1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
6
7 #include "base/command_line.h"
8 #include "base/metrics/histogram.h"
9 #include "base/timer/timer.h"
10 #include "content/browser/accessibility/accessibility_mode_helper.h"
11 #include "content/browser/renderer_host/render_widget_host_impl.h"
12 #include "content/public/browser/browser_thread.h"
13 #include "content/public/browser/render_process_host.h"
14 #include "content/public/browser/render_widget_host_iterator.h"
15 #include "content/public/common/content_switches.h"
16 #include "ui/gfx/sys_color_change_listener.h"
17
18 #if defined(OS_WIN)
19 #include "base/win/windows_version.h"
20 #endif
21
22 namespace content {
23
24 // Update the accessibility histogram 45 seconds after initialization.
25 static const int kAccessibilityHistogramDelaySecs = 45;
26
27 // static
GetInstance()28 BrowserAccessibilityState* BrowserAccessibilityState::GetInstance() {
29 return BrowserAccessibilityStateImpl::GetInstance();
30 }
31
32 // static
GetInstance()33 BrowserAccessibilityStateImpl* BrowserAccessibilityStateImpl::GetInstance() {
34 return Singleton<BrowserAccessibilityStateImpl,
35 LeakySingletonTraits<BrowserAccessibilityStateImpl> >::get();
36 }
37
BrowserAccessibilityStateImpl()38 BrowserAccessibilityStateImpl::BrowserAccessibilityStateImpl()
39 : BrowserAccessibilityState(),
40 accessibility_mode_(AccessibilityModeOff) {
41 ResetAccessibilityModeValue();
42 #if defined(OS_WIN)
43 // On Windows, UpdateHistograms calls some system functions with unknown
44 // runtime, so call it on the file thread to ensure there's no jank.
45 // Everything in that method must be safe to call on another thread.
46 BrowserThread::ID update_histogram_thread = BrowserThread::FILE;
47 #else
48 // On all other platforms, UpdateHistograms should be called on the main
49 // thread.
50 BrowserThread::ID update_histogram_thread = BrowserThread::UI;
51 #endif
52
53 // We need to AddRef() the leaky singleton so that Bind doesn't
54 // delete it prematurely.
55 AddRef();
56 BrowserThread::PostDelayedTask(
57 update_histogram_thread, FROM_HERE,
58 base::Bind(&BrowserAccessibilityStateImpl::UpdateHistograms, this),
59 base::TimeDelta::FromSeconds(kAccessibilityHistogramDelaySecs));
60 }
61
~BrowserAccessibilityStateImpl()62 BrowserAccessibilityStateImpl::~BrowserAccessibilityStateImpl() {
63 }
64
OnScreenReaderDetected()65 void BrowserAccessibilityStateImpl::OnScreenReaderDetected() {
66 if (CommandLine::ForCurrentProcess()->HasSwitch(
67 switches::kDisableRendererAccessibility)) {
68 return;
69 }
70 EnableAccessibility();
71 }
72
EnableAccessibility()73 void BrowserAccessibilityStateImpl::EnableAccessibility() {
74 AddAccessibilityMode(AccessibilityModeComplete);
75 }
76
DisableAccessibility()77 void BrowserAccessibilityStateImpl::DisableAccessibility() {
78 ResetAccessibilityMode();
79 }
80
ResetAccessibilityModeValue()81 void BrowserAccessibilityStateImpl::ResetAccessibilityModeValue() {
82 accessibility_mode_ = AccessibilityModeOff;
83 #if defined(OS_WIN)
84 // On Windows 8, always enable accessibility for editable text controls
85 // so we can show the virtual keyboard when one is enabled.
86 if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
87 !CommandLine::ForCurrentProcess()->HasSwitch(
88 switches::kDisableRendererAccessibility)) {
89 accessibility_mode_ = AccessibilityModeEditableTextOnly;
90 }
91 #endif // defined(OS_WIN)
92
93 if (CommandLine::ForCurrentProcess()->HasSwitch(
94 switches::kForceRendererAccessibility)) {
95 accessibility_mode_ = AccessibilityModeComplete;
96 }
97 }
98
ResetAccessibilityMode()99 void BrowserAccessibilityStateImpl::ResetAccessibilityMode() {
100 ResetAccessibilityModeValue();
101
102 // Iterate over all RenderWidgetHosts, even swapped out ones in case
103 // they become active again.
