| <!doctype HTML> |
| <html id=html> |
| <meta charset="utf8"> |
| <title>Content Visibility: scroll position restoration</title> |
| <link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org"> |
| <link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility"> |
| <meta name="assert" content="if an scroller is hidden via content-visibility and then shown again, its scroll offset should be restored"> |
| |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="support/helper.js"></script> |
| |
| <style> |
| .scroller { |
| width: 100px; |
| height: 500px; |
| overflow-y: scroll; |
| } |
| .spacer { height: 3000px; } |
| .hidden { content-visibility: hidden; } |
| </style> |
| |
| <div id=target class=scroller> |
| <div class=spacer></div> |
| </div> |
| </style> |
| |
| <script> |
| function removeHiddenAndScheduleTest(t) { |
| target.classList.remove("hidden"); |
| requestAnimationFrame(() => { |
| requestAnimationFrame(() => { |
| testScrollTop(t); |
| }); |
| }); |
| } |
| |
| function testScrollTop(t) { |
| t.step(() => assert_equals(target.scrollTop, 2000)); |
| t.done(); |
| } |
| |
| async_test((t) => { |
| target.scrollTop = 2000; |
| target.classList.add("hidden"); |
| |
| requestAnimationFrame(() => { |
| requestAnimationFrame(() => { |
| removeHiddenAndScheduleTest(t); |
| }); |
| }); |
| }, "Scroll offset is restored when content-visibility hidden is removed"); |
| </script> |
| </html> |
