<!DOCTYPE html>
<title>Tests that anchored element's actual rendered location is property exposed via JS APIs under scrolling</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#scroll">
<link rel="author" href="mailto:[email protected]">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
#container {
position: absolute;
top: 0px;
left: 0px;
}
#scroller {
margin-left: 100px;
margin-top: 100px;
width: 400px;
height: 400px;
overflow: scroll;
}
#anchor-container {
width: 2000px;
height: 1000px;
}
#anchor {
margin: 400px;
margin-left: 1400px;
width: 100px;
height: 100px;
background-color: yellow;
anchor-name: --anchor;
}
#anchored {
position: absolute;
left: anchor(left);
bottom: anchor(top);
width: 100px;
height: 100px;
position-anchor: --anchor;
background-color: green;
}
</style>
<div id="container">
<div id="scroller">
<div id="anchor"></div>
</div>
<div id="anchored">Text</div>
</div>
<script>
promise_setup(async () => {
// Move both the anchor and the anchored elements into the visible area of the
// scroller. This also runs layout to setup an empty scroll snapshot.
scroller.scrollTop = 300;
scroller.scrollLeft = 1300;
// Ensure up-to-date scroll snapshot.
await new Promise(resolve => requestAnimationFrame(resolve));
});
promise_test(async () => {
let rect = anchored.getBoundingClientRect();
assert_equals(rect.x, 200);
assert_equals(rect.y, 100);
}, 'Element.getBoundingClientRect() returns the actual rendered location');
promise_test(async () => {
let range = document.createRange();
let text = anchored.firstChild;
range.setStart(text, 0);
range.setEnd(text, text.length);
let rect = range.getBoundingClientRect();
assert_equals(rect.x, 200);
assert_equals(rect.y, 100);
}, 'Range.getBoundingClientRect() returns the actual rendered location');
promise_test(async () => {
assert_equals(anchored.offsetLeft, 200);
assert_equals(anchored.offsetTop, 100);
}, 'Element.offset* return adjusted offsets');
promise_test(() => new Promise(resolve => {
let observer = new IntersectionObserver(entryList => {
if (entryList.some(entry => entry.isIntersecting))
resolve();
});
observer.observe(anchored);
}), 'IntersectionObserver should fire when anchored element is moved into visible area');
</script>