| <html class="reftest-wait"> |
| <title>Layout changes on percentage-based scroll timeline</title> |
| <link rel="help" href="https://drafts.csswg.org/scroll-animations/"> |
| <meta name="assert" content="Scroll timeline should properly handle |
| layout changes on percentage-based scroll offset"> |
| <link rel="match" href="animation-ref.html"> |
| |
| <script src="/web-animations/testcommon.js"></script> |
| <script src="/common/reftest-wait.js"></script> |
| |
| <style> |
| #box { |
| width: 100px; |
| height: 100px; |
| background-color: green; |
| } |
| |
| #covered { |
| width: 100px; |
| height: 100px; |
| background-color: red; |
| } |
| |
| #scroller { |
| overflow: auto; |
| height: 100px; |
| width: 100px; |
| will-change: transform; |
| } |
| |
| #contents { |
| height: 500px; |
| width: 100%; |
| } |
| |
| #spacer { |
| height: 80px; |
| } |
| |
| .invisible { |
| display: none; |
| } |
| </style> |
| |
| <div id="box"></div> |
| <div id="covered"></div> |
| <div id="scroller"> |
| <div id="contents"></div> |
| <div id="spacer" class="invisible"></div> |
| </div> |
| |
| <script> |
| const box = document.getElementById('box'); |
| const effect = new KeyframeEffect(box, |
| [ |
| { transform: 'translateY(0)', opacity: 1 }, |
| { transform: 'translateY(200px)', opacity: 0 } |
| ], { |
| duration: 1000, |
| } |
| ); |
| |
| const scroller = document.getElementById('scroller'); |
| const timeline = new ScrollTimeline({ |
| scrollSource: scroller, |
| timeRange: 1000, |
| scrollOffsets: [CSS.percent(20), CSS.percent(80)] |
| }); |
| const animation = new Animation(effect, timeline); |
| animation.play(); |
| |
| // Moves the scroller to the end point (240px). |
| const maxScroll = scroller.scrollHeight - scroller.clientHeight; |
| scroller.scrollTop = maxScroll * 0.6; |
| |
| // Makes sure that the animation runs on compositor with current scroll offset |
| waitForAnimationFrames(2).then(_ => { |
| // Adds 80px to scroll height which pushes scroll progress back to 50%. |
| const spacer = document.getElementById('spacer'); |
| spacer.classList.remove('invisible'); |
| // Makes sure that the change is propagated to the compositor. |
| waitForAnimationFrames(2).then(_ => { |
| takeScreenshot(); |
| }); |
| }); |
| </script> |