content/browser/accessibility/browser_accessibility_state_impl.cc

   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/browser/web_contents/web_contents_impl.h"
  13 #include "content/public/browser/browser_thread.h"
  14 #include "content/public/common/content_switches.h"
  15 #include "ui/gfx/sys_color_change_listener.h"
  16
  17 #if defined(OS_WIN)
  18 #include "base/win/windows_version.h"
  19 #endif
  20
  21 namespace content {
  22
  23 // Update the accessibility histogram 45 seconds after initialization.
  24 static const int kAccessibilityHistogramDelaySecs = 45;
  25
  26 // static
  27 BrowserAccessibilityState* BrowserAccessibilityState::GetInstance() {
  28   return BrowserAccessibilityStateImpl::GetInstance();
  29 }
  30
  31 // static
  32 BrowserAccessibilityStateImpl* BrowserAccessibilityStateImpl::GetInstance() {
  33   return Singleton<BrowserAccessibilityStateImpl,
  34                    LeakySingletonTraits<BrowserAccessibilityStateImpl> >::get();
  35 }
  36
  37 BrowserAccessibilityStateImpl::BrowserAccessibilityStateImpl()
  38     : BrowserAccessibilityState(),
  39       accessibility_mode_(AccessibilityModeOff) {
  40   ResetAccessibilityModeValue();
  41 #if defined(OS_WIN)
  42   // On Windows, UpdateHistograms calls some system functions with unknown
  43   // runtime, so call it on the file thread to ensure there's no jank.
  44   // Everything in that method must be safe to call on another thread.
  45   BrowserThread::ID update_histogram_thread = BrowserThread::FILE;
  46 #else
  47   // On all other platforms, UpdateHistograms should be called on the main
  48   // thread.
  49   BrowserThread::ID update_histogram_thread = BrowserThread::UI;
  50 #endif
  51
  52   // We need to AddRef() the leaky singleton so that Bind doesn't
  53   // delete it prematurely.
  54   AddRef();
  55   BrowserThread::PostDelayedTask(
  56       update_histogram_thread, FROM_HERE,
  57       base::Bind(&BrowserAccessibilityStateImpl::UpdateHistograms, this),
  58       base::TimeDelta::FromSeconds(kAccessibilityHistogramDelaySecs));
  59 }
  60
  61 BrowserAccessibilityStateImpl::~BrowserAccessibilityStateImpl() {
  62 }
  63
  64 void BrowserAccessibilityStateImpl::OnScreenReaderDetected() {
  65   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
  66           switches::kDisableRendererAccessibility)) {
  67     return;
  68   }
  69   EnableAccessibility();
  70 }
  71
  72 void BrowserAccessibilityStateImpl::EnableAccessibility() {
  73   AddAccessibilityMode(AccessibilityModeComplete);
  74 }
  75
  76 void BrowserAccessibilityStateImpl::DisableAccessibility() {
  77   ResetAccessibilityMode();
  78 }
  79
  80 void BrowserAccessibilityStateImpl::ResetAccessibilityModeValue() {
  81   accessibility_mode_ = AccessibilityModeOff;
  82 #if defined(OS_WIN)
  83   // On Windows 8, always enable accessibility for editable text controls
  84   // so we can show the virtual keyboard when one is enabled.
  85   if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
  86       !base::CommandLine::ForCurrentProcess()->HasSwitch(
  87           switches::kDisableRendererAccessibility)) {
  88     accessibility_mode_ = AccessibilityModeEditableTextOnly;
  89   }
  90 #endif  // defined(OS_WIN)
  91
  92   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
  93           switches::kForceRendererAccessibility)) {
  94     accessibility_mode_ = AccessibilityModeComplete;
  95   }
  96 }
  97
  98 void BrowserAccessibilityStateImpl::ResetAccessibilityMode() {
  99   ResetAccessibilityModeValue();
 100
 101   std::vector<WebContentsImpl*> web_contents_vector =
 102       WebContentsImpl::GetAllWebContents();
 103   for (size_t i = 0; i < web_contents_vector.size(); ++i)
 104     web_contents_vector[i]->SetAccessibilityMode(accessibility_mode());
 105 }
 106
 107 bool BrowserAccessibilityStateImpl::IsAccessibleBrowser() {
 108   return ((accessibility_mode_ & AccessibilityModeComplete) ==
 109           AccessibilityModeComplete);
 110 }
 111
 112 void BrowserAccessibilityStateImpl::AddHistogramCallback(
 113     base::Closure callback) {
 114   histogram_callbacks_.push_back(callback);
 115 }
 116
 117 void BrowserAccessibilityStateImpl::UpdateHistogramsForTesting() {
 118   UpdateHistograms();
 119 }
 120
 121 void BrowserAccessibilityStateImpl::UpdateHistograms() {
 122   UpdatePlatformSpecificHistograms();
 123
 124   for (size_t i = 0; i < histogram_callbacks_.size(); ++i)
 125     histogram_callbacks_[i].Run();
 126
 127   UMA_HISTOGRAM_BOOLEAN("Accessibility.State", IsAccessibleBrowser());
 128   UMA_HISTOGRAM_BOOLEAN("Accessibility.InvertedColors",
 129                         gfx::IsInvertedColorScheme());
 130   UMA_HISTOGRAM_BOOLEAN("Accessibility.ManuallyEnabled",
 131                         base::CommandLine::ForCurrentProcess()->HasSwitch(
 132                             switches::kForceRendererAccessibility));
 133 }
 134
 135 #if !defined(OS_WIN)
 136 void BrowserAccessibilityStateImpl::UpdatePlatformSpecificHistograms() {
 137 }
 138 #endif
 139
 140 void BrowserAccessibilityStateImpl::AddAccessibilityMode(
 141     AccessibilityMode mode) {
 142   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
 143           switches::kDisableRendererAccessibility)) {
 144     return;
 145   }
 146
 147   accessibility_mode_ =
 148       content::AddAccessibilityModeTo(accessibility_mode_, mode);
 149
 150   AddOrRemoveFromAllWebContents(mode, true);
 151 }
 152
 153 void BrowserAccessibilityStateImpl::RemoveAccessibilityMode(
 154     AccessibilityMode mode) {
 155   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
 156           switches::kForceRendererAccessibility) &&
 157       mode == AccessibilityModeComplete) {
 158     return;
 159   }
 160
 161   accessibility_mode_ =
 162       content::RemoveAccessibilityModeFrom(accessibility_mode_, mode);
 163
 164   AddOrRemoveFromAllWebContents(mode, false);
 165 }
 166
 167 void BrowserAccessibilityStateImpl::AddOrRemoveFromAllWebContents(
 168     AccessibilityMode mode,
 169     bool add) {
 170   std::vector<WebContentsImpl*> web_contents_vector =
 171       WebContentsImpl::GetAllWebContents();
 172   for (size_t i = 0; i < web_contents_vector.size(); ++i) {
 173     if (add)
 174       web_contents_vector[i]->AddAccessibilityMode(mode);
 175     else
 176       web_contents_vector[i]->RemoveAccessibilityMode(mode);
 177   }
 178 }
 179
 180 }  // namespace content