| <!doctype html> |
| <meta charset=utf-8> |
| <title>Seamlessly updating the playback rate of an animation</title> |
| <link rel="help" |
| href="https://drafts.csswg.org/web-animations-1/#seamlessly-updating-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); |
| await animation.ready; |
| |
| animation.currentTime = 50 * MS_PER_SEC; |
| |
| animation.updatePlaybackRate(0.5); |
| await animation.ready; |
| // Since the animation is in motion (and we want to test it while it is in |
| // motion!) we can't assert that the current time == 50s but we can check |
| // that the current time is NOT re-calculated by simply substituting in the |
| // new playback rate (i.e. without adjusting the start time). If that were |
| // the case the currentTime would jump to 25s. So we just test the currentTime |
| // hasn't gone backwards. |
| assert_greater_than_equal(animation.currentTime, 50 * MS_PER_SEC, |
| 'Reducing the playback rate should not change the current time ' + |
| 'of a playing animation'); |
| |
| animation.updatePlaybackRate(2); |
| await animation.ready; |
| // Likewise, we test here that the current time does not jump to 100s as it |
| // would if we naively applied a playbackRate of 2 without adjusting the |
| // startTime. |
| assert_less_than(animation.currentTime, 100 * MS_PER_SEC, |
| 'Increasing the playback rate should not change the current time ' + |
| 'of a playing animation'); |
| }, 'Updating the playback rate maintains the current time'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| await animation.ready; |
| |
| assert_false(animation.pending); |
| animation.updatePlaybackRate(2); |
| assert_true(animation.pending); |
| }, 'Updating the playback rate while running makes the animation pending'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.currentTime = 50 * MS_PER_SEC; |
| assert_true(animation.pending); |
| |
| animation.updatePlaybackRate(0.5); |
| |
| // Check that the hold time is updated as expected |
| assert_time_equals_literal(animation.currentTime, 50 * MS_PER_SEC); |
| |
| await animation.ready; |
| |
| // As above, check that the currentTime is not calculated by simply |
| // substituting in the updated playbackRate without updating the startTime. |
| assert_greater_than_equal(animation.currentTime, 50 * MS_PER_SEC, |
| 'Reducing the playback rate should not change the current time ' + |
| 'of a play-pending animation'); |
| }, 'Updating the playback rate on a play-pending animation maintains' |
| + ' 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.pause(); |
| animation.updatePlaybackRate(0.5); |
| |
| assert_greater_than_equal(animation.currentTime, 50 * MS_PER_SEC); |
| }, 'Updating the playback rate on a pause-pending animation maintains' |
| + ' the current time'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| |
| animation.updatePlaybackRate(2); |
| animation.updatePlaybackRate(3); |
| animation.updatePlaybackRate(4); |
| |
| assert_equals(animation.playbackRate, 1); |
| await animation.ready; |
| |
| assert_equals(animation.playbackRate, 4); |
| }, 'If a pending playback rate is set multiple times, the latest wins'); |
| |
| test(t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.cancel(); |
| |
| animation.updatePlaybackRate(2); |
| assert_equals(animation.playbackRate, 2); |
| assert_false(animation.pending); |
| }, 'In the idle state, the playback rate is applied immediately'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.pause(); |
| await animation.ready; |
| |
| animation.updatePlaybackRate(2); |
| assert_equals(animation.playbackRate, 2); |
| assert_false(animation.pending); |
| }, 'In the paused state, the playback rate is applied immediately'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.finish(); |
| assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC); |
| assert_false(animation.pending); |
| |
| animation.updatePlaybackRate(2); |
| assert_equals(animation.playbackRate, 2); |
| assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC); |
| assert_false(animation.pending); |
| }, 'Updating the playback rate on a finished animation maintains' |
| + ' the current time'); |
| |
| promise_test(async t => { |
| const animation = createDiv(t).animate(null, 100 * MS_PER_SEC); |
| animation.finish(); |
| assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC); |
| assert_false(animation.pending); |
| |
| animation.updatePlaybackRate(0); |
| assert_equals(animation.playbackRate, 0); |
| assert_time_equals_literal(animation.currentTime, 100 * MS_PER_SEC); |
| assert_false(animation.pending); |
| }, 'Updating the playback rate to zero on a finished animation maintains' |
| + ' the current time'); |
| |
| </script> |
| </body> |