1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Element Timing: src change triggers new entry</title>
<body>
<style>
body {
margin: 0;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/element-timing-helpers.js"></script>
<img elementtiming='my_image' id='my_id' />
<script>
const getObservedEntry = async (pathname) => {
return await new Promise(resolve => {
new PerformanceObserver(entryList => {
if (entryList.getEntries()[0].url == pathname) {
resolve(entryList.getEntries()[0]);
}
}).observe({ type: 'element', buffered: true });
});
}
promise_test(async (t) => {
assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
// Take beforeRender timestamp.
let beforeRender = performance.now();
//Load image
const img = document.getElementById('my_id');
const url1 = 'resources/square100.png';
await new Promise(resolve => {
img.addEventListener('load', resolve);
img.src = url1;
});
// Get element entry.
let pathname = window.location.origin + '/element-timing/' + url1;
let entry = await getObservedEntry(pathname);
// Check entry.
checkElement(entry, pathname, 'my_image', 'my_id', beforeRender, img);
checkRect(entry, [0, 100, 0, 100]);
checkNaturalSize(entry, 100, 100);
// Take beforeRender timestamp before changing image src.
beforeRender = performance.now();
// Set the src to trigger another entry.
const url2 = '/images/black-rectangle.png';
//Load image with changed src.
await new Promise(resolve => {
img.addEventListener('load', resolve);
img.src = url2;
});
// Get the corresponding element entry.
pathname = window.location.origin + url2;
entry = await getObservedEntry(pathname);
// Check entry.
checkElement(entry, pathname, 'my_image', 'my_id', beforeRender, img);
checkRect(entry, [0, 100, 0, 50]);
checkNaturalSize(entry, 100, 50);
}, 'Element Timing: changing src causes a new entry to be dispatched.')
</script>
</body>
|
