44 lines
1.6 KiB
HTML
44 lines
1.6 KiB
HTML
<!DOCTYPE html>
|
|
<html>
|
|
<meta charset=utf-8 />
|
|
<title>Element Timing: buffer elements before onload</title>
|
|
<script src=/resources/testharness.js></script>
|
|
<script src=/resources/testharnessreport.js></script>
|
|
<script src="resources/element-timing-helpers.js"></script>
|
|
<body>
|
|
<img src=resources/slow-image.py?name=square20.png&sleep=500>
|
|
<script>
|
|
/*
|
|
In this test, a slow image is added to the frame to delay onload. The entry
|
|
is available from the observer with the buffered flag set to true.
|
|
*/
|
|
async_test(function(t) {
|
|
assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
|
|
beforeRender = performance.now();
|
|
const img = document.createElement('img');
|
|
img.src = 'resources/square20.jpg';
|
|
img.setAttribute('elementtiming', 'my_image');
|
|
img.setAttribute('id', 'my_id');
|
|
document.body.appendChild(img);
|
|
|
|
// this PerformanceObserver should be notified about the previously
|
|
// buffered element entry
|
|
new PerformanceObserver(t.step_func((entryList, observer) => {
|
|
assert_equals(entryList.getEntries().length, 1);
|
|
entryList.getEntries().forEach(entry => {
|
|
assert_equals(entry.entryType, "element");
|
|
const pathname = window.location.origin + '/element-timing/resources/square20.jpg';
|
|
checkElement(entry, pathname, 'my_image', 'my_id', beforeRender, img);
|
|
checkNaturalSize(entry, 20, 20);
|
|
observer.disconnect();
|
|
t.done();
|
|
});
|
|
})).observe({
|
|
type: "element",
|
|
buffered: true
|
|
});
|
|
}, "Element Timing: image loads before onload available from buffered flag.");
|
|
|
|
</script>
|
|
</body>
|
|
</html>
|