| <!DOCTYPE html> |
| <title>`intended direction` scroll snaps only at points ahead of the scroll direction</title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-type" /> |
| <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1766805"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| div { |
| position: absolute; |
| margin: 0px; |
| } |
| #scroller { |
| width: 200px; |
| height: 100px; |
| overflow: scroll; |
| scroll-snap-type: x mandatory; |
| } |
| .snap { |
| scroll-snap-align: start; |
| background: green; |
| } |
| </style> |
| |
| <div id="scroller"> |
| <div style="width: 2000px; height: 100px;"></div> |
| <div class="snap" style="left: 0px; width: 20px; height: 100px;">1</div> |
| <div class="snap" style="left: 100px; width: 20px; height: 100px;">2</div> |
| <div class="snap" style="left: 120px; width: 20px; height: 100px;">3</div> |
| <div class="snap" style="left: 300px; width: 20px; height: 100px;">4</div> |
| <div class="snap" style="left: 400px; width: 20px; height: 100px;">5</div> |
| </div> |
| |
| <script> |
| test(() => { |
| scroller.scrollBy(10, 0); |
| assert_equals(scroller.scrollLeft, 100); |
| |
| scroller.scrollBy(10, 0); |
| assert_equals(scroller.scrollLeft, 120); |
| |
| scroller.scrollBy(10, 0); |
| // Snaps to the next snap point even if the previous snap point is closer to |
| // the current position. |
| assert_equals(scroller.scrollLeft, 300); |
| }, "`intended direction` scroll snaps only at points ahead of the scroll " + |
| "direction"); |
| |
| </script> |
