` > `Build` > `Flash` > `Run`**.
+Using LVGL, Linux and NuttX you can reduce this process and just test everything on your computer and when it is done, compile it on NuttX and that is it.
+
+### NuttX + LVGL could be used for
+
+- GUI demos to demonstrate your board graphics capacities.
+- Fast prototyping GUI for MVP (Minimum Viable Product) presentation.
+- visualize sensor data directly and easily on the board without using a computer.
+- Final products with a GUI without a touchscreen (i.e. 3D Printer Interface using Rotary Encoder to Input data).
+- Final products with a touchscreen (and all sorts of bells and whistles).
+
+---
+
+## How to get started with NuttX and LVGL?
+
+There are many boards in the NuttX mainline (https://github.com/apache/incubator-nuttx) with support for LVGL.
+Let's use the [STM32F429IDISCOVERY](https://www.st.com/en/evaluation-tools/32f429idiscovery.html) as example because it is a very popular board.
+
+### First you need to install the pre-requisite on your system
+
+Let's use the [Windows Subsystem for Linux](https://acassis.wordpress.com/2018/01/10/how-to-build-nuttx-on-windows-10/)
+
+```shell
+$ sudo apt-get install automake bison build-essential flex gcc-arm-none-eabi gperf git libncurses5-dev libtool libusb-dev libusb-1.0.0-dev pkg-config kconfig-frontends openocd
+```
+
+### Now let's to create a workspace to save our files
+
+```shell
+$ mkdir ~/nuttxspace
+$ cd ~/nuttxspace
+```
+
+### Clone the NuttX and Apps repositories:
+
+```shell
+$ git clone https://github.com/apache/incubator-nuttx nuttx
+$ git clone https://github.com/apache/incubator-nuttx-apps apps
+```
+
+### Configure NuttX to use the stm32f429i-disco board and the LVGL Demo
+
+```shell
+$ ./tools/configure.sh stm32f429i-disco:lvgl
+$ make
+```
+
+If everything went fine you should have now the file `nuttx.bin` to flash on your board:
+
+```shell
+$ ls -l nuttx.bin 
+-rwxrwxr-x 1 alan alan 287144 Jun 27 09:26 nuttx.bin
+```
+
+### Flashing the firmware in the board using OpenOCD:
+```shell
+$ sudo openocd -f interface/stlink-v2.cfg -f target/stm32f4x.cfg -c init -c "reset halt" -c "flash write_image erase nuttx.bin 0x08000000"
+```
+
+Reset the board and using the 'NSH>' terminal start the LVGL demo:
+```shell
+nsh> lvgldemo
+```
+
+## Where can I find more information?
+
+- This blog post: [LVGL on LPCXpresso54628](https://acassis.wordpress.com/2018/07/19/running-nuttx-on-lpcxpresso54628-om13098/)
+- NuttX mailing list: [Apache NuttX Mailing List](http://nuttx.incubator.apache.org/community/)
+

docs/get-started/nxp.md

@@ -0,0 +1,73 @@
+```eval_rst
+.. include:: /header.rst
+:github_url: |github_link_base|/get-started/nxp.md
+```
+# NXP
+NXP has integrated LVGL into the MCUXpresso SDK packages for several of their general
+purpose and crossover microcontrollers, allowing easy evaluation and migration into your
+product design. [Download an SDK for a supported board](https://www.nxp.com/design/software/embedded-software/littlevgl-open-source-graphics-library:LITTLEVGL-OPEN-SOURCE-GRAPHICS-LIBRARY?&tid=vanLITTLEVGL-OPEN-SOURCE-GRAPHICS-LIBRARY)
+today and get started with your next GUI application.
+
+## Creating new project with LVGL
+Downloading the MCU SDK example project is recommended as a starting point. It comes fully
+configured with LVGL (and with PXP support if module is present), no additional integration
+work is required.
+
+## Adding HW acceleration for NXP iMX RT platforms using PXP (PiXel Pipeline) engine for existing projects
+Several drawing features in LVGL can be offloaded to PXP engine. In order to use CPU time while PXP
+is running, RTOS is required to block the LVGL drawing thread and switch to another task, or simply to
+idle task, where CPU could be suspended to save power.
+
+#### Features supported:
+  - RGB565 color format
+  - Area fill + optional transparency
+  - BLIT (BLock Image Transfer) + optional transparency
+  - Color keying + optional transparency
+  - Recoloring (color tint) + optional transparency
+  - RTOS integration layer
+  - Default FreeRTOS and bare metal code provided
+
+#### Basic configuration:
+  - Select NXP PXP engine in lv_conf.h: Set `LV_USE_GPU_NXP_PXP` to 1
+  - Enable default implementation for interrupt handling, PXP start function and automatic initialization: Set `LV_USE_GPU_NXP_PXP_AUTO_INIT` to 1
+  - If `FSL_RTOS_FREE_RTOS` symbol is defined, FreeRTOS implementation will be used, otherwise bare metal code will be included
+
+#### Basic initialization:
+  - If `LV_USE_GPU_NXP_PXP_AUTO_INIT` is enabled, no user code is required; PXP is initialized automatically in `lv_init()`
+  - For manual PXP initialization, default configuration structure for callbacks can be used. Initialize PXP before calling `lv_init()`
+```c
+      #if LV_USE_GPU_NXP_PXP
+        #include "lv_gpu/lv_gpu_nxp_pxp.h"
+        #include "lv_gpu/lv_gpu_nxp_pxp_osa.h"
+      #endif
+      . . .
+      #if LV_USE_GPU_NXP_PXP
+        if (lv_gpu_nxp_pxp_init(&pxp_default_cfg) != LV_RES_OK) {
+            PRINTF("PXP init error. STOP.\n");
+            for ( ; ; ) ;
+        }
+      #endif
+```
+
+#### Project setup:
+  - Add PXP related files to project:
+    - lv_gpu/lv_gpu_nxp.c, lv_gpu/lv_gpu_nxp.h: low level drawing calls for LVGL
+    - lv_gpu/lv_gpu_nxp_osa.c, lv_gpu/lv_gpu_osa.h: default implementation of OS-specific functions (bare metal and FreeRTOS only)
+        - optional, required only if `LV_USE_GPU_NXP_PXP_AUTO_INIT` is set to 1
+  - PXP related code depends on two drivers provided by MCU SDK. These drivers need to be added to project:
+      - fsl_pxp.c, fsl_pxp.h: PXP driver
+      - fsl_cache.c, fsl_cache.h: CPU cache handling functions
+
+#### Advanced configuration:
+  - Implementation depends on multiple OS-specific functions. Structure `lv_nxp_pxp_cfg_t` with callback pointers is used
+    as a parameter for `lv_gpu_nxp_pxp_init()` function. Default implementation for FreeRTOS and baremetal is provided in lv_gpu_nxp_osa.c
+      - `pxp_interrupt_init()`: Initialize PXP interrupt (HW setup, OS setup)
+      - `pxp_interrupt_deinit()`: Deinitialize PXP interrupt (HW setup, OS setup)
+      - `pxp_run()`: Start PXP job. Use OS-specific mechanism to block drawing thread. PXP must finish drawing before leaving this function.
+  - There are configurable area thresholds which are used to decide whether the area will be processed by CPU, or by PXP. Areas smaller than
+    defined value will be processed by CPU, areas bigger than the threshold will be processed by PXP. These thresholds may be defined as a
+    preprocessor variables. Default values are defined lv_gpu/lv_gpu_nxp_pxp.h
+      - `GPU_NXP_PXP_BLIT_SIZE_LIMIT`: size threshold for image BLIT, BLIT with color keying, and BLIT with recolor (OPA > LV_OPA_MAX)
+      - `GPU_NXP_PXP_BLIT_OPA_SIZE_LIMIT`: size threshold for image BLIT and BLIT with color keying with transparency (OPA < LV_OPA_MAX)
+      - `GPU_NXP_PXP_FILL_SIZE_LIMIT`: size threshold for fill operation (OPA > LV_OPA_MAX)
+      - `GPU_NXP_PXP_FILL_OPA_SIZE_LIMIT`: size threshold for fill operation with transparency (OPA < LV_OPA_MAX)

docs/get-started/pc-simulator.md

@@ -0,0 +1,98 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/pc-simulator.md
+```
+# Simulator on PC
+
+
+You can try out LVGL **using only your PC** (i.e. without any development boards). LVGL will run on a simulator environment on the PC where anyone can write and experiment the real LVGL applications.
+
+Using the simulator on the PC has the following advantages:
+- Hardware independent - Write code, run it on the PC and see the result on the PC monitor.
+- Cross-platform - Any Windows, Linux or MacOS system can run the PC simulator.  
+- Portability - the written code is portable, which means you can simply copy it when using an embedded hardware.
+- Easy Validation - The simulator is also very useful to report bugs because it means common platform for every user. So it's a good idea to reproduce a bug in the simulator and use the code snippet in the [Forum](https://forum.lvgl.io).
+
+## Select an IDE
+
+The simulator is ported to various IDEs (Integrated Development Environments). Choose your favorite IDE, read its README on GitHub, download the project, and load it to the IDE.
+
+- [Eclipse with SDL driver](https://github.com/lvgl/lv_sim_eclipse_sdl): Recommended on Linux and Mac
+- [CodeBlocks](https://github.com/lvgl/lv_sim_codeblocks_win): Recommended on Windows
+- [VisualStudio with SDL driver](https://github.com/lvgl/lv_sim_visual_studio_sdl): For Windows
+- [VSCode with SDL driver](https://github.com/lvgl/lv_sim_vscode_sdl): Recommended on Linux and Mac
+- [PlatformIO with SDL driver](https://github.com/lvgl/lv_platformio): Recommended on Linux and Mac
+
+You can use any IDE for the development but, for simplicity, the configuration for Eclipse CDT is what we'll focus on in this tutorial.
+The following section describes the set-up guide of Eclipse CDT in more details.
+
+**Note: If you are on Windows, it's usually better to use the Visual Studio or CodeBlocks projects instead. They work out of the box without requiring extra steps.**
+
+## Set-up Eclipse CDT
+
+### Install Eclipse CDT
+
+[Eclipse CDT](https://eclipse.org/cdt/) is a C/C++ IDE.
+
+Eclipse is a Java based software therefore be sure **Java Runtime Environment** is installed on your system.   
+
+On Debian-based distros (e.g. Ubuntu): `sudo apt-get install default-jre`
+
+Note: If you are using other distros, then please refer and install 'Java Runtime Environment' suitable to your distro.
+Note: If you are using macOS and get a "Failed to create the Java Virtual Machine" error, uninstall any other Java JDK installs and install Java JDK 8u. This should fix the problem.
+
+You can download Eclipse's CDT from: [https://www.eclipse.org/cdt/downloads.php](https://www.eclipse.org/cdt/downloads.php). Start the installer and choose *Eclipse CDT* from the list.
+
+### Install SDL 2
+
+The PC simulator uses the [SDL 2](https://www.libsdl.org/download-2.0.php) cross platform library to simulate a TFT display and a touch pad. 
+
+#### Linux
+On **Linux** you can easily install SDL2 using a terminal:
+
+1. Find the current version of SDL2: `apt-cache search libsdl2 (e.g. libsdl2-2.0-0)`
+2. Install SDL2: `sudo apt-get install libsdl2-2.0-0` (replace with the found version)
+3. Install SDL2 development package: `sudo apt-get install libsdl2-dev`
+4. If build essentials are not installed yet: `sudo apt-get install build-essential`
+
+#### Windows
+If you are using **Windows** firstly you need to install MinGW ([64 bit version](http://mingw-w64.org/doku.php/download)). After installing MinGW, do the following steps to add SDL2:
+
+1. Download the development libraries of SDL.   
+Go to [https://www.libsdl.org/download-2.0.php](https://www.libsdl.org/download-2.0.php) and download _Development Libraries: SDL2-devel-2.0.5-mingw.tar.gz_
+2. Decompress the file and go to _x86_64-w64-mingw32_ directory (for 64 bit MinGW) or to _i686-w64-mingw32_ (for 32 bit MinGW)
+3. Copy _..._mingw32/include/SDL2_ folder to _C:/MinGW/.../x86_64-w64-mingw32/include_
+4. Copy _..._mingw32/lib/_ content to _C:/MinGW/.../x86_64-w64-mingw32/lib_
+5. Copy _..._mingw32/bin/SDL2.dll_ to _{eclipse_worksapce}/pc_simulator/Debug/_.  Do it later when Eclipse is installed. 
+
+Note: If you are using **Microsoft Visual Studio** instead of Eclipse then you don't have to install MinGW. 
+
+#### OSX
+On **OSX** you can easily install SDL2 with brew: `brew install sdl2`
+
+If something is not working, then please refer [this tutorial](http://lazyfoo.net/tutorials/SDL/01_hello_SDL/index.php) to get started with SDL.
+
+### Pre-configured project
+
+A pre-configured graphics library project (based on the latest release) is always available to get started easily. 
+You can find the latest one on [GitHub](https://github.com/lvgl/lv_sim_eclipse_sdl).
+(Please note that, the project is configured for Eclipse CDT). 
+
+### Add the pre-configured project to Eclipse CDT
+
+Run Eclipse CDT. It will show a dialogue about the **workspace path**. Before accepting the path, check that path and copy (and unzip) the downloaded pre-configured project there. After that, you can accept the workspace path. Of course you can modify this path but, in that case copy the project to the corresponding location.
+
+Close the start up window and go to **File->Import** and choose **General->Existing project into Workspace**. **Browse the root directory** of the project and click **Finish**
+
+On **Windows** you have to do two additional things:
+
+- Copy the **SDL2.dll** into the project's Debug folder 
+- Right click on the project -> Project properties -> C/C++ Build -> Settings -> Libraries -> Add ... and add _mingw32_ above SDLmain and SDL. (The order is important: mingw32, SDLmain, SDL)
+
+### Compile and Run
+
+Now you are ready to run LVGL on your PC. Click on the Hammer Icon on the top menu bar to Build the project. If you have done everything right, then you will not get any errors. Note that on some systems additional steps might be required to "see" SDL 2 from Eclipse but, in most of cases the configurations in the downloaded project is enough.
+
+After a success build, click on the Play button on the top menu bar to run the project. Now a window should appear in the middle of your screen.
+
+Now you are ready to use LVGL and begin development on your PC.

docs/get-started/quick-overview.md

@@ -0,0 +1,270 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/quick-overview.md
+```
+
+# Quick overview
+
+Here you can learn the most important things about LVGL.
+You should read this first to get a general impression and read the detailed [Porting](/porting/index) and [Overview](/overview/index) sections after that.
+
+## Get started in a simulator
+
+Instead of porting LVGL to embedded hardware straight away, it's highly recommended to get started in a simulator first. 
+
+LVGL is ported to many IDEs to be sure you will find your favorite one. 
+Go to the [Simulators](/get-started/pc-simulator) section to get ready-to-use projects that can be run on your PC. 
+This way you can save the time of porting for now and get some experience with LVGL immediately. 
+
+## Add LVGL into your project
+If you would rather try LVGL on your own project follow these steps:
+
+- [Download](https://github.com/lvgl/lvgl/archive/master.zip) or clone the library from GitHub with `git clone https://github.com/lvgl/lvgl.git`.
+- Copy the `lvgl` folder into your project.
+- Copy `lvgl/lv_conf_template.h` as `lv_conf.h` next to the `lvgl` folder, change the first `#if 0` to `1` to enable the file's content and set the `LV_COLOR_DEPTH` defines.
+- Include `lvgl/lvgl.h` in files where you need to use LVGL related functions.
+- Call `lv_tick_inc(x)` every `x` milliseconds in a Timer or Task (`x` should be between 1 and 10). It is required for the internal timing of LVGL. 
+Alternatively, configure `LV_TICK_CUSTOM` (see `lv_conf.h`) so that LVGL can retrieve the current time directly.
+- Call `lv_init()`
+- Create a draw buffer: LVGL will render the graphics here first, and send the rendered image to the display. 
+The buffer size can be set freely but 1/10 screen size is a good starting point. 
+```c
+static lv_disp_draw_buf_t draw_buf;
+static lv_color_t buf1[DISP_HOR_RES * DISP_VER_RES / 10];                        /*Declare a buffer for 1/10 screen size*/
+lv_disp_draw_buf_init(&draw_buf, buf1, NULL, MY_DISP_HOR_RES * MY_DISP_VER_SER / 10);  /*Initialize the display buffer.*/
+```
+- Implement and register a function which can copy the rendered image to an area of your display:
+```c
+lv_disp_drv_t disp_drv;               /*Descriptor of a display driver*/
+lv_disp_drv_init(&disp_drv);          /*Basic initialization*/
+disp_drv.flush_cb = my_disp_flush;    /*Set your driver function*/
+disp_drv.buffer = &draw_buf;          /*Assign the buffer to the display*/
+disp_drv.hor_res = MY_DISP_HOR_RES;   /*Set the horizontal resolution of the display*/
+disp_drv.hor_res = MY_DISP_VER_RES;   /*Set the verizontal resolution of the display*/
+lv_disp_drv_register(&disp_drv);      /*Finally register the driver*/
+
+void my_disp_flush(lv_disp_drv_t * disp, const lv_area_t * area, lv_color_t * color_p)
+{
+    int32_t x, y;
+    /*It's a very slow but simple implementation.
+     *`set_pixel` needs to be written by you to a set pixel on the screen*/
+    for(y = area->y1; y <= area->y2; y++) {
+        for(x = area->x1; x <= area->x2; x++) {
+            set_pixel(x, y, *color_p);
+            color_p++;
+        }
+    }
+
+    lv_disp_flush_ready(disp);         /* Indicate you are ready with the flushing*/
+}
+
+```
+- Implement and register a function which can read an input device. E.g. for a touch pad:
+```c
+lv_indev_drv_t indev_drv;                  /*Descriptor of a input device driver*/
+lv_indev_drv_init(&indev_drv);             /*Basic initialization*/
+indev_drv.type = LV_INDEV_TYPE_POINTER;    /*Touch pad is a pointer-like device*/
+indev_drv.read_cb = my_touchpad_read;      /*Set your driver function*/
+lv_indev_drv_register(&indev_drv);         /*Finally register the driver*/
+
+bool my_touchpad_read(lv_indev_t * indev, lv_indev_data_t * data)
+{
+    /*`touchpad_is_pressed` and `touchpad_get_xy` needs to be implemented by you*/
+    if(touchpad_is_pressed()) {
+      data->state = LV_INDEV_STATE_PRESSED;
+      touchpad_get_xy(&data->point.x, &data->point.y);
+    } else {
+      data->state = LV_INDEV_STATE_RELEASED;
+    }
+ 
+}
+```
+- Call `lv_timer_handler()` periodically every few milliseconds in the main `while(1)` loop or in an operating system task.
+It will redraw the screen if required, handle input devices, animation etc.
+
+For a more detailed guide go to the [Porting](/porting/index) section.
+
+## Learn the basics
+
+### Widgets
+
+The graphical elements like Buttons, Labels, Sliders, Charts etc. are called objects or widgets. Go to [Widgets](/widgets/index) to see the full list of available widgets.
+
+Every object has a parent object where it is created. For example if a label is created on a button, the button is the parent of label. 
+
+The child object moves with the parent and if the parent is deleted the children will be deleted too. 
+
+Children can be visible only on their parent. It other words, the parts of the children outside of the parent are clipped.
+
+A Screen is the "root" parent. You can have any number of screens. 
+
+To get the current screen call `lv_scr_act()`, and to load a screen use `lv_scr_load(scr1)`.
+
+You can create a new object with `lv_<type>_create(parent)`. It will return an `lv_obj_t *` variable that can be used as a reference to the object to set its parameters.
+
+For example:
+```c
+lv_obj_t * slider1 = lv_slider_create(lv_scr_act());
+```
+
+To set some basic attributes `lv_obj_set_<parameter_name>(obj, <value>)` functions can be used. For example:
+```c
+lv_obj_set_x(btn1, 30);
+lv_obj_set_y(btn1, 10);
+lv_obj_set_size(btn1, 200, 50);
+```
+
+The widgets have type specific parameters too which can be set by `lv_<widget_type>_set_<parameter_name>(obj, <value>)` functions. For example:
+```c
+lv_slider_set_value(slider1, 70, LV_ANIM_ON);
+```
+
+To see the full API visit the documentation of the widgets or the related header file (e.g. [lvgl/src/widgets/lv_slider.h](https://github.com/lvgl/lvgl/blob/master/src/widgets/lv_slider.h)).
+
+
+
+### Events
+Events are used to inform the user that something has happened with an object. 
+You can assign one or more callbacks to an object which will be called if the object is clicked, released, dragged, being deleted etc. 
+
+A callback is assigned like this:
+
+```c
+lv_obj_add_event_cb(btn, btn_event_cb, LV_EVENT_CLICKED, NULL); /*Assign a callback to the button*/
+
+...
+
+void btn_event_cb(lv_event_t * e)
+{
+    printf("Clicked\n");
+}
+```
+
+Instead of `LV_EVENT_CLICKED` `LV_EVENT_ALL` can be used too to call the callback for any event. 
+
+From `lv_event_t * e` the current event code can be get with
+```c
+lv_event_code_t code = lv_event_get_code(e);
+```
+
+The object that triggered the event can be retrieved with
+```c
+lv_obj_t * obj = lv_event_get_target(e);
+```
+
+To learn all features of the events go to the [Event overview](/overview/event) section.
+
+### Parts
+Widgets might be built from one or more *parts*. For example a button has only one part called `LV_PART_MAIN`.
+However, a [Slider](/widgets/core/slider) has `LV_PART_MAIN`, `LV_PART_INDICATOR` and `LV_PART_KNOB`.
+
+By using parts you can apply different styles to different parts. (See below)
+
+To learn which parts are used by which object read the widgets' documentation.
+
+### States
+The objects can be in a combination of the following states:
+- `LV_STATE_DEFAULT`  Normal, released state
+- `LV_STATE_CHECKED`  Toggled or checked state
+- `LV_STATE_FOCUSED` Focused via keypad or encoder or clicked via touchpad/mouse 
+- `LV_STATE_FOCUS_KEY`  Focused via keypad or encoder but not via touchpad/mouse 
+- `LV_STATE_EDITED` Edit by an encoder
+- `LV_STATE_HOVERED` Hovered by mouse (not supported now)
+- `LV_STATE_PRESSED` Being pressed
+- `LV_STATE_SCROLLED` Being scrolled
+- `LV_STATE_DISABLED` Disabled 
+
+For example, if you press an object it will automatically go to `LV_STATE_FOCUSED` and `LV_STATE_PRESSED` state and when you release it, the  `LV_STATE_PRESSED` state will be removed.
+ 
+To check if an object is in a given state use `lv_obj_has_state(obj, LV_STATE_...)`. It will return `true` if the object is in that state at that time.
+
+To manually add or remove states use
+```c
+lv_obj_add_state(obj, LV_STATE_...);
+lv_obj_clear_state(obj, LV_STATE_...);
+```
+
+### Styles
+Styles contains properties such as background color, border width, font, etc to describe the appearance of the objects.
+
+The styles are `lv_style_t` variables. Only their pointer is saved in the objects so they need to be static or global.
+Before using a style it needs to be initialized with `lv_style_init(&style1)`. After that properties can be added. For example:
+```
+static lv_style_t style1;
+lv_style_init(&style1);
+lv_style_set_bg_color(&style1, lv_color_hex(0xa03080))
+lv_style_set_border_width(&style1, 2))
+```
+See the full list of properties [here](/overview/style.html#properties).
+
+
+The styles are assigned to an object's part and state. For example to *"Use this style on the slider's indicator when the slider is pressed"*:
+```c
+lv_obj_add_style(slider1, &style1, LV_PART_INDICATOR | LV_STATE_PRESSED);
+```
+
+If the *part* is `LV_PART_MAIN` it can be omitted:
+```c
+lv_obj_add_style(btn1, &style1, LV_STATE_PRESSED); /*Equal to LV_PART_MAIN | LV_STATE_PRESSED*/
+```
+
+Similarly, `LV_STATE_DEFAULT` can be omitted too:
+```c
+lv_obj_add_style(slider1, &style1, LV_PART_INDICATOR); /*Equal to LV_PART_INDICATOR | LV_STATE_DEFAULT*/
+```
+
+For `LV_STATE_DEFAULT` and `LV_PART_MAIN` simply write `0`:
+```c
+lv_obj_add_style(btn1, &style1, 0); /*Equal to LV_PART_MAIN | LV_STATE_DEFAULT*/
+```
+
+
+The styles can be cascaded (similarly to CSS). It means you can add more styles to a part of an object. 
+For example `style_btn` can set a default button appearance, and `style_btn_red` can overwrite the background color to make the button red: 
+```c
+lv_obj_add_style(btn1, &style_btn, 0);
+lv_obj_add_style(btn1, &style1_btn_red, 0);
+```
+
+
+If a property is not set on for the current state the style with `LV_STATE_DEFAULT` will be used. If the property is not defined even in the default state a default value is used.
+
+Some properties (typically the text-related ones) can be inherited. It means if a property is not set in an object it will be searched in its parents too. 
+For example, you can set the font once in the screen's style and all text on that screen will inherit it by default. 
+
+
+Local style properties also can be added to the objects. It creates a style which resides inside the object and which is used only by the object:
+```c
+lv_obj_set_style_bg_color(slider1, lv_color_hex(0x2080bb), LV_PART_INDICATOR | LV_STATE_PRESSED);
+``` 
+
+To learn all the features of styles see the [Style overview](/overview/style) section.
+
+
+### Themes
+Themes are the default styles of the objects. 
+The styles from the themes are applied automatically when the objects are created. 
+
+You can select the theme to use in `lv_conf.h`. 
+
+## Examples
+
+```eval_rst
+
+.. include:: ../../examples/get_started/index.rst
+```
+
+## Micropython
+Learn more about [Micropython](/get-started/micropython).
+```python
+# Create a Button and a Label
+scr = lv.obj()
+btn = lv.btn(scr)
+btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
+label = lv.label(btn)
+label.set_text("Button")
+
+# Load the screen
+lv.scr_load(scr)
+```
+

docs/get-started/stm32.md

@@ -0,0 +1,8 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/get-started/stm32.md
+```
+
+# STM32
+
+TODO

docs/header.rst

@@ -0,0 +1 @@
+.. |github_link_base| replace:: https://github.com/lvgl/docs/blob/master

docs/index.md

@@ -0,0 +1,39 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/index.md
+```
+
+```eval_rst
+
+PDF version: :download:`LVGL.pdf <LVGL.pdf>`
+```
+
+# Welcome to the documentation of LVGL!
+
+<img src="_static/img/home_banner.jpg" style="width:100%">
+
+
+<div style="margin-bottom:48px"> 
+    <a href="intro/index.html"><img class="home-img" src="_static/img/home_1.png" alt="Get familiar with the LVGL project"></a>
+    <a href="get-started/index.html"><img class="home-img" src="_static/img/home_2.png" alt="Learn the basic of LVGL and its usage on various platforms"></a>
+    <a href="porting/index.html"><img class="home-img" src="_static/img/home_3.png" alt="See how to port LVGL to any platform"></a>
+    <a href="overview/index.html"><img class="home-img" src="_static/img/home_4.png" alt="Learn the how LVGL works in more detail"></a>
+    <a href="widgets/index.html"><img class="home-img" src="_static/img/home_5.png" alt="Take a look at the description of the available widgets"></a>
+    <a href="CONTRIBUTING.html"><img class="home-img" src="_static/img/home_6.png" alt="Be part of the development of LVGL"></a>
+</div> 
+ 
+
+```eval_rst
+.. toctree::
+   :maxdepth: 2
+   
+   intro/index
+   get-started/index
+   porting/index
+   overview/index
+   widgets/index
+   layouts/index
+   CONTRIBUTING
+   CHANGELOG
+   ROADMAP
+```

