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
|
<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Element Timing: observe text</title>
<body>
<style>
body {
margin: 20px;
}
p {
font-size: 12px;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/element-timing-helpers.js"></script>
<script>
async_test((t) => {
assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
let paragraph;
let beforeRender;
const observer = new PerformanceObserver(
t.step_func_done((entryList) => {
assert_equals(entryList.getEntries().length, 1);
const entry = entryList.getEntries()[0];
checkTextElement(entry, 'my_text', 'text_id', beforeRender, paragraph);
assert_equals(entry.intersectionRect.left, 20, 'left should be 20.');
// Text box size will vary from device to device, so try lower bounding height by 12, width by 100.
assert_greater_than_equal(entry.intersectionRect.right, 120);
assert_equals(entry.intersectionRect.top, 20, 'top should be 20.');
assert_greater_than_equal(entry.intersectionRect.bottom, 32);
})
);
observer.observe({entryTypes: ['element']});
// We add the iframe during onload to be sure that the observer is registered
// in time for it to observe the element timing.
window.onload = () => {
paragraph = document.createElement('p');
paragraph.innerHTML = 'This is text I care about';
paragraph.setAttribute('elementtiming', 'my_text');
paragraph.setAttribute('id', 'text_id');
document.body.appendChild(paragraph);
beforeRender = performance.now();
};
}, 'Paragraph with elementtiming attribute is observed.');
</script>
</body>
|
