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Test Info: Warnings
- This test has a WPT meta file that expects 1 subtest issues.
- This WPT test may be referenced by the following Test IDs:
- /intersection-observer/clip-path-animation.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<meta name="viewport" content="width=device-width,initial-scale=1">
<link rel="help" href="https://w3c.github.io/IntersectionObserver/#calculate-intersection-rect-algo">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="./resources/intersection-observer-test-utils.js"></script>
<style>
@keyframes clippath {
0% {
clip-path: inset(30%);
}
100% {
clip-path: inset(40%);
}
}
body { margin: 0 }
pre, #log {
position: absolute;
top: 0;
left: 200px;
}
#target {
position: absolute;
top: 0px;
background-color: green;
width: 100px;
height: 100px;
}
#container {
margin: 20px;
position: relative;
padding: 8px;
width: 0px;
height: 0px;
}
.animation {
animation: clippath 100s steps(2, jump-end);
}
</style>
<div id="container">
<div id="target"></div>
</div>
<script>
var vw = document.documentElement.clientWidth;
var vh = document.documentElement.clientHeight;
var target = undefined;
var container = undefined;
var observer = undefined;
var entries = [];
// See crbug.com/40690885. In principle, this test should not need this,
// however browser support of updating intersection obsevers in response
// to animations (and in particular, clip-paths) is spotty. Forcing a
// fresh listener allows the test to guard against regression of
// crbug.com/394244260, and test that resolution of clip rects with
// animations isn't particularly broken in some way.
async function forceReset() {
if(observer) { observer.disconnect(); }
observer = new IntersectionObserver(function(changes) {
entries = entries.concat(changes)
}, {
root: container
});
observer.observe(target);
await waitForNotification();
}
promise_test(async function(t) {
target = document.getElementById("target");
container = document.getElementById("container");
await forceReset();
// See intersection-observer-test-utils.js for the meaning of these values.
checkLastEntry(
entries,
0,
[28, 128, 20, 120, 28, 36, 20, 36, 20, 36, 20, 36, true],
);
target.className = "animation";
await forceReset();
checkLastEntry(
entries,
1,
[28, 128, 20, 120, 0, 0, 0, 0, 20, 36, 20, 36, false],
);
target.className = "";
await forceReset();
checkLastEntry(
entries,
2,
[28, 128, 20, 120, 28, 36, 20, 36, 20, 36, 20, 36, true],
);
});
</script>