<!DOCTYPE html>
<html dir="rtl">
<title>Tests position fallback with rtl scroller</title>
<link rel="author" href="mailto:[email protected]">
<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;
}
#anchor {
anchor-name: --a;
width: 100px;
height: 100px;
margin-right: 200px;
background: orange;
}
#spacer {
width: 1000vw;
height: 1px;
}
#anchored {
position: fixed;
width: 100px;
height: 100px;
background: green;
position-anchor: --a;
top: anchor(top);
left: anchor(right);
position-try-fallbacks: --pf;
}
@position-try --pf {
left: auto;
right: anchor(left);
}
</style>
<div id="anchor"></div>
<div id="spacer"></div>
<div id="anchored"></div>
<script>
promise_test(async () => {
await waitUntilNextAnimationFrame();
assert_fallback_position(anchored, anchor, 'right');
}, 'Should use the first fallback position at the initial scroll offset');
promise_test(async () => {
document.documentElement.scrollLeft = -101;
await waitUntilNextAnimationFrame();
assert_fallback_position(anchored, anchor, 'left');
}, 'Should use the second fallback position after scrolling left');
</script>
</html>