summaryrefslogtreecommitdiffstats
path: root/layout/style/test/test_mq_prefers_contrast_dynamic.html
blob: c3ccebbe82c4a9d102a247bbb62557538601f4cb (plain)
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
<!DOCTYPE HTML>
<html>
<!--
https://bugzilla.mozilla.org/show_bug.cgi?id=1691793
-->
<head>
  <meta charset="utf-8">
  <title>Test for Bug 1691793</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
</head>
<body>
<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1691793">Mozilla Bug 1691793</a>
<p id="display"></p>
<div id="content" style="display: none">

</div>
<pre id="test">
</pre>
<script>
"use strict";

SimpleTest.registerCleanupFunction(async () => {
  await SpecialPowers.flushPrefEnv();
});

// Returns a Promise which will be resolved when the "change" event is received
// for the given media query string.
function promiseForChange(mediaQuery) {
  return new Promise(resolve => {
    window.matchMedia(mediaQuery).addEventListener("change", event => {
      resolve(event.matches);
    }, { once: true });
  });
}

add_task(async () => {
  await SpecialPowers.pushPrefEnv({ set: [["layout.css.prefers-contrast.enabled", true]]});
  const initiallyMatches =
    window.matchMedia("(prefers-contrast: more)").matches;
  const changePromise = initiallyMatches ?
    promiseForChange("(prefers-contrast: more)") : null;
  await SpecialPowers.pushPrefEnv({ set: [["ui.useAccessibilityTheme", 0]]});

  if (changePromise) {
    await changePromise;
  }

  ok(!window.matchMedia("(prefers-contrast: more)").matches,
     "Does not match prefers-contrast: more) when the system unsets " +
     "UseAccessibilityTheme");
  ok(!window.matchMedia("(prefers-contrast)").matches,
     "Does not match (prefers-contrast) when the system unsets " +
     "UseAccessibilityTheme");
  ok(window.matchMedia("(prefers-contrast: no-preference)").matches,
     "Matches (prefers-contrast: no-preference) when the system unsets " +
     "UseAccessibilityTheme");
});

add_task(async () => {
  const more = promiseForChange("(prefers-contrast: more)");
  const booleanContext = promiseForChange("(prefers-contrast)");
  const noPreference = promiseForChange("(prefers-contrast: no-preference)");

  await SpecialPowers.pushPrefEnv({ set: [["ui.useAccessibilityTheme", 1]]});

  const [ moreResult, booleanContextResult, noPreferenceResult ] =
    await Promise.all([ more, booleanContext, noPreference ]);

  ok(moreResult,
     "Matches (prefers-contrast: more) when the system sets " +
     "UseAccessibilityTheme");
  ok(booleanContextResult,
     "Matches (prefers-contrast) when the system sets UseAccessibilityTheme");
  ok(!noPreferenceResult,
     "Does not match (prefers-contrast: no-preference) when the " +
     "system sets UseAccessibilityTheme");
});

</script>
</body>
</html>