| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>ScrollTimeline snapshotting</title> |
| <link rel="help" href="https://wicg.github.io/scroll-animations/#avoiding-cycles"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/resources/testdriver.js"></script> |
| <script src="/resources/testdriver-vendor.js"></script> |
| <script src="/resources/testdriver-actions.js"></script> |
| <script src="/web-animations/testcommon.js"></script> |
| |
| <style> |
| body { |
| height: 800px; |
| width: 800px; |
| } |
| </style> |
| <div id="log"></div> |
| |
| <script> |
| 'use strict'; |
| |
| promise_test(async t => { |
| const scroller = document.scrollingElement; |
| const maxScroll = scroller.scrollHeight - scroller.clientHeight; |
| const timeline = new ScrollTimeline( |
| {scrollSource: scroller, timeRange: maxScroll}); |
| scroller.scrollTo(0, 0); |
| assert_equals(scroller.scrollTop, 0, "verify test pre-condition"); |
| |
| scroller.scrollBy({top:100, behavior:'smooth'}) |
| // Wait for the scroll to change. |
| const startScroll = scroller.scrollTop; |
| do { |
| await waitForNextFrame(); |
| } while(scroller.scrollTop == startScroll); |
| assert_times_equal(timeline.currentTime, scroller.scrollTop, |
| 'Scroll timeline current time corresponds to the scroll position.'); |
| }, 'ScrollTimeline current time is updated after programmatic animated scroll.'); |
| |
| </script> |
