Animation: remove event
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2020.
The remove
event of the Animation
interface fires when the animation is automatically removed by the browser.
Syntax
Use the event name in methods like addEventListener()
, or set an event handler property.
addEventListener('remove', (event) => { })
onremove = (event) => { }
Event type
An AnimationPlaybackEvent
. Inherits from Event
.
Event properties
In addition to the properties listed below, properties from the parent interface, Event
, are available.
AnimationPlaybackEvent.currentTime
Read only-
The current time of the animation that generated the event.
AnimationPlaybackEvent.timelineTime
Read only-
The time value of the timeline of the animation that generated the event.
Examples
Removing replaced animations
In this example we have a <button id="start">
element, and an event listener that runs whenever the mouse moves. The mousemove
event handler sets up an animation that animates the <button>
to the position of the mouse pointer. This could result in a huge animations list, which could create a memory leak. For this reason, modern browsers automatically remove forwards-filling animations that are overridden by other animations.
The number of animations created is displayed. A remove
event listener is used to count and display the number of animations removed as well.
All but one of the animations should eventually be removed.
HTML
<button id="start">Click to drag</button>
<br />
<button id="reset">Reset example</button>
<p>
Click the button to start the animation (disabled by default to protect those
who suffer migraines when experiencing such animations).
</p>
<p>Animations created: <span id="count-created">0</span></p>
<p>Animations removed: <span id="count-removed">0</span></p>
CSS
:root,
body {
margin: 0;
padding: 0;
height: 100%;
}
button {
margin: 0.5rem 0;
}
JavaScript
const button = document.querySelector("#start");
let created = 0;
let removed = 0;
button.addEventListener(
"click",
() => {
document.body.addEventListener("mousemove", (event) => {
const animation = button.animate(
{ transform: `translate(${event.clientX}px, ${event.clientY}px)` },
{ duration: 500, fill: "forwards" },
);
created++;
showCounts();
// the remove event fires after the animation is removed
animation.addEventListener("remove", () => {
removed++;
showCounts();
});
});
},
{ once: true },
);
function showCounts() {
document.getElementById("count-created").textContent = created;
document.getElementById("count-removed").textContent = removed;
}
const reset = document.querySelector("#reset");
reset.addEventListener("click", () => {
document.location.reload();
});
Result
Specifications
Specification |
---|
Web Animations # dom-animation-onremove |
Web Animations # remove-event |
Browser compatibility
BCD tables only load in the browser
See also
- Web Animations API
Animation
,AnimationPlaybackEvent
Animation.replaceState
, to check whether an animation has been removedAnimation.persist()
, to prevent removal of an animation