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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /resize-observer/fragments.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<meta charset="utf-8">
<title>ResizeObserver with multiple fragments</title>
<link rel="author" title="Oriol Brufau" href="mailto:obrufau@igalia.com">
<meta name="assert" content="Tests ResizeObserver supports multiple fragments." />
<style>
#wrapper {
column-width: 100px;
width: max-content;
height: 100px;
margin: 10px;
}
#target {
outline: solid;
background: orange;
}
.w50 {
width: 50px;
}
.w75 {
width: 75px;
}
.h100 {
height: 100px;
}
.h150 {
height: 150px;
}
.h175 {
height: 175px;
}
</style>
<div id="log"></div>
<div id="wrapper">
<div id="target"></div>
</div>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
const target = document.getElementById("target");
const nextSizes = (() => {
let callback = null;
new ResizeObserver((entries) => {
if (callback) {
callback(entries[0].contentBoxSize);
callback = null;
}
}).observe(target);
return () => {
if (callback) {
throw "Already awaiting another notification";
}
return new Promise((resolve, reject) => {
callback = resolve;
requestAnimationFrame(() => {
requestAnimationFrame(() => {
reject("Missing ResizeObserver notification");
callback = null;
});
});
});
};
})();
function checkSizes(className, expectedSizes, msg) {
promise_test(async () => {
await new Promise(requestAnimationFrame);
target.className = className;
let sizes;
try {
sizes = await nextSizes();
} catch (error) {
assert_unreached(error);
}
assert_equals(sizes.length, expectedSizes.length, "number of fragments");
for (let i = 0; i < sizes.length; ++i) {
assert_equals(sizes[i].inlineSize, expectedSizes[i][0], `fragment #${i+1} inline size`);
assert_equals(sizes[i].blockSize, expectedSizes[i][1], `fragment #${i+1} block size`);
}
}, msg);
}
checkSizes(
"w50 h100",
[[50, 100]],
"Single fragment"
);
checkSizes(
"w50 h150",
[[50, 100], [50, 50]],
"Adding 2nd fragment"
);
checkSizes(
"w50 h175",
[[50, 100], [50, 75]],
"Resizing 2nd fragment"
);
checkSizes(
"w75 h175",
[[75, 100], [75, 75]],
"Resizing all fragments"
);
checkSizes(
"w75 h100",
[[75, 100]],
"Removing 2nd fragment"
);
</script>