docs/intro/index.md

@@ -0,0 +1,212 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/intro/index.md
+```
+
+# Introduction
+
+LVGL (Light and Versatile Graphics Library) is a free and open-source graphics library providing everything you need to create embedded GUI with easy-to-use graphical elements, beautiful visual effects and a low memory footprint.
+
+
+## Key features
+- Powerful building blocks such as buttons, charts, lists, sliders, images, etc.
+- Advanced graphics with animations, anti-aliasing, opacity, smooth scrolling
+- Various input devices such as touchpad, mouse, keyboard, encoder, etc.
+- Multi-language support with UTF-8 encoding
+- Multi-display support, i.e. use multiple TFT, monochrome displays simultaneously
+- Fully customizable graphic elements with CSS-like styles
+- Hardware independent: use with any microcontroller or display
+- Scalable: able to operate with little memory (64 kB Flash, 16 kB RAM)
+- OS, external memory and GPU supported but not required
+- Single frame buffer operation even with advanced graphic effects
+- Written in C for maximal compatibility (C++ compatible)
+- Simulator to start embedded GUI design on a PC without embedded hardware
+- Binding to MicroPython
+- Tutorials, examples, themes for rapid GUI design
+- Documentation is available online and PDF
+- Free and open-source under MIT license
+
+## Requirements
+Basically, every modern controller  (which is able to drive a display) is suitable to run LVGL. The minimal requirements are:
+<ul>
+<li> 16, 32 or 64 bit microcontroller or processor</li>
+<li>&gt; 16 MHz clock speed is recommended</li>
+<li> Flash/ROM: &gt; 64 kB for the very essential components (&gt; 180 kB is recommended)</li>
+<li> RAM: 
+  <ul>
+    <li> Static RAM usage: ~2 kB depending on the used features and objects types</li>
+    <li> Stack: &gt; 2kB (&gt; 8 kB is recommended)</li>
+    <li> Dynamic data (heap): &gt; 4 KB (&gt; 32 kB is recommended if using several objects).
+	    Set by <em>LV_MEM_SIZE</em> in <em>lv_conf.h</em>. </li>
+    <li> Display buffer:  &gt; <em>"Horizontal resolution"</em> pixels (&gt; 10 &times; <em>"Horizontal resolution"</em> is recommended) </li>
+    <li> One frame buffer in the MCU or in external display controller</li>
+	</ul>
+</li>
+<li> C99 or newer compiler</li>
+<li> Basic C (or C++) knowledge: 
+          <a href="https://www.tutorialspoint.com/cprogramming/c_pointers.htm">pointers</a>, 
+          <a href="https://www.tutorialspoint.com/cprogramming/c_structures.htm">structs</a>, 
+          <a href="https://www.geeksforgeeks.org/callbacks-in-c/">callbacks</a>.</li>
+</ul>
+<em>Note that memory usage may vary depending on architecture, compiler and build options.</em>
+
+## License
+The LVGL project (including all repositories) is licensed under [MIT license](https://github.com/lvgl/lvgl/blob/master/LICENCE.txt). 
+It means you can use it even in commercial projects.
+
+It's not mandatory but we highly appreciate it if you write a few words about your project in the [My projects](https://forum.lvgl.io/c/my-projects/10) category of the forum or a private message to [lvgl.io](https://lvgl.io/#contact).
+
+Although you can get LVGL for free there is a massive amount of work behind it. It's created by a group of volunteers who made it available for you in their free time.
+
+To make the LVGL project sustainable, please consider [contributing](/CONTRIBUTING) to the project. 
+You can choose from [many different ways of contributing](/CONTRIBUTING) such as simply writing a tweet about you are using LVGL, fixing bugs, translating the documentation, or even becoming a maintainer.
+
+## Repository layout
+All repositories of the LVGL project are hosted on GitHub: https://github.com/lvgl
+
+You will find these repositories there:
+- [lvgl](https://github.com/lvgl/lvgl) The library itself with many [examples](https://github.com/lvgl/lvgl/blob/master/examples/).
+- [lv_demos](https://github.com/lvgl/lv_demos) Demos created with LVGL.
+- [lv_drivers](https://github.com/lvgl/lv_drivers) Display and input device drivers
+- [blog](https://github.com/lvgl/blog) Source of the blog's site (https://blog.lvgl.io)
+- [sim](https://github.com/lvgl/sim) Source of the online simulator's site (https://sim.lvgl.io)
+- [lv_sim_...](https://github.com/lvgl?q=lv_sim&type=&language=) Simulator projects for various IDEs and platforms
+- [lv_port_...](https://github.com/lvgl?q=lv_port&type=&language=) LVGL ports to development boards
+- [lv_binding_..](https://github.com/lvgl?q=lv_binding&type=&language=l) Bindings to other languages
+- [lv_...](https://github.com/lvgl?q=lv_&type=&language=) Ports to other platforms
+
+## Release policy
+
+The core repositories follow the rules of [Semantic versioning](https://semver.org/):
+- Major versions for incompatible API changes. E.g. v5.0.0, v6.0.0
+- Minor version for new but backward-compatible functionalities. E.g. v6.1.0, v6.2.0
+- Patch version for backward-compatible bug fixes. E.g. v6.1.1, v6.1.2
+
+Tags like `vX.Y.Z` are created for every release.
+
+### Release cycle
+- Bugfixes: Released on demand even weekly
+- Minor releases: Every 3-4 months
+- Major releases: Approximatelly yearly
+
+### Branches
+The core repositories have at least the following branches:
+- `master` latest version, patches are merged directly here. 
+- `release/vX.Y` stable versions of the minor releases
+- `fix/some-description` temporal branches for bug fixes
+- `feat/some-description` temporal branches for features
+
+
+### Changelog
+
+The changes are recorded in [CHANGELOG.md](/CHANGELOG).
+
+### Version support
+Before v8 every minor release of major releases is supported for 1 year.
+From v8 every minor release is supported for 1 year.
+
+| Version | Release date | Support end | Active |
+|---------|--------------|-------------|--------|
+| v5.3    | Feb 1, 2019  |Feb 1, 2020  | No     |
+| v6.1    | Nov 26, 2019 |Nov 26, 2020 | No     |
+| v7.11   | Mar 16, 2021 |Mar 16, 2022 | Yes    |
+| v8.0    | In progress  |             |        |
+
+
+## FAQ
+
+### Where can I ask questions?
+You can ask questions in the forum: [https://forum.lvgl.io/](https://forum.lvgl.io/).
+
+We use [GitHub issues](https://github.com/lvgl/lvgl/issues) for development related discussion. 
+So you should use them only if your question or issue is tightly related to the development of the library. 
+
+### Is my MCU/hardware supported?
+Every MCU which is capable of driving a display via Parallel port, SPI, RGB interface or anything else and fulfills the [Requirements](#requirements) is supported by LLVGL.
+
+This includes:
+- "Common" MCUs like STM32F, STM32H, NXP Kinetis, LPC, iMX, dsPIC33, PIC32 etc. 
+- Bluetooth, GSM, WiFi modules like Nordic NRF and Espressif ESP32
+- Linux with frame buffer device such as /dev/fb0. This includes Single-board computers like the Raspberry Pi
+- And anything else with a strong enough MCU and a periphery to drive a display
+
+### Is my display supported?
+LVGL needs just one simple driver function to copy an array of pixels into a given area of the display. 
+If you can do this with your display then you can use that display with LVGL.
+
+Some examples of the supported display types:
+- TFTs with 16 or 24 bit color depth 
+- Monitors with HDMI port
+- Small monochrome displays
+- Gray-scale displays
+- even LED matrices
+- or any other display where you can control the color/state of the pixels
+
+See the [Porting](/porting/display) section to learn more.
+
+### Nothing happens, my display driver is not called. What have I missed?
+Be sure you are calling `lv_tick_inc(x)` in an interrupt and `lv_timer_handler()` in your main `while(1)`.
+
+Learn more in the [Tick](/porting/tick) and [Task handler](/porting/task-handler) section.
+
+### Why is the display driver called only once? Only the upper part of the display is refreshed. 
+Be sure you are calling `lv_disp_flush_ready(drv)` at the end of your "*display flush callback*". 
+
+### Why do I see only garbage on the screen?
+Probably there a bug in your display driver. Try the following code without using LVGL. You should see a square with red-blue gradient.
+
+```c
+#define BUF_W 20
+#define BUF_H 10
+
+lv_color_t buf[BUF_W * BUF_H];
+lv_color_t * buf_p = buf;
+uint16_t x, y;
+for(y = 0; y &lt; BUF_H; y++) {
+    lv_color_t c = lv_color_mix(LV_COLOR_BLUE, LV_COLOR_RED, (y * 255) / BUF_H);
+    for(x = 0; x &lt; BUF_W; x++){
+        (*buf_p) =  c;
+        buf_p++;
+    }
+}
+
+lv_area_t a;
+a.x1 = 10;
+a.y1 = 40;
+a.x2 = a.x1 + BUF_W - 1;
+a.y2 = a.y1 + BUF_H - 1;
+my_flush_cb(NULL, &a, buf);
+```
+
+### Why I see nonsense colors on the screen? 
+Probably LVGL's color format is not compatible with your displays color format. Check `LV_COLOR_DEPTH` in *lv_conf.h*.
+
+If you are using 16 bit colors with SPI (or other byte-oriented interface) probably you need to set `LV_COLOR_16_SWAP  1` in *lv_conf.h*. 
+It swaps the upper and lower bytes of the pixels.
+
+### How to speed up my UI?
+- Turn on compiler optimization and enable cache if your MCU has
+- Increase the size of the display buffer
+- Use 2 display buffers and flush the buffer with DMA (or similar periphery) in the background 
+- Increase the clock speed of the SPI or Parallel port if you use them to drive the display
+- If your display has SPI port consider changing to a model with parallel because it has much higher throughput
+- Keep the display buffer in the internal RAM (not in external SRAM) because LVGL uses it a lot and it should have a small access time
+ 
+### How to reduce flash/ROM usage?
+You can disable all the unused features (such as animations, file system, GPU etc.) and object types in *lv_conf.h*.
+
+If you are using GCC you can add 
+- `-fdata-sections -ffunction-sections` compiler flags 
+- `--gc-sections` linker flag
+
+to remove unused functions and variables from the final binary
+
+### How to reduce the RAM usage
+- Lower the size of the *Display buffer* 
+- Reduce `LV_MEM_SIZE` in *lv_conf.h*. This memory used when you create objects like buttons, labels, etc.
+- To work with lower `LV_MEM_SIZE` you can create the objects only when required and deleted them when they are not required anymore
+ 
+### How to work with an operating system?
+
+To work with an operating system where tasks can interrupt each other (preemptive) you should protect LVGL related function calls with a mutex.
+See the [Operating system and interrupts](/porting/os) section to learn more.

docs/layouts/flex.md

@@ -0,0 +1,113 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/layouts/flex.md
+```
+
+# Flex
+
+## Overview
+
+The Flexbox (or Flex for short) is a subset of [CSS Flexbox](https://css-tricks.com/snippets/css/a-guide-to-flexbox/).
+
+It can arrange items into rows or columns (tracks), handle wrapping, adjust the spacing between the items and tracks, handle *grow* to make the item(s) fill the remaining space with respect to min/max width and height.
+
+To make an object flex container call `lv_obj_set_layout(obj, LV_LAYOUT_FLEX)`.
+
+Note that the flex layout feature of LVGL needs to be globally enabled with `LV_USE_FLEX` in `lv_conf.h`. 
+
+## Terms
+- tracks: the rows or columns
+- main direction: row or column, the direction in which the items are placed
+- cross direction: perpendicular to the main direction
+- wrap: if there there is no more space in the track a new track is started
+- grow: if set on an item it will grow to fill the remaining space on the track. 
+The available space will be distributed among items respective to the their grow value (larger value means more space)
+- gap: the space between the rows and columns or the items on a track
+
+## Simple interface
+
+With the following functions you can set a Flex layout on any parent.
+
+### Flex flow
+
+`lv_obj_set_flex_flow(obj, flex_flow)`
+
+The possible values for `flex_flow` are:
+- `LV_FLEX_FLOW_ROW` Place the children in a row without wrapping
+- `LV_FLEX_FLOW_COLUMN` Place the children in a column without wrapping
+- `LV_FLEX_FLOW_ROW_WRAP` Place the children in a row with wrapping
+- `LV_FLEX_FLOW_COLUMN_WRAP` Place the children in a column with wrapping
+- `LV_FLEX_FLOW_ROW_REVERSE` Place the children in a row without wrapping but in reversed order
+- `LV_FLEX_FLOW_COLUMN_REVERSE` Place the children in a column without wrapping but in reversed order
+- `LV_FLEX_FLOW_ROW_WRAP_REVERSE` Place the children in a row without wrapping but in reversed order
+- `LV_FLEX_FLOW_COLUMN_WRAP_REVERSE` Place the children in a column without wrapping but in reversed order
+
+### Flex align
+To manage the placement of the children use `lv_obj_set_flex_align(obj,  main_place, cross_place, track_cross_place)`
+
+- `main_place` determines how to distribute the items in their track on the main axis. E.g. flush the items to the right on `LV_FLEX_FLOW_ROW_WRAP`.  (It's called `justify-content` in CSS)
+- `cross_place` determines how to distribute the items in their track on the cross axis. E.g. if the items have different height place them to the bottom of the track.  (It's called `align-items` in CSS)
+- `track_cross_place` determines how to distribute the tracks (It's called `align-content` in CSS)
+
+The possible values are:
+- `LV_FLEX_ALIGN_START` means left on a horizontally and top vertically. (default)
+- `LV_FLEX_ALIGN_END` means right on a horizontally and bottom vertically
+- `LV_FLEX_ALIGN_CENTER` simply center
+- `LV_FLEX_ALIGN_SPACE_EVENLY` items are distributed so that the spacing between any two items (and the space to the edges) is equal. Does not apply to `track_cross_place`.
+- `LV_FLEX_ALIGN_SPACE_AROUND` items are evenly distributed in the track with equal space around them. 
+Note that visually the spaces aren’t equal, since all the items have equal space on both sides. 
+The first item will have one unit of space against the container edge, but two units of space between the next item because that next item has its own spacing that applies. Not applies to `track_cross_place`.
+- `LV_FLEX_ALIGN_SPACE_BETWEEN` items are evenly distributed in the track: first item is on the start line, last item on the end line. Not applies to `track_cross_place`.
+
+
+### Flex grow
+
+Flex grow can be used to make one or more children fill the available space on the track. If more children has grow the available space will be distributed proportionally to the grow values.
+For example let's there is 400 px remaining space and 4 object with grow:
+- `A` with grow = 1
+- `B` with grow = 1
+- `C` with grow = 2
+
+`A` and `B` will have 100 px size, and `C` will have 200 px size.
+
+Flex grow can be set on a child with `lv_obj_set_flex_flow(child, value)`. `value` needs to be > 1 or 0 to disable grow on the child.
+
+
+## Style interface
+
+All the Flex-related values are style properties under the hood and you can use them similarly to any other style property. The following flex related style properties exist:
+
+- `FLEX_FLOW`
+- `FLEX_MAIN_PLACE`
+- `FLEX_CROSS_PLACE`
+- `FLEX_TRACK_PLACE`
+- `FLEX_GROW`
+
+## Other features 
+
+### RTL
+If the base direction of the container is set the `LV_BASE_DIR_RTL` the meaning of `LV_FLEX_ALIGN_START` and `LV_FLEX_ALIGN_END` is swapped on `ROW` layouts. I.e. `START` will mean right.
+
+The items on `ROW` layouts, and tracks of `COLUMN` layouts will be placed from right to left.
+
+### New track
+
+You can force Flex to put an item into a new line with `lv_obj_add_flag(child, LV_OBJ_FLAG_FLEX_IN_NEW_TRACK)`.
+
+
+## Example
+
+```eval_rst
+
+.. include:: ../../examples/layouts/flex/index.rst
+
+```
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_flex.h
+  :project: lvgl
+
+```

docs/layouts/grid.md

@@ -0,0 +1,110 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/layouts/grid.md
+```
+
+# Grid
+
+## Overview
+
+The Grid layout is a subset of [CSS Flexbox](https://css-tricks.com/snippets/css/complete-guide-grid/).
+
+It can arrange items into 2D "table" that has rows or columns (tracks). The item can span through multiple columns or rows.
+The track's size can be set in pixel, to the largest item (`LV_GRID_CONTENT`) or in "Free unit" (FR) to distribute the free space proportionally.
+
+To make an object a grid container call `lv_obj_set_layout(obj, LV_LAYOUT_GRID)`.
+
+Note that the grid layout feature of LVGL needs to be globally enabled with `LV_USE_GRID` in `lv_conf.h`. 
+
+## Terms
+- tracks: the rows or columns
+- free unit (FR): if set on track's size is set in `FR` it will grow to fill the remaining space on the parent. 
+- gap: the space between the rows and columns or the items on a track
+
+## Simple interface
+
+With the following functions you can easily set a Grid layout on any parent.
+
+### Grid descriptors
+
+First you need to describe the size of rows and columns. It can be done by declaring 2 arrays and the track sizes in them. The last element must be `LV_GRID_TEMPLATE_LAST`.
+
+For example:
+```
+static lv_coord_t column_dsc[] = {100, 400, LV_GRID_TEMPLATE_LAST};   /*2 columns with 100 and 400 ps width*/
+static lv_coord_t row_dsc[] = {100, 100, 100, LV_GRID_TEMPLATE_LAST}; /*3 100 px tall rows*/
+```
+
+To set the descriptors on a parent use `lv_obj_set_grid_dsc_array(obj, col_dsc, row_dsc)`.
+
+Besides simple settings the size in pixel you can use two special values:
+- `LV_GRID_CONTENT` set the width to the largest children on this track
+- `LV_GRID_FR(X)` tell what portion of the remaining space should be used by this track. Larger value means larger space.
+
+### Grid items
+By default the children are not added to the grid. They need to be added manually to a cell. 
+
+To do this call `lv_obj_set_grid_cell(child, column_align, column_pos, column_span, row_align, row_pos, row_span)`.
+
+`column_align` and `row_align` determine how to align the children in its cell. The possible values are:
+- `LV_GRID_ALIGN_START` means left on a horizontally and top vertically. (default)
+- `LV_GRID_ALIGN_END` means right on a horizontally and bottom vertically
+- `LV_GRID_ALIGN_CENTER` simply center
+
+`colum_pos` and `row_pos` means the zero based index of the cell into the item should be placed. 
+
+`colum_span` and `row_span` means how many tracks should the item involve from the start cell. Must be > 1. 
+
+### Grid align
+
+If there are some empty space the track can be aligned several ways:
+- `LV_GRID_ALIGN_START` means left on a horizontally and top vertically. (default)
+- `LV_GRID_ALIGN_END` means right on a horizontally and bottom vertically
+- `LV_GRID_ALIGN_CENTER` simply center
+- `LV_GRID_ALIGN_SPACE_EVENLY` items are distributed so that the spacing between any two items (and the space to the edges) is equal. Not applies to `track_cross_place`.
+- `LV_GRID_ALIGN_SPACE_AROUND` items are evenly distributed in the track with equal space around them. 
+Note that visually the spaces aren’t equal, since all the items have equal space on both sides. 
+The first item will have one unit of space against the container edge, but two units of space between the next item because that next item has its own spacing that applies. Not applies to `track_cross_place`.
+- `LV_GRID_ALIGN_SPACE_BETWEEN` items are evenly distributed in the track: first item is on the start line, last item on the end line. Not applies to `track_cross_place`.
+
+To set the track's alignment use `lv_obj_set_grid_align(obj, column_align, row_align)`.
+
+## Style interface
+
+All the Grid related values are style properties under the hood and you can use them similarly to any other style properties. The following Grid related style properties exist:
+
+- `GRID_COLUMN_DSC_ARRAY`
+- `GRID_ROW_DSC_ARRAY`
+- `GRID_COLUMN_ALIGN`
+- `GRID_ROW_ALIGN`
+- `GRID_CELL_X_ALIGN`
+- `GRID_CELL_COLUMN_POS`
+- `GRID_CELL_COLUMN_SPAN`
+- `GRID_CELL_Y_ALIGN`
+- `GRID_CELL_ROW_POS`
+- `GRID_CELL_ROW_SPAN`
+
+## Other features 
+
+### RTL
+If the base direction of the container is set to `LV_BASE_DIR_RTL`, the meaning of `LV_GRID_ALIGN_START` and `LV_GRID_ALIGN_END` is swapped. I.e. `START` will mean right-most.
+
+The columns will be placed from right to left.
+
+
+## Example
+
+```eval_rst
+
+.. include:: ../../examples/layouts/grid/index.rst
+
+```
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_grid.h
+  :project: lvgl
+
+```

docs/layouts/index.md

@@ -0,0 +1,15 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/layouts/index.md
+```
+
+# Layouts
+
+
+```eval_rst
+.. toctree::
+   :maxdepth: 2
+   
+   flex
+   grid
+```

docs/overview/animation.md

@@ -0,0 +1,122 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/animation.md
+```
+# Animations
+
+You can automatically change the value of a variable between a start and an end value using animations.
+The animation will happen by periodically calling an "animator" function with the corresponding value parameter.
+
+The *animator* functions have the following prototype:
+```c
+void func(void * var, lv_anim_var_t value);
+```
+This prototype is compatible with the majority of the *set* functions of LVGL. For example `lv_obj_set_x(obj, value)` or `lv_obj_set_width(obj, value)`
+
+
+## Create an animation
+To create an animation an `lv_anim_t` variable has to be initialized and configured with `lv_anim_set_...()` functions.
+
+```c
+
+/* INITIALIZE AN ANIMATION
+ *-----------------------*/
+
+lv_anim_t a;
+lv_anim_init(&a);
+
+/* MANDATORY SETTINGS
+ *------------------*/
+
+/*Set the "animator" function*/
+lv_anim_set_exec_cb(&a, (lv_anim_exec_xcb_t) lv_obj_set_x); 
+
+/*Set the "animator" function*/
+lv_anim_set_var(&a, obj); 
+
+/*Length of the animation [ms]*/
+lv_anim_set_time(&a, duration);
+
+/*Set start and end values. E.g. 0, 150*/
+lv_anim_set_values(&a, start, end);
+
+/* OPTIONAL SETTINGS
+ *------------------*/
+
+/*Time to wait before starting the animation [ms]*/
+lv_anim_set_delay(&a, delay);
+
+/*Set path (curve). Default is linear*/
+lv_anim_set_path(&a, lv_anim_path_ease_in);
+
+/*Set a callback to call when animation is ready.*/
+lv_anim_set_ready_cb(&a, ready_cb);
+
+/*Set a callback to call when animation is started (after delay).*/
+lv_anim_set_start_cb(&a, start_cb);
+
+/*Play the animation backward too with this duration. Default is 0 (disabled) [ms]*/
+lv_anim_set_playback_time(&a, wait_time); 
+
+/*Delay before playback. Default is 0 (disabled) [ms]*/
+lv_anim_set_playback_delay(&a, wait_time);
+
+/*Number of repetitions. Default is 1.  LV_ANIM_REPEAT_INFINIT for infinite repetition*/
+lv_anim_set_repeat_count(&a, wait_time);
+
+/*Delay before repeat. Default is 0 (disabled) [ms]*/
+lv_anim_set_repeat_delay(&a, wait_time);
+
+/*true (default): apply the start vale immediately, false: apply start vale after delay when then anim. really starts. */
+lv_anim_set_early_apply(&a, true/false);
+
+/* START THE ANIMATION
+ *------------------*/
+lv_anim_start(&a);                             /*Start the animation*/
+```
+
+
+You can apply multiple different animations on the same variable at the same time.
+For example, animate the x and y coordinates with `lv_obj_set_x` and `lv_obj_set_y`. However, only one animation can exist with a given variable and function pair.
+Therefore `lv_anim_start()` will delete the already existing variable-function animations.
+
+## Animation path
+
+You can determinate the path of animation. The most simple case is linear, meaning the current value between *start* and *end* is changed with fixed steps.
+A *path* is a function which calculates the next value to set based on the current state of the animation. Currently, there are the following built-in paths functions:
+
+- `lv_anim_path_linear` linear animation
+- `lv_anim_path_step` change in one step at the end
+- `lv_anim_path_ease_in` slow at the beginning
+- `lv_anim_path_ease_out` slow at the end
+- `lv_anim_path_ease_in_out` slow at the beginning and at the end
+- `lv_anim_path_overshoot` overshoot the end value
+- `lv_anim_path_bounce` bounce back a little from the end value (like hitting a wall)
+
+
+## Speed vs time
+By default, you set the animation time. But in some cases, setting the animation speed is more practical.
+
+The `lv_anim_speed_to_time(speed, start, end)` function calculates the required time in milliseconds to reach the end value from a start value with the given speed.
+The speed is interpreted in _unit/sec_ dimension. For example,  `lv_anim_speed_to_time(20,0,100)` will yield 5000 milliseconds. For example, in case of `lv_obj_set_x` *unit* is pixels so *20* means *20 px/sec* speed.
+
+## Delete animations
+
+You can delete an animation with `lv_anim_del(var, func)` if you provide the animated variable and its animator function.
+
+
+## Examples
+
+```eval_rst
+
+.. include:: ../../examples/anim/index.rst
+
+```
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_anim.h
+  :project: lvgl
+
+```

