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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /scroll-animations/view-timelines/sticky/view-timeline-sticky-containing-block-clamp.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<html id="top">
<head>
<meta charset="utf-8">
<title>View timeline with sticky clamped by its containing block mid-timeline</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/web-animations/testcommon.js"></script>
<script src="/scroll-animations/scroll-timelines/testcommon.js"></script>
<script src="/scroll-animations/view-timelines/testcommon.js"></script>
<style>
#container {
height: 500px;
overflow: auto;
}
.space {
height: 550px;
}
/* The sticky element's containing block. It is short, so the sticky element
runs out of room and is pulled away from the top edge part-way through the
timeline. */
.space.tight {
height: 400px;
}
/* bottom-sticky during entry, top-sticky during contain */
.stickycase {
background: yellow;
position: sticky;
top: 300px;
bottom: -100px;
height: 200px;
}
#target {
position: relative;
top: 50px;
background: orange;
height: 100px;
}
</style>
</head>
<body>
<div id="container">
<div class="space"></div>
<div class="space tight">
<div style="height: 150px"></div>
<div id="sticky" class="stickycase">
<div id="target">Subject</div>
</div>
</div>
<div class="space"></div>
</div>
<script type="text/javascript">
// The "cover" range would be [STATIC_START, STATIC_END] if we ignored
// stickiness (i.e., considered only static position).
//
// STATIC_START = scroll distance to second spacer (50px)
// + position of sticky element within its container (150px)
// + position of target within sticky element (50px)
// STATIC_END = STATIC_START
// + viewport height (500px)
// + target height (100px)
const STATIC_START = 250;
const STATIC_END = 850;
// This is how far the sticky element can move upwards when bottom-stuck
// (150px of containing block above it).
const ROOM_ABOVE = 150;
// This is how far the sticky element can move downwards when top-stuck. The
// containing block is only 400px tall and the sticky element already occupies
// 150px..350px of it, so the element unsticks from the top edge again after
// only 50px of travel, at scroll offset 450 - well before the end of the
// timeline.
const ROOM_BELOW = 50;
const TARGET_HEIGHT = 100;
const VIEWPORT_HEIGHT = 500;
// The sticky element is bottom-stuck for scroll offsets below 300 and
// top-stuck for scroll offsets in [400, 450]. Only the offsets on the far side
// of the top-stuck interval pick up ROOM_BELOW, and only the offsets below 300
// pick up ROOM_ABOVE. STATIC_START + TARGET_HEIGHT = 350 falls between the two
// stuck intervals and is therefore unadjusted.
promise_test(async t => {
await runTimelineRangeTest(t, {
rangeStart: { rangeName: 'cover', offset: CSS.percent(0) },
rangeEnd: { rangeName: 'cover', offset: CSS.percent(100) },
startOffset: STATIC_START - ROOM_ABOVE,
endOffset: STATIC_END + ROOM_BELOW,
axis: 'block'
});
await runTimelineRangeTest(t, {
rangeStart: { rangeName: 'contain', offset: CSS.percent(0) },
rangeEnd: { rangeName: 'contain', offset: CSS.percent(100) },
startOffset: STATIC_START + TARGET_HEIGHT,
endOffset: STATIC_END + ROOM_BELOW - TARGET_HEIGHT,
axis: 'block'
});
await runTimelineRangeTest(t, {
rangeStart: { rangeName: 'entry', offset: CSS.percent(0) },
rangeEnd: { rangeName: 'entry', offset: CSS.percent(100) },
startOffset: STATIC_START - ROOM_ABOVE,
endOffset: STATIC_START + TARGET_HEIGHT,
axis: 'block'
});
await runTimelineRangeTest(t, {
rangeStart: { rangeName: 'entry-crossing', offset: CSS.percent(0) },
rangeEnd: { rangeName: 'entry-crossing', offset: CSS.percent(100) },
startOffset: STATIC_START - ROOM_ABOVE,
endOffset: STATIC_START + TARGET_HEIGHT,
axis: 'block'
});
await runTimelineRangeTest(t, {
rangeStart: { rangeName: 'exit', offset: CSS.percent(0) },
rangeEnd: { rangeName: 'exit', offset: CSS.percent(100) },
startOffset: STATIC_END + ROOM_BELOW - TARGET_HEIGHT,
endOffset: STATIC_END + ROOM_BELOW,
axis: 'block'
});
await runTimelineRangeTest(t, {
rangeStart: { rangeName: 'exit-crossing', offset: CSS.percent(0) },
rangeEnd: { rangeName: 'exit-crossing', offset: CSS.percent(100) },
startOffset: STATIC_END + ROOM_BELOW - TARGET_HEIGHT,
endOffset: STATIC_END + ROOM_BELOW,
axis: 'block'
});
}, 'View timeline with a sticky element whose stuck range is cut short by ' +
'its containing block.');
</script>
</body>
</html>