| <!DOCTYPE html> |
| <title>Layout Instability: shift with counterscroll not counted, with 2 scrollers</title> |
| <link rel="help" href="https://wicg.github.io/layout-instability/" /> |
| <style> |
| .scroller { |
| overflow: scroll; |
| position: absolute; |
| left: 20px; |
| top: 20px; |
| width: 200px; |
| height: 200px; |
| } |
| .content { |
| width: 170px; |
| height: 600px; |
| } |
| .changer { |
| position: relative; |
| background: yellow; |
| left: 10px; |
| top: 100px; |
| width: 150px; |
| height: 150px; |
| } |
| |
| </style> |
| <div id="scroller1" class="scroller"> |
| <div class="content"> |
| <div id="changer1" class="changer"></div> |
| </div> |
| </div> |
| <div id="scroller2" class="scroller"> |
| <div class="content"> |
| <div id="changer2" class="changer"></div> |
| </div> |
| </div> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/util.js"></script> |
| <script> |
| |
| promise_test(async () => { |
| const watcher = new ScoreWatcher; |
| |
| // Wait for the initial render to complete. |
| await waitForAnimationFrames(2); |
| |
| // Top goes from 100 to 200. scroll by 100 to counter it. |
| changer1.style.top = "200px"; |
| scroller1.scrollTop = 100; |
| // Top goes from 100 to 300. scroll by 200 to counter it. |
| changer2.style.top = "300px"; |
| scroller2.scrollTop = 200; |
| |
| await waitForAnimationFrames(3); |
| assert_equals(watcher.score, 0); |
| }, "Shift with counterscroll not counted, with 2 scrollers."); |
| |
| </script> |