1
0
mirror of https://github.com/lvgl/lvgl.git synced 2025-01-14 06:42:58 +08:00
Gabor Kiss-Vamosi 88c485949f feat(event, widgets) improve the paramter of LV_EVENT_DRAW_PART_BEGIN/END
Add lv_<widget>_draw_part_type_t to widgets to precisly describe the hooked drawings.
Also add class_p element to lv_obj_draw_part_dsc_t to show what widgets lv_<widget>_draw_part_type_t needs to be used.

Related to: https://forum.lvgl.io/t/how-to-add-minor-division-lines-to-a-chart/5366/
2021-07-07 16:19:06 +02:00

51 lines
1.2 KiB
Markdown

```eval_rst
.. include:: /header.rst
:github_url: |github_link_base|/widgets/btn.md
```
# Button (lv_btn)
## Overview
Buttons have no new features compared to the [Base object](/widgets/obj). They are usuful for semantic purposes and have slightly different default settings.
Buttons, by default, differ from Base object in the following ways:
- Not scrollable
- Added to the default group
- Default height and width set to `LV_SIZE_CONTENT`
## Parts and Styles
- `LV_PART_MAIN` The background of the button. Uses the typical background style properties.
## Usage
There are no new features compared to [Base object](/widgets/obj).
## Events
- `LV_EVENT_VALUE_CHANGED` when the `LV_OBJ_FLAG_CHECKABLE` flag is enabled and the object is clicked. The event happens on transition to/from the checked state.
Learn more about [Events](/overview/event).
## Keys
Note that the state of `LV_KEY_ENTER` is translated to `LV_EVENT_PRESSED/PRESSING/RELEASED` etc.
See the events of the [Base object](/widgets/obj) too.
Learn more about [Keys](/overview/indev).
## Example
```eval_rst
.. include:: ../../../examples/widgets/btn/index.rst
```
## API
```eval_rst
.. doxygenfile:: lv_btn.h
:project: lvgl
```