docs/overview/color.md

@@ -0,0 +1,157 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/color.md
+```
+# Colors
+
+The color module handles all color-related functions like changing color depth, creating colors from hex code, converting between color depths, mixing colors, etc.
+
+`lv_color_t` is used to store a color, its fileds are set according to `LV_COLOR_DEPTH` in `lv_conf.h`. (See below)
+
+You may set `LV_COLOR_16_SWAP` in `lv_conf.h` to swap the bytes of *RGB565* colors. You may need this to send the 16-bit colors via a byte-oriented interface like SPI. As 16-bit numbers are stored in Little Endian format (lower byte on the lower address), the interface will send the lower byte first. However, displays usually need the higher byte first. A mismatch in the byte order will result in highly distorted colors.
+
+## Creating colors
+
+### RGB
+Create colors from Red, Green and Blue channel values
+```c
+//All channels are 0-255
+lv_color_t c = lv_color_make(red, green, blue);
+
+//From hex code 0x000000..0xFFFFFF interpreted as RED + GREEN + BLUE
+lv_color_t c = lv_color_hex(0x123456); 
+
+//From 3 digits. Same as lv_color_hex(0x112233)
+lv_color_t c = lv_color_hex3(0x123); 
+```
+
+### HSV
+Create colors from Hue, Saturation and Value values
+
+```c
+//h = 0..359, s = 0..100, v = 0..100
+lv_color_t c = lv_color_hsv_to_rgb(h, s, v);
+
+//All channels are 0-255
+lv_color_hsv_t c_hsv = lv_color_rgb_to_hsv(r, g, b);
+
+
+//From lv_color_t variable
+lv_color_hsv_t c_hsv = lv_color_to_hsv(color);
+```
+
+### Palette
+LVGL includes [material design's palette](https://vuetifyjs.com/en/styles/colors/#material-colors). In this all color have a main as well as four darker and five lighter variants.
+
+The names of the colors are as follows:
+- `LV_PALETTE_RED`
+- `LV_PALETTE_PINK`
+- `LV_PALETTE_PURPLE`
+- `LV_PALETTE_DEEP_PURPLE`
+- `LV_PALETTE_INDIGO`
+- `LV_PALETTE_BLUE`
+- `LV_PALETTE_LIGHT_BLUE`
+- `LV_PALETTE_CYAN`
+- `LV_PALETTE_TEAL`
+- `LV_PALETTE_GREEN`
+- `LV_PALETTE_LIGHT_GREEN`
+- `LV_PALETTE_LIME`
+- `LV_PALETTE_YELLOW`
+- `LV_PALETTE_AMBER`
+- `LV_PALETTE_ORANGE`
+- `LV_PALETTE_DEEP_ORANGE`
+- `LV_PALETTE_BROWN`
+- `LV_PALETTE_BLUE_GREY`
+- `LV_PALETTE_GREY`
+
+
+To get the main color use `lv_color_t c = lv_palette_main(LV_PALETTE_...)`.
+
+For the lighter variants of a palette color use `lv_color_t c = lv_palette_lighten(LV_PALETTE_..., v)`. `v` can be 1..5.
+For the darker variants of a palette color use `lv_color_t c = lv_palette_darken(LV_PALETTE_..., v)`. `v` can be 1..4.
+
+### Modify and mix colors
+The following functions can modify a color:
+```c
+// Lighten a color. 0: no change, 255: white
+lv_color_t c = lv_color_lighten(c, lvl);
+
+// Darken a color. 0: no change, 255: black
+lv_color_t c = lv_color_darken(lv_color_t c, lv_opa_t lvl);
+
+// Lighten or darken a color. 0: black, 128: no change 255: black
+lv_color_t c = lv_color_change_lightness(lv_color_t c, lv_opa_t lvl);
+
+
+// Mix 2 colors with a given ratio 0: full c2, 255: full c1, 128: half c1 and half c2
+lv_color_t c = lv_color_mix(c1, c2, ratio);
+```
+
+### Built-in colors
+`lv_color_white()` and `lv_color_black()` return `0xFFFFFF` and `0x000000` respectively.
+
+## Opacity
+To describe opacity the `lv_opa_t` type is created as a wrapper to `uint8_t`. Some defines are also introduced:
+
+- `LV_OPA_TRANSP` Value: 0, means the opacity makes the color completely transparent
+- `LV_OPA_10` Value: 25, means the color covers only a little
+- `LV_OPA_20 ... OPA_80` come logically
+- `LV_OPA_90` Value: 229, means the color near completely covers
+- `LV_OPA_COVER` Value: 255, means the color completely covers
+
+You can also use the `LV_OPA_*` defines in `lv_color_mix()` as a *ratio*.
+
+
+## Color types
+The following variable types are defined by the color module:
+
+- `lv_color1_t` Monochrome color. Also has R, G, B fields for compatibility but they are always the same value (1 byte)
+- `lv_color8_t` A structure to store R (3 bit),G (3 bit),B (2 bit) components for 8-bit colors (1 byte)
+- `lv_color16_t` A structure to store R (5 bit),G (6 bit),B (5 bit) components for 16-bit colors (2 byte)
+- `lv_color32_t` A structure to store R (8 bit),G (8 bit), B (8 bit) components for 24-bit colors (4 byte)
+- `lv_color_t` Equal to `lv_color1/8/16/24_t` depending on current color depth setting
+- `lv_color_int_t` `uint8_t`, `uint16_t` or `uint32_t` depending on color depth setting. Used to build color arrays from plain numbers.
+- `lv_opa_t` A simple `uint8_t` type to describe opacity.
+
+The `lv_color_t`, `lv_color1_t`, `lv_color8_t`, `lv_color16_t` and `lv_color32_t` types have four fields:
+
+- `ch.red` red channel
+- `ch.green` green channel
+- `ch.blue` blue channel
+- `full*` red + green + blue as one number
+
+You can set the current color depth in *lv_conf.h*, by setting the `LV_COLOR_DEPTH` define to 1 (monochrome), 8, 16 or 32.
+
+
+### Convert color
+You can convert a color from the current color depth to another. The converter functions return with a number, so you have to use the `full` field:
+
+```c
+lv_color_t c;
+c.red   = 0x38;
+c.green = 0x70;
+c.blue  = 0xCC;
+
+lv_color1_t c1;
+c1.full = lv_color_to1(c);	/*Return 1 for light colors, 0 for dark colors*/
+
+lv_color8_t c8;
+c8.full = lv_color_to8(c);	/*Give a 8 bit number with the converted color*/
+
+lv_color16_t c16;
+c16.full = lv_color_to16(c); /*Give a 16 bit number with the converted color*/
+
+lv_color32_t c24;
+c32.full = lv_color_to32(c);	/*Give a 32 bit number with the converted color*/
+```
+
+
+## API
+
+
+```eval_rst
+
+.. doxygenfile:: lv_color.h
+  :project: lvgl
+
+```

docs/overview/coords.md

@@ -0,0 +1,368 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/coords.md
+```
+# Positions, sizes, and layouts
+
+## Overview
+Similarly to many other parts of LVGL, the concept of setting the coordinates was inspired by CSS. By no means a complete implementation of the standard but subsets of CSS were implemented (sometimes with minor adjustments).
+In shorts this means:
+- the set coordinates (size, position, layouts, etc) are stored in styles
+- support min-width, max-width, min-height, max-height
+- have pixel, percentage, and "content" units 
+- x=0; y=0 coordinate means the to top-left corner of the parent plus the left/top padding plus border width
+- width/height means the full size, the "content area" is smaller with padding and border width 
+- a subset of flexbox and grid layouts are supported
+ 
+###  Units
+- pixel: Simply a position in pixels. A simple integer always means pixel. E.g. `lv_obj_set_x(btn, 10)`
+- percentage: The percentage of the size of the object or its parent (depending on the property). The `lv_pct(value)` converts a value to percentage. E.g. `lv_obj_set_width(btn, lv_pct(50))`
+- `LV_SIZE_CONTENT`: Special value to set the width/height of an object to involve all the children. Its similar to `auto` in CSS. E.g. `lv_obj_set_width(btn, LV_SIZE_CONTENT)`.
+
+### Boxing model
+LVGL follows CSS's [border-box](https://developer.mozilla.org/en-US/docs/Web/CSS/box-sizing) model.
+An object's "box" is built from the following parts:
+- bounding box: the width/height of the elements.
+- border width: the width of the border. 
+- padding: space between the sides of the object and its children. 
+- content: the content area which size if the bounding box reduced by the border width and the size of the paddings.
+
+![The box models of LVGL: The content area is smaller then the bounding box with the padding and border width](/misc/boxmodel.png)
+
+The border is drawn inside the bounding box. Inside the border LVGL keeps "padding size" to place the children. 
+
+The outline is drawn outside of the bounding box.
+
+### Important notes
+This section describes special cases in which LVGL's behavior might be unexpected.
+
+#### Postponed coordinate calculation
+LVGL doesn't recalculate all the coordinate changes immediately. This is done to improve performance. 
+Instead, the objects are marked as "dirty" and before redrawing the screen LVGL checks if there are any "dirty" objects. If so it refreshes their position, size and layout.
+
+In other words, if you need to get the any coordinate of an object and it the coordinates were just changed LVGL's needs to be forced to recalculate the coordinates. 
+To do this call `lv_obj_update_layout(obj)`.
+ 
+The size and position might depend on the parent or layout. Therefore `lv_obj_update_layout` recalculates the coordinates of all objects on the screen of `obj`.
+
+#### Removing styles
+As it's described in the [Using styles](#using-styles) section the coordinates can be set via style properties too. 
+To be more precise under the hood every style coordinate related property is stored as style a property. If you use `lv_obj_set_x(obj, 20)` LVGL saves `x=20` in the local style of the object.
+
+It's an internal mechanism and doesn't matter much as you use LVGL. However, there is one case in which you need to aware of that. If the style(s) of an object are removed by 
+```c
+lv_obj_remove_style_all(obj)
+```
+
+or
+```c
+lv_obj_remove_style(obj, NULL, LV_PART_MAIN);
+```
+the earlier set coordinates will be removed as well.
+
+For example:
+```c
+/*The size of obj1 will be set back to the default in the end*/
+lv_obj_set_size(obj1, 200, 100);  /*Now obj1 has 200;100 size*/
+lv_obj_remove_style_all(obj1);    /*It removes the set sizes*/
+
+
+/*obj2 will have 200;100 size in the end */
+lv_obj_remove_style_all(obj2);
+lv_obj_set_size(obj2, 200, 100);
+```
+
+## Position
+
+### Simple way
+To simple set the x and y coordinates of an object use 
+```c
+lv_obj_set_x(obj, 10);
+lv_obj_set_y(obj, 20);
+lv_obj_set_pos(obj, 10, 20); 	//Or in one function
+```
+
+By default the the x and y coordinates are measured from the top left corner of the parent's content area. 
+For example if the parent has 5 pixels padding on every side, the above code will place `obj` at (15, 25) because the content area starts after the padding.
+
+If percentage values are calculated from the parents content area size. 
+```c
+lv_obj_set_x(btn, lv_pct(10)); //x = 10 % of parant content area width
+```
+
+### Align
+In some cases it's convenient to change the origin of the positioning from the the default top left. If the origin is changed e.g. to bottom-right, the (0,0) position means: align to the bottom-right corner. 
+To change the origin use:
+```c
+lv_obj_set_align(obj, align);
+``` 
+
+To change the alignment and set new coordinates:
+```c
+lv_obj_align(obj, align, x, y);
+```
+
+The following alignment options can be used:
+- `LV_ALIGN_TOP_LEFT`
+- `LV_ALIGN_TOP_MID`
+- `LV_ALIGN_TOP_RIGHT`
+- `LV_ALIGN_BOTTOM_LEFT`
+- `LV_ALIGN_BOTTOM_MID`
+- `LV_ALIGN_BOTTOM_RIGHT`
+- `LV_ALIGN_LEFT_MID`
+- `LV_ALIGN_RIGHT_MID`
+- `LV_ALIGN_CENTER`
+
+It quite common to align a children to the center of its parent, there fore is a dedicated function for it:
+```c
+lv_obj_center(obj);
+
+//Has the same effect
+lv_obj_align(obj, LV_ALIGN_CENTER, 0, 0);
+```
+
+If the parent's size changes the set alignment and position of the children is applied again automatically.
+
+The functions introduced above aligns the object to its parent. However it's also possible to align an object to an arbitrary object.
+```c
+lv_obj_align_to(obj_to_align, reference_obj, align, x, y);
+```
+
+Besides the alignments options above the following can be used to align the object outside of the reference object:
+
+- `LV_ALIGN_OUT_TOP_LEFT`
+- `LV_ALIGN_OUT_TOP_MID`
+- `LV_ALIGN_OUT_TOP_RIGHT`
+- `LV_ALIGN_OUT_BOTTOM_LEFT`
+- `LV_ALIGN_OUT_BOTTOM_MID`
+- `LV_ALIGN_OUT_BOTTOM_RIGHT`
+- `LV_ALIGN_OUT_LEFT_TOP`
+- `LV_ALIGN_OUT_LEFT_MID`
+- `LV_ALIGN_OUT_LEFT_BOTTOM`
+- `LV_ALIGN_OUT_RIGHT_TOP`
+- `LV_ALIGN_OUT_RIGHT_MID`
+- `LV_ALIGN_OUT_RIGHT_BOTTOM`
+
+For example to align a label above a button and center the label horizontally:
+```c
+lv_obj_align_to(label, btn, LV_ALIGN_OUT_TOP_MID, 0, -10);
+```
+
+Note that - unlike with `lv_obj_align()` - `lv_obj_align_to()` can not realign the object if its coordinates or the reference object's coordinates changes. 
+
+## Size
+
+### Simple way
+The width and the height of an object can be set easily as well:
+```c
+lv_obj_set_width(obj, 200);
+lv_obj_set_height(obj, 100);
+lv_obj_set_size(obj, 200, 100); 	//Or in one function
+```
+
+Percentage values are calculated based on the parent's content area size. For example to set the object's height to the screen height:
+```c
+lv_obj_set_height(obj, lv_pct(100));
+``` 
+
+Size setting supports a value: `LV_SIZE_CONTENT`. It means the object's size in the respective direction will be set to the size of its children. 
+Note that only children on the right and bottom will be considered and children on the top and left remain cropped. This limitation makes the behavior more predictable.
+
+Objects with `LV_OBJ_FLAG_HIDDEN` or `LV_OBJ_FLAG_FLOATING` will be ignored by the `LV_SIZE_CONTENT` calculation.
+
+The above functions set the size of the bounding box of the object but the size of the content area can be set as well. It means the object's bounding box will be larger with the paddings than the set size. 
+```c
+lv_obj_set_content_width(obj, 50); //The actual width: padding left + 50 + padding right
+lv_obj_set_content_height(obj, 30); //The actual width: padding top + 30 + padding bottom
+```
+
+The size of the bounding box and the content area can be get with the following functions:
+```c
+lv_coord_t w = lv_obj_get_width(obj);
+lv_coord_t h = lv_obj_get_height(obj);
+lv_coord_t content_w = lv_obj_get_content_width(obj);
+lv_coord_t content_h = lv_obj_get_content_height(obj);
+```
+
+## Using styles
+Under the hood the position, size and alignment properties are style properties. 
+The above described "simple functions" hide the style related code for the sake of simplicity and set the position, size, and alignment properties in the local styles of the obejct.
+
+However, using styles as to set the coordinates has some great advantages:
+- It makes it easy to set the width/height/etc for several objects together. E.g. make all the sliders 100x10 pixels sized. 
+- It also makes possible to modify the values in one place.
+- The values can be overwritten by other styles. For example `style_btn` makes the object `100x50` by default but adding `style_full_width` overwrites only the width of the object.
+- The object can have different position or size in different state. E.g. 100 px wide in `LV_STATE_DEFAULT` but 120 px in `LV_STATE_PRESSED`.
+- Style transitions can be used to make the coordinate changes smooth. 
+
+
+Here are some examples to set an object's size using a style:
+```c
+static lv_style_t style;
+lv_style_init(&style);
+lv_style_set_width(&style, 100);
+
+lv_obj_t * btn = lv_btn_create(lv_scr_act());
+lv_obj_add_style(btn, &style, LV_PART_MAIN);
+```
+
+As you will see below there are some other great features of size and position setting. 
+However, to keep the LVGL's API lean only the most common coordinate setting features have a "simple" version and the more complex features can be used via styles. 
+
+## Translation
+
+Let's say the there are 3 buttons next to each other. Their position is set as described above. 
+Now you want to move a buttons up a little when it's pressed. 
+
+One way to achieve this is setting a new Y coordinate for pressed state:
+```c
+static lv_style_t style_normal;
+lv_style_init(&style_normal);
+lv_style_set_y(&style_normal, 100);
+
+static lv_style_t style_pressed;
+lv_style_init(&style_pressed);
+lv_style_set_y(&style_pressed, 80);
+
+lv_obj_add_style(btn1, &style_normal, LV_STATE_DEFAULT);
+lv_obj_add_style(btn1, &style_pressed, LV_STATE_PRESSED);
+
+lv_obj_add_style(btn2, &style_normal, LV_STATE_DEFAULT);
+lv_obj_add_style(btn2, &style_pressed, LV_STATE_PRESSED);
+
+lv_obj_add_style(btn3, &style_normal, LV_STATE_DEFAULT);
+lv_obj_add_style(btn3, &style_pressed, LV_STATE_PRESSED);
+```
+
+It works but it's not really flexible because the pressed coordinate is hard-coded. If the buttons are not at y=100 `style_pressed` won't work as expected. To solve this translations can be used:
+```c
+static lv_style_t style_normal;
+lv_style_init(&style_normal);
+lv_style_set_y(&style_normal, 100);
+
+static lv_style_t style_pressed;
+lv_style_init(&style_pressed);
+lv_style_set_translate_y(&style_pressed, -20);
+
+lv_obj_add_style(btn1, &style_normal, LV_STATE_DEFAULT);
+lv_obj_add_style(btn1, &style_pressed, LV_STATE_PRESSED);
+
+lv_obj_add_style(btn2, &style_normal, LV_STATE_DEFAULT);
+lv_obj_add_style(btn2, &style_pressed, LV_STATE_PRESSED);
+
+lv_obj_add_style(btn3, &style_normal, LV_STATE_DEFAULT);
+lv_obj_add_style(btn3, &style_pressed, LV_STATE_PRESSED);
+```
+
+Translation is applied from the current position of the object. 
+
+Percentage values can be used in translations as well. The percentage is relative to the size of the object (and not to the size of the parent). For example `lv_pct(50)` will move the object with half of its width/height.
+
+The translation is applied after the layouts are calculated. Therefore, even the layouted objects' position can be translated.
+
+The translation actually moves the object. It means it makes the scrollbars and `LV_SIZE_CONTENT` sized objects react to the position change.
+
+
+## Transformation
+Similarly to the position the size can be changed relative to the current size as well. 
+The transformed width and height are added on both sides of the object. This means 10 px transformed width makes the object 2x10 pixel wider.
+
+Unlike position translation, the size transformation doesn't make the object "really" larger. In other words scrollbars, layouts, `LV_SIZE_CONTENT` will not consider the transformed size. 
+Hence size transformation if "only" a visual effect. 
+
+This code makes the a button larger when it's pressed:
+```c
+static lv_style_t style_pressed;
+lv_style_init(&style_pressed);
+lv_style_set_transform_width(&style_pressed, 10);
+lv_style_set_transform_height(&style_pressed, 10);
+
+lv_obj_add_style(btn, &style_pressed, LV_STATE_PRESSED);
+```
+
+### Min and Max size
+Similarly to CSS, LVGL also support `min-width`, `max-width`, `min-height` and `max-height`. These are limits preventing an object's size to be smaller/larger then these values. 
+They are especially useful if the size is set by percentage or `LV_SIZE_CONTENT`.
+```c
+static lv_style_t style_max_height;
+lv_style_init(&style_max_height);
+lv_style_set_y(&style_max_height, 200);
+
+lv_obj_set_height(obj, lv_pct(100));
+lv_obj_add_style(obj, &style_max_height, LV_STATE_DEFAULT); //Limit the  height to 200 px
+```
+
+Percentage values can be used as well which are relative to the size of the parent's content area size.
+```c
+static lv_style_t style_max_height;
+lv_style_init(&style_max_height);
+lv_style_set_y(&style_max_height, lv_pct(50));
+
+lv_obj_set_height(obj, lv_pct(100));
+lv_obj_add_style(obj, &style_max_height, LV_STATE_DEFAULT); //Limit the height to half parent height
+```
+
+## Layout
+
+### Overview
+Layouts can update the position and size of an object's children. They can be used to automatically arrange the children into a line or column, or in much more complicated forms. 
+
+The position and size set by the layout overwrites the "normal" x, y, width, and height settings. 
+
+There is only one function that is the same for every layout: `lv_obj_set_layout(obj, <LAYOUT_NAME>)` sets the layout on an object.  
+For the further settings of the parent and children see the documentations of the given layout.
+
+### Built-in layout
+LVGL comes with two very powerful layouts:
+- Flexbox
+- Grid
+
+Both are heavily inspired by the CSS layouts with the same name.
+
+### Flags
+There are some flags that can be used on object to affect how they behave with layouts:
+- `LV_OBJ_FLAG_HIDDEN` Hidden object are ignored from layout calculations.
+- `LV_OBJ_FLAG_IGNORE_LAYOUT` The object is simply ignored by the layouts. Its coordinates can be set as usual.
+- `LV_OBJ_FLAG_FLOATING` Same as `LV_OBJ_FLAG_IGNORE_LAYOUT` but the object with `LV_OBJ_FLAG_FLOATING` will be ignored from `LV_SIZE_CONTENT` calculations.
+
+These flags can be added/removed with `lv_obj_add/clear_flag(obj, FLAG);`
+
+### Adding new layouts
+
+LVGL can be freely extended by a custom layouts like this:
+```c
+uint32_t MY_LAYOUT;
+
+...
+
+MY_LAYOUT = lv_layout_register(my_layout_update, &user_data);
+
+...
+
+void my_layout_update(lv_obj_t * obj, void * user_data)
+{
+	/*Will be called automatically if required to reposition/resize the children of "obj" */	
+}
+```
+
+Custom style properties can be added too that can be get and used in the update callback. For example:
+```c
+uint32_t MY_PROP;
+...
+
+LV_STYLE_MY_PROP = lv_style_register_prop();
+
+...
+static inline void lv_style_set_my_prop(lv_style_t * style, uint32_t value)
+{
+    lv_style_value_t v = {
+        .num = (int32_t)value
+    };
+    lv_style_set_prop(style, LV_STYLE_MY_PROP, v);
+}
+
+```
+
+## Examples
+
+

docs/overview/display.md

@@ -0,0 +1,108 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/display.md
+```
+# Displays
+
+``` important:: The basic concept of *display* in LVGL is explained in the [Porting](/porting/display) section. So before reading further, please read the [Porting](/porting/display) section first.
+```
+
+## Multiple display support
+
+In LVGL, you can have multiple displays, each with their own driver and objects. The only limitation is that every display needs to be have same color depth (as defined in `LV_COLOR_DEPTH`). 
+If the displays are different in this regard the rendered image can be converted to the correct format in the drivers `flush_cb`.
+
+Creating more displays is easy: just initialize more display buffers and register another driver for every display.
+When you create the UI, use `lv_disp_set_default(disp)` to tell the library on which display to create objects.
+
+Why would you want multi-display support? Here are some examples:
+- Have a "normal" TFT display with local UI and create "virtual" screens on VNC on demand. (You need to add your VNC driver).
+- Have a large TFT display and a small monochrome display.
+- Have some smaller and simple displays in a large instrument or technology.
+- Have two large TFT displays: one for a customer and one for the shop assistant.
+
+### Using only one display
+Using more displays can be useful but in most cases it's not required. Therefore, the whole concept of multi-display is completely hidden if you register only one display.
+By default, the lastly created (and only) display is used.
+
+`lv_scr_act()`, `lv_scr_load(scr)`, `lv_layer_top()`, `lv_layer_sys()`, `LV_HOR_RES` and `LV_VER_RES` are always applied on the most recently created (default) screen.
+If you pass `NULL` as `disp` parameter to display related function, usually the default display will be used.
+E.g. `lv_disp_trig_activity(NULL)` will trigger a user activity on the default screen. (See below in [Inactivity](#Inactivity)).
+
+### Mirror display
+
+To mirror the image of the display to another display, you don't need to use the multi-display support. Just transfer the buffer received in `drv.flush_cb` to the other display too.
+
+### Split image
+You can create a larger display from smaller ones. You can create it as below:
+1. Set the resolution of the displays to the large display's resolution.
+2. In `drv.flush_cb`, truncate and modify the `area` parameter for each display.
+3. Send the buffer's content to each display with the truncated area.
+
+## Screens
+
+Every display has each set of [Screens](overview/object#screen-the-most-basic-parent) and the object on the screens.
+
+Be sure not to confuse displays and screens:
+
+* **Displays** are the physical hardware drawing the pixels.
+* **Screens** are the high-level root objects associated with a particular display. One display can have multiple screens associated with it, but not vice versa.
+
+Screens can be considered the highest level containers which have no parent.
+The screen's size is always equal to its display and size their position is (0;0). Therefore, the screens coordinates can't be changed, i.e. `lv_obj_set_pos()`, `lv_obj_set_size()` or similar functions can't be used on screens.
+
+A screen can be created from any object type but the two most typical types are the [Base object](/widgets/obj) and the [Image](/widgets/core/img) (to create a wallpaper).
+
+To create a screen, use `lv_obj_t * scr = lv_<type>_create(NULL, copy)`. `copy` can be an other screen to copy it.
+
+To load a screen, use `lv_scr_load(scr)`. To get the active screen, use `lv_scr_act()`. These functions works on the default display. If you want to to specify which display to work on, use `lv_disp_get_scr_act(disp)` and `lv_disp_load_scr(disp, scr)`. Screen can be loaded with animations too. Read more [here](object.html#load-screens).
+
+Screens can be deleted with `lv_obj_del(scr)`, but ensure that you do not delete the currently loaded screen.
+
+### Transparent screens
+
+Usually, the opacity of the screen is `LV_OPA_COVER` to provide a solid background for its children. If it's not the case (opacity &lt; 100%) the display's background color or image will be visible. 
+See the [Display background](#display-background) section for more details. If the display's background opacity is also not `LV_OPA_COVER` LVGL has no solid background to draw. 
+
+This configuration (transparent screen and display) could be used to create for example OSD menus where a video is played on a lower layer, and a menu is overlayed on an upper layer.
+ 
+To handle transparent displays special (slower) color mixing algorithms need to be used by LVGL so this feature needs to enabled with `LV_COLOR_SCREEN_TRANSP` in `lv_conf.h`. 
+As this mode operates on the Alpha channel of the pixels `LV_COLOR_DEPTH = 32` is also required. The Alpha channel of 32-bit colors will be 0 where there are no objects and 255 where there are solid objects.
+
+In summary, to enable transparent screen and displays to create OSD menu-like UIs:
+- Enable `LV_COLOR_SCREEN_TRANSP` in `lv_conf.h`
+- Be sure to use `LV_COLOR_DEPTH 32`
+- Set the screens opacity to `LV_OPA_TRANSP` e.g. with `lv_obj_set_style_local_bg_opa(lv_scr_act(), LV_OBJMASK_PART_MAIN, LV_STATE_DEFAULT, LV_OPA_TRANSP)`
+- Set the display opacity to `LV_OPA_TRANSP` with `lv_disp_set_bg_opa(NULL, LV_OPA_TRANSP);`
+
+## Features of displays
+
+### Inactivity
+
+The user's inactivity is measured on each display. Every use of an [Input device](/overview/indev) (if [associated with the display](/porting/indev#other-features)) counts as an activity.
+To get time elapsed since the last activity, use `lv_disp_get_inactive_time(disp)`. If `NULL` is passed, the overall smallest inactivity time will be returned from all displays (**not the default display**).
+
+You can manually trigger an activity using `lv_disp_trig_activity(disp)`. If `disp` is `NULL`, the default screen will be used (**and not all displays**).
+
+### Background
+Every display has background color, a background image and background opacity properties. They become visible when the current screen is transparent or not positioned to cover the whole display.
+
+Background color is a simple color to fill the display. It can be adjusted with `lv_disp_set_bg_color(disp, color)`;
+
+Background image is a path to a file or a pointer to an `lv_img_dsc_t` variable (converted image) to be used as wallpaper. It can be set with `lv_disp_set_bg_color(disp, &my_img)`;
+If the background image is set (not `NULL`) the background won't be filled with `bg_color`.
+
+The opacity of the background color or image can be adjusted with `lv_disp_set_bg_opa(disp, opa)`. 
+
+The `disp` parameter of these functions can be `NULL` to refer it to the default display.
+
+
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_disp.h
+  :project: lvgl
+
+```

