xref: /docs/en/application-dev/ui/ui-js-building-ui-animation.md

# Developing Animations


Animations are classified into [Static Animation](#static-animation) and [Continuous Animation](#continuous-animation).


## Static Animation

The transform attributes are the core of the static animation. A static animation can transform in the following three ways and only once in each way at a time:

- translate: moves a specified component horizontally or vertically.

- scale: scales a specified component horizontally or vertically to the required scale.

- rotate: rotates a specified component by a specified angle along the horizontal axis, vertical axis, or center point.

For more information, see [Component Methods](../reference/apis-arkui/arkui-js/js-components-common-methods.md). The following is an example:

```html
<!-- xxx.hml -->
<div class="container">
  <text class="translate">hello</text>
  <text class="rotate">hello</text>
  <text class="scale">hello</text>
</div>
```

```css
/* xxx.css */
.container {
  width: 100%;
  flex-direction: column;
  align-items: center;
}
.translate {
  height: 150px;
  width: 300px;
  margin: 50px;
  font-size: 50px;
  background-color: #008000;
  transform: translate(200px);
}
.rotate {
  height: 150px;
  width: 300px;
  margin: 50px;
  font-size: 50px;
  background-color: #008000;
  transform-origin: 200px 100px;
  transform: rotate(45deg);
}
.scale {
  height: 150px;
  width: 300px;
  margin: 50px;
  font-size: 50px;
  background-color: #008000;
  transform: scaleX(1.5);
}
```

**Figure 1** Static animation

![en-us_image_0000001071134933](figures/en-us_image_0000001071134933.png)


## Continuous Animation

The static animation has only the start and end states. To set the transition state and conversion effect, use continuous animations.

The core of a continuous animation is animation attributes, which define the start and end states of the animation and the curve of time and speed. Animation attributes can implement the following effects:

- **animation-name**: background color, opacity, width, height, and transformation type applied to the element after the animation is executed

- **animation-delay** and **animation-duration**: element delay and duration after the animation is executed

- **animation-timing-function**: speed curve of an animation, which makes the animation more fluent

- **animation-iteration-count**: number of animation playback times

- **animation-fill-mode**: whether to restore the initial state after the animation is executed

To use the animation attributes, you need to define a @keyframes rule in the .css file, set the animation transition effect in **@keyframes**, and invoke the effect through a style class in the .hml file. The following is an example for **animation-name**:

```html
<!-- xxx.hml -->
<div class="item-container">
    <div class="item {{colorParam}}">
        <text class="txt">color</text>
    </div>
    <div class="item {{opacityParam}}">
        <text class="txt">opacity</text>
    </div>
    <input class="button" type="button" name="" value="show" onclick="showAnimation"/>
</div>
```

```css
/* xxx.css */
.item-container {
  margin: 60px;
  flex-direction: column;
}
.item {
  width: 80%;
  background-color: #f76160;
}
.txt {
  text-align: center;
  width: 200px;
  height: 100px;
}
.button {
  width: 200px;
  margin: 10px;
  font-size: 30px;
  background-color: #09ba07;
}
.color {
  animation-name: Color;
  animation-duration: 8000ms;
}
.opacity {
  animation-name: Opacity;
  animation-duration: 8000ms;
}
@keyframes Color {
  from {
    background-color: #f76160;
  }
  to {
    background-color: #09ba07;
  }
}
@keyframes Opacity {
  from {
    opacity: 0.9;
  }
  to {
    opacity: 0.1;
  }
}
```

```js
// xxx.js
export default {
  data: {
    colorParam: '',
    opacityParam: '',
  },
  showAnimation: function () {
    this.colorParam = '';
    this.opacityParam = '';
    this.colorParam = 'color';
    this.opacityParam = 'opacity';
  }
}
```

**Figure 2** Continuous animation effect

![en-us_image_0000001063148757](figures/en-us_image_0000001063148757.gif)