mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 00:22:43 +00:00
72 lines
1.7 KiB
HTML
72 lines
1.7 KiB
HTML
<!DOCTYPE html>
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<head>
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<style>
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#outer {
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width: 200px;
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height: 200px;
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background-color: lightblue;
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}
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#inner {
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width: 100px;
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height: 100px;
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background-color: pink;
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}
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</style>
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</head>
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<body>
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<div id="outer">
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<div id="inner"></div>
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</div>
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</body>
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<script src="../include.js"></script>
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<script>
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asyncTest(async done => {
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const outerBox = document.getElementById("outer");
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const innerBox = document.getElementById("inner");
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function createTimeoutPromise(timeout) {
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return new Promise(r => {
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setTimeout(r, timeout);
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});
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}
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function createResizeObserverCallback() {
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let resolve;
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const promise = new Promise(r => {
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resolve = r;
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});
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const callback = (entries) => {
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for (let entry of entries) {
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const { width, height } = entry.contentRect;
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println(`Size changed: ${width}px x ${height}px`);
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}
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resolve();
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};
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return { promise, callback };
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}
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const { callback, promise } = createResizeObserverCallback();
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const resizeObserver = new ResizeObserver(callback);
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resizeObserver.observe(innerBox);
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resizeObserver.observe(outerBox);
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await promise;
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resizeObserver.disconnect();
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innerBox.style.width = "500px";
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outerBox.style.width = "600px";
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// Let event loop run to ensure that observer callback is not invoked.
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await createTimeoutPromise(0);
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done();
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});
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</script>
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