47 lines
1.5 KiB
HTML
47 lines
1.5 KiB
HTML
<!DOCTYPE html>
|
|
<title>Layout Instability: off-screen content-visibility:auto content</title>
|
|
<link rel="help" href="https://wicg.github.io/layout-instability/" />
|
|
<script src="/resources/testharness.js"></script>
|
|
<script src="/resources/testharnessreport.js"></script>
|
|
<script src="resources/util.js"></script>
|
|
<script>
|
|
// These scripts need to be before the contents because we need to ensure no
|
|
// layout shifts during page load.
|
|
promise_test(async () => {
|
|
const watcher = new ScoreWatcher;
|
|
|
|
// Wait for the initial render to complete.
|
|
await waitForAnimationFrames(2);
|
|
|
|
window.scrollTo(0, 100000 + 100);
|
|
await waitForAnimationFrames(2);
|
|
|
|
assert_equals(watcher.score, 0);
|
|
|
|
// This should report a layout shift as target is now visible.
|
|
target.style.top = '100100px';
|
|
|
|
await watcher.promise;
|
|
const expectedScore = computeExpectedScore(100 * 100, 1);
|
|
assert_approx_equals(watcher.score, expectedScore, 1e-8, "before scroll to top");
|
|
|
|
// No new layout shift should be reported when target is scrolled out of screen.
|
|
window.scrollTo(0, 0);
|
|
await waitForAnimationFrames(2);
|
|
|
|
assert_approx_equals(watcher.score, expectedScore, 1e-8, "after scroll to top");
|
|
}, 'off-screen content-visibility:auto');
|
|
</script>
|
|
<style>
|
|
.auto {
|
|
content-visibility: auto;
|
|
contain-intrinsic-size: 1px;
|
|
width: 100px;
|
|
}
|
|
</style>
|
|
<div class=auto>
|
|
<div style="width: 100px; height: 100px; background: blue"></div>
|
|
</div>
|
|
<div id="target" class=auto style="position: relative; top: 100000px">
|
|
<div style="width: 100px; height: 100px; background: blue"></div>
|
|
</div>
|