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