Animation.playState - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The Animation.playState property of the Web Animations API returns and sets an enumerated value describing the playback state of an animation.

This property is read-only for CSS Animations and Transitions.

Syntax

var currentPlayState = Animation.playState;

Animation.playState = newState;

Value

idle

The current time of the animation is unresolved and there are no pending tasks.

running

The animation is running.

paused

The animation was suspended and the Animation.currentTime property is not updating.

finished

The animation has reached one of its boundaries and the Animation.currentTime property is not updating.

Previously, Web Animations defined a pending value to indicate that some asynchronous operation such as initiating playback was yet to complete. This is now indicated by the separate Animation.pending property.

Example

In the Growing/Shrinking Alice Game example, players can get an ending with Alice crying into a pool of tears. In the game, for performance reasons, the tears should only be animating when they're visible. So they must be paused as soon as they are animated like so:

// Setting up the tear animations

tears.forEach(function(el) {
  el.animate(
    tearsFalling,
    {
      delay: getRandomMsRange(-1000, 1000), // randomized for each tear
      duration: getRandomMsRange(2000, 6000), // randomized for each tear
      iterations: Infinity,
      easing: 'cubic-bezier(0.6, 0.04, 0.98, 0.335)'
    });
  el.pause();
});

// Play the tears falling when the ending needs to be shown.

tears.forEach(function(el) {
  el.play();
});

// Reset the crying tears animations and pause them.

tears.forEach(function(el) {
  el.pause();
  el.currentTime = 0;
});

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Web Animations API
• Animation for other methods and properties you can use to control web page animation.