# Arc Button (ArcButton)


The **ArcButton** component represents an arc button specifically designed for circular screens. It offers various button styles, such as emphasized, normal, and warning, tailored for watch UIs. For details, see [ArcButton](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md).


## Creating a Button

To create an **ArcButton** component, use the following:

  ```ts
ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      position: ArcButtonPosition.TOP_EDGE,
      styleMode: ArcButtonStyleMode.EMPHASIZED_LIGHT
    })
})
  ```

- [label](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions): sets the text displayed on the button.

- [position](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions): sets the type of the button.

- [styleMode](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions): sets the style mode of the button.

  ![top](figures/ArcButtonTop.png)

## Setting the Button Type

The **ArcButton** component offers two types: top arc button and bottom arc button. Use the [position](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) attribute to set the type.

- Lower arc button (default type)

  Set [position](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) to **ArcButtonPosition.BOTTOM_EDGE**.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      position: ArcButtonPosition.BOTTOM_EDGE,
      styleMode: ArcButtonStyleMode.EMPHASIZED_LIGHT
    })
  })
  ```

  ![bottom](figures/ArcButtonBottom.png)

- Upper arc button

  Set [position](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) to **ArcButtonPosition.TOP_EDGE**.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      position: ArcButtonPosition.TOP_EDGE,
      styleMode: ArcButtonStyleMode.EMPHASIZED_LIGHT
    })
  })
  ```

  ![top](figures/ArcButtonTOP_EDGE.png)

## Customizing the Style

- Setting the background color

  Use the [backgroundColor](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) attribute to set the background color of the button.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      styleMode: ArcButtonStyleMode.CUSTOM,
      backgroundColor: ColorMetrics.resourceColor('#707070')
    })
  })
  ```

  ![custom_bg](figures/ArcButtonCustom_bg.png)

- Setting the font color

  Use the [fontColor](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) attribute to set the font color of the button.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      styleMode: ArcButtonStyleMode.CUSTOM,
      backgroundColor: ColorMetrics.resourceColor('#E84026'),
      fontColor: ColorMetrics.resourceColor('#707070')
    })
  })
  ```

  ![custom_font](figures/ArcButtonCustom_font.png)

- Setting the shadow color

  Enable the button shadow using the [shadowEnabled](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) attribute and set the shadow color using the [shadowColor](../reference/apis-arkui/arkui-ts/ohos-arkui-advanced-ArcButton.md#arcbuttonoptions) attribute.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      shadowEnabled: true,
      shadowColor: ColorMetrics.resourceColor('#ffec1022')
    })
  })
  ```

  ![custom_shadow](figures/ArcButtonCustom_shadow.png)

## Adding Events

- Bind the **onClick** event to define custom behavior to be executed when the button is clicked.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      onClick: () => {
        console.info('ArcButton onClick')
      }
    })
  })
  ```

- Bind the **onTouch** event to define custom behavior to be executed when the button is touched.

  ```ts
  ArcButton({
    options: new ArcButtonOptions({
      label: 'OK',
      onTouch: (event: TouchEvent) => {
        console.info('ArcButton onTouch')
      }
    })
  })
  ```

## Example

This example demonstrates a brightness settings screen where a slider displays the current brightness level at 30%. When the reset button is clicked, the brightness value is reset to the default value of 50%.

  ```ts
import { LengthMetrics, LengthUnit, ArcButton, ArcButtonOptions, ArcButtonStyleMode } from '@kit.ArkUI';

@Entry
@ComponentV2
struct BrightnessPage {
  @Local brightnessValue: number = 30;
  private defaultBrightnessValue: number = 50;

  build() {
    RelativeContainer() {
      Text('Set brightness')
        .fontColor(Color.White)
        .id('id_brightness_set_text')
        .fontSize(24)
        .margin({ top: 16 })
        .alignRules({
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        })

      Text(`${this.brightnessValue} %`)
        .fontColor(Color.White)
        .id('id_brightness_min_text')
        .margin({ left: 16 })
        .alignRules({
          start: { anchor: '__container__', align: HorizontalAlign.Start },
          center: { anchor: '__container__', align: VerticalAlign.Center }
        })

      Slider({
        value: this.brightnessValue,
        min: 0,
        max: 100,
        style: SliderStyle.InSet
      })
        .blockColor('#191970')
        .trackColor('#ADD8E6')
        .selectedColor('#4169E1')
        .width(150)
        .id('id_brightness_slider')
        .margin({ left: 16, right: 16 })
        .onChange((value: number, mode: SliderChangeMode) => {
          this.brightnessValue = value;
        })
        .alignRules({
          center: { anchor: 'id_brightness_min_text', align: VerticalAlign.Center },
          start: { anchor: 'id_brightness_min_text', align: HorizontalAlign.End }
        })

      ArcButton({
        options: new ArcButtonOptions({
          label: 'Reset',
          styleMode: ArcButtonStyleMode.EMPHASIZED_LIGHT,
          fontSize: new LengthMetrics(19, LengthUnit.FP),
          onClick: () => {
            this.brightnessValue = this.defaultBrightnessValue;
          }
        })
      })
        .alignRules({
          middle: { anchor: '__container__', align: HorizontalAlign.Center },
          bottom: { anchor: '__container__', align: VerticalAlign.Bottom }
        })
    }
    .height('100%')
    .width('100%')
    .backgroundColor(Color.Black)
  }
}
  ```

  ![example](figures/example_normal.png)