1
2# Switch (lv_switch)
3
4## Overview
5
6The Switch looks like a little slider and can be used to turn something on and off.
7
8
9## Parts and Styles
10- `LV_PART_MAIN` The background of the switch uses all the typical background style properties. `padding` makes the indicator smaller in the respective direction.
11- `LV_PART_INDICATOR` The indicator that shows the current state of the switch. Also uses all the typical background style properties.
12- `LV_PART_KNOB` A rectangle (or circle) drawn at left or right side of the indicator. Also uses all the typical background properties to describe the knob(s). By default, the knob is square (with an optional corner radius) with side length equal to the smaller side of the slider. The knob can be made larger with the `padding` values. Padding values can be asymmetric too.
13
14## Usage
15
16### Change state
17The switch uses the standard `LV_STATE_CHECKED` state.
18
19To get the current state of the switch (with `true` being on), use `lv_obj_has_state(switch, LV_STATE_CHECKED)`.
20
21Call `lv_obj_add_state(switch, LV_STATE_CHECKED)` to turn it on, or `lv_obj_clear_state(switch, LV_STATE_CHECKED)` to turn it off.
22
23
24## Events
25- `LV_EVENT_VALUE_CHANGED` Sent when the switch changes state.
26
27See the events of the [Base object](/widgets/obj) too.
28
29Learn more about [Events](/overview/event).
30
31## Keys
32- `LV_KEY_UP/RIGHT` Turns on the slider
33- `LV_KEY_DOWN/LEFT` Turns off the slider
34- `LV_KEY_ENTER` Toggles the switch
35
36Learn more about [Keys](/overview/indev).
37
38## Example
39
40```eval_rst
41
42.. include:: ../../../examples/widgets/switch/index.rst
43
44```
45
46## API
47
48```eval_rst
49
50.. doxygenfile:: lv_switch.h
51  :project: lvgl
52
53```
54