| <!DOCTYPE html> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| |
| body { height: 4000px } |
| #A, #B { width: 100px; background-color: #afa; } |
| #B { height: 100px; } |
| #inner { width: 100px; height: 100px; background-color: pink; } |
| #A { overflow-anchor: none; } |
| |
| </style> |
| <div id="changer1"></div> |
| <div id="A"> |
| <div id="inner"></div> |
| <div id="changer2"></div> |
| </div> |
| <div id="B"></div> |
| <script> |
| |
| // Tests that an element with overflow-anchor: none is excluded, along with its |
| // DOM descendants, from the anchor selection algorithm. |
| |
| test(() => { |
| var changer1 = document.querySelector("#changer1"); |
| var changer2 = document.querySelector("#changer2"); |
| |
| document.scrollingElement.scrollTop = 50; |
| changer1.style.height = "100px"; |
| changer2.style.height = "50px"; |
| |
| // We should anchor to #B, not #A or #inner, despite them being visible. |
| assert_equals(document.scrollingElement.scrollTop, 200); |
| |
| document.querySelector("#A").style.overflowAnchor = "auto"; |
| document.scrollingElement.scrollTop = 150; |
| |
| changer1.style.height = "200px"; |
| changer2.style.height = "100px"; |
| |
| // We should now anchor to #inner, which is moved only by #changer1. |
| assert_equals(document.scrollingElement.scrollTop, 250); |
| }, "Subtree exclusion with overflow-anchor."); |
| |
| </script> |
