52 lines
1.4 KiB
HTML
52 lines
1.4 KiB
HTML
<!DOCTYPE html>
|
|
<title>Layout Instability: element with compositing layer hint</title>
|
|
<link rel="help" href="https://wicg.github.io/layout-instability/" />
|
|
<style>
|
|
|
|
#shift {
|
|
position: relative;
|
|
width: 500px;
|
|
height: 200px;
|
|
background: yellow;
|
|
}
|
|
#container {
|
|
position: absolute;
|
|
width: 350px;
|
|
height: 400px;
|
|
right: 50px;
|
|
top: 100px;
|
|
background: #ccc;
|
|
}
|
|
.promote { will-change: transform; }
|
|
|
|
</style>
|
|
<div id="container" class="promote">
|
|
<div id="space"></div>
|
|
<div id="shift" class="promote"></div>
|
|
</div>
|
|
<script src="/resources/testharness.js"></script>
|
|
<script src="/resources/testharnessreport.js"></script>
|
|
<script src="resources/util.js"></script>
|
|
<script>
|
|
|
|
promise_test(async () => {
|
|
const watcher = new ScoreWatcher;
|
|
|
|
// Wait for the initial render to complete.
|
|
await waitForAnimationFrames(2);
|
|
|
|
// Induce a shift.
|
|
document.querySelector("#space").style = "height: 100px";
|
|
|
|
// #shift is 400x200 after viewport intersection with correct application of
|
|
// composited #container offset, and 100px lower after shifting, so impact
|
|
// region is 400 * (200 + 100).
|
|
const expectedScore = computeExpectedScore(400 * (200 + 100), 100);
|
|
|
|
// Observer fires after the frame is painted.
|
|
assert_equals(watcher.score, 0);
|
|
await watcher.promise;
|
|
assert_equals(watcher.score, expectedScore);
|
|
}, "Element with compositing layer hint.");
|
|
|
|
</script>
|