# Property Animation

You can animate certain properties of a component, including **width**, **height**, **backgroundColor**, **opacity**, **scale**, **rotate**, and **translate**.

> **NOTE**
>
> This event is supported since API version 7. Updates will be marked with a superscript to indicate their earliest API version.

animation(value: {duration?: number, tempo?: number, curve?: string | Curve | ICurve, delay?:number, iterations?: number, playMode?: PlayMode, onFinish?: () => void})

Since API version 9, this API is supported in ArkTS widgets.

**Parameters**

| Name        | Type                                      | Mandatory   | Description                                                        |
| ---------- | ------------------------------------------| ---- | ------------------------------------------------------------ |
| duration   | number                                    | No   | Animation duration, in ms.<br>Default value: **1000**<br>Unit: ms<br>Since API version 9, this API is supported in ArkTS widgets.<br>**NOTE**<br>- The maximum animation duration on an ArkTS widget is 1000 ms.<br>- A value less than 0 evaluates to the value **0**.<br>- Floating-point values will be rounded down to integers. For example, if the value set is 1.2, **1** will be used.|
| tempo      | number                                    | No   | Animation playback speed. A larger value indicates a higher animation playback speed.<br>The value **0** indicates that no animation is applied.<br>Default value: **1**<br>**NOTE**<br>A value less than 0 evaluates to the value **1**.|
| curve      | string \| [Curve](ts-appendix-enums.md#curve) \| [ICurve](../apis/js-apis-curve.md#icurve)<sup>9+</sup> | No  | Animation curve.<br>Default value: **Curve.EaseInOut**<br>Since API version 9, this API is supported in ArkTS widgets.|
| delay      | number                                    | No   | Delay of animation playback, in ms. The value **0** indicates that the playback is not delayed.<br>Default value: **0**<br>Value range: [0, +∞)<br>**NOTE**<br>- A value less than 0 evaluates to the value **0**.<br>- Floating-point values will be rounded down to integers. For example, if the value set is 1.2, **1** will be used.|
| iterations | number                                    | No   | Number of times that the animation is played.<br>Default value: **1**<br>Value range: [-1, +∞)<br>**NOTE**<br>The value **-1** indicates that the animation is played for an unlimited number of times. The value **0** indicates that no animation is applied.|
| playMode   | [PlayMode](ts-appendix-enums.md#playmode) | No   | Animation playback mode. By default, the animation is played from the beginning after the playback is complete.<br>Default value: **PlayMode.Normal**<br>Since API version 9, this API is supported in ArkTS widgets.<br>For details about the restrictions, see **Notes about PlayMode**.|
| onFinish   | () => void                                | No   | Callback invoked when the animation playback is complete.<br>Since API version 9, this API is supported in ArkTS widgets.<br>**NOTE**<br>This callback is not invoked when **iterations** is set to **-1**.|

> **Notes about PlayMode**:
> - **PlayMode.Normal** and **PlayMode.Alternate** are recommended. Under these settings, the first round of the animation is played forwards. If **PlayMode.Reverse** or **PlayMode.AlternateReverse** is used, the first round of the animation is played backwards. In this case, the animation jumps to the end state and then starts from there.
> - When using **PlayMode.Alternate** or **PlayMode.AlternateReverse**, make sure the final state of the animation is the same as the value of the state variable. In other words, make sure the last round of the animation is played forwards. When **PlayMode.Alternate** is used, **iterations** must be set to an odd number. When **PlayMode.AlternateReverse** is used, **iterations** must be set to an even number.
> - **PlayMode.Reverse** is not recommended. Under this setting, the animation jumps to the end state at the beginning, and its final state will be different from the value of the state variable.

## Example

```ts
// xxx.ets
@Entry
@Component
struct AttrAnimationExample {
  @State widthSize: number = 250
  @State heightSize: number = 100
  @State rotateAngle: number = 0
  @State flag: boolean = true

  build() {
    Column() {
      Button('change size')
        .onClick(() => {
          if (this.flag) {
            this.widthSize = 150
            this.heightSize = 60
          } else {
            this.widthSize = 250
            this.heightSize = 100
          }
          this.flag = !this.flag
        })
        .margin(30)
        .width(this.widthSize)
        .height(this.heightSize)
        .animation({
          duration: 2000,
          curve: Curve.EaseOut,
          iterations: 3,
          playMode: PlayMode.Normal
        })
      Button('change rotate angle')
        .onClick(() => {
          this.rotateAngle = 90
        })
        .margin(50)
        .rotate({ angle: this.rotateAngle })
        .animation({
          duration: 1200,
          curve: Curve.Friction,
          delay: 500,
          iterations: -1, // The value -1 indicates that the animation is played for an unlimited number of times.
          playMode: PlayMode.Alternate
        })
    }.width('100%').margin({ top: 20 })
  }
}
```

![animation](figures/animation.gif)