зеркало из https://github.com/mozilla/gecko-dev.git
54 строки
1.4 KiB
HTML
54 строки
1.4 KiB
HTML
<!DOCTYPE html>
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<meta name="viewport" content="width=device-width,initial-scale=1">
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<script src="/resources/testharness.js"></script>
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<script src="/resources/testharnessreport.js"></script>
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<script src="./resources/intersection-observer-test-utils.js"></script>
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<style>
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#scroller { width: 100px; height: 100px; overflow: scroll; }
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#scroller > div { height: 800px; }
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#target { margin-top: 25px; height: 50px; background-color: blue; }
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</style>
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<div id="scroller">
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<div>
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<div id="target"></div>
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</div>
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</div>
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<script>
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let entries = [];
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window.onload = function() {
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runTestCycle(step2, "At initial scroll position");
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scroller.scrollTop = 0;
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let observer = new IntersectionObserver(
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es => entries = entries.concat(es),
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{ threshold: 1 }
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);
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observer.observe(target);
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};
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function step2() {
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runTestCycle(step3, "Scrolled to half way through target element");
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assert_equals(entries.length, 1);
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assert_equals(entries[0].intersectionRatio, 1);
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assert_equals(entries[0].isIntersecting, true);
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scroller.scrollTop = 50;
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}
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function step3() {
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runTestCycle(step4, "Scrolled to target element completely off screen");
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assert_equals(entries.length, 2);
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assert_true(entries[1].intersectionRatio >= 0.5 &&
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entries[1].intersectionRatio < 1);
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assert_equals(entries[1].isIntersecting, true);
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scroller.scrollTop = 100;
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}
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function step4() {
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assert_equals(entries.length, 2);
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}
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</script>
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