| <!DOCTYPE html> |
| <title>CSS Anchor Positioning: Transition when the anchor attribute changes</title> |
| <link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/"> |
| <link rel="help" href="https://github.com/w3c/csswg-drafts/issues/9598"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| #cb { |
| display: inline-block; |
| position: relative; |
| width: 250px; |
| height: 250px; |
| border: 1px solid black; |
| } |
| #anchor1, #anchor2 { |
| width: 100px; |
| } |
| #anchor1 { |
| background: wheat; |
| height: 50px; |
| } |
| #anchor2 { |
| background: tomato; |
| height: 90px; |
| } |
| #anchored { |
| position: absolute; |
| width: anchor-size(width); |
| height: anchor-size(height); |
| top: anchor(top); |
| left: anchor(right); |
| transition-duration: 1000s; |
| transition-timing-function: steps(2, start); |
| transition-property: top, height; |
| background-color: skyblue; |
| } |
| </style> |
| <div id=cb> |
| <div id=anchor1>Anchor1</div> |
| <div id=anchor2>Anchor2</div> |
| <div id=anchored anchor=anchor1></div> |
| </div> |
| <script> |
| test(() => { |
| assert_equals(anchored.offsetTop, 0); |
| assert_equals(anchored.offsetHeight, 50); |
| anchored.setAttribute('anchor', 'anchor2'); |
| assert_equals(anchored.offsetTop, 25); |
| assert_equals(anchored.offsetHeight, 70); |
| }, 'Transition when the anchor attribute changes'); |
| </script> |
