| <!DOCTYPE html> |
| <title>Tests CSS animation of anchor(), dynamic position-anchor changes</title> |
| <link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| #cb { |
| border: 1px solid black; |
| width: 400px; |
| height: 400px; |
| position: relative; |
| } |
| #anchor1, #anchor2 { |
| width: 100px; |
| height: 100px; |
| background: tomato; |
| } |
| #anchor1 { |
| background: coral; |
| anchor-name: --a1; |
| } |
| #anchor2 { |
| background: seagreen; |
| anchor-name: --a2; |
| } |
| #anchored { |
| width: 50px; |
| height: 50px; |
| background: skyblue; |
| animation: --anim 9999s steps(2, start); |
| position: absolute; |
| position-anchor: --a1; |
| } |
| @keyframes --anim { |
| from { top: anchor(top); } |
| to { top: anchor(bottom); } |
| } |
| </style> |
| <div id=cb> |
| <div id=anchor1></div> |
| <div id=anchor2></div> |
| <div id=anchored></div> |
| </div> |
| <script> |
| test(() => { |
| assert_equals(anchored.offsetTop, 50); |
| anchored.style.positionAnchor = '--a2'; |
| assert_equals(anchored.offsetTop, 150); |
| }, 'Animation with anchor() responds to position-anchor change'); |
| </script> |