docs/overview/drawing.md

@@ -0,0 +1,206 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/drawing.md
+```
+# Drawing
+
+With LVGL, you don't need to draw anything manually. Just create objects (like buttons, labels, arc, etc), move and change them, and LVGL will refresh and redraw what is required.
+
+However, it might be useful to have a basic understanding of how drawing happens in LVGL to add customization, make it easier to find bugs or just out of curiosity.
+
+The basic concept is to not draw directly to the screen, but draw to an internal draw buffer first. When drawing (rendering) is ready, that buffer is copied to the screen. 
+
+The draw buffer can be smaller than the screen's size. LVGL will simply render in "tiles" that fit into the given draw buffer.
+
+This approach has two main advantages compared to directly drawing to the screen:
+1. It avoids flickering while the layers of the UI are drawn. For example, if LVGL drawn directly into the display, when drawing a *background + button + text*, each "stage" would be visible for a short time .
+2. It's faster to modify a buffer in internal RAM and finally write one pixel only once than reading/writing the display directly on each pixel access. 
+(e.g. via a display controller with SPI interface). 
+
+Note that this concept is different from "traditional" double buffering where there are 2 screen sized frame buffers: 
+one holds the current image to show on the display, and rendering happens to the other (inactive) frame buffer, and they are swapped when the rendering is finished. 
+The main difference is that with LVGL you don't have to store 2 frame buffers (which usually requires external RAM) but only smaller draw buffer(s) that can easily fit into the internal RAM too.
+
+
+## Mechanism of screen refreshing
+
+Be sure to get familiar with the [Buffering modes of LVGL](/porting/display) first.
+
+LVGL refreshes the screen in the following steps:
+1. Something happens on the UI which requires redrawing. For example, a button is pressed, a chart is changed, an animation happened, etc.
+2. LVGL saves the changed object's old and new area into a buffer, called an *Invalid area buffer*. For optimization, in some cases, objects are not added to the buffer:
+    - Hidden objects are not added.
+    - Objects completely out of their parent are not added.
+    - Areas partially out of the parent are cropped to the parent's area.
+    - The objects on other screens are not added.
+3. In every `LV_DISP_DEF_REFR_PERIOD` (set in `lv_conf.h`) the followings happen:
+    - LVGL checks the invalid areas and joins the adjacent or intersecting areas.
+    - Takes the first joined area, if it's smaller than the *draw buffer*, then simply render the area's content into the *draw buffer*. 
+      If the area doesn't fit into the buffer, draw as many lines as possible to the *draw buffer*.
+    - When the area is rendered, call `flush_cb` from the display driver to refresh the display.
+    - If the area was larger than the buffer, render the remaining parts too.
+    - Do the same with all the joined areas.
+
+When an area is redrawn, the library searches the top most object which covers that area, and starts drawing from that object.
+For example, if a button's label has changed, the library will see that it's enough to draw the button under the text, and that it's not required to draw the screen under the button too.
+
+The difference between buffering modes regarding the drawing mechanism is the following:
+1. **One buffer** - LVGL needs to wait for `lv_disp_flush_ready()` (called from `flush_cb`) before starting to redraw the next part.
+2. **Two buffers** -  LVGL can immediately draw to the second buffer when the first is sent to `flush_cb` because the flushing should be done by DMA (or similar hardware) in the background.
+3. **Double buffering** -  `flush_cb` should only swap the address of the frame buffer.
+
+## Masking
+*Masking* is the basic concept of LVGL's draw engine. 
+To use LVGL it's not required to know about the mechanisms described here, but you might find interesting to know how drawing works under hood. 
+Knowing about masking comes in handy if you want to customize drawing.
+
+To learn masking let's learn the steps of drawing first. 
+LVGL performs the following steps to render any shape, image or text. It can be considered as a drawing pipeline.
+
+1. **Prepare the draw descriptors** Create a draw descriptor from an object's styles (e.g. `lv_draw_rect_dsc_t`).  This gives us the parameters for drawing, for example the colors, widths, opacity, fonts, radius, etc. 
+2. **Call the draw function** Call the draw function with the draw descriptor and some other parameters (e.g. `lv_draw_rect()`).  It renders the primitive shape to the current draw buffer. 
+3. **Create masks** If the shape is very simple and doesn't require masks go to #5.  Else create the required masks (e.g. a rounded rectangle mask)
+4. **Calculate all the added mask**. It creates 0..255 values into a *mask buffer* with the "shape" of the created masks. 
+E.g. in case of a "line mask" according to the parameters of the mask, keep one side of the buffer as it is (255 by default) and set the rest to 0 to indicate that this side should be removed.
+5. **Blend a color or image** During blending masks (make some pixels transparent or opaque), blending modes (additive, subtractive, etc) and opacity are handled.
+
+LVGL has the following built-in mask types which can be calculated and applied real-time:
+- `LV_DRAW_MASK_TYPE_LINE` Removes a side from a line (top, bottom, left or right). `lv_draw_line` uses 4 of it. 
+Essentially, every (skew) line is bounded with 4 line masks by forming a rectangle.
+- `LV_DRAW_MASK_TYPE_RADIUS` Removes the inner or outer parts of a rectangle which can have radius. It's also used to create circles by setting the radius to large value (`LV_RADIUS_CIRCLE`) 
+- `LV_DRAW_MASK_TYPE_ANGLE` Removes a circle sector. It is used by `lv_draw_arc` to remove the "empty" sector. 
+- `LV_DRAW_MASK_TYPE_FADE` Create a vertical fade (change opacity) 
+- `LV_DRAW_MASK_TYPE_MAP` The mask is stored in an array and the necessary parts are applied 
+
+Masks are used the create almost every basic primitives:
+- **letters** Create a mask from the letter and draw a rectangle with the letter's color considering the mask.
+- **line** Created from 4 "line masks", to mask out the left, right, top and bottom part of the line to get perfectly perpendicular line ending.
+- **rounded rectangle** A mask is created real-time to add radius to the corners.
+- **clip corner** To clip to overflowing content (usually children) on the rounded corners also a rounded rectangle mask is applied.
+- **rectangle border** Same as a rounded rectangle, but inner part is masked out too.
+- **arc drawing** A circle border is drawn, but an arc mask is applied too.
+- **ARGB images** The alpha channel is separated into a mask and the image is drawn as a normal RGB image.
+
+## Hook drawing
+Although widgets can be very well customized by styles there might be cases when something really custom is required. 
+To ensure a great level of flexibility LVGL sends a lot events during drawing with parameters that tell what LVGL is about to draw. 
+Some fields of these parameters can be modified to draw something else or any custom drawing can be added manually.
+
+A good use case for it is the [Button matrix](/widgets/core/btnmatrix) widget. By default its buttons can be styled in different states but you can't style the buttons one by one. 
+However, an event is sent for every button and you can for example tell LVGL to use different colors on a specific button or to manually draw an image on some buttons.
+
+Below each of these events are described in detail.
+
+### Main drawing
+
+These events are related to the actual drawing of the object. E.g. drawing of buttons, texts, etc happens here.
+
+`lv_event_get_clip_area(event)` can be used to get the current clip area. The clip area is required in draw functions to make them draw only on a limited area. 
+
+#### LV_EVENT_DRAW_MAIN_BEGIN
+
+Sent before starting to draw an object. This is a good place to add masks manually. E.g. add a line mask that "removes" the right side of an object.
+
+#### LV_EVENT_DRAW_MAIN
+
+The actual drawing of the object happens in this event. E.g. a rectangle for a button is drawn here. First, the widgets' internal events are called to perform drawing and after that you can draw anything on top of them.
+For example you can add a custom text or an image.
+
+#### LV_EVENT_DRAW_MAIN_END
+
+Called when the main drawing is finished. You can draw anything here as well and it's also good place to remove the masks created in `LV_EVENT_DRAW_MAIN_BEGIN`.
+
+### Post drawing
+
+Post drawing events are called when all the children of an object are drawn. For example LVGL use the post drawing phase to draw the scrollbars because they should be above all the children. 
+
+`lv_event_get_clip_area(event)` can be used to get the current clip area.
+
+#### LV_EVENT_DRAW_POST_BEGIN
+
+Sent before starting the post draw phase. Masks can be added here too to mask out the post drawn content.
+
+#### LV_EVENT_DRAW_POST
+
+The actual drawing should happen here.
+
+#### LV_EVENT_DRAW_POST_END
+
+Called when post drawing has finished. If the masks were not removed in `LV_EVENT_DRAW_MAIN_END` they should be removed here.
+
+### Part drawing
+
+When LVGL draws a part of an object (e.g. a slider's indicator, a table's cell or a button matrix's button) it sends events before and after drawing that part with some context of the drawing.
+It allows changing the parts on a very low level with masks, extra drawing, or changing the parameters that LVGL is planning to use for drawing.
+
+In these events an `lv_obj_draw_part_t` structure is used to describe the context of the drawing. Not all fields are set for every part and widget. 
+To see which fields are set for a widget see the widget's documentation.
+
+`lv_obj_draw_part_t` has the following fields:
+
+```c
+// Always set
+const lv_area_t * clip_area;        // The current clip area, required if you need to draw something in the event
+uint32_t part;                      // The current part for which the event is sent
+uint32_t id;                        // The index of the part. E.g. a button's index on button matrix or table cell index.
+
+// Draw desciptors, set only if related
+lv_draw_rect_dsc_t * rect_dsc;      // A draw descriptor that can be modified to changed what LVGL will draw. Set only for rectangle-like parts
+lv_draw_label_dsc_t * label_dsc;    // A draw descriptor that can be modified to changed what LVGL will draw. Set only for text-like parts
+lv_draw_line_dsc_t * line_dsc;      // A draw descriptor that can be modified to changed what LVGL will draw. Set only for line-like parts
+lv_draw_img_dsc_t *  img_dsc;       // A draw descriptor that can be modified to changed what LVGL will draw. Set only for image-like parts
+lv_draw_arc_dsc_t *  arc_dsc;       // A draw descriptor that can be modified to changed what LVGL will draw. Set only for arc-like parts
+
+// Other paramters 
+lv_area_t * draw_area;              // The area of the part being drawn
+const lv_point_t * p1;              // A point calculated during drawing. E.g. a point of chart or the center of an arc.
+const lv_point_t * p2;              // A point calculated during drawing. E.g. a point of chart.
+char text[16];                      // A text calculated during drawing. Can be modified. E.g. tick labels on a chart axis.
+lv_coord_t radius;                  // E.g. the radius of an arc (not the corner radius).
+int32_t value;                      // A value calculated during drawing. E.g. Chart's tick line value.
+const void * sub_part_ptr;          // A pointer the identifies something in the part. E.g. chart series. 
+```
+
+`lv_event_get_draw_part_dsc(event)` can be used to get a pointer to `lv_obj_draw_part_t`.
+
+#### LV_EVENT_DRAW_PART_BEGIN
+
+Start the drawing of a part. This is a good place to modify the draw descriptors (e.g. `rect_dsc`), or add masks.
+ 
+#### LV_EVENT_DRAW_PART_END
+ 
+Finish the drawing of a part. This is a good place to draw extra content on the part, or remove the masks added in `LV_EVENT_DRAW_PART_BEGIN`.
+
+### Others
+
+#### LV_EVENT_COVER_CHECK   
+
+This event is used to check whether an object fully covers an area or not. 
+
+`lv_event_get_cover_area(event)` returns an pointer to an area to check and `lv_event_set_cover_res(event, res)` can be used to set one of these results:
+- `LV_COVER_RES_COVER` the areas is fully covered by the object
+- `LV_COVER_RES_NOT_COVER` the areas is not covered by the object
+- `LV_COVER_RES_MASKED` there is a mask on the object so it can not cover the area
+
+Here are some reasons why an object would be unable to fully cover an area:
+- It's simply not fully in area
+- It has a radius
+- It has not 100% background opacity
+- It's an ARGB or chroma keyed image
+- It does not have normal blending mode. In this case LVGL needs to know the colors under the object to do the blending properly
+- It's a text, etc 
+
+In short if for any reason the area below the object is visible than it doesn't cover that area.
+
+Before sending this event LVGL checks if at least the widget's coordinates fully cover the area or not. If not the event is not called.
+
+You need to check only the drawing you have added. The existing properties known by widget are handled in the widget's internal events. 
+E.g. if a widget has > 0 radius it might not cover an area but you need to handle `radius` only if you will modify it and the widget can't know about it. 
+
+#### LV_EVENT_REFR_EXT_DRAW_SIZE
+
+If you need to draw outside of a widget LVGL needs to know about it to provide the extra space for drawing. 
+Let's say you create an event the writes the current value of a slider above its knob. In this case LVGL needs to know that the slider's draw area should be larger with the size required for the text.
+
+You can simple set the required draw area with `lv_event_set_ext_draw_size(e, size)`. 
+

docs/overview/event.md

@@ -0,0 +1,168 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/event.md
+```
+# Events
+
+Events are triggered in LVGL when something happens which might be interesting to the user, e.g. when an object
+- is clicked
+- is scrolled
+- has its value changed
+- is redrawn, etc.
+
+## Add events to the object
+
+The user can assign callback functions to an object to see its events. In practice, it looks like this:
+```c
+lv_obj_t * btn = lv_btn_create(lv_scr_act());
+lv_obj_add_event_cb(btn, my_event_cb, LV_EVENT_CLICKED, NULL);   /*Assign an event callback*/
+
+...
+
+static void my_event_cb(lv_event_t * event)
+{
+    printf("Clicked\n");
+}
+```
+In the example `LV_EVENT_CLICKED` means that only the click event will call `my_event_cb`. See the [list of event codes](#event-codes) for all the options.
+`LV_EVENT_ALL` can be used to receive all the events.
+
+The last parameter of `lv_obj_add_event_cb` is a pointer to any custom data that will be available in the event. It will be described later in more detail.
+
+More events can be added to an object, like this:
+```c
+lv_obj_add_event_cb(obj, my_event_cb_1, LV_EVENT_CLICKED, NULL);
+lv_obj_add_event_cb(obj, my_event_cb_2, LV_EVENT_PRESSED, NULL);
+lv_obj_add_event_cb(obj, my_event_cb_3, LV_EVENT_ALL, NULL);		/*No filtering, receive all events*/
+```
+
+Even the same event callback can be used on an object with different `user_data`. For example:
+```c
+lv_obj_add_event_cb(obj, increment_on_click, LV_EVENT_CLICKED, &num1);
+lv_obj_add_event_cb(obj, increment_on_click, LV_EVENT_CLICKED, &num2);
+```
+
+The events will be called in the order as they were added. 
+
+
+More objects can use the same *event callback*.
+
+
+## Remove event(s) from an object
+
+Events can be removed from an object with the `lv_obj_remove_event_cb(obj, event_cb)` function or `lv_obj_remove_event_dsc(obj, event_dsc)`. `event_dsc` is a pointer returned by `lv_obj_add_event_cb`. 
+
+## Event codes
+
+The event codes can be grouped into these categories:
+- Input device events
+- Drawing events
+- Other events
+- Special events
+- Custom events
+
+All objects (such as Buttons/Labels/Sliders etc.) regardless their type receive the *Input device*, *Drawing* and *Other* events. 
+
+However the *Special events* are specific to a particular widget type. See the [widgets' documentation](/widgets/index) to learn when they are sent, 
+
+*Custom events* are added by the user and therefore these are never sent by LVGL.
+
+The following event codes exist:
+
+### Input device events
+- `LV_EVENT_PRESSED`      The object has been pressed
+- `LV_EVENT_PRESSING`     The object is being pressed (called continuously while pressing)
+- `LV_EVENT_PRESS_LOST`   The object is still being pressed but slid cursor/finger off of the object 
+- `LV_EVENT_SHORT_CLICKED`    The object was pressed for a short period of time, then released it. Not called if scrolled.
+- `LV_EVENT_LONG_PRESSED` Object has been pressed for at least the `long_press_time` specified in the input device driver.  Not called if scrolled.
+- `LV_EVENT_LONG_PRESSED_REPEAT`  Called after `long_press_time` in every `long_press_repeat_time` ms.  Not called if scrolled.
+- `LV_EVENT_CLICKED`      Called on release if the object did not scroll (regardless of long press)
+- `LV_EVENT_RELEASED`     Called in every case when the object has been released
+- `LV_EVENT_SCROLL_BEGIN` Scrolling begins. The event paramter is `NULL` or an `lv_anim_t *` with the scroll animation descriptor to modify if required. 
+- `LV_EVENT_SCROLL_END`   Scrolling ends.
+- `LV_EVENT_SCROLL`       The object was scrolled
+- `LV_EVENT_GESTURE`      A gesture is detected. Get the gesture with `lv_indev_get_gesture_dir(lv_indev_get_act());`
+- `LV_EVENT_KEY`          A key is sent to the object. Get the key with `lv_indev_get_key(lv_indev_get_act());`
+- `LV_EVENT_FOCUSED`      The object is focused 
+- `LV_EVENT_DEFOCUSED`    The object is defocused
+- `LV_EVENT_LEAVE`        The object is defocused but still selected
+- `LV_EVENT_HIT_TEST`     Perform advanced hit-testing. Use `lv_hit_test_info_t * a = lv_event_get_hit_test_info(e)` and check if `a->point` can click the object or not. If not set `a->res = false` 
+
+
+### Drawing events
+- `LV_EVENT_COVER_CHECK` Check if the object fully covers an area. The event parameter is `lv_cover_check_info_t *`.
+- `LV_EVENT_REFR_EXT_DRAW_SIZE`  Get the required extra draw area around the object (e.g. for shadow). The event parameter is `lv_coord_t *` to store the size. Overwrite it only with a larger value.
+- `LV_EVENT_DRAW_MAIN_BEGIN` Starting the main drawing phase.
+- `LV_EVENT_DRAW_MAIN`   Perform the main drawing
+- `LV_EVENT_DRAW_MAIN_END`   Finishing the main drawing phase
+- `LV_EVENT_DRAW_POST_BEGIN` Starting the post draw phase (when all children are drawn)
+- `LV_EVENT_DRAW_POST`   Perform the post draw phase (when all children are drawn)
+- `LV_EVENT_DRAW_POST_END`   Finishing the post draw phase (when all children are drawn)
+- `LV_EVENT_DRAW_PART_BEGIN` Starting to draw a part. The event parameter is `lv_obj_draw_dsc_t *`. Learn more [here](/overview/drawing).
+- `LV_EVENT_DRAW_PART_END`   Finishing to draw a part. The event parameter is `lv_obj_draw_dsc_t *`. Learn more [here](/overview/drawing).
+
+### Other events
+- `LV_EVENT_DELETE`       Object is being deleted
+- `LV_EVENT_CHILD_CHANGED`    Child was removed/added
+- `LV_EVENT_SIZE_CHANGED`    Object coordinates/size have changed
+- `LV_EVENT_STYLE_CHANGED`    Object's style has changed
+- `LV_EVENT_BASE_DIR_CHANGED` The base dir has changed
+- `LV_EVENT_GET_SELF_SIZE`    Get the internal size of a widget
+
+### Special events
+- `LV_EVENT_VALUE_CHANGED`    The object's value has changed (i.e. slider moved)
+- `LV_EVENT_INSERT`       A text is being inserted to the object. The event data is `char *` being inserted.
+- `LV_EVENT_REFRESH`      Notify the object to refresh something on it (for the user)
+- `LV_EVENT_READY`        A process has finished
+- `LV_EVENT_CANCEL`       A process has been canceled 
+
+
+### Custom events
+Any custom event codes can be registered by `uint32_t MY_EVENT_1 = lv_event_register_id();` 
+
+And can be sent to any object with `lv_event_send(obj, MY_EVENT_1, &some_data)`
+
+## Sending events
+
+To manually send events to an object, use `lv_event_send(obj, <EVENT_CODE> &some_data)`.
+
+For example, this can be used to manually close a message box by simulating a button press (although there are simpler ways to do this):
+```c
+/*Simulate the press of the first button (indexes start from zero)*/
+uint32_t btn_id = 0;
+lv_event_send(mbox, LV_EVENT_VALUE_CHANGED, &btn_id);
+```
+
+### Refresh event
+
+`LV_EVENT_REFRESH` is special event because it's designed to be used by the user to notify an object to refresh itself. Some examples:
+- notify a label to refresh its text according to one or more variables (e.g. current time)
+- refresh a label when the language changes
+- enable a button if some conditions are met (e.g. the correct PIN is entered)
+- add/remove styles to/from an object if a limit is exceeded, etc
+
+## Fields of lv_event_t
+
+`lv_event_t` is the only parameter passed to event callback and it contains all the data about the event. The following values can be gotten from it:
+- `lv_event_get_code(e)` get the event code
+- `lv_event_get_target(e)` get the object to which the event is sent
+- `lv_event_get_original_target(e)` get the object to which the event is sent originally sent (different from `lv_event_get_target` if [event bubbling](#event-bubbling) is enabled)
+- `lv_event_get_user_data(e)` get the pointer passed as the last parameter of `lv_obj_add_event_cb`.
+- `lv_event_get_param(e)` get the parameter passed as the last parameter of `lv_event_send` 
+
+
+## Event bubbling
+
+If `lv_obj_add_flag(obj, LV_OBJ_FLAG_EVENT_BUBBLE)` is enabled all events will be sent to the object's parent too. If the parent also has `LV_OBJ_FLAG_EVENT_BUBBLE` enabled the event will be sent to its parent too, and so on. 
+
+The *target* parameter of the event is always the current target object, not the original object. To get the original target call `lv_event_get_original_target(e)` in the event handler.  
+
+
+
+## Examples
+
+```eval_rst
+
+.. include:: ../../examples/event/index.rst
+
+```

docs/overview/file-system.md

@@ -0,0 +1,133 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/file-system.md
+```
+# File system
+
+LVGL has a 'File system' abstraction module that enables you to attach any type of file system.
+The file system is identified by a drive letter.
+For example, if the SD card is associated with the letter `'S'`, a file can be reached like `"S:path/to/file.txt"`.
+
+## Ready to use drivers
+The [lv_fs_if](https://github.com/lvgl/lv_fs_if) repository contains ready to use drivers using POSIX, standard C and [FATFS](http://elm-chan.org/fsw/ff/00index_e.html) API.
+See it's [README](https://github.com/lvgl/lv_fs_if#readme) for the details.
+
+## Add a driver
+
+### Registering a driver
+To add a driver, `lv_fs_drv_t` needs to be initialized like below. `lv_fs_drv_t` needs to be static, global or dynamically allocated and not a local varaible.
+```c
+static lv_fs_drv_t drv;                   /*Needs to be static or global*/
+lv_fs_drv_init(&drv);                     /*Basic initialization*/
+
+drv.letter = 'S';                         /*An uppercase letter to identify the drive */
+drv.ready_cb = my_ready_cb;               /*Callback to tell if the drive is ready to use */
+drv.open_cb = my_open_cb;                 /*Callback to open a file */
+drv.close_cb = my_close_cb;               /*Callback to close a file */
+drv.read_cb = my_read_cb;                 /*Callback to read a file */
+drv.write_cb = my_write_cb;               /*Callback to write a file */
+drv.seek_cb = my_seek_cb;                 /*Callback to seek in a file (Move cursor) */
+drv.tell_cb = my_tell_cb;                 /*Callback to tell the cursor position  */
+
+drv.dir_open_cb = my_dir_open_cb;         /*Callback to open directory to read its content */
+drv.dir_read_cb = my_dir_read_cb;         /*Callback to read a directory's content */
+drv.dir_close_cb = my_dir_close_cb;       /*Callback to close a directory */
+
+drv.user_data = my_user_data;             /*Any custom data if required*/
+
+lv_fs_drv_register(&drv);                 /*Finally register the drive*/
+
+```
+
+Any of the callbacks can be `NULL` to indicate that operation is not supported.
+
+
+### Implementing the callbacks
+
+#### Open callback
+The prototype of `open_cb` looks like this:
+```c
+void * (*open_cb)(lv_fs_drv_t * drv, const char * path, lv_fs_mode_t mode);
+```
+
+`path` is path after the driver letter (e.g. "S:path/to/file.txt" -> "path/to/file.txt"). `mode` can be `LV_FS_MODE_WR` or `LV_FS_MODE_RD` to open for write or read.
+
+The return value is a pointer the *file object* the describes the opened file or `NULL` if there were any issues (e.g. the file wasn't found). 
+The returned file object will be passed to to other file system related callbacks. (see below)
+
+### Other callbacks
+The other callbacks are quite similar. For example `write_cb` looks like this:
+```c
+lv_fs_res_t (*write_cb)(lv_fs_drv_t * drv, void * file_p, const void * buf, uint32_t btw, uint32_t * bw);
+```
+
+As `file_p` LVGL passes the return value of `open_cb`, `buf` is the data to write, `btw` is the Bytes To Write, `bw` is the actually written bytes. 
+
+For a template to the callbacks see [lv_fs_template.c](https://github.com/lvgl/lvgl/blob/master/examples/porting/lv_port_fs_template.c).
+
+
+## Usage example
+
+The example below shows how to read from a file:
+```c
+lv_fs_file_t f;
+lv_fs_res_t res;
+res = lv_fs_open(&f, "S:folder/file.txt", LV_FS_MODE_RD);
+if(res != LV_FS_RES_OK) my_error_handling();
+
+uint32_t read_num;
+uint8_t buf[8];
+res = lv_fs_read(&f, buf, 8, &read_num);
+if(res != LV_FS_RES_OK || read_num != 8) my_error_handling();
+
+lv_fs_close(&f);
+```
+*The mode in `lv_fs_open` can be `LV_FS_MODE_WR` to open for write or `LV_FS_MODE_RD | LV_FS_MODE_WR` for both*
+
+This example shows how to read a directory's content. It's up to the driver how to mark the directories, but it can be a good practice to insert a `'/'` in front of the directory name.
+```c
+lv_fs_dir_t dir;
+lv_fs_res_t res;
+res = lv_fs_dir_open(&dir, "S:/folder");
+if(res != LV_FS_RES_OK) my_error_handling();
+
+char fn[256];
+while(1) {
+    res = lv_fs_dir_read(&dir, fn);
+    if(res != LV_FS_RES_OK) {
+        my_error_handling();
+        break;
+    }
+
+    /*fn is empty, if not more files to read*/
+    if(strlen(fn) == 0) {
+        break;
+    }
+
+    printf("%s\n", fn);
+}
+
+lv_fs_dir_close(&dir);
+```
+
+## Use drivers for images
+
+[Image](/widgets/core/img) objects can be opened from files too (besides variables stored in the flash).
+
+To use files in image widgets the following callbacks are required:
+- open
+- close
+- read
+- seek
+- tell
+
+
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_fs.h
+  :project: lvgl
+
+```

