add lv_components as src/extra and minor fixes

examples/widgets/btn/index.rst

@@ -0,0 +1,16 @@
+C
+^
+
+Simple Buttons 
+""""""""""""""""
+
+.. lv_example:: lv_ex_widgets/lv_ex_btn/lv_ex_btn_1
+  :language: c
+
+.. lv_example:: lv_ex_widgets/lv_ex_btn/lv_ex_btn_2
+  :language: c
+
+MicroPython
+^^^^^^^^^^^
+
+No examples yet.

examples/widgets/btn/lv_btn_example_1.c

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+#include "../../../lvgl.h"
+#include <stdio.h>
+#if LV_USE_BTN
+
+static void event_handler(lv_obj_t * obj, lv_event_t event)
+{
+    if(event == LV_EVENT_CLICKED) {
+        printf("Clicked\n");
+    }
+    else if(event == LV_EVENT_VALUE_CHANGED) {
+        printf("Toggled\n");
+    }
+}
+
+void lv_ex_btn_1(void)
+{
+    lv_obj_t * label;
+
+    lv_obj_t * btn1 = lv_btn_create(lv_scr_act(), NULL);
+    lv_obj_add_event_cb(btn1, event_handler, NULL);
+    lv_obj_align(btn1, NULL, LV_ALIGN_CENTER, 0, -40);
+
+    label = lv_label_create(btn1, NULL);
+    lv_label_set_text(label, "Button");
+
+    lv_obj_t * btn2 = lv_btn_create(lv_scr_act(), NULL);
+    lv_obj_add_event_cb(btn2, event_handler, NULL);
+    lv_obj_align(btn2, NULL, LV_ALIGN_CENTER, 0, 40);
+    lv_obj_add_flag(btn2, LV_OBJ_FLAG_CHECKABLE);
+    lv_obj_set_height(btn2, LV_SIZE_AUTO);
+
+    label = lv_label_create(btn2, NULL);
+    lv_label_set_text(label, "Toggle");
+}
+#endif

examples/widgets/btn/lv_btn_example_1.py

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+def event_handler(obj, event):
+    if event == lv.EVENT.CLICKED:
+        print("Clicked")
+
+btn1 = lv.btn(lv.scr_act())
+btn1.set_event_cb(event_handler)
+btn1.align(None, lv.ALIGN.CENTER, 0, -40)
+
+label = lv.label(btn1)
+label.set_text("Button")
+
+btn2 = lv.btn(lv.scr_act())
+# callback can be lambda:
+btn2.set_event_cb(lambda obj, event: print("Toggled") if event == lv.EVENT.VALUE_CHANGED else None)
+btn2.align(None, lv.ALIGN.CENTER, 0, 40)
+btn2.set_toggle(True)
+btn2.toggle()
+btn2.set_fit2(lv.FIT.NONE, lv.FIT.TIGHT)
+
+label = lv.label(btn2)
+label.set_text("Toggled")

