The AnimationEvent() constructor returns a new AnimationEvent object, representing an event in relation with an animation.
new AnimationEvent(type)
new AnimationEvent(type, options)typeA string with the name of the type of the AnimationEvent. It is case-sensitive and browsers set it to animationstart, animationend, or animationiteration.
options OptionalAn object that, in addition of the properties defined in Event(), has the following properties:
animation OptionalA CSSAnimation containing the animation associated with the event. It defaults to null.
animationName OptionalA string containing the value of the animation-name CSS property associated with the transition. It defaults to "".
elapsedTime OptionalA float giving the amount of time the animation has been running, in seconds, when this event fired, excluding any time the animation was paused. For an animationstart event, elapsedTime is 0.0 unless there was a negative value for animation-delay, in which case the event will be fired with elapsedTime containing (-1 * delay). It defaults to 0.0.
pseudoElement OptionalA string, starting with "::", containing the name of the pseudo-element the animation runs on. If the animation doesn't run on a pseudo-element but on the element itself, specify an empty string: "". It defaults to "".
animation, animation-delay, animation-direction, animation-duration, animation-fill-mode, animation-iteration-count, animation-name, animation-play-state, animation-timing-function, @keyframesAnimationEvent interface it belongs to.