File: defaults_utils.mm

package info (click to toggle)
chromium 138.0.7204.183-1
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 6,071,908 kB
  • sloc: cpp: 34,937,088; ansic: 7,176,967; javascript: 4,110,704; python: 1,419,953; asm: 946,768; xml: 739,971; pascal: 187,324; sh: 89,623; perl: 88,663; objc: 79,944; sql: 50,304; cs: 41,786; fortran: 24,137; makefile: 21,806; php: 13,980; tcl: 13,166; yacc: 8,925; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (85 lines) | stat: -rw-r--r-- 2,938 bytes parent folder | download | duplicates (7)
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
// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/base/cocoa/defaults_utils.h"

#include <AppKit/AppKit.h>

#include <optional>

#include "base/time/time.h"

namespace {

bool& BlinkPeriodNeedsRefresh() {
  static bool blink_period_needs_refresh = []() {
    [NSNotificationCenter.defaultCenter
        addObserverForName:NSApplicationWillBecomeActiveNotification
                    object:nil
                     queue:nil
                usingBlock:^(NSNotification* notification) {
                  // Refresh the insertion point blink period in case the user
                  // changed it in System Preferences. Call the original
                  // function to set the flag. The compiler doesn't like
                  // blink_period_needs_refresh's static scope so it won't let
                  // us pass it into the block. There's no worry of infinite
                  // recursion as well never hit this code path a second time.
                  BlinkPeriodNeedsRefresh() = true;
                }];
    return true;
  }();

  return blink_period_needs_refresh;
}

}  // namespace

namespace ui {

std::optional<base::TimeDelta> TextInsertionCaretBlinkPeriodFromDefaults() {
  static std::optional<base::TimeDelta> blink_period;

  if (!BlinkPeriodNeedsRefresh()) {
    return blink_period;
  }

  BlinkPeriodNeedsRefresh() = false;

  NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
  // See AppKit's `-[NSTextView _restartBlinkTimer]`.
  NSInteger on_period_ms =
      [defaults integerForKey:@"NSTextInsertionPointBlinkPeriodOn"];
  NSInteger off_period_ms =
      [defaults integerForKey:@"NSTextInsertionPointBlinkPeriodOff"];

  // If any of the periods is negative the requested blink time makes no sense.
  // In that case use the default blink time.
  if ((on_period_ms == 0 && off_period_ms == 0) || on_period_ms < 0 ||
      off_period_ms < 0) {
    blink_period = std::nullopt;
    return blink_period;
  }

  const int kMaximumReasonableIntervalMs =
      60 * base::Time::kMillisecondsPerSecond;
  if (on_period_ms > kMaximumReasonableIntervalMs) {
    // Treat an exceedingly long `on_period_ms` as permanently enabling
    // the cursor. In Blink/Views this is signaled by a blink period of 0.
    // Conversely, a high `off_period_ms` would permanently disable the cursor,
    // but Blink and Views don't support that so it's not implemented here.
    blink_period = base::TimeDelta();
  } else if (on_period_ms || off_period_ms) {
    // When both on and off periods are defined take the average (neither Blink
    // nor Views support separate on and off intervals).
    blink_period = base::Milliseconds((on_period_ms + off_period_ms) / 2);
  }

  return blink_period;
}

bool& BlinkPeriodRefreshFlagForTesting() {
  return BlinkPeriodNeedsRefresh();
}

}  // namespace ui