docs/overview/font.md

@@ -0,0 +1,254 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/font.md
+```
+# Fonts
+
+In LVGL fonts are collections of bitmaps and other information required to render the images of the letters (glyph). 
+A font is stored in a `lv_font_t` variable and can be set in a style's *text_font* field. For example:
+```c
+lv_style_set_text_font(&my_style, LV_STATE_DEFAULT, &lv_font_montserrat_28);  /*Set a larger font*/
+```
+
+The fonts have a **bpp (bits per pixel)** property. It shows how many bits are used to describe a pixel in the font. The value stored for a pixel determines the pixel's opacity.
+This way, with higher *bpp*, the edges of the letter can be smoother. The possible *bpp* values are 1, 2, 4 and 8 (higher value means better quality).
+
+The *bpp* also affects the required memory size to store the font. For example, *bpp = 4* makes the font nearly 4 times larger compared to *bpp = 1*.  
+
+## Unicode support
+
+LVGL supports **UTF-8** encoded Unicode characters.
+Your editor needs to be configureed to save your code/text as UTF-8 (usually this the default) and be sure that, `LV_TXT_ENC` is set to `LV_TXT_ENC_UTF8` in *lv_conf.h*. (This is the default value)
+
+To test it try
+```c
+lv_obj_t * label1 = lv_label_create(lv_scr_act(), NULL);
+lv_label_set_text(label1, LV_SYMBOL_OK);
+```
+
+If all works well, a ✓ character should be displayed.
+
+## Built-in fonts
+
+There are several built-in fonts in different sizes, which can be enabled in `lv_conf.h` by *LV_FONT_...* defines.
+### Normal fonts
+Containing all the ASCII characters, the degree symbol (U+00B0), the bullet symbol (U+2022) and the built-in symbols (see below).
+- `LV_FONT_MONTSERRAT_12` 12 px font
+- `LV_FONT_MONTSERRAT_14` 14 px font
+- `LV_FONT_MONTSERRAT_16` 16 px font
+- `LV_FONT_MONTSERRAT_18` 18 px font
+- `LV_FONT_MONTSERRAT_20` 20 px font
+- `LV_FONT_MONTSERRAT_22` 22 px font
+- `LV_FONT_MONTSERRAT_24` 24 px font
+- `LV_FONT_MONTSERRAT_26` 26 px font
+- `LV_FONT_MONTSERRAT_28` 28 px font
+- `LV_FONT_MONTSERRAT_30` 30 px font
+- `LV_FONT_MONTSERRAT_32` 32 px font
+- `LV_FONT_MONTSERRAT_34` 34 px font
+- `LV_FONT_MONTSERRAT_36` 36 px font
+- `LV_FONT_MONTSERRAT_38` 38 px font
+- `LV_FONT_MONTSERRAT_40` 40 px font
+- `LV_FONT_MONTSERRAT_42` 42 px font
+- `LV_FONT_MONTSERRAT_44` 44 px font
+- `LV_FONT_MONTSERRAT_46` 46 px font
+- `LV_FONT_MONTSERRAT_48` 48 px font
+
+### Special fonts
+- `LV_FONT_MONTSERRAT_12_SUBPX` Same as normal 12 px font but with [subpixel rendering](#subpixel-rendering) 
+- `LV_FONT_MONTSERRAT_28_COMPRESSED` Same as normal 28 px font but  [compressed font](#compress-fonts) with 3 bpp
+- `LV_FONT_DEJAVU_16_PERSIAN_HEBREW` 16 px font with normal range + Hebrew, Arabic, Persian letters and all their forms
+- `LV_FONT_SIMSUN_16_CJK`16 px font with normal range + 1000 most common CJK radicals
+- `LV_FONT_UNSCII_8` 8 px pixel perfect font with only ASCII characters
+- `LV_FONT_UNSCII_16` 16 px pixel perfect font with only ASCII characters
+
+
+The built-in fonts are **global variables** with names like `lv_font_montserrat_16` for a 16 px hight font. To use them in a style, just add a pointer to a font variable like shown above.
+
+The built-in fonts with *bpp = 4* contain the ASCII characters and use the [Montserrat](https://fonts.google.com/specimen/Montserrat) font.
+
+In addition to the ASCII range, the following symbols are also added to the built-in fonts from the [FontAwesome](https://fontawesome.com/) font.
+
+![](/misc/symbols.png "Built-in Symbols in LVGL")
+
+The symbols can be used as:
+```c
+lv_label_set_text(my_label, LV_SYMBOL_OK);
+```
+
+Or with together with strings:
+```c
+lv_label_set_text(my_label, LV_SYMBOL_OK "Apply");
+```
+
+Or more symbols together:
+```c
+lv_label_set_text(my_label, LV_SYMBOL_OK LV_SYMBOL_WIFI LV_SYMBOL_PLAY);
+```
+
+## Special features
+
+### Bidirectional support
+Most of the languages use Left-to-Right (LTR for short) writing direction, however some languages (such as Hebrew, Persian or Arabic) uses Right-to-Left (RTL for short) direction. 
+
+LVGL not only supports RTL texts but supports mixed (a.k.a. bidirectional, BiDi) text rendering too. Some examples:
+
+![](/misc/bidi.png "Bidirectional text examples")
+
+BiDi support is enabled by `LV_USE_BIDI` in *lv_conf.h*
+
+All texts have a base direction (LTR or RTL) which determines some rendering rules and the default alignment of the text (Left or Right).
+However, in LVGL, base direction is applied not only for labels. It's a general property which can be set for every object. 
+If unset then it will be inherited from the parent. 
+So it's enough to set the base direction of the screen and every object will inherit it.
+
+The default base direction of screen can be set by `LV_BIDI_BASE_DIR_DEF` in *lv_conf.h* and other objects inherit the base direction from their parent.
+
+To set an object's base direction use `lv_obj_set_base_dir(obj, base_dir)`.  The possible base direction are:
+- `LV_BIDI_DIR_LTR`: Left to Right base direction
+- `LV_BIDI_DIR_RTL`: Right to Left base direction
+- `LV_BIDI_DIR_AUTO`: Auto detect base direction
+- `LV_BIDI_DIR_INHERIT`: Inherit the base direction from the parent (default for non-screen objects)
+
+This list summarizes the effect of RTL base direction on objects:
+- Create objects by default on the right
+- `lv_tabview`: displays tabs from right to left
+- `lv_checkbox`: Show the box on the right
+- `lv_btnmatrix`: Show buttons from right to left
+- `lv_list`: Show the icon on the right
+- `lv_dropdown`: Align the options to the right
+- The texts in `lv_table`, `lv_btnmatrix`, `lv_keyboard`, `lv_tabview`, `lv_dropdown`, `lv_roller` are "BiDi processed" to be displayed correctly
+
+### Arabic and Persian support
+There are some special rules to display Arabic and Persian characters: the *form* of the character depends on their position in the text. 
+A different form of the same letter needs to be used if it isolated, start, middle or end position. Besides these some conjunction rules also should be taken into account.
+
+LVGL supports to apply these rules if `LV_USE_ARABIC_PERSIAN_CHARS` is enabled.  
+
+However, there some limitations:
+- Only displaying texts is supported (e.g. on labels), text inputs (e.g. text area) don't support this feature.
+- Static text (i.e. const) is not processed. E.g. texts set by `lv_label_set_text()` will be "Arabic processed" but `lv_lable_set_text_static()` won't.
+- Text get functions (e.g. `lv_label_get_text()`) will return the processed text. 
+
+### Subpixel rendering
+
+Subpixel rendering allows for tripling the horizontal resolution by rendering on Red, Green and Blue channel instead of pixel level. This takes advantage of the position of physical color channels of each pixel, resulting in higher quality letter anti-aliasing. Learn more [here](https://en.wikipedia.org/wiki/Subpixel_rendering).
+
+For subpixel rendering the fonts need to be generated with special settings: 
+- In the online converter tick the `Subpixel` box
+- In the command line tool use `--lcd` flag. Note that the generated font needs about 3 times more memory.
+
+Subpixel rendering works only if the color channels of the pixels have a horizontal layout. That is the R, G, B channels are next each other and not above each other. 
+The order of color channels also needs to match with the library settings. By default LVGL assumes `RGB` order, however this can be swapped by setting `LV_SUBPX_BGR  1` in *lv_conf.h*.
+
+### Compress fonts
+The bitmaps of the fonts can be compressed by 
+- ticking the `Compressed` check box in the online converter
+- not passing `--no-compress` flag to the offline converter (compression is applied by default) 
+
+The compression is more effective with larger fonts and higher bpp. However, it's about 30% slower to render the compressed fonts.
+Therefore it's recommended to compress only the largest fonts of user interface, because
+- they need the most memory 
+- they can be compressed better
+- and probably they are used less frequently then the medium sized fonts, so the performance cost is smaller.
+
+## Add new font
+
+There are several ways to add a new font to your project:
+1. The simplest method is to use the [Online font converter](https://lvgl.io/tools/fontconverter). Just set the parameters, click the *Convert* button, copy the font to your project and use it. **Be sure to carefully read the steps provided on that site or you will get an error while converting.**
+2. Use the [Offline font converter](https://github.com/lvgl/lv_font_conv). (Requires Node.js to be installed)
+3. If you want to create something like the built-in fonts (Roboto font and symbols) but in different size and/or ranges, you can use the `built_in_font_gen.py` script in `lvgl/scripts/built_in_font` folder.
+(This requires Python and `lv_font_conv` to be installed)
+
+To declare the font in a file, use `LV_FONT_DECLARE(my_font_name)`.
+
+To make the fonts globally available (like the builtin fonts), add them to `LV_FONT_CUSTOM_DECLARE` in *lv_conf.h*.
+
+## Add new symbols
+The built-in symbols are created from the [FontAwesome](https://fontawesome.com/) font. 
+
+1. Search symbol on [https://fontawesome.com](https://fontawesome.com). For example the [USB symbol](https://fontawesome.com/icons/usb?style=brands). Copy it's Unicode ID which is `0xf287` in this case.
+2. Open the [Online font converter](https://lvgl.io/tools/fontconverter). Add Add [FontAwesome.woff](https://lvgl.io/assets/others/FontAwesome5-Solid+Brands+Regular.woff). . 
+3. Set the parameters such as Name, Size, BPP. You'll use this name to declare and use the font in your code.
+4. Add the Unicode ID of the symbol to the range field. E.g.` 0xf287` for the USB symbol. More symbols can be enumerated with `,`.
+5. Convert the font and copy it to your project. Make sure to compile the .c file of your font.
+6. Declare the font using `extern lv_font_t my_font_name;` or simply `LV_FONT_DECLARE(my_font_name);`.
+
+**Using the symbol**
+1. Convert the Unicode value to UTF8, for example on [this site](http://www.ltg.ed.ac.uk/~richard/utf-8.cgi?input=f287&mode=hex). For `0xf287` the *Hex UTF-8 bytes* are `EF 8A 87`.
+2. Create a `define` from the UTF8 values: `#define MY_USB_SYMBOL "\xEF\x8A\x87"`
+3. Create a label and set the text. Eg. `lv_label_set_text(label, MY_USB_SYMBOL)`
+
+Note - `lv_label_set_text(label, MY_USB_SYMBOL)` searches for this symbol in the font defined in `style.text.font` properties. To use the symbol you may need to change it. Eg ` style.text.font = my_font_name` 
+
+## Load font at run-time
+`lv_font_load` can be used to load a font from a file. The font to load needs to have a special binary format. (Not TTF or WOFF). 
+Use [lv_font_conv](https://github.com/lvgl/lv_font_conv/) with `--format bin` option to generate an LVGL compatible font file.
+
+Note that to load a font [LVGL's filesystem](/overview/file-system) needs to be enabled and a driver needs to be added.
+
+Example
+```c
+lv_font_t * my_font;
+my_font = lv_font_load(X/path/to/my_font.bin);
+
+/*Use the font*/
+
+/*Free the font if not required anymore*/
+lv_font_free(my_font);
+```
+
+
+## Add a new font engine
+
+LVGL's font interface is designed to be very flexible.
+But even so you don't need to use LVGL's internal font engine: you can add your own.
+For example, use [FreeType](https://www.freetype.org/) to real-time render glyphs from TTF fonts or use an external flash to store the font's bitmap and read them when the library needs them.
+
+A ready to use FreeType can be found in [lv_freetype](https://github.com/lvgl/lv_lib_freetype) repository.
+
+To do this a custom `lv_font_t` variable needs to be created:
+```c
+/*Describe the properties of a font*/
+lv_font_t my_font;
+my_font.get_glyph_dsc = my_get_glyph_dsc_cb;        /*Set a callback to get info about gylphs*/
+my_font.get_glyph_bitmap = my_get_glyph_bitmap_cb;  /*Set a callback to get bitmap of a glyp*/
+my_font.line_height = height;                       /*The real line height where any text fits*/
+my_font.base_line = base_line;                      /*Base line measured from the top of line_height*/
+my_font.dsc = something_required;                   /*Store any implementation specific data here*/
+my_font.user_data = user_data;                      /*Optionally some extra user data*/
+
+...
+
+/* Get info about glyph of `unicode_letter` in `font` font.
+ * Store the result in `dsc_out`.
+ * The next letter (`unicode_letter_next`) might be used to calculate the width required by this glyph (kerning)
+ */
+bool my_get_glyph_dsc_cb(const lv_font_t * font, lv_font_glyph_dsc_t * dsc_out, uint32_t unicode_letter, uint32_t unicode_letter_next)
+{
+    /*Your code here*/
+
+    /* Store the result.
+     * For example ...
+     */
+    dsc_out->adv_w = 12;        /*Horizontal space required by the glyph in [px]*/
+    dsc_out->box_h = 8;         /*Height of the bitmap in [px]*/
+    dsc_out->box_w = 6;         /*Width of the bitmap in [px]*/
+    dsc_out->ofs_x = 0;         /*X offset of the bitmap in [pf]*/
+    dsc_out->ofs_y = 3;         /*Y offset of the bitmap measured from the as line*/
+    dsc_out->bpp   = 2;         /*Bits per pixel: 1/2/4/8*/
+
+    return true;                /*true: glyph found; false: glyph was not found*/
+}
+
+
+/* Get the bitmap of `unicode_letter` from `font`. */
+const uint8_t * my_get_glyph_bitmap_cb(const lv_font_t * font, uint32_t unicode_letter)
+{
+    /* Your code here */
+
+    /* The bitmap should be a continuous bitstream where
+     * each pixel is represented by `bpp` bits */
+
+    return bitmap;    /*Or NULL if not found*/
+}
+```

docs/overview/image.md

@@ -0,0 +1,330 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/image.md
+```
+# Images
+
+An image can be a file or variable which stores the bitmap itself and some metadata.
+
+## Store images
+You can store images in two places
+- as a variable in the internal memory (RAM or ROM)
+- as a file
+
+### Variables
+The images stored internally in a variable are composed mainly of an `lv_img_dsc_t` structure with the following fields:
+- **header**
+  - *cf* Color format. See [below](#color-format)
+  - *w* width in pixels (<= 2048)
+  - *h* height in pixels (<= 2048)
+  - *always zero* 3 bits which need to be always zero
+  - *reserved* reserved for future use
+- **data** pointer to an array where the image itself is stored
+- **data_size** length of `data` in bytes
+
+These are usually stored within a project as C files. They are linked into the resulting executable like any other constant data.
+
+### Files
+To deal with files you need to add a *Drive* to LVGL. In short, a *Drive* is a collection of functions (*open*, *read*, *close*, etc.) registered in LVGL to make file operations.
+You can add an interface to a standard file system (FAT32 on SD card) or you create your simple file system to read data from an SPI Flash memory.
+In every case, a *Drive* is just an abstraction to read and/or write data to memory.
+See the [File system](/overview/file-system) section to learn more.
+
+Images stored as files are not linked into the resulting executable, and must be read to RAM before being drawn. As a result, they are not as resource-friendly as variable images. However, they are easier to replace without needing to recompile the main program.
+
+## Color formats
+Various built-in color formats are supported:
+- **LV_IMG_CF_TRUE_COLOR** Simply stores the RGB colors (in whatever color depth LVGL is configured for).
+- **LV_IMG_CF_TRUE_COLOR_ALPHA** Like `LV_IMG_CF_TRUE_COLOR` but it also adds an alpha (transparency) byte for every pixel.
+- **LV_IMG_CF_TRUE_COLOR_CHROMA_KEYED** Like `LV_IMG_CF_TRUE_COLOR` but if a pixel has `LV_COLOR_TRANSP` (set in *lv_conf.h*) color the pixel will be transparent.
+- **LV_IMG_CF_INDEXED_1/2/4/8BIT** Uses a palette with 2, 4, 16 or 256 colors and stores each pixel in 1, 2, 4 or 8 bits.
+- **LV_IMG_CF_ALPHA_1/2/4/8BIT** **Only stores the Alpha value on 1, 2, 4 or 8 bits.** The pixels take the color of `style.image.color` and the set opacity. The source image has to be an alpha channel. This is ideal for bitmaps similar to fonts (where the whole image is one color but you'd like to be able to change it).
+
+The bytes of the `LV_IMG_CF_TRUE_COLOR` images are stored in the following order.
+
+For 32-bit color depth:
+- Byte 0: Blue
+- Byte 1: Green
+- Byte 2: Red
+- Byte 3: Alpha
+
+For 16-bit color depth:
+- Byte 0: Green 3 lower bit, Blue 5 bit
+- Byte 1: Red 5 bit, Green 3 higher bit
+- Byte 2: Alpha byte (only with LV_IMG_CF_TRUE_COLOR_ALPHA)
+
+For 8-bit color depth:
+- Byte 0: Red 3 bit, Green 3 bit, Blue 2 bit
+- Byte 2: Alpha byte (only with LV_IMG_CF_TRUE_COLOR_ALPHA)
+
+
+You can store images in a *Raw* format to indicate that it's not encoded with one of the built-in color formats and an external [Image decoder](#image-decoder) needs to be used to decode the image.
+- **LV_IMG_CF_RAW** Indicates a basic raw image (e.g. a PNG or JPG image).
+- **LV_IMG_CF_RAW_ALPHA** Indicates that the image has alpha and an alpha byte is added for every pixel.
+- **LV_IMG_CF_RAW_CHROME_KEYED** Indicates that the image is chroma-keyed as described in `LV_IMG_CF_TRUE_COLOR_CHROMA_KEYED` above.
+
+
+## Add and use images
+
+You can add images to LVGL in two ways:
+- using the online converter
+- manually create images
+
+### Online converter
+The online Image converter is available here: https://lvgl.io/tools/imageconverter
+
+Adding an image to LVGL via online converter is easy.
+
+1. You need to select a *BMP*, *PNG* or *JPG* image first.
+2. Give the image a name that will be used within LVGL.
+3. Select the [Color format](#color-formats).
+4. Select the type of image you want. Choosing a binary will generate a `.bin` file that must be stored separately and read using the [file support](#files). Choosing a variable will generate a standard C file that can be linked into your project.
+5. Hit the *Convert* button. Once the conversion is finished, your browser will automatically download the resulting file.
+
+In the converter C arrays (variables), the bitmaps for all the color depths (1, 8, 16 or 32) are included in the C file, but only the color depth that matches `LV_COLOR_DEPTH` in *lv_conf.h* will actually be linked into the resulting executable.
+
+In case of binary files, you need to specify the color format you want:
+- RGB332 for 8-bit color depth
+- RGB565 for 16-bit color depth
+- RGB565 Swap for 16-bit color depth (two bytes are swapped)
+- RGB888 for 32-bit color depth
+
+### Manually create an image
+If you are generating an image at run-time, you can craft an image variable to display it using LVGL. For example:
+
+```c
+uint8_t my_img_data[] = {0x00, 0x01, 0x02, ...};
+
+static lv_img_dsc_t my_img_dsc = {
+    .header.always_zero = 0,
+    .header.w = 80,
+    .header.h = 60,
+    .data_size = 80 * 60 * LV_COLOR_DEPTH / 8,
+    .header.cf = LV_IMG_CF_TRUE_COLOR,          /*Set the color format*/
+    .data = my_img_data,
+};
+
+```
+
+If the color format is `LV_IMG_CF_TRUE_COLOR_ALPHA` you can set `data_size` like `80 * 60 * LV_IMG_PX_SIZE_ALPHA_BYTE`.
+
+Another (possibly simpler) option to create and display an image at run-time is to use the [Canvas](/widgets/core/canvas) object.
+
+### Use images
+
+The simplest way to use an image in LVGL is to display it with an [lv_img](/widgets/core/img) object:
+
+```c
+lv_obj_t * icon = lv_img_create(lv_scr_act(), NULL);
+
+/*From variable*/
+lv_img_set_src(icon, &my_icon_dsc);
+
+/*From file*/
+lv_img_set_src(icon, "S:my_icon.bin");
+```
+
+If the image was converted with the online converter, you should use `LV_IMG_DECLARE(my_icon_dsc)` to declare the image in the file where you want to use it.
+
+
+## Image decoder
+As you can see in the [Color formats](#color-formats) section, LVGL supports several built-in image formats. In many cases, these will be all you need. LVGL doesn't directly support, however, generic image formats like PNG or JPG.
+
+To handle non-built-in image formats, you need to use external libraries and attach them to LVGL via the *Image decoder* interface.
+
+The image decoder consists of 4 callbacks:
+- **info** get some basic info about the image (width, height and color format).
+- **open** open the image: either store the decoded image or set it to `NULL` to indicate the image can be read line-by-line.
+- **read** if *open* didn't fully open the image this function should give some decoded data (max 1 line) from a given position.
+- **close** close the opened image, free the allocated resources.
+
+You can add any number of image decoders. When an image needs to be drawn, the library will try all the registered image decoders until it finds one which can open the image, i.e. one which knows that format.
+
+The `LV_IMG_CF_TRUE_COLOR_...`, `LV_IMG_INDEXED_...` and `LV_IMG_ALPHA_...` formats (essentially, all non-`RAW` formats) are understood by the built-in decoder.
+
+### Custom image formats
+
+The easiest way to create a custom image is to use the online image converter and set `Raw`, `Raw with alpha` or `Raw with chroma-keyed` format. It will just take every byte of the binary file you uploaded and write it as the image "bitmap". You then need to attach an image decoder that will parse that bitmap and generate the real, renderable bitmap.
+
+`header.cf` will be `LV_IMG_CF_RAW`, `LV_IMG_CF_RAW_ALPHA` or `LV_IMG_CF_RAW_CHROME_KEYED` accordingly. You should choose the correct format according to your needs: fully opaque image, use alpha channel or use chroma keying.
+
+After decoding, the *raw* formats are considered *True color* by the library. In other words, the image decoder must decode the *Raw* images to *True color* according to the format described in [#color-formats](Color formats) section.
+
+If you want to create a custom image, you should use `LV_IMG_CF_USER_ENCODED_0..7` color formats. However, the library can draw the images only in *True color* format (or *Raw* but finally it's supposed to be in *True color* format).
+The `LV_IMG_CF_USER_ENCODED_...` formats are not known by the library and therefore they should be decoded to one of the known formats from [#color-formats](Color formats) section.
+It's possible to decode the image to a non-true color format first (for example: `LV_IMG_INDEXED_4BITS`) and then call the built-in decoder functions to convert it to *True color*.
+
+With *User encoded* formats, the color format in the open function (`dsc->header.cf`) should be changed according to the new format.
+
+
+### Register an image decoder
+
+Here's an example of getting LVGL to work with PNG images.
+
+First, you need to create a new image decoder and set some functions to open/close the PNG files. It should looks like this:
+
+```c
+/*Create a new decoder and register functions */
+lv_img_decoder_t * dec = lv_img_decoder_create();
+lv_img_decoder_set_info_cb(dec, decoder_info);
+lv_img_decoder_set_open_cb(dec, decoder_open);
+lv_img_decoder_set_close_cb(dec, decoder_close);
+
+
+/**
+ * Get info about a PNG image
+ * @param decoder pointer to the decoder where this function belongs
+ * @param src can be file name or pointer to a C array
+ * @param header store the info here
+ * @return LV_RES_OK: no error; LV_RES_INV: can't get the info
+ */
+static lv_res_t decoder_info(lv_img_decoder_t * decoder, const void * src, lv_img_header_t * header)
+{
+  /*Check whether the type `src` is known by the decoder*/
+  if(is_png(src) == false) return LV_RES_INV;
+
+  /* Read the PNG header and find `width` and `height` */
+  ...
+
+  header->cf = LV_IMG_CF_RAW_ALPHA;
+  header->w = width;
+  header->h = height;
+}
+
+/**
+ * Open a PNG image and return the decided image
+ * @param decoder pointer to the decoder where this function belongs
+ * @param dsc pointer to a descriptor which describes this decoding session
+ * @return LV_RES_OK: no error; LV_RES_INV: can't get the info
+ */
+static lv_res_t decoder_open(lv_img_decoder_t * decoder, lv_img_decoder_dsc_t * dsc)
+{
+
+  /*Check whether the type `src` is known by the decoder*/
+  if(is_png(src) == false) return LV_RES_INV;
+
+  /*Decode and store the image. If `dsc->img_data` is `NULL`, the `read_line` function will be called to get the image data line-by-line*/
+  dsc->img_data = my_png_decoder(src);
+
+  /*Change the color format if required. For PNG usually 'Raw' is fine*/
+  dsc->header.cf = LV_IMG_CF_...
+
+  /*Call a built in decoder function if required. It's not required if`my_png_decoder` opened the image in true color format.*/
+  lv_res_t res = lv_img_decoder_built_in_open(decoder, dsc);
+
+  return res;
+}
+
+/**
+ * Decode `len` pixels starting from the given `x`, `y` coordinates and store them in `buf`.
+ * Required only if the "open" function can't open the whole decoded pixel array. (dsc->img_data == NULL)
+ * @param decoder pointer to the decoder the function associated with
+ * @param dsc pointer to decoder descriptor
+ * @param x start x coordinate
+ * @param y start y coordinate
+ * @param len number of pixels to decode
+ * @param buf a buffer to store the decoded pixels
+ * @return LV_RES_OK: ok; LV_RES_INV: failed
+ */
+lv_res_t decoder_built_in_read_line(lv_img_decoder_t * decoder, lv_img_decoder_dsc_t * dsc, lv_coord_t x,
+                                                  lv_coord_t y, lv_coord_t len, uint8_t * buf)
+{
+   /*With PNG it's usually not required*/
+
+   /*Copy `len` pixels from `x` and `y` coordinates in True color format to `buf` */
+
+}
+
+/**
+ * Free the allocated resources
+ * @param decoder pointer to the decoder where this function belongs
+ * @param dsc pointer to a descriptor which describes this decoding session
+ */
+static void decoder_close(lv_img_decoder_t * decoder, lv_img_decoder_dsc_t * dsc)
+{
+  /*Free all allocated data*/
+
+  /*Call the built-in close function if the built-in open/read_line was used*/
+  lv_img_decoder_built_in_close(decoder, dsc);
+
+}
+
+```
+
+So in summary:
+- In `decoder_info`, you should collect some basic information about the image and store it in `header`.
+- In `decoder_open`, you should try to open the image source pointed by `dsc->src`. Its type is already in `dsc->src_type == LV_IMG_SRC_FILE/VARIABLE`.
+If this format/type is not supported by the decoder, return `LV_RES_INV`.
+However, if you can open the image, a pointer to the decoded *True color* image should be set in `dsc->img_data`.
+If the format is known but you don't want to decode the entire image (e.g. no memory for it) set `dsc->img_data = NULL` to call `read_line` to get the pixels.
+- In `decoder_close` you should free all the allocated resources.
+- `decoder_read` is optional. Decoding the whole image requires extra memory and some computational overhead.
+However, if can decode one line of the image without decoding the whole image, you can save memory and time.
+To indicate that the *line read* function should be used, set `dsc->img_data = NULL` in the open function.
+
+
+### Manually use an image decoder
+
+LVGL will use the registered image decoder automatically if you try and draw a raw image (i.e. using the `lv_img` object) but you can use them manually too. Create a `lv_img_decoder_dsc_t` variable to describe the decoding session and call `lv_img_decoder_open()`.
+
+```c
+
+lv_res_t res;
+lv_img_decoder_dsc_t dsc;
+res = lv_img_decoder_open(&dsc, &my_img_dsc, LV_COLOR_WHITE);
+
+if(res == LV_RES_OK) {
+  /*Do something with `dsc->img_data`*/
+  lv_img_decoder_close(&dsc);
+}
+
+```
+
+
+## Image caching
+Sometimes it takes a lot of time to open an image.
+Continuously decoding a PNG image or loading images from a slow external memory would be inefficient and detrimental to the user experience.
+
+Therefore, LVGL caches a given number of images. Caching means some images will be left open, hence LVGL can quickly access them from `dsc->img_data` instead of needing to decode them again.
+
+Of course, caching images is resource-intensive as it uses more RAM (to store the decoded image). LVGL tries to optimize the process as much as possible (see below), but you will still need to evaluate if this would be beneficial for your platform or not. If you have a deeply embedded target which decodes small images from a relatively fast storage medium, image caching may not be worth it.
+
+### Cache size
+The number of cache entries can be defined in `LV_IMG_CACHE_DEF_SIZE` in *lv_conf.h*. The default value is 1 so only the most recently used image will be left open.
+
+The size of the cache can be changed at run-time with `lv_img_cache_set_size(entry_num)`.
+
+### Value of images
+When you use more images than cache entries, LVGL can't cache all of the images. Instead, the library will close one of the cached images (to free space).
+
+To decide which image to close, LVGL uses a measurement it previously made of how long it took to open the image. Cache entries that hold slower-to-open images are considered more valuable and are kept in the cache as long as possible.
+
+If you want or need to override LVGL's measurement, you can manually set the *time to open* value in the decoder open function in `dsc->time_to_open = time_ms` to give a higher or lower value. (Leave it unchanged to let LVGL set it.)
+
+Every cache entry has a *"life"* value. Every time an image opening happens through the cache, the *life* value of all entries is decreased to make them older.
+When a cached image is used, its *life* value is increased by the *time to open* value to make it more alive.
+
+If there is no more space in the cache, the entry with the smallest life value will be closed.
+
+### Memory usage
+Note that the cached image might continuously consume memory. For example, if 3 PNG images are cached, they will consume memory while they are open.
+
+Therefore, it's the user's responsibility to be sure there is enough RAM to cache even the largest images at the same time.
+
+### Clean the cache
+Let's say you have loaded a PNG image into a `lv_img_dsc_t my_png` variable and use it in an `lv_img` object. If the image is already cached and you then change the underlying PNG file, you need to notify LVGL to cache the image again. Otherwise, there is no easy way of detecting that the underlying file changed and LVGL will still draw the old image.
+
+To do this, use `lv_img_cache_invalidate_src(&my_png)`. If `NULL` is passed as a parameter, the whole cache will be cleaned.
+
+
+## API
+
+
+### Image buffer
+
+```eval_rst
+
+.. doxygenfile:: lv_img_buf.h
+  :project: lvgl
+
+```

