<!DOCTYPE html>
<meta charset=utf-8>
<title>Playing an animation</title>
<link rel="help"
      href="https://drafts.csswg.org/web-animations/#playing-an-animation-section">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/web-animations/testcommon.js"></script>
<script src="testcommon.js"></script>
<style>
.scroller {
  overflow: auto;
  height: 100px;
  width: 100px;
  will-change: transform;
}

.contents {
  height: 1000px;
  width: 100%;
}
</style>
<body>
<script>
'use strict';

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  assert_equals(animation.startTime, null);
  await animation.ready;
  assert_percents_equal(animation.startTime, 0);

  animation.cancel();
  const scroller = animation.timeline.source;
  const maxScroll = scroller.scrollHeight - scroller.clientHeight;
  scroller.scrollTop = maxScroll / 2;
  animation.play();
  await animation.ready;
  assert_percents_equal(animation.currentTime, 50);

}, 'Playing an animations aligns the start time with the start of the active ' +
   'range');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.playbackRate = -1;
  animation.play();
  await animation.ready;
  assert_percents_equal(animation.startTime, 100);
}, 'Playing an animations with a negative playback rate aligns the start ' +
   'time with the end of the active range');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.startTime = CSSNumericValue.parse("10%");
  await animation.ready;
  assert_percents_equal(animation.startTime, 10);
}, 'Start time set while play pending is preserved.');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.currentTime = CSSNumericValue.parse("10%");
  await animation.ready;
  assert_percents_equal(animation.currentTime, 10);
}, 'Current time set while play pending is preserved.');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  await animation.ready;
  animation.currentTime = CSSNumericValue.parse("10%");
  assert_percents_equal(animation.currentTime, 10);
  animation.play();
  await animation.ready;
  assert_percents_equal(animation.currentTime, 0);
}, 'Playing a running animation resets a sticky start time');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.finish();
  assert_percents_equal(animation.currentTime, 100);
  animation.play();
  await animation.ready;
  assert_percents_equal(animation.currentTime, 0);
}, 'Playing a finished animation restarts the animation aligned at the start');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.playbackRate = -1;
  animation.currentTime = CSSNumericValue.parse("0%");
  assert_percents_equal(animation.currentTime, 0);
  animation.play();
  await animation.ready;

  assert_percents_equal(animation.currentTime, 100);
}, 'Playing a finished and reversed animation restarts the animation aligned ' +
   'at the end');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.finish();
  await animation.finished;

  // Start time is now sticky since modified by an explicit API call.
  // All current time calculations will be based on the new start time
  // while running.
  assert_percents_equal(animation.startTime, -100,
                        'start time when finished');
  assert_percents_equal(animation.currentTime, 100,
                        'current time when finished');

  const scroller = animation.timeline.source;
  const maxScroll = scroller.scrollHeight - scroller.clientHeight;
  scroller.scrollTop = maxScroll / 2;
  await waitForNextFrame();
  assert_percents_equal(animation.startTime, -100,
                        'start time after scrolling a finished animation');
  // Clamped at effect end time.
  assert_percents_equal(animation.currentTime, 100,
                        'current time after scrolling a finished animation');

  // Initiate a pause then abort it
  animation.pause();
  animation.play();

  // Wait to return to running state
  await animation.ready;

  assert_percents_equal(animation.startTime, 0,
      'After aborting a pause when finished, the start time should no ' +
      'longer be sticky');
  assert_percents_equal(animation.currentTime, 50,
      'After aborting a pause when finished, the current time should realign ' +
      'with the scroll position');
}, 'Playing a pause-pending but previously finished animation realigns'
   + ' with the scroll position');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.finish();
  await animation.ready;

  animation.play();
  assert_equals(animation.startTime, null);
  await animation.ready;
  assert_percents_equal(animation.startTime, 0, 'start time is zero');
}, 'Playing a finished animation clears the start time');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.cancel();
  const promise = animation.ready;
  animation.play();
  assert_not_equals(animation.ready, promise);
}, 'The ready promise should be replaced if the animation is not already'
   + ' pending');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  const promise = animation.ready;
  const promiseResult = await promise;
  assert_equals(promiseResult, animation);
  assert_equals(animation.ready, promise);
}, 'A pending ready promise should be resolved and not replaced when the'
   + ' animation enters the running state');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.currentTime = CSSNumericValue.parse("50%");
  await animation.ready;

  assert_percents_equal(animation.currentTime, 50);

  animation.pause();
  await animation.ready;

  assert_percents_equal(animation.currentTime, 50);

  animation.play();
  await animation.ready;

  assert_percents_equal(animation.startTime, 0);
}, 'Resuming an animation from paused realigns with scroll position.');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  await animation.ready;

  // Go to pause-pending state
  animation.pause();
  assert_true(animation.pending, 'Animation is pending');
  const pauseReadyPromise = animation.ready;

  // Now play again immediately (abort the pause)
  animation.play();
  assert_true(animation.pending, 'Animation is still pending');
  assert_equals(animation.ready, pauseReadyPromise,
      'The pause Promise is re-used when playing while waiting to pause');

  // Sanity check: Animation proceeds to running state
  await animation.ready;
  assert_true(!animation.pending && animation.playState === 'running',
      'Animation is running after aborting a pause');
}, 'If a pause operation is interrupted, the ready promise is reused');

promise_test(async t => {
  // Seek animation beyond target end
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.currentTime = CSSNumericValue.parse("-100%");
  await animation.ready;
  assert_percents_equal(animation.currentTime, -100);

  // Set pending playback rate to the opposite direction
  animation.updatePlaybackRate(-1);
  assert_true(animation.pending);
  // Note: Updating the playback rate calls play without rewind. For a
  // scroll-timeline, this will immediately apply the playback rate.
  // TODO: Determine if we should defer applying the new playback rate.
  assert_equals(animation.playbackRate, 1);

  // When we play, we should align to the target end, NOT to zero (which
  // is where we would seek to if we used the playbackRate of 1.
  animation.play();
  await animation.ready;
  assert_percents_equal(animation.startTime, 100);
  assert_percents_equal(animation.currentTime, 100);
}, 'A pending playback rate is used when determining timeline range alignment');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.cancel();
  assert_equals(animation.startTime, null,
                'Start time should be unresolved');

  animation.play();
  assert_true(animation.pending, 'Animation should be play-pending');

  await animation.ready;

  assert_false(animation.pending, 'animation should no longer be pending');
  assert_percents_equal(animation.startTime, 0,
      'The start time of the playing animation should be zero');
}, 'Playing a canceled animation sets the start time');

promise_test(async t => {
  const animation = createScrollLinkedAnimation(t);
  animation.play();
  animation.playbackRate = -1;
  animation.cancel();
  assert_equals(animation.startTime, null, 'Start time should be unresolved');

  animation.play();
  assert_true(animation.pending, 'Animation should be play-pending');

  await animation.ready;

  assert_false(animation.pending, 'Animation should no longer be pending');
  assert_percents_equal(animation.startTime, 100,
      'The start time of the playing animation should be set');
}, 'Playing a canceled animation backwards sets the start time');

</script>
</body>
