GlobalEventHandler.onanimationend
Обработчик события animationend (en-US)
. Это событие вызывается когда CSS-анимация достигает конца своего активного периода, который вычисляется как (animation-duration
* animation-iteration-count
) + animation-delay
.
Синтаксис
var animEndHandler = target.onanimationend;
target.onanimationend = Function
Значение
A Function
вызывается, когда происходит событие animationend (en-US)
, указывающее, что анимация CSS начинается с цели, где целевой объект является HTML-элементом (HTMLElement
), документ (Document
) или окно (Window
). Функция получает в качестве входного параметра один параметр: AnimationEvent
объект, описывающий событие, которое произошло.
Example
CSS content
Leaving out some bits of the CSS that don't matter for the discussion here, let's take
a look at the styles for the box that we're animating. First is the box itself. We set
its size, position, color, and layout. Note that there's nothing there about animation.
That's because we don't want the box to start animating right away. We'll add the
animation
style later to start animating the box.
#box {
width: var(--boxwidth);
height: var(--boxwidth);
left: 0;
top: 0;
border: 1px solid #7788FF;
margin: 0;
position: relative;
background-color: #2233FF;
display: flex;
justify-content: center;
}
The animation sequence is described next. First, the "slideAnimation"
class, which establishes the animation
that will cause the box to move
over the course of five seconds, one time, using the "slideBox"
keyframe
set. The keyframes are defined next; they describe an animation which causes the box to
migrate from the top-left corner of the container to the bottom-right corner.
.slideAnimation {
animation: 5s ease-in-out 0s 1 slideBox;
}
@keyframes slideBox {
from {
left:0;
top:0;
}
to {
left:calc(100% - var(--boxwidth));
top:calc(100% - var(--boxwidth))
}
}
Since the CSS describes the animation but doesn't connect it to the box, we'll need some JavaScript code to do that. We'll get to that shortly.
JavaScript content
Before we get to the animation code, we define a function which logs information to a
box on the user's screen. We'll use this to show information about the events we
receive. Note the use of AnimationEvent.animationName
and
AnimationEvent.elapsedTime
to get information about the event which occurred.
function log(msg, event) {
let logBox = document.getElementById("log");
logBox.innerHTML += msg;
if (event) {
logBox.innerHTML += " <code>"+ event.animationName +
"</code> at time " + event.elapsedTime.toFixed(2) +
" seconds.";
}
logBox.innerHTML += "\n";
};
Then we set up the event handlers for the animationstart
and
animationend
events:
let box = document.getElementById("box");
box.onanimationstart = function(event) {
log("Animation started", event);
}
box.onanimationend = function(event) {
log("Animation stopped", event);
};
Finally, we set up a handler for a click on the button that runs the animation:
document.getElementById("play").addEventListener("click", function(event) {
document.getElementById("box").className = "slideAnimation";
event.target.style.display = "none";
}, false);
This sets the class of the box we want to animate to the class that contains the
animation
description, then hides the play button because this example
will only run the animation once. For information about why, and how to support running
an animation more than once, see
Run an animation again in CSS Animations tips and tricks.
Result
Assembled together, you get this:
Specification
Specification | Status | Comment |
---|---|---|
CSS Animations Level 1 Определение 'onanimationend' в этой спецификации. |
Рабочий черновик |
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Смотрите также
- The
animationend (en-US)
event this event handler is triggered by AnimationEvent
- The
animationstart (en-US)
event