104 scoped_ptr<RenderWidgetHostIterator> widgets(
105 RenderWidgetHostImpl::GetAllRenderWidgetHosts());
106 while (RenderWidgetHost* widget = widgets->GetNextHost()) {
107 // Ignore processes that don't have a connection, such as crashed tabs.
108 if (!widget->GetProcess()->HasConnection())
109 continue;
110 if (!widget->IsRenderView())
111 continue;
112
113 RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(widget);
114 rwhi->ResetAccessibilityMode();
115 }
116 }
117
IsAccessibleBrowser()118 bool BrowserAccessibilityStateImpl::IsAccessibleBrowser() {
119 return ((accessibility_mode_ & AccessibilityModeComplete) ==
120 AccessibilityModeComplete);
121 }
122
AddHistogramCallback(base::Closure callback)123 void BrowserAccessibilityStateImpl::AddHistogramCallback(
124 base::Closure callback) {
125 histogram_callbacks_.push_back(callback);
126 }
127
UpdateHistogramsForTesting()128 void BrowserAccessibilityStateImpl::UpdateHistogramsForTesting() {
129 UpdateHistograms();
130 }
131
UpdateHistograms()132 void BrowserAccessibilityStateImpl::UpdateHistograms() {
133 UpdatePlatformSpecificHistograms();
134
135 for (size_t i = 0; i < histogram_callbacks_.size(); ++i)
136 histogram_callbacks_[i].Run();
137
138 UMA_HISTOGRAM_BOOLEAN("Accessibility.State", IsAccessibleBrowser());
139 UMA_HISTOGRAM_BOOLEAN("Accessibility.InvertedColors",
140 gfx::IsInvertedColorScheme());
141 UMA_HISTOGRAM_BOOLEAN("Accessibility.ManuallyEnabled",
142 CommandLine::ForCurrentProcess()->HasSwitch(
143 switches::kForceRendererAccessibility));
144 }
145
146 #if !defined(OS_WIN)
UpdatePlatformSpecificHistograms()147 void BrowserAccessibilityStateImpl::UpdatePlatformSpecificHistograms() {
148 }
149 #endif
150
AddAccessibilityMode(AccessibilityMode mode)151 void BrowserAccessibilityStateImpl::AddAccessibilityMode(
152 AccessibilityMode mode) {
153 if (CommandLine::ForCurrentProcess()->HasSwitch(
154 switches::kDisableRendererAccessibility)) {
155 return;
156 }
157
158 accessibility_mode_ =
159 content::AddAccessibilityModeTo(accessibility_mode_, mode);
160
161 AddOrRemoveFromRenderWidgets(mode, true);
162 }
163
RemoveAccessibilityMode(AccessibilityMode mode)164 void BrowserAccessibilityStateImpl::RemoveAccessibilityMode(
165 AccessibilityMode mode) {
166 if (CommandLine::ForCurrentProcess()->HasSwitch(
167 switches::kForceRendererAccessibility) &&
168 mode == AccessibilityModeComplete) {
169 return;
170 }
171
172 accessibility_mode_ =
173 content::RemoveAccessibilityModeFrom(accessibility_mode_, mode);
174
175 AddOrRemoveFromRenderWidgets(mode, false);
176 }
177
AddOrRemoveFromRenderWidgets(AccessibilityMode mode,bool add)178 void BrowserAccessibilityStateImpl::AddOrRemoveFromRenderWidgets(
179 AccessibilityMode mode,
180 bool add) {
181 // Iterate over all RenderWidgetHosts, even swapped out ones in case
182 // they become active again.
183 scoped_ptr<RenderWidgetHostIterator> widgets(
184 RenderWidgetHostImpl::GetAllRenderWidgetHosts());
185 while (RenderWidgetHost* widget = widgets->GetNextHost()) {
186 // Ignore processes that don't have a connection, such as crashed tabs.
187 if (!widget->GetProcess()->HasConnection())
188 continue;
189 if (!widget->IsRenderView())
190 continue;
191
192 RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(widget);
193 if (add)
194 rwhi->AddAccessibilityMode(mode);
195 else
196 rwhi->RemoveAccessibilityMode(mode);
197 }
198 }
199
200 } // namespace content
201