Element.animate()

The Element interface's animate() method is a shortcut method which creates a new Animation, applies it to the element, then plays the animation. It returns the created Animation object instance.

语法

var animation = element.animate(keyframes, options); 

参数

keyframes

An Object formatted to represent a set of keyframes.

options

Either an integer representing the animation's duration (in milliseconds), or an Object containing one or more timing properties: 

id 可选

A property unique to animate(): a DOMString with which to reference the animation.

delay Optional

The number of milliseconds to delay the start of the animation. Defaults to 0.

direction Optional

Whether the animation runs forwards (normal), backwards (reverse), switches direction after each iteration (alternate), or runs backwards and switches direction after each iteration (alternate-reverse). Defaults to "normal".

duration Optional

The number of milliseconds each iteration of the animation takes to complete. Defaults to 0. Although this is technically optional, keep in mind that your animation will not run if this value is 0.

easing Optional

The rate of the animation's change over time. Accepts the pre-defined values "linear", "ease", "ease-in", "ease-out", and "ease-in-out", or a custom "cubic-bezier" value like "cubic-bezier(0.42, 0, 0.58, 1)". Defaults to "linear".

endDelay Optional

The number of milliseconds to delay after the end of an animation. This is primarily of use when sequencing animations based on the end time of another animation. Defaults to 0. 

fill Optional

Dictates whether the animation's effects should be reflected by the element(s) prior to playing ("backwards"), retained after the animation has completed playing ("forwards"), or both. Defaults to "none".

iterationStart Optional

Describes at what point in the iteration the animation should start. 0.5 would indicate starting halfway through the first iteration for example, and with this value set, an animation with 2 iterations would end halfway through a third iteration. Defaults to 0.0.

iterations Optional

The number of times the animation should repeat. Defaults to 1, and can also take a value of Infinity to make it repeat for as long as the element exists.

Future Options

The following options are currently not shipped anywhere, but will be added in the near future.

composite 可选

Determines how values are combined between this animation and other, separate animations that do not specify their own specific composite operation. Defaults to replace.

• add dictates an additive effect, where each successive iteration builds on the last. For instance with transform, a translateX(-200px) would not override an earlier rotate(20deg) value but result in translateX(-200px) rotate(20deg).
• accumulate is similar but a little smarter: blur(2) and blur(5) become blur(7), not blur(2) blur(5).
• replace overwrites the previous value with the new one. 

iterationComposite 可选

Determines how values build from iteration to iteration in this animation. Can be set to accumulate or replace (see above). Defaults to replace.

spacing 可选

Determines how keyframes without temporal offsets should be distributed during the animation's duration. Defaults to distribute.

• distribute positions keyframes so that the difference between subsequent keyframe offsets are equal, that is to say, without any offsets, it will equally distribute the keyframes across play time.
• paced positions keyframes so that the distance between subsequent values of a specified paced property are equal, that is to say, keyframes are spaced further apart the greater the difference in their property values.

 

返回值

Returns an Animation.

Example

In the demo Down the Rabbit Hole (with the Web Animation API), we use the convenient animate() method to immediately create and play an animation on the #tunnel element to make it flow upwards, infinitely. Notice the array of objects passed as keyframes and also the timing options block.

document.getElementById("tunnel").animate([
  // keyframes
  { transform: 'translateY(0px)' }, 
  { transform: 'translateY(-300px)' }
], { 
  // timing options
  duration: 1000,
  iterations: Infinity
});

规范

浏览器兼容性

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See also

• Web Animations API
• Element.getAnimations()
• Animation