| <!DOCTYPE html> |
| <title>Tests position fallback with scrollers with mixed writing modes</title> |
| <link rel="author" href="mailto:xiaochengh@chromium.org"> |
| <link rel="help" href="https://drafts.csswg.org/css-anchor-1/#scroll"> |
| <link rel="help" href="https://drafts.csswg.org/css-anchor-1/#fallback-apply"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="support/test-common.js"></script> |
| |
| <style> |
| body { |
| margin: 0; |
| } |
| |
| #vrl-scroller { |
| writing-mode: vertical-rl; |
| overflow-x: scroll; |
| width: calc(100vw - 90px); |
| height: 400px; |
| outline: 1px solid black; |
| } |
| |
| #anchor { |
| anchor-name: --a; |
| width: 100px; |
| height: 100px; |
| margin-left: 1000px; |
| background: orange; |
| } |
| |
| #anchored { |
| position: fixed; |
| width: 100px; |
| height: 100px; |
| background: green; |
| anchor-scroll: --a; |
| position-fallback: --pf; |
| } |
| |
| @position-fallback --pf { |
| /* Top of the anchor */ |
| @try { bottom: anchor(--a top); left: anchor(--a left); } |
| /* Bottom of the anchor */ |
| @try { top: anchor(--a bottom); left: anchor(--a left); } |
| /* Left of the anchor */ |
| @try { top: anchor(--a top); right: anchor(--a left); } |
| } |
| </style> |
| |
| <div style="height: 200px"></div> |
| <div id="vrl-scroller"> |
| <div id="anchor"></div> |
| </div> |
| <div style="height: 1000px"></div> |
| <div id="anchored"></div> |
| |
| <script> |
| promise_test(async () => { |
| await waitUntilNextAnimationFrame(); |
| assert_fallback_position(anchored, anchor, 'top'); |
| }, 'Should use the first fallback position at the initial scroll offsets'); |
| |
| promise_test(async () => { |
| document.documentElement.scrollTop = 101; |
| await waitUntilNextAnimationFrame(); |
| assert_fallback_position(anchored, anchor, 'bottom'); |
| }, 'Should use the second fallback position after scrolling viewport down'); |
| |
| promise_test(async () => { |
| let vrlScroller = document.getElementById('vrl-scroller'); |
| vrlScroller.scrollLeft = -100; |
| await waitUntilNextAnimationFrame(); |
| assert_fallback_position(anchored, anchor, 'left'); |
| }, 'Should use the third fallback position after scrolling the vrl scroller left'); |
| </script> |