docs/overview/indev.md

@@ -0,0 +1,118 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/indev.md
+```
+# Input devices
+
+An input device usually means:
+- Pointer-like input device like touchpad or mouse
+- Keypads like a normal keyboard or simple numeric keypad
+- Encoders with left/right turn and push options
+- External hardware buttons which are assigned to specific points on the screen
+
+
+``` important:: Before reading further, please read the [Porting](/porting/indev) section of Input devices
+```
+
+## Pointers
+
+Pointer input devices (like a mouse) can have a cursor.
+
+```c
+...
+lv_indev_t * mouse_indev = lv_indev_drv_register(&indev_drv);
+
+LV_IMG_DECLARE(mouse_cursor_icon);                          /*Declare the image file.*/
+lv_obj_t * cursor_obj =  lv_img_create(lv_scr_act(), NULL); /*Create an image object for the cursor */
+lv_img_set_src(cursor_obj, &mouse_cursor_icon);             /*Set the image source*/
+lv_indev_set_cursor(mouse_indev, cursor_obj);               /*Connect the image  object to the driver*/
+
+```
+
+Note that the cursor object should have `lv_obj_set_click(cursor_obj, false)`.
+For images, *clicking* is disabled by default.
+
+## Keypad and encoder
+
+You can fully control the user interface without touchpad or mouse using a keypad or encoder(s). It works similar to the *TAB* key on the PC to select the element in an application or a web page.
+
+### Groups
+
+The objects, you want to control with keypad or encoder, needs to be added to a *Group*.
+In every group, there is exactly one focused object which receives the pressed keys or the encoder actions.
+For example, if a [Text area](/widgets/core/textarea) is focused and you press some letter on a keyboard, the keys will be sent and inserted into the text area.
+Similarly, if a [Slider](/widgets/core/slider) is focused and you press the left or right arrows, the slider's value will be changed.
+
+You need to associate an input device with a group. An input device can send the keys to only one group but, a group can receive data from more than one input device too.
+
+To create a group use `lv_group_t * g = lv_group_create()` and to add an object to the group use `lv_group_add_obj(g, obj)`.
+
+To associate a group with an input device use `lv_indev_set_group(indev, g)`, where `indev` is the return value of `lv_indev_drv_register()`
+
+#### Keys
+There are some predefined keys which have special meaning:
+- **LV_KEY_NEXT** Focus on the next object
+- **LV_KEY_PREV** Focus on the previous object
+- **LV_KEY_ENTER** Triggers `LV_EVENT_PRESSED/CLICKED/LONG_PRESSED` etc. events
+- **LV_KEY_UP** Increase value or move upwards
+- **LV_KEY_DOWN** Decrease value or move downwards
+- **LV_KEY_RIGHT** Increase value or move the the right
+- **LV_KEY_LEFT** Decrease value or move the the left
+- **LV_KEY_ESC**  Close or exit (E.g. close a [Drop down list](/widgets/core/dropdown))
+- **LV_KEY_DEL**  Delete (E.g. a character on the right in a [Text area](/widgets/core/textarea))
+- **LV_KEY_BACKSPACE** Delete a character on the left (E.g. in a [Text area](/widgets/core/textarea))
+- **LV_KEY_HOME** Go to the beginning/top (E.g. in a [Text area](/widgets/core/textarea))
+- **LV_KEY_END** Go to the end (E.g. in a [Text area](/widgets/core/textarea)))
+
+The most important special keys are `LV_KEY_NEXT/PREV`, `LV_KEY_ENTER` and `LV_KEY_UP/DOWN/LEFT/RIGHT`.
+In your `read_cb` function, you should translate some of your keys to these special keys to navigate in the group and interact with the selected object.
+
+Usually, it's enough to use only `LV_KEY_LEFT/RIGHT` because most of the objects can be fully controlled with them.
+
+With an encoder, you should use only `LV_KEY_LEFT`, `LV_KEY_RIGHT`, and `LV_KEY_ENTER`.
+
+#### Edit and navigate mode
+
+Since a keypad has plenty of keys, it's easy to navigate between the objects and edit them using the keypad. But the encoders have a limited number of "keys" and hence it is difficult to navigate using the default options. *Navigate* and *Edit* are created to avoid this problem with the encoders.
+
+In *Navigate* mode, the encoders `LV_KEY_LEFT/RIGHT` is translated to `LV_KEY_NEXT/PREV`. Therefore the next or previous object will be selected by turning the encoder.
+Pressing `LV_KEY_ENTER` will change to *Edit* mode.
+
+In *Edit* mode, `LV_KEY_NEXT/PREV` is usually used to edit the object.
+Depending on the object's type, a short or long press of `LV_KEY_ENTER` changes back to *Navigate* mode.
+Usually, an object which can not be pressed (like a [Slider](/widgets/core/slider)) leaves *Edit* mode on short click. But with objects where short click has meaning (e.g. [Button](/widgets/core/btn)), a long press is required.
+
+#### Default group
+Interactive widgets - such as buttons, checkboxes, sliders, etc - can be automatically added to a default group.
+Just create a group with `lv_group_t * g = lv_group_create();` and set the default group with `lv_group_set_default(g);`
+
+Don't forget to assign the input device(s) to the default group with ` lv_indev_set_group(my_indev, g);`.
+
+### Styling
+
+If an object is focused either by clicking it via touchpad, or focused via an encoder or keypad it goes to `LV_STATE_FOCUSED`. Hence focused styles will be applied on it. 
+
+If the object goes to edit mode it goes to `LV_STATE_FOCUSED | LV_STATE_EDITED` state so these style properties will be shown. 
+
+For a more detaild description read the [Style](https://docs.lvgl.io/v7/en/html/overview/style.html) section.
+
+## API
+
+
+### Input device
+
+```eval_rst
+
+.. doxygenfile:: lv_indev.h
+  :project: lvgl
+
+```
+
+### Groups
+
+```eval_rst
+
+.. doxygenfile:: lv_group.h
+  :project: lvgl
+
+```

docs/overview/index.md

@@ -0,0 +1,32 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/index.md
+```
+
+# Overview
+
+
+```eval_rst
+
+.. toctree::
+   :maxdepth: 2
+
+   object
+   coords
+   style
+   style-props
+   scroll
+   layer
+   event
+   indev
+   display
+   color
+   font
+   image
+   file-system
+   animation
+   timer
+   drawing
+   new_widget
+```
+

docs/overview/layer.md

@@ -0,0 +1,60 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/layer.md
+```
+
+# Layers
+
+## Order of creation
+
+By default, LVGL draws new objects on top of old objects.
+
+For example, assume we added a button to a parent object named button1 and then another button named button2. Then button1 (with its child object(s)) will be in the background and can be covered by button2 and its children.
+
+
+![](/misc/layers.png "Creating graphical objects in Littlev Graphics Library")  
+
+```c
+/*Create a screen*/
+lv_obj_t * scr = lv_obj_create(NULL, NULL);
+lv_scr_load(scr);          /*Load the screen*/
+
+/*Create 2 buttons*/
+lv_obj_t * btn1 = lv_btn_create(scr, NULL);         /*Create a button on the screen*/
+lv_btn_set_fit(btn1, true, true);                   /*Enable to automatically set the size according to the content*/
+lv_obj_set_pos(btn1, 60, 40);              	   /*Set the position of the button*/
+
+lv_obj_t * btn2 = lv_btn_create(scr, btn1);         /*Copy the first button*/
+lv_obj_set_pos(btn2, 180, 80);                    /*Set the position of the button*/
+
+/*Add labels to the buttons*/
+lv_obj_t * label1 = lv_label_create(btn1, NULL);	/*Create a label on the first button*/
+lv_label_set_text(label1, "Button 1");          	/*Set the text of the label*/
+
+lv_obj_t * label2 = lv_label_create(btn2, NULL);  	/*Create a label on the second button*/
+lv_label_set_text(label2, "Button 2");            	/*Set the text of the label*/
+
+/*Delete the second label*/
+lv_obj_del(label2);
+```
+
+## Bring to the foreground
+
+There are several ways to bring an object to the foreground:
+- Use `lv_obj_set_top(obj, true)`. If `obj` or any of its children is clicked, then LVGL will automatically bring the object to the foreground.
+It works similarly to a typical GUI on a PC. When a window in the background is clicked, it will come to the foreground automatically.
+- Use `lv_obj_move_foreground(obj)` to explicitly tell the library to bring an object to the foreground. Similarly, use `lv_obj_move_background(obj)` to move to the background.
+- When `lv_obj_set_parent(obj, new_parent)` is used, `obj` will be on the foreground on the `new_parent`.
+
+
+## Top and sys layers
+
+LVGL uses two special layers named as `layer_top` and `layer_sys`.
+Both are visible and common on all screens of a display. **They are not, however, shared among multiple physical displays.** The `layer_top` is always on top of the default screen (`lv_scr_act()`), and `layer_sys` is on top of `layer_top`.
+
+The `layer_top` can be used by the user to create some content visible everywhere. For example, a menu bar, a pop-up, etc. If the `click` attribute is enabled, then `layer_top` will absorb all user click and acts as a modal.
+```c
+lv_obj_set_click(lv_layer_top(), true);
+```
+
+The `layer_sys` is also used for similar purposes on LVGL. For example, it places the mouse cursor above all layers to be sure it's always visible.

docs/overview/new_widget.md

@@ -0,0 +1,7 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/new_widget.md
+```
+
+# New widget
+

docs/overview/object.md

@@ -0,0 +1,218 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/object.md
+```
+# Objects
+
+In LVGL the **basic building blocks** of a user interface are the objects, also called *Widgets*.
+For example a [Button](/widgets/core/btn), [Label](/widgets/core/label), [Image](/widgets/core/img), [List](/widgets/extra/list), [Chart](/widgets/extra/chart) or [Text area](/widgets/core/textarea).
+
+You can see all the [Object types](/widgets/index) here.
+
+All objects are referenced using an `lv_obj_t` pointer as a handle. This pointer can later be used to set or get the attributes of the object.
+
+## Attributes
+
+### Basic attributes
+
+All object types share some basic attributes:
+- Position
+- Size
+- Parent
+- Styles
+- Event handlers
+- Etc
+
+You can set/get these attributes with `lv_obj_set_...` and `lv_obj_get_...` functions. For example:
+
+```c
+/*Set basic object attributes*/
+lv_obj_set_size(btn1, 100, 50);	  /*Set a button's size*/
+lv_obj_set_pos(btn1, 20,30);      /*Set a button's position*/
+```
+
+To see all the available functions visit the [Base object's documentation](/widgets/obj).
+
+### Specific attributes
+
+The object types have special attributes too. For example, a slider has
+- Minimum and maximum values
+- Current value
+
+For these special attributes, every object type may have unique API functions. For example for a slider:
+
+```c
+/*Set slider specific attributes*/
+lv_slider_set_range(slider1, 0, 100);	   				/*Set the min. and max. values*/
+lv_slider_set_value(slider1, 40, LV_ANIM_ON);		/*Set the current value (position)*/
+```
+
+The API of the widgets is described in their [Documentation](/widgets/index) but you can also check the respective header files (e.g. *widgets/lv_slider.h*)
+
+## Working mechanisms
+
+### Parent-child structure
+
+A parent object can be considered as the container of its children. Every object has exactly one parent object (except screens), but a parent can have any number of children.
+There is no limitation for the type of the parent but, there are typical parent (e.g. button) and typical child (e.g. label) objects.
+
+### Moving together
+
+If the position of the parent changes the children will move with the parent.
+Therefore all positions are relative to the parent.
+
+![](/misc/par_child1.png "Objects are moving together 1")
+
+```c
+lv_obj_t * parent = lv_obj_create(lv_scr_act());   /*Create a parent object on the current screen*/
+lv_obj_set_size(parent, 100, 80);	                 /*Set the size of the parent*/
+
+lv_obj_t * obj1 = lv_obj_create(parent);	         /*Create an object on the previously created parent object*/
+lv_obj_set_pos(obj1, 10, 10);	                     /*Set the position of the new object*/
+```
+
+Modify the position of the parent:
+
+![](/misc/par_child2.png "Graphical objects are moving together 2")  
+
+```c
+lv_obj_set_pos(parent, 50, 50);	/*Move the parent. The child will move with it.*/
+```
+
+(For simplicity the adjusting of colors of the objects is not shown in the example.)
+
+### Visibility only on the parent
+
+If a child is partially or fully out of its parent then the parts outside will not be visible.
+
+![](/misc/par_child3.png "A graphical object is visible on its parent")  
+
+```c
+lv_obj_set_x(obj1, -30);	/*Move the child a little bit off the parent*/
+```
+
+### Create and delete objects
+
+In LVGL objects can be created and deleted dynamically in run time. It means only the currently created (existing) objects consume RAM.
+
+This allows for the creation of a screen just when a button is clicked to open it, and for deletion of screens when a new screen is loaded.
+
+UIs can be created based on the current environment of the device. For example one can create meters, charts, bars and sliders based on the currently attached sensors.
+ 
+Every widget has its own **create** function with a prototype like this:
+```c
+lv_obj_t * lv_<widget>_create(lv_obj_t * parent, <other paramaters if any>);
+```
+
+In most of the cases the create functions have only a *parent* parameter that tells on which object create the new widget.
+
+The return value is a pointer to the created object with `lv_obj_t *` type.
+
+
+There is a common **delete** function for all object types. It deletes the object and all of its children.
+
+```c
+void lv_obj_del(lv_obj_t * obj);
+```
+
+`lv_obj_del` will delete the object immediately.
+If for any reason you can't delete the object immediately you can use `lv_obj_del_async(obj)` that will perform the deletion on the next call of `lv_timer_handler()`.
+This is useful e.g. if you want to delete the parent of an object in the child's `LV_EVENT_DELETE` handler.
+
+You can remove all the children of an object (but not the object itself) using `lv_obj_clean(obj)`.
+
+
+## Screens
+
+### Create screens
+The screens are special objects which have no parent object. So they can be created like:
+```c
+lv_obj_t * scr1 = lv_obj_create(NULL);
+```
+
+Screens can be created with any object type. For example, a [Base object](/widgets/obj) or an image to make a wallpaper.
+
+### Get the active screen
+There is always an active screen on each display. By default, the library creates and loads a "Base object" as a screen for each display.
+
+To get the currently active screen use the `lv_scr_act()` function. 
+
+### Load screens
+
+To load a new screen, use `lv_scr_load(scr1)`.
+
+### Layers
+There are two automatically generated layers:
+- top layer
+- system layer
+
+They are independent of the screens and they will be shown on every screen. The *top layer* is above every object on the screen and the *system layer* is above the *top layer* too.
+You can add any pop-up windows to the *top layer* freely. But, the *system layer* is restricted to system-level things (e.g. mouse cursor will be placed here in `lv_indev_set_cursor()`).
+
+The `lv_layer_top()` and `lv_layer_sys()` functions return pointers to the top and system layers respectively.
+
+Read the [Layer overview](/overview/layer) section to learn more about layers.
+
+
+#### Load screen with animation
+
+A new screen can be loaded with animation too using `lv_scr_load_anim(scr, transition_type, time, delay, auto_del)`. The following transition types exist:
+- `LV_SCR_LOAD_ANIM_NONE`: switch immediately after `delay` milliseconds
+- `LV_SCR_LOAD_ANIM_OVER_LEFT/RIGHT/TOP/BOTTOM` move the new screen over the current towards the given direction
+- `LV_SCR_LOAD_ANIM_MOVE_LEFT/RIGHT/TOP/BOTTOM` move both the current and new screens towards the given direction
+- `LV_SCR_LOAD_ANIM_FADE_ON` fade the new screen over the old screen
+
+Setting `auto_del` to `true` will automatically delete the old screen when the animation is finished.
+
+The new screen will become active (returned by `lv_scr_act()`) when the animations starts after `delay` time.
+
+### Handling multiple displays
+Screens are created on the currently selected *default display*.
+The *default display* is the last registered display with `lv_disp_drv_register` or you can explicitly select a new default display using `lv_disp_set_default(disp)`.
+
+`lv_scr_act()`, `lv_scr_load()` and `lv_scr_load_anim()` operate on the default screen.
+
+Visit [Multi-display support](/overview/display) to learn more.
+
+## Parts
+
+The widgets are built from multiple parts. For example a [Base object](/widgets/obj) uses the main and scrollbar parts but a [Slider](/widgets/core/slider) uses the main, the indicator and the knob parts. 
+Parts are similar to *pseudo elements* in CSS.
+
+The following predefined parts exist in LVGL:
+- `LV_PART_MAIN` A background like rectangle*/``
+- `LV_PART_SCROLLBAR`  The scrollbar(s)
+- `LV_PART_INDICATOR` Indicator, e.g. for slider, bar, switch, or the tick box of the checkbox
+- `LV_PART_KNOB` Like a handle to grab to adjust the value*/
+- `LV_PART_SELECTED` Indicate the currently selected option or section
+- `LV_PART_ITEMS` Used if the widget has multiple similar elements (e.g. tabel cells)*/
+- `LV_PART_TICKS` Ticks on scales e.g. for a chart or meter
+- `LV_PART_CURSOR` Mark a specific place e.g. text area's or chart's cursor
+- `LV_PART_CUSTOM_FIRST` Custom parts can be added from here.
+
+The main purpose of parts to allow styling the "components" of the widgets. 
+Therefore the parts are described in more detail in the [Style overview](/overview/style) section.
+
+## States
+The object can be in a combination of the following states:
+- `LV_STATE_DEFAULT` Normal, released state
+- `LV_STATE_CHECKED` Toggled or checked state
+- `LV_STATE_FOCUSED` Focused via keypad or encoder or clicked via touchpad/mouse 
+- `LV_STATE_FOCUS_KEY` Focused via keypad or encoder but not via touchpad/mouse 
+- `LV_STATE_EDITED` Edit by an encoder
+- `LV_STATE_HOVERED` Hovered by mouse (not supported now)
+- `LV_STATE_PRESSED` Being pressed
+- `LV_STATE_SCROLLED` Being scrolled
+- `LV_STATE_DISABLED` Disabled state
+- `LV_STATE_USER_1` Custom state
+- `LV_STATE_USER_2` Custom state
+- `LV_STATE_USER_3` Custom state
+- `LV_STATE_USER_4` Custom state
+
+The states are usually automatically changed by the library as the user presses, releases, focuses etc an object. 
+However, the states can be changed manually too. 
+To set or clear given state (but leave the other states untouched) use `lv_obj_add/clear_state(obj, LV_STATE_...)`
+In both cases ORed state values can be used as well. E.g. `lv_obj_add_state(obj, part, LV_STATE_PRESSED | LV_PRESSED_CHECKED)`.
+
+To learn more about the states read the related section of the [Style overview](/overview/style).
+

docs/overview/scroll.md

@@ -0,0 +1,169 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/scroll.md
+```
+# Scroll
+
+## Overview
+In LVGL scrolling works very intuitively: if an object is out of its parent content area (the size without paddings), the parent becomes scrollable and scrollbar(s) will appear. That's it.
+
+Any object can be scrollable including `lv_obj_t`, `lv_img`, `lv_btn`, `lv_meter`, etc
+
+The object can either be scrolled either horizontally or vertically in one stroke; diagonal scrolling is not possible.
+
+### Scrollbar
+ 
+#### Mode
+The scrollbars are displayed according to the set `mode`. The following `mode`s exist:
+- `LV_SCROLLBAR_MODE_OFF`  Never show the scrollbars
+- `LV_SCROLLBAR_MODE_ON`  Always show the scrollbars
+- `LV_SCROLLBAR_MODE_ACTIVE` Show scroll bars while object is being scrolled
+- `LV_SCROLLBAR_MODE_AUTO`  Show scroll bars when the content is large enough to be scrolled
+
+`lv_obj_set_scrollbar_mode(obj, LV_SCROLLBAR_MODE_...)` set the scrollbar mode on an object.
+
+
+#### Styling
+The scrollbars have their own dedicated part, called `LV_PART_SCROLLBAR`. For example a scrollbar can turned to red like this:
+```c
+static lv_style_t style_red;
+lv_style_init(&style_red);
+lv_style_set_bg_color(&style_red, lv_color_red());
+
+...
+
+lv_obj_add_style(obj, &style_red, LV_PART_SCROLLBAR);
+```
+
+The object goes to `LV_STATE_SCROLLED` state while it's being scrolled. It allows adding different style to the scrollbar or the object itself when scrolled.
+This code makes the scrollbar blue when the object is scrolled:
+```c
+static lv_style_t style_blue;
+lv_style_init(&style_blue);
+lv_style_set_bg_color(&style_red, lv_color_blue());
+
+...
+
+lv_obj_add_style(obj, &style_blue, LV_STATE_SCROLLED | LV_PART_SCROLLBAR);
+```
+
+### Events
+The following events are related to scrolling:
+- `LV_EVENT_SCROLL_BEGIN` Scrolling begins
+- `LV_EVENT_SCROLL_END` Scrolling ends
+- `LV_EVENT_SCROLL` Scroll happened. Triggered on every position change.
+Scroll events
+
+## Basic example
+TODO
+
+## Features of scrolling
+
+Besides managing "normal" scrolling there are many interesting and useful additional features too.
+
+
+### Scrollable
+
+It's possible to make an object non-scrollable with `lv_obj_clear_flag(obj, LV_OBJ_FLAG_SCROLLABLE)`.
+
+Non-scrollable object can still propagate the scrolling (chain) to the parents.
+
+The direction in which scrolling can happen can be controlled by `lv_obj_set_scroll_dir(obj, LV_DIR_...)`.
+The following values are possible for the direction:
+- `LV_DIR_TOP` only scroll up
+- `LV_DIR_LEFT` only scroll left
+- `LV_DIR_BOTTOM` only scroll down
+- `LV_DIR_RIGHT` only scroll right
+- `LV_DIR_HOR` only scroll horizontally
+- `LV_DIR_TOP` only scroll vertically
+- `LV_DIR_ALL` scroll any directions
+
+OR-ed values are also possible. E.g. `LV_DIR_TOP | LV_DIR_LEFT`.
+
+
+### Scroll chain
+If an object can't be scrolled further (e.g. it's content has reached the bottom most position) the scrolling is propagated to it's parent. If the parent an be scrolled in that direction than it will be scrolled instead.
+It propagets to the grandparent and grand-grandparents too.
+
+The propagation on scrolling is called "scroll chaining" and it can be enabled/disabled with the `LV_OBJ_FLAG_SCROLL_CHAIN` flag. 
+If chaining is disabled the propagation stops on the object and the parent(s) won't be scrolled.
+
+### Scroll momentum
+When the user scrolls an object and releases it, LVGL can emulate a momentum for the scrolling. It's like the object was thrown and scrolling slows down smoothly. 
+
+The scroll momentum can be enabled/disabled with the `LV_OBJ_FLAG_SCROLL_MOMENTUM` flag. 
+
+### Elastic scroll
+Normally the content can't be scrolled inside the object. That is the top side of the content can't be below the top side of the object. 
+
+However, with `LV_OBJ_FLAG_SCROLL_ELASTIC` a fancy effect can be added when the user "over-scrolls" the content. The scrolling slows down, and the content can be scrolled inside the object. 
+When the object is released the content scrolled in it will be animated back to the valid position. 
+
+### Snapping
+The children of an object can be snapped according to specific rules when scrolling ends. Children can be made snappable individually with the `LV_OBJ_FLAG_SNAPABLE` flag. (Note misspelling of the flag name: your code needs to spell it with one P.)
+The object can align the snapped children in 4 ways: 
+- `LV_SCROLL_SNAP_NONE` Snapping is disabled. (default)
+- `LV_SCROLL_SNAP_START` Align the children to the left/top side of the scrolled object
+- `LV_SCROLL_SNAP_END` Align the children to the right/bottom side of the scrolled object
+- `LV_SCROLL_SNAP_CENTER` Align the children to the center of the scrolled object
+  
+The alignment can be set with `lv_obj_set_scroll_snap_x/y(obj, LV_SCROLL_SNAP_...)`:
+ 
+Under the hood the following happens:
+1. User scrolls an object and releases the screen
+2. LVGL calculates where the scroll would end considering scroll momentum
+3. LVGL finds the nearest scroll point
+4. LVGL scrolls to the snap point with an animation
+ 
+### Scroll one
+The "scroll one" feature tells LVGL to allow scrolling only one snappable child at a time. 
+So this requires to make the children snappable (LV_OBJ_FLAG_SNAPABLE spelled with one P in code) and and set a scroll snap alignment different from `LV_SCROLL_SNAP_NONE`.
+
+This feature can be enabled by the `LV_OBJ_FLAG_SCROLL_ONE` flag.
+
+### Scroll on focus
+Imagine that there a lot of objects in a group that are on scrollable object. Pressing the "Tab" button focuses the next object but it might be out of the visible area of the scrollable object. 
+If the "scroll on focus" features is enabled LVGL will automatically scroll to the objects to bring the children into the view. 
+The scrolling happens recursively therefore even nested scrollable object are handled properly. 
+The object will be scrolled to the view even if it's on a different page of a tabview. 
+
+## Scroll manually
+The following API functions allow to manually scroll objects:
+- `lv_obj_scroll_by(obj, x, y, LV_ANIM_ON/OFF)` scroll by `x` and `y` values
+- `lv_obj_scroll_to(obj, x, y, LV_ANIM_ON/OFF)` scroll to bring the given coordinate to the top left corner
+- `lv_obj_scroll_to_x(obj, x, LV_ANIM_ON/OFF)` scroll to bring the given coordinate to the left side
+- `lv_obj_scroll_to_y(obj, y, LV_ANIM_ON/OFF)` scroll to bring the given coordinate to the left side
+
+## Self size
+
+Self size is a property of an object. Normally, the user shouldn't use this parameter but if a custom widget is created it might be useful.
+
+In short, self size tell the size of the content. To understand it better take the example of a table. 
+Let's say it has 10 rows each with 50 px height. So the total height of the content is 500 px. In other words the "self height" is 500 px. 
+If the user sets only 200 px height for the table LVGL will see that the self size is larger and make the table scrollable.
+
+It means not only the children can make an object scrollable but a larger self size too.
+
+LVGL uses the `LV_EVENT_GET_SELF_SIZE` event to get the self size of an object. Here is an example to see how to handle the event
+```c
+if(event_code == LV_EVENT_GET_SELF_SIZE) {
+	lv_point_t * p = lv_event_get_param(e);
+  
+  //If x or y < 0 then it doesn't neesd to be calculated now
+  if(p->x >= 0) {
+    p->x = 200;	//Set or calculate the self width
+  }
+  
+  if(p->y >= 0) {
+    p->y = 50;	//Set or calculate the self height
+  }
+}
+```
+
+## Examples
+
+```eval_rst
+
+.. include:: ../../examples/scroll/index.rst
+
+```

