KeyframeEffect.KeyframeEffect()

The KeyframeEffect() constructor of the Web Animations API returns a new KeyframeEffect object instance.

Syntax

var keyframes = new keyframeEffect(element, keyframeSet, keyframeOptions);

Parameters

element

The DOM element to be animated.

keyframeSet

An array of keyframe objects — these are property value pairs (as seen in the Examples section.)

keyframeOptions

Either an integer representing the animation's duration (in milliseconds), or an object containing optional animation timing options, which can include those detailed in the animation timing options reference, and can also include the Additional keyframeOptions listed below.

Additional keyframeOptions

composite Optional

Determines how values are combined between this animation and other, separate animations that do not specify their own composite operation. The available options are as follows (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 instead result in translateX(-200px) rotate(20deg).
• accumulate is similar but a little smarter: blur(2) and blur(5) would combine to become blur(7), not blur(2) blur(5).
• replace overwrites the previous value with the new one. 

iterationComposite Optional

Determines how values build from iteration to iteration in the current animation. This can be set to accumulate or replace (see above), and defaults to replace.

spacing Optional

Determines how keyframes without temporal offsets should be distributed during the animation's duration. It cna take the following values (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.

Examples

In the Follow the White Rabbit example, the KeyframeEffect constructor is used to create a set of keyframes that dictate how the White Rabbit should animate down the hole:

 var rabbitDownKeyframes = new KeyframeEffect( 
    whiteRabbit, // element to animate
    [
      { transform: 'translateY(0%)' }, // keyframe 
      { transform: 'translateY(100%)' } // keyframe
    ], 
    { duration: 3000, fill: 'forwards' } // keyframe options
  );

Specifications

Browser compatibility

See also

• KeyframeEffect Interface
• Web Animations API
• Animation