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