css/css-animations/Element-getAnimations-dynamic-changes.tentative.html

<!doctype html>
<meta charset=utf-8>
<title>
Element.getAnimations() - Dynamic changes to the list of CSS animations
</title>
<!-- TODO: Add a more specific link for this once it is specified. -->
<link rel="help" href="https://drafts.csswg.org/css-animations-2/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/testcommon.js"></script>
<style>
@keyframes anim1 {
  to { left: 100px }
}
@keyframes anim2 { }
</style>
<div id="log"></div>
<script>
'use strict';

promise_test(async t => {
  const div = addDiv(t);
  div.style.animation = 'anim1 100s';
  const originalAnimation = div.getAnimations()[0];

  // Wait a moment so we can confirm the startTime doesn't change (and doesn't
  // simply reflect the current time).
  await originalAnimation.ready;

  const originalStartTime = originalAnimation.startTime;
  const originalCurrentTime = originalAnimation.currentTime;

  // Wait a moment so we can confirm the startTime doesn't change (and
  // doesn't simply reflect the current time).
  await waitForNextFrame();

  div.style.animationDuration = '200s';
  const animation = div.getAnimations()[0];
  assert_equals(animation, originalAnimation,
                'The same Animation is returned after updating'
                + ' animation duration');
  assert_equals(animation.startTime, originalStartTime,
                'Animations returned by getAnimations preserve'
                + ' their startTime even when they are updated');
  // Sanity check
  assert_not_equals(animation.currentTime, originalCurrentTime,
                    'Animation.currentTime has updated in next'
                    + ' requestAnimationFrame callback');
}, 'Animations preserve their startTime when changed');

test(t => {
  const div = addDiv(t);
  div.style.animation = 'anim1 100s, anim1 100s';

  // Store original state
  let animations = div.getAnimations();
  const animation1 = animations[0];
  const animation2 = animations[1];

  // Update first in list
  div.style.animationDuration = '200s, 100s';
  animations = div.getAnimations();
  assert_equals(animations[0], animation1,
                'First Animation is in same position after update');
  assert_equals(animations[1], animation2,
                'Second Animation is in same position after update');
}, 'Updated Animations maintain their order in the list');

promise_test(async t => {
  const div = addDiv(t);
  div.style.animation = 'anim1 200s, anim1 100s';

  // Store original state
  let animations = div.getAnimations();
  const animation1 = animations[0];
  const animation2 = animations[1];

  // Wait before continuing so we can compare start times (otherwise the
  // new Animation objects and existing Animation objects will all have the same
  // start time).
  await waitForAllAnimations(animations);
  await waitForFrame();

  // Swap duration of first and second in list and prepend animation at the
  // same time
  div.style.animation = 'anim1 100s, anim1 100s, anim1 200s';
  animations = div.getAnimations();
  assert_true(animations[0] !== animation1 && animations[0] !== animation2,
              'New Animation is prepended to start of list');
  assert_equals(animations[1], animation1,
                'First animation is in second position after update');
  assert_equals(animations[2], animation2,
                'Second animation is in third position after update');
  assert_equals(animations[1].startTime, animations[2].startTime,
                'Old animations have the same start time');
  assert_equals(animations[0].startTime, null,
                'New animation has a null start time');

  await animations[0].ready;

  assert_greater_than(animations[0].startTime, animations[1].startTime,
                      'New animation has later start time');
}, 'Only the startTimes of existing animations are preserved');

promise_test(async t => {
  const div = addDiv(t);
  div.style.animation = 'anim1 100s, anim1 100s';
  const secondAnimation = div.getAnimations()[1];

  // Wait before continuing so we can compare start times
  await secondAnimation.ready;
  await waitForNextFrame();

  // Trim list of animations
  div.style.animationName = 'anim1';
  const animations = div.getAnimations();
  assert_equals(animations.length, 1, 'List of Animations was trimmed');
  assert_equals(animations[0], secondAnimation,
                'Remaining Animation is the second one in the list');
  assert_equals(typeof(animations[0].startTime), 'number',
                'Remaining Animation has resolved startTime');
  assert_less_than(animations[0].startTime,
                   animations[0].timeline.currentTime,
                   'Remaining Animation preserves startTime');
}, 'Animations are removed from the start of the list while preserving'
   + ' the state of existing Animations');

promise_test(async t => {
  const div = addDiv(t);
  div.style.animation = 'anim1 100s';
  const firstAddedAnimation = div.getAnimations()[0];

  // Wait and add second Animation
  await firstAddedAnimation.ready;
  await waitForFrame();

  div.style.animation = 'anim1 100s, anim1 100s';
  const secondAddedAnimation = div.getAnimations()[0];

  // Wait again and add another Animation
  await secondAddedAnimation.ready;
  await waitForFrame();

  div.style.animation = 'anim1 100s, anim2 100s, anim1 100s';
  const animations = div.getAnimations();
  assert_not_equals(firstAddedAnimation, secondAddedAnimation,
                    'New Animations are added to start of the list');
  assert_equals(animations[0], secondAddedAnimation,
                'Second Animation remains in same position after'
                + ' interleaving');
  assert_equals(animations[2], firstAddedAnimation,
                'First Animation remains in same position after'
                + ' interleaving');
  await animations[1].ready;

  assert_greater_than(animations[1].startTime, animations[0].startTime,
                      'Interleaved animation starts later than existing ' +
                      'animations');
  assert_greater_than(animations[0].startTime, animations[2].startTime,
                      'Original animations retain their start time');
}, 'Animation state is preserved when interleaving animations in list');

</script>