| 12
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 
 | <!DOCTYPE html>
<meta charset=utf8>
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>Test getComputedStyle on a CSS animation with scroll timeline in a content visibility subtree using content-visibility: auto</title>
<link rel="help" href="https://drafts.csswg.org/css-contain-2/">
<script src="/web-animations/testcommon.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
#container {
  content-visibility: auto;
}
#scrollContainer {
  height: 100vh;
  overflow-y: scroll;
  scroll-timeline-name: --targetTimeline;
}
#innerspacer {
    height: 300vh;
}
@keyframes fade {
  from { opacity: 1; }
  to { opacity: 0;  }
}
#target {
  background: green;
  height: 100px;
  width: 100px;
}
.animate {
  animation-name: fade;
  animation-duration: 1ms;
  animation-direction: alternate;
  animation-timeline: --targetTimeline;
}
</style>
<body>
  <div id="log"></div>
  <div id="spacer"></div>
  <div id="scrollContainer">
    <div id="container"></div>
    <div id="innerspacer"></div>
  </div>
</body>
<script>
"use strict";
function createAnimatingElement(test, name) {
  const container = document.getElementById('container');
  const target = document.createElement('div');
  container.appendChild(target);
  target.id = 'target';
  target.className = name;
  return target;
}
promise_test(async t => {
  const container = document.getElementById('container');
  const target = createAnimatingElement(t, 'animate');
  scrollContainer.scrollTop = 10000;
  const animation = target.getAnimations()[0];
  await animation.ready;
  await waitForAnimationFrames(1);
  let expectedOpacity = parseFloat(getComputedStyle(target).opacity);
  assert_approx_equals(expectedOpacity, 0, 0.1, 'scrollContainer scrolls to bottom, so the opacity should be 0');
  document.getElementById('spacer').style.height = '300vh';
  await waitForAnimationFrames(1);
  assert_equals(parseFloat(getComputedStyle(target).opacity), expectedOpacity, 'Opacity does not change when it is hidden by c-v');
  scrollContainer.scrollTop = 0;
  assert_equals(parseFloat(getComputedStyle(target).opacity), expectedOpacity, 'The animation is hidden by c-v, so opacity does not change even if scrollTop changes');
  await waitForAnimationFrames(2);
  document.getElementById('spacer').style.height = '0vh';
  await waitForAnimationFrames(2);
  assert_equals(getComputedStyle(target).opacity, '1', 'Now that the animation is visible, opacity should be updated');
}, 'Animation with scroll-timeline should be affected c-v');
</script>
 |