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lvgl/docs/widgets/led.rst
2023-04-27 14:42:02 +02:00

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LED (lv_led)
============
Overview
********
The LEDs are rectangle-like (or circle) object whose brightness can be
adjusted. With lower brightness the colors of the LED become darker.
Parts and Styles
****************
The LEDs have only one main part, called :cpp:enumerator:`LV_LED_PART_MAIN` and it
uses all the typical background style properties.
Usage
*****
Color
-----
You can set the color of the LED with
:cpp:expr:`lv_led_set_color(led, lv_color_hex(0xff0080))`. This will be used as
background color, border color, and shadow color.
Brightness
----------
You can set their brightness with :cpp:expr:`lv_led_set_bright(led, bright)`.
The brightness should be between 0 (darkest) and 255 (lightest).
Toggle
------
Use :cpp:expr:`lv_led_on(led)` and :cpp:expr:`lv_led_off(led)` to set the brightness to
a predefined ON or OFF value. The :cpp:expr:`lv_led_toggle(led)` toggles between
the ON and OFF state.
Events
******
- :cpp:enumerator:`LV_EVENT_DRAW_PART_BEGIN` and :cpp:enumerator:`LV_EVENT_DRAW_PART_END` is sent
for the following types:
- :cpp:enumerator:`LV_LED_DRAW_PART_RECTANGLE` The main rectangle.
:cpp:enumerator:`LV_OBJ_DRAW_PART_RECTANGLE` is not sent by the base object.
- ``part``: :cpp:enumerator:`LV_PART_MAIN`
- ``rect_dsc``
- ``draw_area``: the area of the rectangle
See the events of the `Base object </widgets/obj>`__ too.
Learn more about :ref:`events`.
Keys
****
No *Keys* are processed by the object type.
Learn more about :ref:`indev_keys`.
Example
*******
.. include:: ../examples/widgets/led/index.rst
API
***