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