| <!doctype html> |
| <meta charset=utf-8> |
| <title>scroll-snap-type on non-scrollers traps snap positions</title> |
| <link rel=author title="Tab Atkins-Bittner" href="https://www.xanthir.com/contact/"> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap/#captures-snap-positions"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| |
| .scroller { |
| width: 100px; |
| height: 100px; |
| overflow: auto; |
| scroll-snap-type: block mandatory; |
| } |
| .item { |
| background: gray; |
| height: 100px; |
| scroll-snap-type: block mandatory; |
| } |
| .item.snapped { |
| background: green; |
| scroll-snap-align: center; |
| } |
| .subitem { |
| background: red; |
| height: 100px; |
| scroll-snap-align: center; |
| } |
| |
| </style> |
| |
| |
| <!-- |
| Boxes with a non-none value for scroll-snap-type |
| will capture snap positions from their descendents, |
| preventing them from affecting higher-up scrollers, |
| even if they are not, themselves, scrollers. |
| --> |
| |
| <div class=scroller> |
| <div class=item></div> |
| <div class=item><div class=subitem></div></div> |
| <div class="item snapped"></div> |
| <div class=item></div> |
| </div> |
| |
| <script> |
| |
| test(()=>{ |
| const el = document.querySelector('.scroller'); |
| assert_equals(el.scrollTop, 200); |
| }, "The third item should be snapped to by default, not the second's child."); |
| |
| </script> |
