| <!DOCTYPE html> |
| <link rel="help" src="https://drafts.csswg.org/scroll-animations-1/#scroll-timeline-at-rule"> |
| <link rel="help" src="https://drafts.csswg.org/scroll-animations-1/#phase-algorithm"> |
| <link rel="help" src="https://drafts.csswg.org/scroll-animations-1/#avoiding-cycles"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/web-animations/testcommon.js"></script> |
| <style> |
| #scroller { |
| overflow: scroll; |
| width: 100px; |
| height: 100px; |
| } |
| #contents { |
| height: 200px; |
| } |
| @keyframes expand { |
| from { width: 100px; } |
| to { width: 200px; } |
| } |
| #element { |
| width: 0px; |
| animation: expand 10s linear paused; |
| animation-timeline: timeline; |
| } |
| </style> |
| <div id="container"> |
| <div id=element></div> |
| </div> |
| <script> |
| |
| promise_test(async (t) => { |
| let div = document.createElement('div'); |
| div.setAttribute('id', 'scroller'); |
| div.innerHTML = '<div id=contents></div>'; |
| let style = document.createElement('style'); |
| style.textContent = ` |
| @scroll-timeline timeline { |
| source: selector(#scroller); |
| } |
| `; |
| try { |
| container.insertBefore(style, element); |
| container.insertBefore(div, style); |
| |
| // The source has no layout box at the time the scroll timeline is created. |
| assert_equals(getComputedStyle(element).width, '0px'); |
| scroller.offsetTop; // Ensure a layout box for the scroller. |
| // Wait for an update to the timeline state: |
| await waitForNextFrame(); |
| // The timeline should now be active, and the animation should apply: |
| assert_equals(getComputedStyle(element).width, '100px'); |
| } finally { |
| style.remove(); |
| div.remove(); |
| } |
| }, 'Animation does not apply when timeline is initially inactive'); |
| |
| </script> |
