<!DOCTYPE html>
<meta charset=utf-8>
<title>Pausing an animation</title>
<link rel="help"
  href="https://drafts.csswg.org/web-animations/#pausing-an-animation-section">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../../testcommon.js"></script>
<body>
<div id="log"></div>
<script>
'use strict';

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  await animation.ready;

  const startTimeBeforePausing = animation.startTime;

  animation.pause();
  assert_equals(animation.startTime, startTimeBeforePausing,
                'The start time does not change when pausing-pending');

  await animation.ready;

  assert_equals(animation.startTime, null,
                'The start time is unresolved when paused');
}, 'Pausing clears the start time');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  await animation.ready;

  animation.pause();
  assert_not_equals(animation.startTime, null,
                    'The start time is resolved when pause-pending');

  animation.play();
  assert_not_equals(animation.startTime, null,
                    'The start time is preserved when a pause is aborted');
}, 'Aborting a pause preserves the start time');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  const promise = animation.ready;
  animation.pause();

  const promiseResult = await promise;

  assert_equals(promiseResult, animation);
  assert_equals(animation.ready, promise);
  assert_false(animation.pending, 'No longer pause-pending');
}, 'A pending ready promise should be resolved and not replaced when the'
   + ' animation is paused');

promise_test(async t => {
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  // Let animation start roughly half-way through
  animation.currentTime = 50 * MS_PER_SEC;
  await animation.ready;

  // Go pause-pending and also set a pending playback rate
  animation.pause();
  animation.updatePlaybackRate(0.5);

  await animation.ready;
  // If the current time was updated using the new playback rate it will jump
  // back to 25s but if we correctly used the old playback rate the current time
  // will be >= 50s.
  assert_greater_than_equal(animation.currentTime, 50 * MS_PER_SEC);
}, 'A pause-pending animation maintains the current time when applying a'
   + ' pending playback rate');

promise_test(async t => {
  // This test does not cover a specific step in the algorithm but serves as a
  // high-level sanity check that pausing does, in fact, freeze the current
  // time.
  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);
  await animation.ready;

  animation.pause();
  await animation.ready;

  const currentTimeAfterPausing = animation.currentTime;

  await waitForNextFrame();

  assert_equals(animation.currentTime, currentTimeAfterPausing,
    'Animation.currentTime is unchanged after pausing');
}, 'The animation\'s current time remains fixed after pausing');


promise_test(async t => {

  const animation = createDiv(t).animate(null, 100 * MS_PER_SEC);

  const originalReadyPromise = animation.ready;
  animation.cancel();
  assert_equals(animation.startTime, null);
  assert_equals(animation.currentTime, null);

  const readyPromise = animation.ready;
  assert_not_equals(originalReadyPromise, readyPromise,
              'Canceling an animation should create a new ready promise');

  animation.pause();
  assert_equals(animation.playState, 'paused',
                'Pausing a canceled animation should update the play state');
  assert_true(animation.pending, 'animation should be pause-pending');
  await animation.ready;
  assert_false(animation.pending,
               'animation should no longer be pause-pending');
  assert_equals(animation.startTime, null, 'start time should be unresolved');
  assert_equals(animation.currentTime, 0, 'current time should be set to zero');

}, 'Pausing a canceled animation sets the current time');

</script>
</body>