docs/overview/style-props.md

@@ -0,0 +1,903 @@
+# Style properties
+
+## Size and position
+TODO
+
+
+### width
+Sets the width of object. Pixel, percentage and `LV_SIZE_CONTENT` values can be used. Percentage values are relative to the width of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### min_width
+Sets a minimal width. Pixel and percentage values can be used. Percentage values are relative to the width of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### max_width
+Sets a maximal width. Pixel and percentage values can be used. Percentage values are relative to the width of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### height
+Sets the height of object. Pixel, percentage and `LV_SIZE_CONTENT` can be used. Percentage values are relative to the height of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### min_height
+Sets a minimal height. Pixel and percentage values can be used. Percentage values are relative to the width of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### max_height
+Sets a maximal height. Pixel and percentage values can be used. Percentage values are relative to the height of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### x
+Set the X coordinate of the object considering the set `align`. Pixel and percentage values can be used. Percentage values are relative to the width of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### y
+Set the Y coordinate of the object considering the set `align`. Pixel and percentage values can be used. Percentage values are relative to the height of the parent's content area.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### align
+Set the alignment which determines from which point of the parent the X and Y coordinates should be interpreted. The possible values are: `LV_ALIGN_TOP_LEFT/MID/RIGHT`, `LV_ALIGN_BOTTOM_LEFT/MID/RIGHT`, `LV_ALIGN_LEFT/RIGHT_MID`, `LV_ALIGN_CENTER`
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### transform_width
+Make the object wider on both sides with this value. Pixel and percentage (with `lv_pct(x)`) values can be used. Percentage values are relative to the object's width.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### transform_height
+Make the object higher on both sides with this value. Pixel and percentage (with `lv_pct(x)`) values can be used. Percentage values are relative to the object's height.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### translate_x
+Move the object with this value in X direction. Applied after layouts, aligns and other positioning. Pixel and percentage (with `lv_pct(x)`) values can be used. Percentage values are relative to the object's width.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### translate_y
+Move the object with this value in Y direction. Applied after layouts, aligns and other positioning. Pixel and percentage (with `lv_pct(x)`) values can be used. Percentage values are relative to the object's height.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### transform_zoom
+Zoom image-like objects. Multiplied with the zoom set on the object. The value 256 (or `LV_IMG_ZOOM_NONE`) means normal size, 128 half size, 512 double size, and so on
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### transform_angle
+ Rotate image-like objects. Added to the rotation set on the object. The value is interpreted in 0.1 degree unit. E.g. 45 deg. = 450 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Padding
+TODO
+
+
+### pad_top
+Sets the padding on the top. It makes the content area smaller in this direction.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### pad_bottom
+Sets the padding on the bottom. It makes the content area smaller in this direction.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### pad_left
+Sets the padding on the left. It makes the content area smaller in this direction.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### pad_right
+Sets the padding on the right. It makes the content area smaller in this direction.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### pad_row
+Sets the padding between the rows. Used by the layouts.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### pad_column
+Sets the padding between the columns. Used by the layouts.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Miscellaneous
+TODO
+
+
+### radius
+Set the radius on every corner. The value is interpreted in pixel (>= 0) or `LV_RADIUS_CIRCLE` for max. radius
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### clip_corner
+Enable to clip the overflowed content on the rounded corner. Can be `true` or `false`.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### opa
+Scale down all opacity values of the object by this factor. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### color_filter_dsc
+Mix a color to all colors of the object.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### color_filter_opa
+The intensity of mixing of color filter.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### anim_time
+The animation time in milliseconds. Its meaning is widget specific. E.g. blink time of the cursor on the text area or scroll time of a roller. See the widgets' documentation to learn more.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### anim_speed
+The animation speed in pixel/sec. Its meaning is widget specific. E.g. scroll speed of label. See the widgets' documentation to learn more.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### transition
+An initialized `lv_style_transition_dsc_t` to describe a transition.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### blend_mode
+Describes how to blend the colors to the background. The possible values are `LV_BLEND_MODE_NORMAL/ADDITIVE/SUBTRACTIVE`
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### layout
+Set the layout if the object. The children will be repositioned and resized according to the policies set for the layout. For the possible values see the documentation of the layouts.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### base_dir
+Set the base direction of the object. The possible values are `LV_BIDI_DIR_LTR/RTL/AUTO`.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Background
+TODO
+
+
+### bg_color
+Set the background color of the object.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_opa
+Set the opacity of the background. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_grad_color
+Set the gradient color of the background. Used only if `grad_dir` is not `LV_GRAD_DIR_NONE`
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_grad_dir
+Set the direction of the gradient of the background. The possible values are `LV_GRAD_DIR_NONE/HOR/VER`.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_main_stop
+Set the point from which the background color should start for gradients. 0 means to top/left side, 255 the bottom/right side, 128 the center, and so on
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_grad_stop
+Set the point from which the background's gradient color should start. 0 means to top/left side, 255 the bottom/right side, 128 the center, and so on
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_img_src
+Set a background image. Can be a pointer to `lv_img_dsc_t`, a path to a file or an `LV_SYMBOL_...`
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_img_opa
+Set the opacity of the background image. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_img_recolor
+Set a color to mix to the background image.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_img_recolor_opa
+Set the intensity of background image recoloring. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means no mixing, 256, `LV_OPA_100` or `LV_OPA_COVER` means full recoloring, other values or LV_OPA_10, LV_OPA_20, etc are interpreted proportionally.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### bg_img_tiled
+If enabled the background image will be tiled. The possible values are `true` or `false`.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Border
+TODO
+
+
+### border_color
+Set the color of the border
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### border_opa
+Set the opcitiy of the border. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### border_width
+Set the width of the border. Only pixel values can be used.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### border_side
+Set which side(s) the border should be drawn. The possible values are `LV_BORDER_SIDE_NONE/TOP/BOTTOM/LEFT/RIGHT/INTERNAL`. OR-ed calues an be used as well, e.g. `LV_BORDER_SIDE_TOP | LV_BORDER_SIDE_LEFT`.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### border_post
+Sets wheter the border should be drawn before or after the children ar drawn. `true`: after children, `false`: before children
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Text
+TODO
+
+
+### text_color
+Sets the color of the text.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### text_opa
+Set the opacity of the text. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### text_font
+Set the font of the text (a pointer `lv_font_t *`). 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### text_letter_space
+Set the letter space in pixels
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### text_line_space
+Set the line space in pixels.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### text_decor
+Set decoration for the text. The possible values are `LV_TEXT_DECOR_NONE/UNDERLINE/STRIKETHROUGH`. OR-ed values can be used as well.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### text_align
+Set how to align the lines of the text. Note that it doesn't align the object itself, only the lines inside the object. The possible values are `LV_TEXT_ALIGN_LEFT/CENTER/RIGHT/AUTO`. `LV_TEXT_ALIGN_AUTO` detect the text base direction and uses left or right alignment accordingly
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Image
+TODO
+
+
+### img_opa
+Set the opacity of an image. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### img_recolor
+Set color to mix to the image.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### img_recolor_opa
+Set the intensity of the color mixing. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Outline
+TODO
+
+
+### outline_width
+Set the width of the outline in pixels. 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### outline_color
+Set the color of the outline.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### outline_opa
+Set the opacity of the outline. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### outline_pad
+Set the padding of the outline, i.e. the gap between object and the outline.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Shadow
+TODO
+
+
+### shadow_width
+Set the width of the shadow in pixels. The value should be >= 0.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### shadow_ofs_x
+Set an offset on the shadow in pixels in X direction. 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### shadow_ofs_y
+Set an offset on the shadow in pixels in Y direction. 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### shadow_spread
+Make the shadow calculation to use a larger or smaller rectangle as base. The value can be in pixel to make the area larger/smaller
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### shadow_color
+Set the color of the shadow
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### shadow_opa
+Set the opacity of the shadow. Value 0, `LV_OPA_0` or `LV_OPA_TRANSP` means fully transparent, 256, `LV_OPA_100` or `LV_OPA_COVER` means fully covering, other values or LV_OPA_10, LV_OPA_20, etc indicate semi-transparency.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Line
+TODO
+
+
+### line_width
+Set the width of the lines in pixel.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### line_dash_width
+Set the width of dashes in pixel. Note that dash works only on horizontal and vertical lines
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### line_dash_gap
+Set the gap between dashes in pixel. Note that dash works only on horizontal and vertical lines
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### line_rounded
+Make the end points of the lines rounded. `true`: rounded, `false`: perpendicular line ending 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### line_color
+Set the color fo the lines.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### line_opa
+Set the opacity of the lines.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+## Arc
+TODO
+
+
+### arc_width
+Set the width (thickness) of the arcs in pixel.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### arc_rounded
+Make the end points of the arcs rounded. `true`: rounded, `false`: perpendicular line ending 
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### arc_color
+Set the color of the arc.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### arc_opa
+Set the opacity of the arcs.
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+
+
+
+### arc_img_src
+Set an image from which the arc will be masked out. It's useful to display complex effects on the arcs. Can be a pointer to `lv_img_dsc_t` or a path to a file
+<ul>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Default</strong> 0</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Inherited</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Layout</strong> No</li>
+<li style='display:inline; margin-right: 20px; margin-left: 0px'><strong>Ext. draw</strong> No</li>
+</ul>
+

docs/overview/style.md

@@ -0,0 +1,318 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/style.md
+```
+# Styles
+
+*Styles* are used to set the appearance of the objects. Styles in lvgl are heavily inspired by CSS. The concept in nutshell is as follows:
+- A style is an `lv_style_t` variable which can hold properties like border width, text color and so on. It's similar to a `class` in CSS. 
+- Styles can be assigned to objects to change their appearance. During the assignment the target part (*pseudo element* in CSS) and target state (*pseudo class*) can be specified.
+For example one can add `style_blue` to the knob of a slider when it's in pressed state.
+- The same style can be used by any number of objects.
+- Styles can be cascaded which means multiple styles can be assigned to an object and each style can have different properties. 
+Therefore not all properties have to be specified in style. LVLG will look for a property until a style defines it or use a default if it's not spefied by any of the styles.
+For example `style_btn` can result in a default gray button and `style_btn_red` can add only a `background-color=red` to overwrite the background color.
+- Later added styles have higher precedence. It means if a property is specified in two styles the later added will be used.
+- Some properties (e.g. text color) can be inherited from the parent(s) if it's not specified in the object. 
+- Objects can have local styles that have higher precedence than "normal" styles.
+- Unlike CSS (where pseudo-classes describe different states, e.g. `:focus`), in LVGL a property is assigned to a given state. 
+- Transitions can be applied when the object changes state.
+
+
+## States
+The objects can be in the combination of the following states:
+- `LV_STATE_DEFAULT` (0x0000) Normal, released state
+- `LV_STATE_CHECKED` (0x0001) Toggled or checked state
+- `LV_STATE_FOCUSED` (0x0002) Focused via keypad or encoder or clicked via touchpad/mouse 
+- `LV_STATE_FOCUS_KEY` (0x0004) Focused via keypad or encoder but not via touchpad/mouse 
+- `LV_STATE_EDITED` (0x0008) Edit by an encoder
+- `LV_STATE_HOVERED` (0x0010) Hovered by mouse (not supported now)
+- `LV_STATE_PRESSED` (0x0020) Being pressed
+- `LV_STATE_SCROLLED` (0x0040) Being scrolled
+- `LV_STATE_DISABLED` (0x0080) Disabled state
+- `LV_STATE_USER_1` (0x1000) Custom state
+- `LV_STATE_USER_2` (0x2000) Custom state
+- `LV_STATE_USER_3` (0x4000) Custom state
+- `LV_STATE_USER_4` (0x8000) Custom state
+  
+The combination states the object can be focused and pressed at the same time. This is represented as `LV_STATE_FOCUSED | LV_STATE_PRESSED`. 
+
+The style can be added to any state and state combination. 
+For example, setting a different background color for default and pressed state. 
+If a property is not defined in a state the best matching state's property will be used. Typically this means the property with `LV_STATE_DEFAULT` is used.˛
+If the property is not set even for the default state the default value will be used. (See later)
+
+But what does the "best matching state's property" really mean? 
+States have a precedence which is shown by their value (see in the above list). A higher value means higher precedence.
+To determine which state's property to use let's take an example. Imagine the background color is defined like this:
+- `LV_STATE_DEFAULT`: white
+- `LV_STATE_PRESSED`: gray
+- `LV_STATE_FOCUSED`: red
+
+1. By the default the object is in default state, so it's a simple case: the property is perfectly defined in the object's current state as white.
+2. When the object is pressed there are 2 related properties: default with white (default is related to every state) and pressed with gray. 
+The pressed state has 0x0020 precedence which is higher than the default state's 0x0000 precedence, so gray color will be used.
+3. When the object is focused the same thing happens as in pressed state and red color will be used. (Focused state has higher precedence than default state).
+4. When the object is focused and pressed both gray and red would work, but the pressed state has higher precedence than focused so gray color will be used.
+5. It's possible to set e.g rose color for `LV_STATE_PRESSED | LV_STATE_FOCUSED`. 
+In this case, this combined state has 0x0020 + 0x0002 = 0x0022 precedence, which is higher than the pressed state's precedence so rose color would be used.
+6. When the object is in checked state there is no property to set the background color for this state. So for lack of a better option, the object remains white from the default state's property.
+
+Some practical notes:
+- The precedence (value) of states is quite intuitive and it's something the user would expect naturally. E.g. if an object is focused the user will still want to see if it's pressed, therefore pressed state has a higher precedence. 
+If the focused state had a higher precedence it would overwrite the pressed color.
+- If you want to set a property for all states (e.g. red background color) just set it for the default state. If the object can't find a property for its current state it will fall back to the default state's property.
+- Use ORed states to describe the properties for complex cases. (E.g. pressed + checked + focused)
+- It might be a good idea to use different style elements for different states. 
+For example, finding background colors for released, pressed, checked + pressed, focused, focused + pressed, focused + pressed + checked, etc states is quite difficult. 
+Instead, for example, use the background color for pressed and checked states and indicate the focused state with a different border color. 
+
+## Cascading styles
+It's not required to set all the properties in one style. It's possible to add more styles to an object and let the later added style to modify or extend appearance.
+For example, create a general gray button style and create a new for red buttons where only the new background color is set. 
+
+This is much like in CSS when used classes are listed like `<div class=".btn .btn-red">`.
+
+Styles added later have precedence over ones set earlier. So in the gray/red button example above, the normal button style should be added first and the red style second. 
+However, the precedence coming from states are still taken into account. 
+So let's examine the following case:
+- the basic button style defines dark-gray color for default state and light-gray color pressed state
+- the red button style defines the background color as red only in the default state
+
+In this case, when the button is released (it's in default state) it will be red because a perfect match is found in the most recently added style (red). 
+When the button is pressed the light-gray color is a better match because it describes the current state perfectly, so the button will be light-gray. 
+
+## Inheritance 
+Some properties (typically that are related to texts) can be inherited from the parent object's styles. 
+Inheritance is applied only if the given property is not set in the object's styles (even in default state). 
+In this case, if the property is inheritable, the property's value will be searched in the parents too until an object specifies a value for the property. The parents will use their own state to detemine the value. 
+So if a button is pressed, and the text color comes from here, the pressed text color will be used.
+
+
+## Parts
+Objects can have *parts* which can have their own styles. 
+
+The following predefined parts exist in LVGL:
+- `LV_PART_MAIN` A background like rectangle*/
+- `LV_PART_SCROLLBAR`  The scrollbar(s)
+- `LV_PART_INDICATOR` Indicator, e.g. for slider, bar, switch, or the tick box of the checkbox
+- `LV_PART_KNOB` Like a handle to grab to adjust the value*/
+- `LV_PART_SELECTED` Indicate the currently selected option or section
+- `LV_PART_ITEMS` Used if the widget has multiple similar elements (e.g. table cells)*/
+- `LV_PART_TICKS` Ticks on scales e.g. for a chart or meter
+- `LV_PART_CURSOR` Mark a specific place e.g. text area's or chart's cursor
+- `LV_PART_CUSTOM_FIRST` Custom parts can be added from here.
+
+
+For example a [Slider](/widgets/core/slider) has three parts:
+- Background
+- Indiactor
+- Knob
+
+It means the all three parts of the slider can have their own styles. See later how to add style styles to objects and parts.
+
+## Initialize styles and set/get properties
+
+Styles are stored in `lv_style_t` variables. Style variables should be `static`, global or dynamically allocated. 
+In other words they can not be local variables in functions which are destroyed when the function exists. 
+Before using a style it should be initialized with `lv_style_init(&my_style)`. 
+After initializing the style properties can be set or added to it.
+
+Property set functions looks like this: `lv_style_set_<property_name>(&style, <value>);` For example: 
+```c
+static lv_style_t style_btn;
+lv_style_init(&style_btn);
+lv_style_set_bg_color(&style_btn, lv_color_grey());
+lv_style_set_bg_opa(&style_btn, LV_OPA_50);
+lv_style_set_border_width(&style_btn, 2);
+lv_style_set_border_color(&style_btn, lv_color_black());
+
+static lv_style_t style_btn_red;
+lv_style_init(&style_btn_red);
+lv_style_set_bg_color(&style_btn_red, lv_color_red());
+lv_style_set_bg_opa(&style_btn_red, LV_OPA_COVER);
+```
+
+To remove a property use:
+
+```c
+lv_style_remove_prop(&style, LV_STYLE_BG_COLOR);
+```
+
+To get a property's value from a style:
+```c
+lv_style_value_t v;
+lv_res_t res = lv_style_rget_prop(&style, LV_STYLE_BG_COLOR, &v);
+if(res == LV_RES_OK) {	/*Found*/
+	do_something(v.color);
+}
+```
+
+`lv_style_value_t` has 3 fields:
+- `num` for integer, boolean and opacity properties
+- `color` for color properties
+- `ptr` for pointer properties
+
+To reset a style (free all its data) use 
+```c
+lv_style_reset(&style);
+```
+
+## Add and remove styles to a widget
+A style on its own is not that useful, it needs to be assigned to an object to take effect.
+
+### Add styles
+To add a style to an object use `lv_obj_add_style(obj, &style, <selector>)`. `<selector>` is an OR-ed value of parts and state to which the style should be added. Some examples:
+- `LV_PART_MAIN | LV_STATE_DEFAULT`
+- `LV_STATE_PRESSED`: The main part in pressed state. `LV_PART_MAIN` can be omitted
+- `LV_PART_SCROLLBAR`: The scrollbar part in the default state. `LV_STATE_DEFAULT` can be omitted.
+- `LV_PART_SCROLLBAR | LV_STATE_SCROLLED`: The scrollbar part when the object is being scrolled
+- `0` Same as `LV_PART_MAIN | LV_STATE_DEFAULT`. 
+- `LV_PART_INDICATOR | LV_STATE_PRESSED | LV_STATE_CHECKED` The indicator part when the object is pressed and checked at the same time.
+
+Using `lv_obj_add_style`: 
+```c
+lv_obj_add_style(btn, &style_btn, 0);      				  /*Default button style*/
+lv_obj_add_style(btn, &btn_red, LV_STATE_PRESSED);  /*Overwrite only a some colors to red when pressed*/
+```
+
+### Remove styles
+To remove all styles from an object use `lv_obj_remove_style_all(obj)`.
+
+To remove specific styles use `lv_obj_remove_style(obj, style, selector)`. This function will remove `style` only if the `selector` matches with the `selector` used in `lv_obj_add_style`. 
+`style` can be `NULL` to check only the `selector` and remove all matching styles. The `selector` can use the `LV_STATE_ANY` and `LV_PART_ANY` values to remove the style with any state or part.
+
+
+### Report style changes
+If a style which is already assigned to object changes (i.e. a property is added or changed) the objects using that style should be notified. There are 3 options to do this:
+1. If you know that the changed properties can be applied by a simple redraw (e.g. color or opacity changes) just call `lv_obj_invalidate(obj)` or `lv_obj_invalideate(lv_scr_act())`. 
+2. If more complex style properties were changed or added, and you know which object(s) are affected by that style call `lv_obj_refresh_style(obj, part, property)`. 
+To refresh all parts and properties use `lv_obj_refresh_style(obj, LV_PART_ANY, LV_STYLE_PROP_ANY)`.
+3. To make LVGL check all objects to see whether they use the style and refresh them when needed call `lv_obj_report_style_change(&style)`. If `style` is `NULL` all objects will be notified about the style change.
+
+### Get a property's value on an object
+To get a final value of property - considering cascading, inheritance, local styles and transitions (see below) - get functions like this can be used: 
+`lv_obj_get_style_<property_name>(obj, <part>)`. 
+These functions uses the object's current state and if no better candidate returns a default value.  
+For example:
+```c
+lv_color_t color = lv_obj_get_style_bg_color(btn, LV_PART_MAIN);
+```
+
+## Local styles
+Besides "normal" styles, the objects can store local styles too. This concept is similar to inline styles in CSS (e.g. `<div style="color:red">`) with some modification. 
+
+So local styles are like normal styles but they can't be shared among other objects. If used, local styles are allocated automatically, and freed when the object is deleted.
+They are useful to add local customization to the object.
+
+Unlike in CSS, in LVGL local styles can be assigned to states (*pseudo-classes*) and parts (*pseudo-elements*).
+
+To set a local property use functions like `lv_obj_set_style_local_<property_name>(obj, <value>, <selector>);`  
+For example:
+```c
+lv_obj_set_style_local_bg_color(slider, lv_color_red(), LV_PART_INDICATOR | LV_STATE_FOCUSED);
+```
+## Properties
+For the full list of style properties click [here](/overview/style-props).
+
+### Typical background properties
+In the documentation of the widgets you will see sentences like "The widget use the typical background properties". The "typical background properties" are the ones related to:
+- Background
+- Border
+- Outline
+- Shadow
+- Padding
+- Width and height transformation
+- X and Y translation
+
+
+## Transitions
+By default, when an object changes state (e.g. it's pressed) the new properties from the new state are set immediately. However, with transitions it's possible to play an animation on state change.
+For example, on pressing a button its background color can be animated to the pressed color over 300 ms.
+
+The parameters of the transitions are stored in the styles. It's possible to set 
+- the time of the transition
+- the delay before starting the transition 
+- the animation path (also known as timing or easing function)
+- the properties to animate 
+
+The transition properties can be defined for each state. For example, setting 500 ms transition time in default state will mean that when the object goes to the default state a 500 ms transition time will be applied. 
+Setting 100 ms transition time in the pressed state will mean a 100 ms transition time when going to pressed state.
+So this example configuration will result in going to pressed state quickly and then going back to default slowly. 
+
+To describe a transition an `lv_transition_dsc_t` variable needs to initialized and added to a style:
+```c
+/*Only its pointer is saved so must static, global or dynamically allocated */
+static const lv_style_prop_t trans_props[] = {
+											LV_STYLE_BG_OPA, LV_STYLE_BG_COLOR,
+											0, /*End marker*/
+};
+
+static lv_style_transition_dsc_t trans1;
+lv_style_transition_dsc_init(&trans1, trans_props, lv_anim_path_ease_out, duration_ms, delay_ms);
+
+lv_style_set_transition(&style1, &trans1);
+```
+
+## Color filter
+TODO
+
+
+## Themes
+Themes are a collection of styles. If there is an active theme LVGL applies it on every created widget.
+This will give a default appearance to the UI which can then be modified by adding further styles.
+
+Every display can have a different theme. For example you could have a colorful theme on a TFT and monochrome theme on a secondary monochrome display.
+
+To set a theme for a display, 2 steps are required:
+1. Initialize a theme
+2. Assign the initialized theme to a display.
+
+Theme initialization functions can have different prototype. This example shows how to set the "default" theme:
+```c
+lv_theme_t * th = lv_theme_default_init(display,  /*Use the DPI, size, etc from this display*/ 
+                                        LV_COLOR_PALETTE_BLUE, LV_COLOR_PALETTE_CYAN,   /*Primary and secondary palette*/
+                                        false,    /*Light or dark mode*/ 
+                                        &lv_font_montserrat_10, &lv_font_montserrat_14, &lv_font_montserrat_18); /*Small, normal, large fonts*/
+                                        
+lv_disp_set_theme(display, th); /*Assign the theme to the display*/
+```
+
+
+The themes can be enabled in `lv_conf.h`. If the default theme is enabled by `LV_USE_THEME_DEFAULT 1` LVGL automatically initializes and sets it when a display is created. 
+
+### Extending themes
+
+Built-in themes can be extended. 
+If a custom theme is created a parent theme can be selected. The parent theme's styles will be added before the custom theme's styles. 
+Any number of themes can be chained this way. E.g. default theme -> custom theme -> dark theme.
+
+`lv_theme_set_parent(new_theme, base_theme)` extends the `base_theme` with the `new_theme`.
+
+There is an example for it below.
+
+## Examples
+
+```eval_rst
+
+.. include:: ../../examples/styles/index.rst
+
+```
+
+## API
+```eval_rst
+
+.. doxygenfile:: lv_style.h
+  :project: lvgl
+
+.. doxygenfile:: lv_theme.h
+  :project: lvgl
+
+.. doxygenfile:: lv_obj_style_gen.h
+  :project: lvgl
+  
+.. doxygenfile:: lv_style_gen.h
+  :project: lvgl
+  
+
+```

