| <!DOCTYPE html> |
| <title>@container: scroll-state(snapped) target selector change</title> |
| <link rel="help" href="https://drafts.csswg.org/css-conditional-5/#snapped"> |
| <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="/css/css-conditional/container-queries/support/cq-testcommon.js"></script> |
| <script src="/css/css-transitions/support/helper.js"></script> |
| <style> |
| html { scroll-snap-type: block mandatory; } |
| body { margin: 0; } |
| #filler { height: 10000px; } |
| #snapped { |
| container-type: scroll-state; |
| scroll-snap-align: start; |
| width: 100px; |
| height: 100px; |
| } |
| @container scroll-state(snapped: block) { |
| .target { --snapped: true; } |
| } |
| </style> |
| <div id="snapped"> |
| <span id="target"></span> |
| </div> |
| <div id="filler"></div> |
| <script> |
| setup(() => assert_implements_scroll_state_container_queries()); |
| |
| promise_test(async t => { |
| await waitForAnimationFrames(2); |
| assert_equals(getComputedStyle(target).getPropertyValue("--snapped"), ""); |
| assert_equals(window.scrollY, 0); |
| }, "Initially snapped to #snapped, but scroll-state() is not queried") |
| |
| promise_test(async t => { |
| target.className = "target"; |
| await waitForAnimationFrames(2); |
| assert_equals(getComputedStyle(target).getPropertyValue("--snapped"), "true"); |
| }, "scroll-state(snapped) queried for #snapped after adding class to #target"); |
| </script> |