examples/widgets/btn/lv_btn_example_2.c

@@ -0,0 +1,52 @@
+#include "../../../lvgl.h"
+#include <stdio.h>
+#if LV_USE_BTN
+
+/**
+ * Style a button from scratch
+ */
+void lv_ex_btn_2(void)
+{
+
+    static lv_style_t style;
+    static lv_style_t style_pr;
+    lv_style_init(&style);
+    lv_style_init(&style_pr);
+
+    /*Init the default style*/
+    lv_style_set_radius(&style, 3);
+
+    lv_style_set_bg_opa(&style, LV_OPA_70);
+    lv_style_set_bg_color(&style, LV_COLOR_BLUE);
+    lv_style_set_bg_grad_color(&style, LV_COLOR_AQUA);
+    lv_style_set_bg_grad_dir(&style, LV_GRAD_DIR_VER);
+
+    lv_style_set_border_opa(&style, LV_OPA_40);
+    lv_style_set_border_width(&style, 2);
+    lv_style_set_border_color(&style, LV_COLOR_GRAY);
+
+    lv_style_set_shadow_width(&style, 8);
+    lv_style_set_shadow_color(&style, LV_COLOR_GRAY);
+    lv_style_set_shadow_ofs_x(&style, 8);
+    lv_style_set_shadow_ofs_y(&style, 8);
+
+    lv_style_set_text_color(&style, LV_COLOR_WHITE);
+
+    /*Init the pressed style*/
+    lv_style_set_shadow_ofs_x(&style_pr, 4);
+    lv_style_set_shadow_ofs_y(&style_pr, 4);
+    lv_style_set_color_filter_cb(&style_pr, lv_color_darken);   /*Darken every color*/
+    lv_style_set_color_filter_opa(&style_pr, LV_OPA_30);
+
+    lv_obj_t * btn1 = lv_btn_create(lv_scr_act(), NULL);
+    lv_obj_remove_style(btn1, LV_PART_ANY, LV_STATE_ANY, NULL);
+    lv_obj_add_style(btn1, LV_PART_MAIN, LV_STATE_DEFAULT, &style);
+    lv_obj_add_style(btn1, LV_PART_MAIN, LV_STATE_PRESSED, &style_pr);
+    lv_obj_align(btn1, NULL, LV_ALIGN_CENTER, 0, 0);
+
+    lv_obj_t * label = lv_label_create(btn1, NULL);
+    lv_label_set_text(label, "Button");
+    lv_obj_align(label, NULL, LV_ALIGN_CENTER, 0, 0);
+
+}
+#endif

examples/widgets/btn/lv_btn_example_3.c

@@ -0,0 +1,57 @@
+#include "../../../lvgl.h"
+#include <stdio.h>
+#if LV_USE_BTN
+
+/**
+ * Create a style transition on a button to act like a gum when clicked
+ */
+void lv_ex_btn_3(void)
+{
+    /*Properties to transition*/
+    static lv_style_prop_t props[] = {
+            LV_STYLE_TRANSFORM_WIDTH, LV_STYLE_TRANSFORM_HEIGHT, LV_STYLE_CONTENT_LETTER_SPACE, 0
+    };
+
+    /*Define animation paths*/
+    static lv_anim_path_t path_ease_in_out;
+    lv_anim_path_init(&path_ease_in_out);
+    lv_anim_path_set_cb(&path_ease_in_out, lv_anim_path_ease_in_out);
+
+    static lv_anim_path_t path_overshoot;
+    lv_anim_path_init(&path_overshoot);
+    lv_anim_path_set_cb(&path_overshoot, lv_anim_path_overshoot);
+
+
+    /* Transition descriptor when going back to the default state.
+     * Add some delay to be sure the press transition is visible even if the press was very short*/
+    static lv_style_transition_dsc_t transition_dsc_def;
+    lv_style_transition_dsc_init(&transition_dsc_def, props, &path_overshoot, 250, 100);
+
+    /* Transition descriptor when going to pressed state.
+     * No delay, go to presses state immediately*/
+    static lv_style_transition_dsc_t transition_dsc_pr;
+    lv_style_transition_dsc_init(&transition_dsc_pr, props, &path_ease_in_out, 250, 0);
+
+    /*Add only the new transition to he default state*/
+    static lv_style_t style_def;
+    lv_style_init(&style_def);
+    lv_style_set_transition(&style_def, &transition_dsc_def);
+
+    /*Add the transition and some transformation to the presses state.*/
+    static lv_style_t style_pr;
+    lv_style_init(&style_pr);
+    lv_style_set_transform_width(&style_pr, 10);
+    lv_style_set_transform_height(&style_pr, -10);
+    lv_style_set_content_letter_space(&style_pr, 10);
+    lv_style_set_transition(&style_pr, &transition_dsc_pr);
+
+
+    lv_obj_t * btn1 = lv_btn_create(lv_scr_act(), NULL);
+    lv_obj_align(btn1, NULL, LV_ALIGN_CENTER, 0, -80);
+    lv_obj_add_style(btn1, LV_PART_MAIN, LV_STATE_PRESSED, &style_pr);
+    lv_obj_add_style(btn1, LV_PART_MAIN, LV_STATE_DEFAULT, &style_def);
+
+    /*Instead of creating a label add a values string*/
+    lv_obj_set_style_content_text(btn1, LV_PART_MAIN, LV_STATE_DEFAULT, "Gum");
+}
+#endif