docs/overview/timer.md

@@ -0,0 +1,102 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/overview/timer.md
+```
+# Timers
+
+LVGL has a built-in timer system. You can register a function to have it be called periodically. The timers are handled and called in `lv_timer_handler()`, which needs to be called every few milliseconds.
+See [Porting](/porting/task-handler) for more information.
+
+The timers are non-preemptive, which means a timer cannot interrupt another timer. Therefore, you can call any LVGL related function in a timer.
+
+
+## Create a timer
+To create a new timer, use `lv_timer_create(timer_cb, period_ms, user_data)`. It will create an `lv_timer_t *` variable, which can be used later to modify the parameters of the timer.
+`lv_timer_create_basic()` can also be used. This allows you to create a new timer without specifying any parameters.
+
+A timer callback should have `void (*lv_timer_cb_t)(lv_timer_t *);` prototype.
+
+For example:
+```c
+void my_timer(lv_timer_t * timer)
+{
+  /*Use the user_data*/
+  uint32_t * user_data = timer->user_data;
+  printf("my_timer called with user data: %d\n", *user_data);
+
+  /*Do something with LVGL*/
+  if(something_happened) {
+    something_happened = false;
+    lv_btn_create(lv_scr_act(), NULL);
+  }
+}
+
+...
+
+static uint32_t user_data = 10;
+lv_timer_t * timer = lv_timer_create(my_timer, 500,  &user_data);
+
+```
+
+## Ready and Reset
+
+`lv_timer_ready(timer)` makes the timer run on the next call of `lv_timer_handler()`.
+
+`lv_timer_reset(timer)` resets the period of a timer. It will be called again after the defined period of milliseconds has elapsed.
+
+
+## Set parameters
+You can modify some parameters of the timers later:
+- `lv_timer_set_cb(timer, new_cb)`
+- `lv_timer_set_period(timer, new_period)`
+
+## Repeat count
+
+You can make a timer repeat only a given number of times with `lv_timer_set_repeat_count(timer, count)`. The timer will automatically be deleted after being called the defined number of times. Set the count to `-1` to repeat indefinitely. 
+
+
+## Measure idle time
+
+You can get the idle percentage time of `lv_timer_handler` with `lv_timer_get_idle()`. Note that, it doesn't measure the idle time of the overall system, only `lv_timer_handler`.
+It can be misleading if you use an operating system and call `lv_timer_handler` in a timer, as it won't actually measure the time the OS spends in an idle thread.
+
+## Asynchronous calls
+
+In some cases, you can't do an action immediately. For example, you can't delete an object because something else is still using it or you don't want to block the execution now.
+For these cases, `lv_async_call(my_function, data_p)` can be used to make `my_function` be called on the next call of `lv_timer_handler`. `data_p` will be passed to function when it's called.
+Note that, only the pointer of the data is saved so you need to ensure that the variable will be "alive" while the function is called. It can be *static*, global or dynamically allocated data.
+
+For example:
+```c
+void my_screen_clean_up(void * scr)
+{
+  /*Free some resources related to `scr`*/
+
+  /*Finally delete the screen*/
+  lv_obj_del(scr);  
+}
+
+...
+
+/*Do somethings with the object on the current screen*/
+
+/*Delete screen on next call of `lv_timer_handler`, so not now.*/
+lv_async_call(my_screen_clean_up, lv_scr_act());
+
+/*The screen is still valid so you can do other things with it*/
+
+```
+
+If you just want to delete an object, and don't need to clean anything up in `my_screen_cleanup`, you could just use `lv_obj_del_async`, which will delete the object on the next call to `lv_timer_handler`.
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_timer.h
+  :project: lvgl
+
+.. doxygenfile:: lv_async.h
+  :project: lvgl
+
+```

docs/porting/display.md

@@ -0,0 +1,196 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/porting/display.md
+```
+# Display interface
+
+To register a display for LVGL a `lv_disp_draw_buf_t` and a `lv_disp_drv_t` variable have to be initialized.
+- `lv_disp_draw_buf_t` contains internal graphic buffer(s) called draw buffer(s).
+- `lv_disp_drv_t` contains callback functions to interact with the display and manipulate drawing related things.
+
+## Draw buffer
+
+Draw buffer(s) are simple array(s) that LVGL uses to render the content of the screen. 
+Once rendering is ready the content of the draw buffer is sent to the display using the `flush_cb` function set in the display driver (see below).
+
+A draw draw buffer can be initialized via a `lv_disp_draw_buf_t` variable like this:
+```c
+/*A static or global variable to store the buffers*/
+static lv_disp_draw_buf_t disp_buf;
+
+/*Static or global buffer(s). The second buffer is optional*/
+static lv_color_t buf_1[MY_DISP_HOR_RES * 10];
+static lv_color_t buf_2[MY_DISP_HOR_RES * 10];
+
+/*Initialize `disp_buf` with the buffer(s). With only one buffer use NULL instead buf_2 */
+lv_disp_draw_buf_init(&disp_buf, buf_1, buf_2, MY_DISP_HOR_RES*10);
+```
+
+Note that `lv_disp_draw_buf_t` needs to be static, global or dynamically allocated and not a local variable destroyed if goes out of the scope. 
+
+As you can see the draw buffer can be smaller than the screen. In this case, the larger areas will be redrawn in smaller parts that fit into the draw buffer(s).
+If only a small area changes (e.g. a button is pressed) then only that area will be refreshed.
+
+A larger buffer results in better performance but above 1/10 screen sized buffer(s) there is no significant performance improvement. 
+Therefore it's recommended to choose the size of the draw buffer(s) to at least 1/10 screen sized.
+
+If only **one buffer** is used LVGL draws the content of the screen into that draw buffer and sends it to the display. 
+This way LVGL needs to wait until the content of the buffer is sent to the display before drawing something new in it.
+
+If **two buffers**  are used LVGL can draw into one buffer while the content of the other buffer is sent to display in the background. 
+DMA or other hardware should be used to transfer the data to the display to let the MCU draw meanwhile.
+This way, the rendering and refreshing of the display become parallel. 
+
+In the display driver (`lv_disp_drv_t`) the `full_refresh` bit can be enabled to force LVGL to always redraw the whole screen. This works in both *one buffer* and *two buffers* modes.
+
+If `full_refresh` is enabled and 2 screen sized draw buffers are provided, LVGL's display handling works like "traditional" double buffering. 
+This means in `flush_cb` only the address of the frame buffer needs to be changed to the provided pointer (`color_p` parameter).
+This configuration should be used if the MCU has LCD controller periphery and not with an external display controller (e.g. ILI9341 or SSD1963). 
+
+You can measure the performance of different draw buffer configurations using the [benchmark example](https://github.com/lvgl/lv_demos/tree/master/src/lv_demo_benchmark).
+
+## Display driver
+
+Once the buffer initialization is ready a `lv_disp_drv_t` display driver needs to be
+1. initialized with `lv_disp_drv_init(&disp_drv)`
+2. its fields need to be set
+3. it needs to be registered in LVGL with `lv_disp_drv_register(&disp_drv)`
+
+Note that `lv_disp_drv_t` also needs to be static, global or dynamically allocated and not a local variable destroyed if goes out of the scope. 
+
+### Mandatory fields
+In the most simple case only the following fields of `lv_disp_drv_t` need to be set:
+- `draw_buf` pointer to an initialized `lv_disp_draw_buf_t` variable.
+- `hor_res` horizontal resolution of the display in pixels. 
+- `ver_res` vertical resolution of the display in pixels.
+- `flush_cb` a callback function to copy a buffer's content to a specific area of the display. 
+`lv_disp_flush_ready(&disp_drv)` needs to be called when flushing is ready. 
+LVGL might render the screen in multiple chunks and therefore call `flush_cb` multiple times. To see if the current one is the last chunk of rendering use `lv_disp_flush_is_last(&disp_drv)`.
+
+### Optional fields 
+There are some optional data fields:
+- `color_chroma_key` A color which will be drawn as transparent on chrome keyed images. Set to `LV_COLOR_CHROMA_KEY` by default from `lv_conf.h`.
+- `anti_aliasing` use anti-aliasing (edge smoothing). Enabled by default if `LV_COLOR_DEPTH` is set to at least 16 in `lv_conf.h`.
+- `rotated` and `sw_rotate` See the [Rotation](#rotation) section below.
+- `screen_transp` if `1` the screen itself can have transparency as well. `LV_COLOR_SCREEN_TRANSP` needs to enabled in `lv_conf.h` and requires `LV_COLOR_DEPTH 32`.
+- `user_data` A custom `void `user data for the driver..
+
+Some other optional callbacks to make easier and more optimal to work with monochrome, grayscale or other non-standard RGB displays:
+- `rounder_cb` Round the coordinates of areas to redraw. E.g. a 2x2 px can be converted to 2x8.
+It can be used if the display controller can refresh only areas with specific height or width (usually 8 px height with monochrome displays).
+- `set_px_cb` a custom function to write the draw buffer. It can be used to store the pixels more compactly in the draw buffer if the display has a special color format. (e.g. 1-bit monochrome, 2-bit grayscale etc.)
+This way the buffers used in `lv_disp_draw_buf_t` can be smaller to hold only the required number of bits for the given area size. Note that, rendering with `set_px_cb` is slower than normal rendering.
+- `monitor_cb` A callback function that tells how many pixels were refreshed in how much time. Called when the last chunk is rendered and sent to the display. 
+- `clean_dcache_cb` A callback for cleaning any caches related to the display.
+
+LVGL has built-in support to several GPUs (see `lv_conf.h`) but if something else is required these functions can be used to make LVGL use a GPU:
+- `gpu_fill_cb` fill an area in the memory with a color.
+- `gpu_wait_cb` if any GPU function returns while the GPU is still working, LVGL will use this function when required to make sure GPU rendering is ready.
+
+### Examples
+All together it looks like this:
+```c
+static lv_disp_drv_t disp_drv;          /*A variable to hold the drivers. Must be static or global.*/
+lv_disp_drv_init(&disp_drv);            /*Basic initialization*/
+disp_drv.draw_buf = &disp_buf;          /*Set an initialized buffer*/
+disp_drv.flush_cb = my_flush_cb;        /*Set a flush callback to draw to the display*/
+disp_drv.hor_res = 320;                 /*Set the horizontal resolution in pixels*/
+disp_drv.ver_res = 240;                 /*Set the vertical resolution in pixels*/
+
+lv_disp_t * disp;
+disp = lv_disp_drv_register(&disp_drv); /*Register the driver and save the created display objects*/
+```
+
+Here are some simple examples of the callbacks:
+```c
+void my_flush_cb(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_color_t * color_p)
+{
+    /*The most simple case (but also the slowest) to put all pixels to the screen one-by-one
+     *`put_px` is just an example, it needs to implemented by you.*/
+    int32_t x, y;
+    for(y = area->y1; y <= area->y2; y++) {
+        for(x = area->x1; x <= area->x2; x++) {
+            put_px(x, y, *color_p)
+            color_p++;
+        }
+    }
+
+    /* IMPORTANT!!!
+     * Inform the graphics library that you are ready with the flushing*/
+    lv_disp_flush_ready(disp_drv);
+}
+
+void my_gpu_fill_cb(lv_disp_drv_t * disp_drv, lv_color_t * dest_buf, const lv_area_t * dest_area, const lv_area_t * fill_area, lv_color_t color);
+{
+    /*It's an example code which should be done by your GPU*/
+    uint32_t x, y;
+    dest_buf += dest_width * fill_area->y1; /*Go to the first line*/
+
+    for(y = fill_area->y1; y < fill_area->y2; y++) {
+        for(x = fill_area->x1; x < fill_area->x2; x++) {
+            dest_buf[x] = color;
+        }
+        dest_buf+=dest_width;    /*Go to the next line*/
+    }
+}
+
+
+void my_rounder_cb(lv_disp_drv_t * disp_drv, lv_area_t * area)
+{
+  /* Update the areas as needed.
+   * For example it makes the area to start only on 8th rows and have Nx8 pixel height.*/
+   area->y1 = area->y1 & 0x07;
+   area->y2 = (area->y2 & 0x07) + 8;
+}
+
+void my_set_px_cb(lv_disp_drv_t * disp_drv, uint8_t * buf, lv_coord_t buf_w, lv_coord_t x, lv_coord_t y, lv_color_t color, lv_opa_t opa)
+{
+   /* Write to the buffer as required for the display.
+    * For example it writes only 1-bit for monochrome displays mapped vertically.*/
+   buf += buf_w * (y >> 3) + x;
+   if(lv_color_brightness(color) > 128) (*buf) |= (1 << (y % 8));
+   else (*buf) &= ~(1 << (y % 8));
+}
+
+void my_monitor_cb(lv_disp_drv_t * disp_drv, uint32_t time, uint32_t px)
+{
+  printf("%d px refreshed in %d ms\n", time, ms);
+}
+
+void my_clean_dcache_cb(lv_disp_drv_t * disp_drv, uint32)
+{
+  /* Example for Cortex-M (CMSIS) */
+  SCB_CleanInvalidateDCache();
+}
+```
+
+## Rotation
+
+LVGL supports rotation of the display in 90 degree increments. You can select whether you'd like software rotation or hardware rotation.
+
+If you select software rotation (`sw_rotate` flag set to 1), LVGL will perform the rotation for you. Your driver can and should assume that the screen width and height have not changed. Simply flush pixels to the display as normal. Software rotation requires no additional logic in your `flush_cb` callback.
+
+There is a noticeable amount of overhead to performing rotation in software, which is why hardware rotation is also available. In this mode, LVGL draws into the buffer as though your screen now has the width and height inverted. You are responsible for rotating the provided pixels yourself.
+
+The default rotation of your display when it is initialized can be set using the `rotated` flag. The available options are `LV_DISP_ROT_NONE`, `LV_DISP_ROT_90`, `LV_DISP_ROT_180`, or `LV_DISP_ROT_270`. The rotation values are relative to how you would rotate the physical display in the clockwise direction. Thus, `LV_DISP_ROT_90` means you rotate the hardware 90 degrees clockwise, and the display rotates 90 degrees counterclockwise to compensate.
+
+(Note for users upgrading from 7.10.0 and older: these new rotation enum values match up with the old 0/1 system for rotating 90 degrees, so legacy code should continue to work as expected. Software rotation is also disabled by default for compatibility.)
+
+Display rotation can also be changed at runtime using the `lv_disp_set_rotation(disp, rot)` API.
+
+Support for software rotation is a new feature, so there may be some glitches/bugs depending on your configuration. If you encounter a problem please open an issue on [GitHub](https://github.com/lvgl/lvgl/issues).
+
+## Further reading
+
+- [lv_port_disp_template.c](https://github.com/lvgl/lvgl/blob/master/examples/porting/lv_port_disp_template.c) for a template for your own driver.
+- [Drawing](/overview/drawing) to learn more about how rendering works in LVGL.
+- [Display features](/overview/display) to learn more about higher level display features.
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_hal_disp.h
+  :project: lvgl
+
+```

docs/porting/indev.md

@@ -0,0 +1,209 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/porting/indev.md
+```
+# Input device interface
+
+## Types of input devices
+
+To register an input device an `lv_indev_drv_t` variable has to be initialized:
+
+```c
+lv_indev_drv_t indev_drv;
+lv_indev_drv_init(&indev_drv);      /*Basic initialization*/
+indev_drv.type =...                 /*See below.*/
+indev_drv.read_cb =...              /*See below.*/
+/*Register the driver in LVGL and save the created input device object*/
+lv_indev_t * my_indev = lv_indev_drv_register(&indev_drv);
+```
+
+`type` can be
+- `LV_INDEV_TYPE_POINTER` touchpad or mouse
+- `LV_INDEV_TYPE_KEYPAD` keyboard or keypad
+- `LV_INDEV_TYPE_ENCODER` encoder with left/right turn and push options
+- `LV_INDEV_TYPE_BUTTON` external buttons virtually pressing the screen
+
+`read_cb` is a function pointer which will be called periodically to report the current state of an input device.
+
+Visit [Input devices](/overview/indev) to learn more about input devices in general.
+
+###  Touchpad, mouse or any pointer
+Input devices that can click points on the screen belong to this category.
+
+```c
+indev_drv.type = LV_INDEV_TYPE_POINTER;
+indev_drv.read_cb = my_input_read;
+
+...
+
+void my_input_read(lv_indev_drv_t * drv, lv_indev_data_t*data)
+{
+  if(touchpad_pressed) {
+    data->point.x = touchpad_x;
+    data->point.y = touchpad_y;
+    data->state = LV_INDEV_STATE_PRESSED;
+  } else {
+    data->state = LV_INDEV_STATE_RELEASED; 
+  }
+}
+```
+
+To set a mouse cursor use `lv_indev_set_cursor(my_indev, &img_cursor)`. (`my_indev` is the return value of `lv_indev_drv_register`)
+
+### Keypad or keyboard
+
+Full keyboards with all the letters or simple keypads with a few navigation buttons belong here.
+
+To use a keyboard/keypad:
+- Register a `read_cb` function with `LV_INDEV_TYPE_KEYPAD` type.
+- An object group has to be created: `lv_group_t * g = lv_group_create()` and objects have to be added to it with `lv_group_add_obj(g, obj)`
+- The created group has to be assigned to an input device: `lv_indev_set_group(my_indev, g)` (`my_indev` is the return value of `lv_indev_drv_register`)
+- Use `LV_KEY_...` to navigate among the objects in the group. See `lv_core/lv_group.h` for the available keys.
+
+```c
+indev_drv.type = LV_INDEV_TYPE_KEYPAD;
+indev_drv.read_cb = keyboard_read;
+
+...
+
+void keyboard_read(lv_indev_drv_t * drv, lv_indev_data_t*data){
+  data->key = last_key();            /*Get the last pressed or released key*/
+
+  if(key_pressed()) data->state = LV_INDEV_STATE_PRESSED;
+  else data->state = LV_INDEV_STATE_RELEASED;
+}
+```
+
+### Encoder
+With an encoder you can do 4 things:
+1. Press its button
+2. Long-press its button
+3. Turn left
+4. Turn right
+
+In short, the Encoder input devices work like this:
+- By turning the encoder you can focus on the next/previous object.
+- When you press the encoder on a simple object (like a button), it will be clicked.
+- If you press the encoder on a complex object (like a list, message box, etc.) the object will go to edit mode whereby turning the encoder you can navigate inside the object.
+- To leave edit mode press long the button.
+
+
+To use an *Encoder* (similarly to the *Keypads*) the objects should be added to groups.
+
+
+```c
+indev_drv.type = LV_INDEV_TYPE_ENCODER;
+indev_drv.read_cb = encoder_read;
+
+...
+
+void encoder_read(lv_indev_drv_t * drv, lv_indev_data_t*data){
+  data->enc_diff = enc_get_new_moves();
+
+  if(enc_pressed()) data->state = LV_INDEV_STATE_PRESSED;
+  else data->state = LV_INDEV_STATE_RELEASED;
+}
+```
+
+#### Using buttons with Encoder logic
+In addition to standard encoder behavior, you can also utilize its logic to navigate(focus) and edit widgets using buttons. 
+This is especially handy if you have only few buttons available, or you want to use other buttons in addition to encoder wheel.
+
+You need to have 3 buttons available:
+- `LV_KEY_ENTER` will simulate press or pushing of the encoder button
+- `LV_KEY_LEFT` will simulate turning encoder left
+- `LV_KEY_RIGHT` will simulate turning encoder right
+- other keys will be passed to the focused widget
+
+If you hold the keys it will simulate encoder click with period specified in `indev_drv.long_press_rep_time`.
+
+```c
+indev_drv.type = LV_INDEV_TYPE_ENCODER;
+indev_drv.read_cb = encoder_with_keys_read;
+
+...
+
+bool encoder_with_keys_read(lv_indev_drv_t * drv, lv_indev_data_t*data){
+  data->key = last_key();            /*Get the last pressed or released key*/
+                                     /* use LV_KEY_ENTER for encoder press */
+  if(key_pressed()) data->state = LV_INDEV_STATE_PRESSED;
+  else {
+      data->state = LV_INDEV_STATE_RELEASED;
+      /* Optionally you can also use enc_diff, if you have encoder*/
+      data->enc_diff = enc_get_new_moves();
+  }
+
+  return false; /*No buffering now so no more data read*/
+}
+```
+
+### Button
+*Buttons* mean external "hardware" buttons next to the screen which are assigned to specific coordinates of the screen.
+If a button is pressed it will simulate the pressing on the assigned coordinate. (Similarly to a touchpad)
+
+To assign buttons to coordinates use `lv_indev_set_button_points(my_indev, points_array)`.   
+`points_array` should look like `const lv_point_t points_array[] =  { {12,30},{60,90}, ...}`
+
+``` important::  The points_array can't go out of scope. Either declare it as a global variable or as a static variable inside a function.
+```
+
+```c
+indev_drv.type = LV_INDEV_TYPE_BUTTON;
+indev_drv.read_cb = button_read;
+
+...
+
+void button_read(lv_indev_drv_t * drv, lv_indev_data_t*data){
+    static uint32_t last_btn = 0;   /*Store the last pressed button*/
+    int btn_pr = my_btn_read();     /*Get the ID (0,1,2...) of the pressed button*/
+    if(btn_pr >= 0) {               /*Is there a button press? (E.g. -1 indicated no button was pressed)*/
+       last_btn = btn_pr;           /*Save the ID of the pressed button*/
+       data->state = LV_INDEV_STATE_PRESSED;  /*Set the pressed state*/
+    } else {
+       data->state = LV_INDEV_STATE_RELEASED; /*Set the released state*/
+    }
+
+    data->btn = last_btn;            /*Save the last button*/
+}
+```
+
+## Other features
+
+### Parameters
+
+The default value of the following parameters can changed in `lv_indev_drv_t`:
+- `scroll_limit` Number of pixels to slide before actually scrolling the object.
+- `scroll_throw`  Scroll throw (momentum) slow-down in [%]. Greater value means faster slow-down.
+- `long_press_time` Press time to send `LV_EVENT_LONG_PRESSED` (in milliseconds)
+- `long_press_rep_time` Interval of sending `LV_EVENT_LONG_PRESSED_REPEAT` (in milliseconds)
+- `read_timer` pointer to the `lv_timer` which reads the input device. Its parameters can be changed by `lv_timer_...()` functions. `LV_INDEV_DEF_READ_PERIOD` in `lv_conf.h` sets the default read period.
+
+### Feedback
+
+Besides `read_cb` a `feedback_cb` callback can be also specified in `lv_indev_drv_t`.
+`feedback_cb` is called when any type of event is sent by the input devices (independently from its type). This allows generating feedback for the user, e.g. to play a sound on `LV_EVENT_CLICKED`.
+
+
+### Associating with a display
+Every input device is associated with a display. By default, a new input device is added to the lastly created or the explicitly selected (using `lv_disp_set_default()`) display.
+The associated display is stored and can be changed in `disp` field of the driver.
+
+### Buffered reading
+By default LVGL calls `read_cb` periodically. This way there is a chance that some user gestures are missed. 
+
+To solve this you can write an event driven driver for your input device that buffers measured data. In `read_cb` you can set the buffered data instead of reading the input device. 
+You can set the `data->continue_reading` flag to tell that LVGL there is more data to read and it should call the `read_cb` again.
+
+## Further reading
+
+- [lv_port_indev_template.c](https://github.com/lvgl/lvgl/blob/master/examples/porting/lv_port_indev_template.c) for a template for your own driver.
+- [INdev features](/overview/display) to learn more about higher level input device features.
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_hal_indev.h
+  :project: lvgl
+
+```

docs/porting/index.md

@@ -0,0 +1,23 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/porting/index.md
+```
+
+# Porting
+
+```eval_rst
+
+.. toctree::
+   :maxdepth: 2
+
+   project
+   display
+   indev
+   tick
+   task-handler
+   sleep
+   os
+   log
+   
+```
+

docs/porting/log.md

@@ -0,0 +1,46 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/porting/log.md
+```
+# Logging
+
+LVGL has built-in *Log* module to inform the user about what is happening in the library.
+
+## Log level
+To enable logging, set `LV_USE_LOG  1` in `lv_conf.h` and set `LV_LOG_LEVEL` to one of the following values:
+- `LV_LOG_LEVEL_TRACE` A lot of logs to give detailed information
+- `LV_LOG_LEVEL_INFO`  Log important events
+- `LV_LOG_LEVEL_WARN`  Log if something unwanted happened but didn't cause a problem
+- `LV_LOG_LEVEL_ERROR` Only critical issues, where the system may fail
+- `LV_LOG_LEVEL_USER` Only user messages
+- `LV_LOG_LEVEL_NONE`  Do not log anything
+
+The events which have a higher level than the set log level will be logged too. E.g. if you `LV_LOG_LEVEL_WARN`, errors will be also logged.
+
+## Printing logs
+
+### Logging with printf
+If your system supports `printf`, you just need to enable `LV_LOG_PRINTF` in `lv_conf.h` to send the logs with `printf`.
+
+
+### Custom log function
+If you can't use `printf` or want to use a custom function to log, you can register a "logger" callback with `lv_log_register_print_cb()`. 
+
+For example:
+
+```c
+void my_log_cb(const char * buf)
+{
+  serial_send(buf, strlen(buf));
+}
+
+...
+
+
+lv_log_register_print_cb(my_log_cb);
+
+```
+
+## Add logs
+
+You can also use the log module via the `LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)` functions.

docs/porting/os.md

@@ -0,0 +1,21 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/porting/os.md
+```
+# Operating system and interrupts
+
+LVGL is **not thread-safe** by default.
+
+However, in the following conditions it's valid to call LVGL related functions:
+- In *events*. Learn more in [Events](/overview/event).
+- In *lv_timer*. Learn more in [Timers](/overview/timer).
+
+
+## Tasks and threads
+If you need to use real tasks or threads, you need a mutex which should be invoked before the call of `lv_timer_handler` and released after it.
+Also, you have to use the same mutex in other tasks and threads around every LVGL (`lv_...`) related function call and code.
+This way you can use LVGL in a real multitasking environment. Just make use of a mutex to avoid the concurrent calling of LVGL functions.
+
+## Interrupts
+Try to avoid calling LVGL functions from interrupt handlers (except `lv_tick_inc()` and `lv_disp_flush_ready()`). But if you need to do this you have to disable the interrupt which uses LVGL functions while `lv_timer_handler` is running.
+It's a better approach to set a flag or some value and periodically check it in an `lv_timer`.

docs/porting/project.md

@@ -0,0 +1,35 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/porting/project.md
+```
+
+# Set-up a project
+
+## Get the library
+
+LVGL is available on GitHub: [https://github.com/lvgl/lvgl](https://github.com/lvgl/lvgl).
+
+You can clone it or download the latest version of the library from GitHub.
+
+The graphics library itself is the **lvgl** directory which should be copied into your project.
+
+## Configuration file
+
+There is a configuration header file for LVGL called **lv_conf.h**. In this you can set the library's basic behavior, disable unused modules and features, adjust the size of memory buffers in compile-time, etc.
+
+Copy **lvgl/lv_conf_template.h** next to the *lvgl* directory and rename it to *lv_conf.h*. Open the file and change the `#if 0` at the beginning to `#if 1` to enable its content.
+
+*lv_conf.h* can be copied to another place as well but then you should add `LV_CONF_INCLUDE_SIMPLE` define to your compiler options (e.g. `-DLV_CONF_INCLUDE_SIMPLE` for gcc compiler) and set the include path manually. 
+In this case LVGL will attempt to include `lv_conf.h` simply with `#include "lv_conf.h"`.
+
+In the config file comments explain the meaning of the options. Be sure to set at least `LV_COLOR_DEPTH` according to your display's color depth.
+
+## Initialization
+
+To use the graphics library you have to initialize it and the other components too. The order of the initialization is:
+
+1. Call `lv_init()`.
+2. Initialize your drivers.
+3. Register the display and input devices drivers in LVGL.  Lear more about [Display](/porting/display) and [Input device](/porting/indev) registration.
+4. Call `lv_tick_inc(x)` every `x` milliseconds in an interrupt to tell the elapsed time. [Learn more](/porting/tick).
+5. Call `lv_timer_handler()` every few milliseconds to handle LVGL related tasks. [Learn more](/porting/task-handler).