summaryrefslogtreecommitdiffstats
path: root/chromium/chrome/browser/accessibility/accessibility_labels_service.cc
blob: 87859f2f9900cc137f721b5ef2d9c4f3b4b5ddb0 (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
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/accessibility/accessibility_labels_service.h"

#include "base/metrics/histogram_functions.h"
#include "build/build_config.h"
#include "chrome/browser/accessibility/accessibility_state_utils.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/ui/tab_contents/tab_contents_iterator.h"
#include "chrome/common/pref_names.h"
#include "components/pref_registry/pref_registry_syncable.h"
#include "components/prefs/pref_service.h"
#include "components/sync_preferences/pref_service_syncable.h"
#include "content/public/browser/browser_accessibility_state.h"
#include "content/public/common/content_features.h"
#include "ui/accessibility/ax_action_data.h"

#if !defined(OS_ANDROID)
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_finder.h"
#include "chrome/browser/ui/browser_list.h"
#endif

AccessibilityLabelsService::~AccessibilityLabelsService() {}

// static
void AccessibilityLabelsService::RegisterProfilePrefs(
    user_prefs::PrefRegistrySyncable* registry) {
  registry->RegisterBooleanPref(
      prefs::kAccessibilityImageLabelsEnabled, false,
      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
  registry->RegisterBooleanPref(
      prefs::kAccessibilityImageLabelsOptInAccepted, false,
      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
}

// static
void AccessibilityLabelsService::InitOffTheRecordPrefs(
    Profile* off_the_record_profile) {
  DCHECK(off_the_record_profile->IsOffTheRecord());
  off_the_record_profile->GetPrefs()->SetBoolean(
      prefs::kAccessibilityImageLabelsEnabled, false);
  off_the_record_profile->GetPrefs()->SetBoolean(
      prefs::kAccessibilityImageLabelsOptInAccepted, false);
}

void AccessibilityLabelsService::Init() {
  // Hidden behind a feature flag.
  if (!base::FeatureList::IsEnabled(features::kExperimentalAccessibilityLabels))
    return;

  pref_change_registrar_.Init(profile_->GetPrefs());
  pref_change_registrar_.Add(
      prefs::kAccessibilityImageLabelsEnabled,
      base::BindRepeating(
          &AccessibilityLabelsService::OnImageLabelsEnabledChanged,
          weak_factory_.GetWeakPtr()));

  // Log whether the feature is enabled after startup. This must be run on the
  // UI thread because it accesses prefs.
  content::BrowserAccessibilityState::GetInstance()
      ->AddUIThreadHistogramCallback(base::BindRepeating(
          &AccessibilityLabelsService::UpdateAccessibilityLabelsHistograms,
          weak_factory_.GetWeakPtr()));
}

AccessibilityLabelsService::AccessibilityLabelsService(Profile* profile)
    : profile_(profile) {}

ui::AXMode AccessibilityLabelsService::GetAXMode() {
  ui::AXMode ax_mode =
      content::BrowserAccessibilityState::GetInstance()->GetAccessibilityMode();

  // Hidden behind a feature flag.
  if (base::FeatureList::IsEnabled(
          features::kExperimentalAccessibilityLabels)) {
    bool enabled = profile_->GetPrefs()->GetBoolean(
        prefs::kAccessibilityImageLabelsEnabled);
    ax_mode.set_mode(ui::AXMode::kLabelImages, enabled);
  }

  return ax_mode;
}

void AccessibilityLabelsService::EnableLabelsServiceOnce() {
  if (!accessibility_state_utils::IsScreenReaderEnabled()) {
    return;
  }

  // TODO(crbug.com/905419): Implement for Android, which does not support
  // BrowserList::GetInstance.
#if !defined(OS_ANDROID)
  Browser* browser = chrome::FindLastActiveWithProfile(profile_);
  if (!browser)
    return;
  auto* web_contents = browser->tab_strip_model()->GetActiveWebContents();
  if (!web_contents)
    return;
  // Fire an AXAction on the active tab to enable this feature once only.
  ui::AXActionData action_data;
  action_data.action = ax::mojom::Action::kAnnotatePageImages;
  for (content::RenderFrameHost* frame : web_contents->GetAllFrames()) {
    if (frame->IsRenderFrameLive())
      frame->AccessibilityPerformAction(action_data);
  }
#endif
}

void AccessibilityLabelsService::OnImageLabelsEnabledChanged() {
  // TODO(dmazzoni) Implement for Android, which doesn't support
  // AllTabContentses(). crbug.com/905419
#if !defined(OS_ANDROID)
  bool enabled = profile_->GetPrefs()->GetBoolean(
                     prefs::kAccessibilityImageLabelsEnabled) &&
                 accessibility_state_utils::IsScreenReaderEnabled();

  for (auto* web_contents : AllTabContentses()) {
    if (web_contents->GetBrowserContext() != profile_)
      continue;

    ui::AXMode ax_mode = web_contents->GetAccessibilityMode();
    ax_mode.set_mode(ui::AXMode::kLabelImages, enabled);
    web_contents->SetAccessibilityMode(ax_mode);
  }
#endif
}

void AccessibilityLabelsService::UpdateAccessibilityLabelsHistograms() {
  if (!profile_ || !profile_->GetPrefs())
    return;

  base::UmaHistogramBoolean("Accessibility.ImageLabels",
                            profile_->GetPrefs()->GetBoolean(
                                prefs::kAccessibilityImageLabelsEnabled));
}