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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
<!DOCTYPE html>
<title>Tests position fallback with initially out-of-viewport anchor in vertial-lr rtl</title>
<link rel="author" href="mailto:xiaochengh@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#scroll">
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#fallback-apply">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/test-common.js"></script>
<style>
body {
margin: 0;
width: 200vw;
height: 200vh;
}
html {
writing-mode: vertical-lr;
direction: rtl;
}
#anchor {
anchor-name: --a;
width: 100px;
height: 100px;
margin-block-start: 100vb;
margin-inline-start: 100vi;
background: orange;
}
#anchored {
position: fixed;
width: 100px;
height: 100px;
background: green;
anchor-default: --a;
position-fallback: --pf;
}
@position-fallback --pf {
@try {
inset-block-start: anchor(--a end);
inset-inline-start: anchor(--a end);
}
@try {
inset-block-end: anchor(--a start);
inset-inline-start: anchor(--a end);
}
@try {
inset-block-start: anchor(--a end);
inset-inline-end: anchor(--a start);
}
@try {
inset-block-end: anchor(--a start);
inset-inline-end: anchor(--a start);
}
}
</style>
<div id="anchor"></div>
<div id="anchored"></div>
<script>
promise_test(async () => {
await waitUntilNextAnimationFrame();
assert_fallback_position(anchored, anchor, 'bottom');
assert_fallback_position(anchored, anchor, 'left');
}, 'Should use the last fallback position initially');
promise_test(async () => {
// Scroll left to have enough space right to the anchor, but not enough above.
document.documentElement.scrollLeft = 250;
document.documentElement.scrollTop = -150;
await waitUntilNextAnimationFrame();
assert_fallback_position(anchored, anchor, 'right');
assert_fallback_position(anchored, anchor, 'bottom');
}, 'Should use the third fallback position with enough space right');
promise_test(async () => {
// Scroll up to have enough space above the anchor, but not enough right.
document.documentElement.scrollLeft = 150;
document.documentElement.scrollTop = -250;
await waitUntilNextAnimationFrame();
assert_fallback_position(anchored, anchor, 'left');
assert_fallback_position(anchored, anchor, 'top');
}, 'Should use the second fallback position with enough space above');
promise_test(async () => {
// Scroll up and right to have enough space on both axes.
document.documentElement.scrollLeft = 250;
document.documentElement.scrollTop = -250;
await waitUntilNextAnimationFrame();
assert_fallback_position(anchored, anchor, 'right');
assert_fallback_position(anchored, anchor, 'top');
}, 'Should use the first fallback position with enough space right and above');
</script>
|
