HTMLElement: animationstart event
The animationstart
event is fired when a CSS Animation has started. If there is an animation-delay
, this event will fire once the delay period has expired. A negative delay will cause the event to fire with an elapsedTime
equal to the absolute value of the delay (and, correspondingly, the animation will begin playing at that time index into the sequence).
Bubbles | Yes |
---|---|
Cancelable | No |
Interface | AnimationEvent |
Event handler property | onanimationstart |
Examples
This listens for the animationstart
event and logs a message when it is fired:
const animated = document.querySelector('.animated');
animated.addEventListener('animationstart', () => {
console.log('Animation started');
});
The same, but using onanimationstart
:
const animated = document.querySelector('.animated');
animated.onanimationstart = () => {
console.log('Animation started');
};
Live example
HTML
<div class="animation-example">
<div class="container">
<p class="animation">You chose a cold night to visit our planet.</p>
</div>
<button class="activate" type="button">Activate animation</button>
<div class="event-log"></div>
</div>
CSS
.container {
height: 3rem;
}
.event-log {
width: 25rem;
height: 2rem;
border: 1px solid black;
margin: 0.2rem;
padding: 0.2rem;
}
.animation.active {
animation-duration: 2s;
animation-name: slidein;
animation-iteration-count: 2;
}
@keyframes slidein {
from {
transform: translateX(100%) scaleX(3);
}
to {
transform: translateX(0) scaleX(1);
}
}
JS
const animation = document.querySelector('p.animation');
const animationEventLog = document.querySelector('.animation-example>.event-log');
const applyAnimation = document.querySelector('.animation-example>button.activate');
let iterationCount = 0;
animation.addEventListener('animationstart', () => {
animationEventLog.textContent = `${animationEventLog.textContent}'animation started' `;
});
animation.addEventListener('animationiteration', () => {
iterationCount++;
animationEventLog.textContent = `${animationEventLog.textContent}'animation iterations: ${iterationCount}' `;
});
animation.addEventListener('animationend', () => {
animationEventLog.textContent = `${animationEventLog.textContent}'animation ended'`;
animation.classList.remove('active');
applyAnimation.textContent = "Activate animation";
});
animation.addEventListener('animationcancel', () => {
animationEventLog.textContent = `${animationEventLog.textContent}'animation canceled'`;
});
applyAnimation.addEventListener('click', () => {
animation.classList.toggle('active');
animationEventLog.textContent = '';
iterationCount = 0;
let active = animation.classList.contains('active');
if (active) {
applyAnimation.textContent = "Cancel animation";
} else {
applyAnimation.textContent = "Activate animation";
}
});
Result
Specifications
Specification |
---|
CSS Animations Level 2 # eventdef-animationevent-animationstart |
Browser compatibility
BCD tables only load in the browser
See also
- CSS Animations
- Using CSS Animations
AnimationEvent
- Related events:
animationend
,animationiteration
,animationcancel
- This event on
Document
targets:animationstart
- This event on
Window
targets:animationstart