lvgl/docs/widgets/switch.md

# Switch (lv_switch)

## Overview

The Switch looks like a little slider and can be used to turn something on and off.


## Parts and Styles
- `LV_PART_MAIN` The background of the switch uses all the typical background style properties. `padding` makes the indicator smaller in the respective direction.
- `LV_PART_INDICATOR` The indicator that shows the current state of the switch. Also uses all the typical background style properties.
- `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.

## Usage

### Change state
The switch uses the standard `LV_STATE_CHECKED` state.

To get the current state of the switch (with `true` being on), use `lv_obj_has_state(switch, LV_STATE_CHECKED)`.

Call `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.


## Events
- `LV_EVENT_VALUE_CHANGED` Sent when the switch changes state.

See the events of the [Base object](/widgets/obj) too.

Learn more about [Events](/overview/event).

## Keys
- `LV_KEY_UP/RIGHT` Turns on the slider
- `LV_KEY_DOWN/LEFT` Turns off the slider
- `LV_KEY_ENTER` Toggles the switch

Learn more about [Keys](/overview/indev).

## Example

```eval_rst

.. include:: ../../examples/widgets/switch/index.rst

```

## API

```eval_rst

.. doxygenfile:: lv_switch.h
  :project: lvgl

```