<html class="reftest-wait">
<title>Scroll timeline with Web Animation and transition from display:none to display:block</title>
<link rel="help" href="https://drafts.csswg.org/scroll-animations/">
<meta name="assert" content="Scroll timeline should properly handle going from display:none to display:block">
<link rel="match" href="animation-ref.html">
<script src="/web-animations/testcommon.js"></script>
<script src="/common/reftest-wait.js"></script>
<style>
#box {
width: 100px;
height: 100px;
background-color: green;
}
#covered {
width: 100px;
height: 100px;
background-color: red;
}
#scroller {
overflow: auto;
height: 100px;
width: 100px;
will-change: transform; /* force compositing */
}
.removed {
display: none;
}
#contents {
height: 1000px;
width: 100%;
}
</style>
<div id="box"></div>
<div id="covered"></div>
<div id="scroller">
<div id="contents"><p>Scrolling Contents</p></div>
</div>
<script>
const box = document.getElementById('box');
const effect = new KeyframeEffect(box,
[
{ transform: 'translateY(0)', opacity: 1 },
{ transform: 'translateY(200px)', opacity: 0 }
], {
duration: 1000,
}
);
const scroller = document.getElementById('scroller');
scroller.classList.add('removed');
const timeline = new ScrollTimeline(
{ source: scroller, orientation: 'block' });
const animation = new Animation(effect, timeline);
animation.play();
waitForAnimationFrames(2).then(_ => {
scroller.classList.remove('removed');
animation.ready.then(() => {
const maxScroll = scroller.scrollHeight - scroller.clientHeight;
scroller.scrollTop = 0.5 * maxScroll;
waitForAnimationFrames(2).then(_ => {
takeScreenshot();
});
});
});
</script>