| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8"> |
| <title> CSS Scroll Snap 2 Test: snapchanged events</title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-2/#snap-events"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/dom/events/scrolling/scroll_support.js"></script> |
| </head> |
| <body> |
| <style> |
| #container { |
| overflow-y: scroll; |
| height: 500px; |
| width: 300px; |
| border: solid 1px black; |
| position: absolute; |
| scroll-snap-type: y mandatory; |
| } |
| .snap_area { |
| scroll-snap-align: start; |
| height: 400px; |
| width: 200px; |
| left: 50px; |
| position: absolute; |
| } |
| #area1 { |
| background-color: blue; |
| } |
| #area2 { |
| top: 400px; |
| background-color: yellow; |
| } |
| #area3 { |
| top: 800px; |
| background-color: green; |
| } |
| </style> |
| <div id="container"> |
| <div id="area1" class="snap_area"></div> |
| <div id="area2" class="snap_area"></div> |
| <div id="area3" class="snap_area"></div> |
| </div> |
| <script> |
| promise_test(async (t) => { |
| await waitForCompositorCommit(); |
| |
| container.addEventListener("snapchanged", |
| t.unreached_func("snapchanged should not fire")); |
| let reset = () => { |
| container.scrollTo({ top: 0, behavior: "smooth"}); |
| container.removeEventListener("scroll", reset); |
| }; |
| container.addEventListener("scroll", reset); |
| |
| let scrollend_promise = waitForScrollendEventNoTimeout(container); |
| container.scrollTo({ top: 250, behavior: "smooth"}); |
| await scrollend_promise; |
| assert_equals(container.scrollTop, 0, "scroll position is reset"); |
| |
| // snapchanged should not fire since the scroll ended on the same snap |
| // target as the one it started on. |
| await waitForCompositorCommit(); |
| }, "snapchanged doesn't fire if interrupting scroll cancels snap"); |
| </script> |
| </body> |
| </html> |
