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Spelling and other language fixes to documentation (#2293)

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Rop Gonggrijp
2021-06-09 15:10:35 +02:00
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docs/widgets/core/dropdown.md
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@@ -11,72 +11,70 @@ The drop-down list allows the user to select one value from a list.
The drop-down list is closed by default and displays a single value or a predefined text.
When activated (by click on the drop-down list), a list is created from which the user may select one option.
When the user selects a new value, the list is deleted.
When the user selects a new value, the list is deleted again.
The Drop-down list is added to the deafult group (if it is set). Besides the Drop-down list is an editable object to allow selecting an option with encoder navigation too.
The Drop-down list is added to the default group (if it is set). Besides the Drop-down list is an editable object to allow selecting an option with encoder navigation too.
## Parts and Styles
The Dropdown widgets is built from the elements: a "button" and a "list" (they are not realted to the butto and list widgets)
The Dropdown widget is built from the elements: "button" and "list" (both not related to the button and list widgets)
### Button
- `LV_PART_MAIN` The background of the button. It uses the typicaly background proeprties and text proeprties for the text on it.
- `LV_PART_MAIN` The background of the button. Uses the typical background properties and text properties for the text on it.
- `LV_PART_INDICATOR` Typically an arrow symbol that can be an image or a text (`LV_SYMBOL`).
The button goes to `LV_STATE_CHECKED` when its opened.
### List
- `LV_PART_MAIN` The list itself and it uses the typical background proeprties. `max_height` can be used to limit the height of the list.
- `LV_PART_SCROLLBAR` The scrollbar the background, border, shadow properties and width (for its width) and right padding for the spacing on the right.
- `LV_PART_SELECTED` Refers to the currently pressed, checked or prssed+checked option.
It also uses the typical background properties.
- `LV_PART_MAIN` The list itself. Uses the typical background properties. `max_height` can be used to limit the height of the list.
- `LV_PART_SCROLLBAR` The scrollbar background, border, shadow properties and width (for its own width) and right padding for the spacing on the right.
- `LV_PART_SELECTED` Refers to the currently pressed, checked or pressed+checked option. Also uses the typical background properties.
As the list not exists when the drop-down list is closed it's not possible to simply add styles to it.
As list does not exist when the drop-down list is closed it's not possible to simply add styles to it.
Instead the following should be done:
1. Ad an event handler to the button for `LV_EVENT_VALUE_CHANGED` (triggered when the list is opened/closed)
2. Use `lv_obj_t * list = lv_dropdown_get_list(dropdown)`
3. `if(list != NULL) {/*Add the styles to the list*/}`
Alternatively the the theme can be extended with the new styles.
Alternatively the theme can be extended with the new styles.
## Usage
## Overview
### Set options
The options are passed to the drop-down list as a string with `lv_dropdown_set_options(dropdown, options)`. The options should be separated by `\n`. For example: `"First\nSecond\nThird"`.
The string will be saved in the drop-down list, so it can in local variable too.
Options are passed to the drop-down list as a string with `lv_dropdown_set_options(dropdown, options)`. Options should be separated by `\n`. For example: `"First\nSecond\nThird"`. This string will be saved in the drop-down list, so it can in a local variable.
The `lv_dropdown_add_option(dropdown, "New option", pos)` function inserts a new option to `pos` index.
To save memory the options can set from a static(constant) string too with `lv_dropdown_set_static_options(dropdown, options)`.
In this case the options string should be alive while the drop-down list exists and `lv_dropdown_add_option` can't be used
In this case the options string should be alive while the drop-down list exists and `lv_dropdown_add_option` can't be used
You can select an option manually with `lv_dropdown_set_selected(dropdown, id)`, where `id` is the index of an option.
### Get selected option
The get the currently selected option, use `lv_dropdown_get_selected(dropdown)`. It will return the *index* of the selected option.
The get the *index* of the selected option, use `lv_dropdown_get_selected(dropdown)`.
`lv_dropdown_get_selected_str(dropdown, buf, buf_size)` copies the name of the selected option to a `buf`.
`lv_dropdown_get_selected_str(dropdown, buf, buf_size)` copies the *name* of the selected option to `buf`.
### Direction
The list can be created on any side. The default `LV_DIR_BOTTOM` can be modified by `lv_dropdown_set_dir(dropdown, LV_DIR_LEFT/RIGHT/UP/BOTTOM)` function.
If the list would be vertically out of the screen, it will aligned to the edge.
If the list would be vertically out of the screen, it will be aligned to the edge.
### Symbol
A symbol (typically an arrow) can be added to the drop down list with `lv_dropdown_set_symbol(dropdown, LV_SYMBOL_...)`
If the direction of the drop-down list is `LV_DIR_LEFT` the symbol will be shown on the left, else on the right.
If the direction of the drop-down list is `LV_DIR_LEFT` the symbol will be shown on the left, otherwise on the right.
### Show selected
The main part can either show the selected option or a static text. If a static is set with `lv_dropdown_set_text(dropdown, "Some text")` it will be shown regardless to th selected option.
Id the text text is `NULL` the selected option is displayed on the button.
If the text is `NULL` the selected option is displayed on the button.
### Manually open/close
To manually open or close the drop-down list the `lv_dropdown_open/close(dropdown)` function can be used.
## Events
Besides the [Generic events](../overview/event.html#generic-events), the following [Special events](../overview/event.html#special-events) are sent by the drop-down list:
Apart from the [Generic events](../overview/event.html#generic-events), the following [Special events](../overview/event.html#special-events) are sent by the drop-down list:
- `LV_EVENT_VALUE_CHANGED` Sent when the new option is selected or the list is opened/closed.
Learn more about [Events](/overview/event).
@@ -84,7 +82,7 @@ Learn more about [Events](/overview/event).
## Keys
- `LV_KEY_RIGHT/DOWN` Select the next option.
- `LV_KEY_LEFT/UP` Select the previous option.
- `LY_KEY_ENTER` Apply the selected option (Send `LV_EVENT_VALUE_CHANGED` event and close the drop-down list).
- `LY_KEY_ENTER` Apply the selected option (Sends `LV_EVENT_VALUE_CHANGED` event and closes the drop-down list).
Learn more about [Keys](/overview/indev).