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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /html/canvas/element/manual/draw-element-image/invalidation-during-onpaint.tentative.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<html class="reftest-wait">
<title>Rendering invalidations in onpaint callback don't affect current rendering update</title>
<link rel="author" href="mailto:szager@chromium.org">
<link rel="match" href="invalidation-during-onpaint-ref.html">
<script src="/common/reftest-wait.js"></script>
<style>
#opacity {
width: 100px;
height: 100px;
background: green;
position: relative;
left: 20px;
top: 30px;
will-change: opacity;
}
#container {
width: 200px;
height: 200px;
background: grey;
}
</style>
<div id=container>
<div id=opacity style="opacity:.9"></div>
</div>
<canvas id=canvas width="1" height="1"></canvas>
<script>
function runTest() {
canvas.onpaint = () => {
// This will run on every rendering update, but at the point of execution
// cc property trees have already been copied off for commit so any
// modification to main thread property trees will *not* be included in the
// display of this update. The rAF callback below ensures that #opacity is
// always painted and drawn with opacity:.9.
opacity.style.opacity = '.1';
const forceLayer = document.elementsFromPoint(50, 50);
requestAnimationFrame(() => {
opacity.style.opacity = '.9';
takeScreenshot();
});
canvas.requestPaint();
};
canvas.requestPaint();
}
onload = runTest;
</script>
</html>