| <!doctype HTML> |
| <html> |
| <meta charset="utf8"> |
| <title>Content Visibility: resize observer interactions</title> |
| <link rel="author" title="Chris Harrelson" href="mailto:chrishtr@chromium.org"> |
| <link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility"> |
| <meta name="assert" content="content-visibility hidden subtrees do not trigger resize observer"> |
| |
| <style> |
| .hidden { |
| content-visibility: hidden; |
| } |
| </style> |
| <div id="container"> |
| <div id="resize" style="width: 50px; height: 50px"> |
| </div> |
| </div> |
| |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| |
| <script> |
| async_test((t) => { |
| let didCallback = false; |
| |
| async function runTest() { |
| let resizeCallback = function (entries) { |
| didCallback = true; |
| } |
| let resizeObserver = new ResizeObserver(resizeCallback); |
| |
| resizeObserver.observe(resize); |
| |
| requestAnimationFrame(step2); |
| } |
| |
| async function step2() { |
| assert_equals(true, didCallback, 'Resize observation should happen in first frame after registering'); |
| didCallback = false; |
| |
| const container = document.getElementById("container"); |
| container.classList.add("hidden"); |
| |
| // Change the size of #resize. This should cause a resize observation, but |
| // only when the element becomes unhidden. |
| resize.style.width = '100px'; |
| |
| requestAnimationFrame(step3); |
| } |
| |
| async function step3() { |
| assert_equals(false, didCallback, |
| 'ResizeObsever should not run during while unrendered'); |
| requestAnimationFrame(step4); |
| } |
| |
| async function step4() { |
| assert_equals(false, didCallback, |
| 'ResizeObsever should not run while unrendered'); |
| const container = document.getElementById("container"); |
| container.classList.remove("hidden"); |
| requestAnimationFrame(step5); |
| } |
| |
| async function step5() { |
| assert_equals(true, didCallback, |
| 'ResizeObsevers should now run once becoming visible'); |
| t.done(); |
| } |
| |
| window.onload = function() { |
| requestAnimationFrame(() => requestAnimationFrame(runTest)); |
| }; |
| }, "ResizeObserver skipped while hidden"); |
| </script> |
| </html> |
