| <!DOCTYPE html> |
| <style> |
| #box { |
| width: 100px; |
| height: 100px; |
| background-color: #00ff00; |
| } |
| |
| #covered { |
| width: 100px; |
| height: 100px; |
| background-color: #ff8080; |
| } |
| |
| /* The scroller is not originally scrollable. */ |
| .scroller { |
| overflow: visible; |
| height: 100px; |
| width: 100px; |
| } |
| |
| .overflow { |
| overflow-y: scroll; |
| will-change: transform; /* force compositing */ |
| } |
| |
| #contents { |
| height: 1000px; |
| } |
| </style> |
| |
| <div id="box"></div> |
| <div id="covered"></div> |
| <div id="scroller" class="scroller"> |
| <div id="contents"></div> |
| </div> |
| |
| <script id="passthrough_animator" type="text/worklet"> |
| registerAnimator("passthrough_animator", class { |
| animate(currentTime, effect) { |
| effect.localTime = currentTime; |
| } |
| }); |
| </script> |
| |
| <script src="resources/animation-worklet-tests.js"></script> |
| <script> |
| if (window.testRunner) { |
| testRunner.waitUntilDone(); |
| } |
| |
| runInAnimationWorklet( |
| document.getElementById('passthrough_animator').textContent |
| ).then(()=>{ |
| const box = document.getElementById('box'); |
| const effect = new KeyframeEffect(box, |
| [ |
| { transform: 'translateY(0)' }, |
| { transform: 'translateY(200px)' } |
| ], { |
| duration: 1000, |
| } |
| ); |
| |
| const scroller = document.getElementById('scroller'); |
| const timeline = new ScrollTimeline({ scrollSource: scroller, timeRange: 1000, orientation: 'block' }); |
| const animation = new WorkletAnimation('passthrough_animator', effect, timeline); |
| animation.play(); |
| |
| // Ensure that the WorkletAnimation will have been started on the compositor. |
| waitTwoAnimationFrames(function() { |
| // Now make the scroller overflow, which will cause it to be composited and |
| // the animation should update on the compositor side. |
| scroller.classList.add('overflow'); |
| const maxScroll = scroller.scrollHeight - scroller.clientHeight; |
| scroller.scrollTop = 0.5 * maxScroll; |
| |
| if (window.testRunner) { |
| waitForAnimationFrames(3, _ => { |
| testRunner.notifyDone(); |
| }); |
| } |
| }); |
| }); |
| </script> |
