| <!DOCTYPE html> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap/#scroll-snap-stop" /> |
| |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| div, html, body { |
| margin: 0; |
| padding: 0; |
| } |
| |
| html { |
| scroll-snap-type: x mandatory; |
| overflow: scroll; |
| } |
| |
| #scroller { |
| scroll-snap-type: x mandatory; |
| overflow: scroll; |
| height: 400px; |
| width: 400px; |
| } |
| |
| .large_space { |
| width: 2000px; |
| height: 2000px; |
| } |
| |
| .snap_area { |
| scroll-snap-align: none start; |
| width: 100px; |
| height: 100px; |
| |
| background-color: blue; |
| } |
| |
| .snap_area:nth-child(1) { |
| margin-left: 0; |
| } |
| |
| .snap_area:nth-child(2) { |
| margin-left: 100px; |
| } |
| |
| .snap_area:nth-child(3) { |
| margin-left: 300px; |
| } |
| |
| .snap_area:nth-child(4) { |
| margin-left: 500px; |
| } |
| </style> |
| |
| <!-- Add snap area to the root scroller --> |
| <div class="snap_area"></div> |
| <div class="snap_area"></div> |
| <div class="snap_area"></div> |
| <div class="snap_area"></div> |
| |
| <div id="scroller"> |
| <div class="snap_area"></div> |
| <div class="snap_area"></div> |
| <div class="snap_area"></div> |
| <div class="snap_area"></div> |
| <div class="large_space"></div> |
| </div> |
| |
| <div class="large_space"></div> |
| |
| <script> |
| const scrollers = [document.scrollingElement, document.getElementById("scroller")]; |
| for (const scroller of scrollers) { |
| test(_ => { |
| assert_equals(scroller.scrollLeft, 0); // sanity check |
| |
| scroller.querySelectorAll('.snap_area').forEach(area => area.style.scrollSnapStop = 'always'); |
| scroller.scrollBy(500, 0); |
| assert_equals(scroller.scrollLeft, 100, "scrollBy should not skip area with stop always"); |
| |
| scroller.querySelectorAll('.snap_area').forEach(area => area.style.scrollSnapStop = 'normal'); |
| scroller.scrollBy(500, 0); |
| assert_equals(scroller.scrollLeft, 500, "scrollBy should skip secon area with stop normal"); |
| |
| // When snap type is changed back to mandatory, scrolling should snap. |
| scroller.querySelectorAll('.snap_area').forEach(area => area.style.scrollSnapStop = 'always'); |
| scroller.scrollBy(-500, 0); |
| assert_equals(scroller.scrollLeft, 300, "scrollBy should not skip area with stop always"); |
| }, `scroll-snap-stop for areas on ${scroller.nodeName} should control snapping behavior and changing it takes effect`); |
| } |
| </script> |
