| <!DOCTYPE html> |
| <html> |
| <title> |
| Resnap when the current snap position is no longer a valid snap target. |
| </title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1/#snap-scope"/> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/css/css-scroll-snap/support/common.js"></script> |
| <style> |
| html { |
| scroll-snap-type: y mandatory; |
| } |
| body { |
| margin: 0; |
| } |
| .snap { |
| scroll-snap-align: center; |
| height: 100vh; |
| margin: 0; |
| } |
| </style> |
| <body onload = "runTest()"> |
| <div id = "card1" class="snap">ONE</div> |
| <div id = "card2" class="snap">TWO</div> |
| <div id = "card3" class="snap">THREE</div> |
| </body> |
| <script type="text/javascript"> |
| function runTest() { |
| promise_test(async t => { |
| const scroller = document.scrollingElement; |
| // scroll to card THREE |
| let expectedSnapPosition = card3.offsetTop; |
| scroller.scrollTo(0, expectedSnapPosition); |
| assert_equals(scroller.scrollTop, expectedSnapPosition, |
| 'Aligned with card THREE before style change'); |
| |
| // Snap to card TWO after invalidating card THREE as a snap target. |
| card3.style.scrollSnapAlign = 'none center'; |
| await waitForNextFrame(); |
| expectedSnapPosition = card2.offsetTop; |
| assert_equals(scroller.scrollTop, expectedSnapPosition, |
| 'Aligned with card TWO after style change'); |
| }, 'Resnap when the current snap position is no longer a valid snap target'); |
| } |
| </script> |
| </html> |