| <!DOCTYPE html> |
| <html> |
| <head> |
| <title> |
| <title> CSS Scroll Snap 2 Test: snapchanged events on proximity strictness container</title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-2/#snap-events"/> |
| </title> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/dom/events/scrolling/scroll_support.js"></script> |
| <script src="/css/css-scroll-snap-2/resources/common.js"></script> |
| <style> |
| div { |
| position: absolute; |
| margin: 0; |
| } |
| |
| #scroller { |
| height: 600px; |
| width: 600px; |
| overflow: hidden; |
| scroll-snap-type: y proximity; |
| } |
| |
| .snap { |
| width: 300px; |
| height: 300px; |
| background-color: green; |
| scroll-snap-align: start; |
| } |
| |
| .area { |
| width: 2000px; |
| height: 2000px; |
| } |
| </style> |
| </head> |
| <body> |
| <div id="scroller"> |
| <div class="area"></div> |
| <div id="target" class="snap" style="top: 0px;"></div> |
| </div> |
| |
| <script> |
| const target = document.getElementById("target"); |
| let resolve_func = null; |
| |
| promise_test(async (test) => { |
| checkSnapEventSupport("snapchanged"); |
| await waitForCompositorCommit(); |
| // The initial snap position is at (0, 0). |
| assert_equals(scroller.scrollTop, 0); |
| assert_equals(scroller.scrollLeft, 0); |
| |
| let snapchanged_promise = waitForSnapChangedEvent(scroller); |
| // Scroll to a position where it's outside of the scroll-snap proximity |
| // threshold, so that it won't trigger snapping. |
| scroller.scrollTo(0, 250); |
| |
| // snapchanged should fire as we've moved from within the proximity range |
| // to outside the proximity range and are no longer snapped. |
| let evt = await snapchanged_promise; |
| assert_equals(scroller.scrollTop, 250); |
| assertSnapEvent(evt, []); |
| evt = null; |
| |
| snapchanged_promise = waitForSnapChangedEvent(scroller); |
| // Scroll to a position within the scroll-snap proximity |
| // threshold, so that it triggers snapping. |
| scroller.scrollTo(0, 190); |
| |
| evt = await snapchanged_promise; |
| assert_equals(scroller.scrollTop, 0); |
| // snapchanged should fire as we've moved from outside the proximity range |
| // to inside the proximity range and are once again snapped. |
| assertSnapEvent(evt, [target.id]); |
| }, "Snapchanged fires when scrolling outside proximity range."); |
| </script> |
| </body> |
| </html> |
