| <!DOCTYPE html> |
| <html class="reftest-wait"> |
| <title>Update callback should only be called once</title> |
| <link rel="author" title="Tim Nguyen" href="https://github.com/nt1m"> |
| <link rel="help" href="https://drafts.csswg.org/css-view-transitions-1/#call-dom-update-callback-algorithm"> |
| <link rel="match" href="../reference/ref-filled-green-100px-square.xht"> |
| <meta name="fuzzy" content="maxDifference=0-1; totalPixels=0-500"> |
| <style> |
| #target { |
| width: 100px; |
| height: 100px; |
| background-color: red; |
| } |
| |
| ::view-transition-group(*), |
| ::view-transition-image-pair(*), |
| ::view-transition-old(*), |
| ::view-transition-new(*) { |
| animation-play-state: paused; |
| } |
| </style> |
| <p>Test passes if there is a filled green square and <strong>no red</strong>.</p> |
| <div id="target"></div> |
| <script> |
| addEventListener("load", () => { |
| let updateCallbackCalled = false; |
| document.startViewTransition(function() { |
| target.style.backgroundColor = updateCallbackCalled ? "red" : "green"; |
| updateCallbackCalled = true; |
| document.startViewTransition(() => {}); |
| requestAnimationFrame(() => { |
| requestAnimationFrame(() => { |
| document.documentElement.classList.remove("reftest-wait"); |
| }); |
| }); |
| }); |
| }); |
| </script> |
| </html> |
