| <!DOCTYPE html> |
| <meta charset=utf-8> |
| <title>Setting the playback rate of an animation</title> |
| <link rel="help" href="https://drafts.csswg.org/web-animations/#setting-the-playback-rate-of-an-animation"> |
| <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); |
| animation.playbackRate = 2; |
| await animation.ready; |
| |
| const previousAnimationCurrentTime = animation.currentTime; |
| const previousTimelineCurrentTime = animation.timeline.currentTime; |
| |
| await waitForAnimationFrames(1); |
| |
| const animationCurrentTimeDifference = |
| animation.currentTime - previousAnimationCurrentTime; |
| const timelineCurrentTimeDifference = |
| animation.timeline.currentTime - previousTimelineCurrentTime; |
| |
| assert_times_equal( |
| animationCurrentTimeDifference, |
| timelineCurrentTimeDifference * animation.playbackRate, |
| 'The current time should increase two times faster than timeline' |
| ); |
| }, 'The playback rate affects the rate of progress of the current time'); |
| |
| test(t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.currentTime = 50 * MS_PER_SEC; |
| animation.playbackRate = 2; |
| assert_time_equals_literal(animation.currentTime, 50 * MS_PER_SEC); |
| }, 'Setting the playback rate while play-pending preserves the current time'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.currentTime = 50 * MS_PER_SEC; |
| await animation.ready; |
| animation.playbackRate = 2; |
| assert_greater_than_equal(animation.currentTime, 50 * MS_PER_SEC); |
| assert_less_than(animation.currentTime, 100 * MS_PER_SEC); |
| }, 'Setting the playback rate while playing preserves the current time'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.currentTime = 50 * MS_PER_SEC; |
| animation.updatePlaybackRate(2); |
| animation.playbackRate = 1; |
| await animation.ready; |
| assert_equals(animation.playbackRate, 1); |
| }, 'Setting the playback rate should clear any pending playback rate'); |
| |
| </script> |
| </body> |
