chrome/browser/chromeos/accessibility/accessibility_manager.h

   1 // Copyright (c) 2013 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 #ifndef CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
   6 #define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
   7
   8 #include <set>
   9
  10 #include "ash/accessibility_delegate.h"
  11 #include "ash/session_state_observer.h"
  12 #include "base/callback_list.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "base/prefs/pref_change_registrar.h"
  15 #include "base/time/time.h"
  16 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
  17 #include "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
  18 #include "content/public/browser/notification_observer.h"
  19 #include "content/public/browser/notification_registrar.h"
  20 #include "extensions/browser/event_router.h"
  21 #include "extensions/browser/extension_system.h"
  22
  23 namespace content {
  24 class RenderViewHost;
  25 }
  26 class Profile;
  27
  28 namespace chromeos {
  29
  30 enum AccessibilityNotificationType {
  31   ACCESSIBILITY_MANAGER_SHUTDOWN,
  32   ACCESSIBILITY_TOGGLE_HIGH_CONTRAST_MODE,
  33   ACCESSIBILITY_TOGGLE_LARGE_CURSOR,
  34   ACCESSIBILITY_TOGGLE_SCREEN_MAGNIFIER,
  35   ACCESSIBILITY_TOGGLE_SPOKEN_FEEDBACK,
  36   ACCESSIBILITY_TOGGLE_VIRTUAL_KEYBOARD
  37 };
  38
  39 struct AccessibilityStatusEventDetails {
  40   AccessibilityStatusEventDetails(
  41       AccessibilityNotificationType notification_type,
  42       bool enabled,
  43       ash::AccessibilityNotificationVisibility notify);
  44
  45   AccessibilityStatusEventDetails(
  46       AccessibilityNotificationType notification_type,
  47       bool enabled,
  48       ash::MagnifierType magnifier_type,
  49       ash::AccessibilityNotificationVisibility notify);
  50
  51   AccessibilityNotificationType notification_type;
  52   bool enabled;
  53   ash::MagnifierType magnifier_type;
  54   ash::AccessibilityNotificationVisibility notify;
  55 };
  56
  57 typedef base::Callback<void(const AccessibilityStatusEventDetails&)>
  58     AccessibilityStatusCallback;
  59
  60 typedef base::CallbackList<void(const AccessibilityStatusEventDetails&)>
  61     AccessibilityStatusCallbackList;
  62
  63 typedef AccessibilityStatusCallbackList::Subscription
  64     AccessibilityStatusSubscription;
  65
  66 // AccessibilityManager changes the statuses of accessibility features
  67 // watching profile notifications and pref-changes.
  68 // TODO(yoshiki): merge MagnificationManager with AccessibilityManager.
  69 class AccessibilityManager : public content::NotificationObserver,
  70     extensions::api::braille_display_private::BrailleObserver,
  71     public ash::SessionStateObserver {
  72  public:
  73   // Creates an instance of AccessibilityManager, this should be called once,
  74   // because only one instance should exist at the same time.
  75   static void Initialize();
  76   // Deletes the existing instance of AccessibilityManager.
  77   static void Shutdown();
  78   // Returns the existing instance. If there is no instance, returns NULL.
  79   static AccessibilityManager* Get();
  80
  81   // On a user's first login into a device, any a11y features enabled/disabled
  82   // by the user on the login screen are enabled/disabled in the user's profile.
  83   // This class watches for profile changes and copies settings into the user's
  84   // profile when it detects a login with a newly created profile.
  85   class PrefHandler {
  86    public:
  87     explicit PrefHandler(const char* pref_path);
  88     virtual ~PrefHandler();
  89
  90     // Should be called from AccessibilityManager::SetProfile().
  91     void HandleProfileChanged(Profile* previous_profile,
  92                               Profile* current_profile);
  93
  94    private:
  95     const char* pref_path_;
  96   };
  97
  98   // Returns true when the accessibility menu should be shown.
  99   bool ShouldShowAccessibilityMenu();
 100
 101   // Returns true when cursor compositing should be enabled.
 102   bool ShouldEnableCursorCompositing();
 103
 104   // Enables or disables the large cursor.
 105   void EnableLargeCursor(bool enabled);
 106   // Returns true if the large cursor is enabled, or false if not.
 107   bool IsLargeCursorEnabled();
 108
 109   // Enables or disable Sticky Keys.
 110   void EnableStickyKeys(bool enabled);
 111
 112   // Returns true if Incognito mode is allowed, or false if not.
 113   bool IsIncognitoAllowed();
 114
 115   // Returns true if the Sticky Keys is enabled, or false if not.
 116   bool IsStickyKeysEnabled();
 117
 118   // Enables or disables spoken feedback. Enabling spoken feedback installs the
 119   // ChromeVox component extension.
 120   void EnableSpokenFeedback(bool enabled,
 121                             ash::AccessibilityNotificationVisibility notify);
 122
 123   // Returns true if spoken feedback is enabled, or false if not.
 124   bool IsSpokenFeedbackEnabled();
 125
 126   // Toggles whether Chrome OS spoken feedback is on or off.
 127   void ToggleSpokenFeedback(ash::AccessibilityNotificationVisibility notify);
 128
 129   // Enables or disables the high contrast mode for Chrome.
 130   void EnableHighContrast(bool enabled);
 131
 132   // Returns true if High Contrast is enabled, or false if not.
 133   bool IsHighContrastEnabled();
 134
 135   // Enables or disables autoclick.
 136   void EnableAutoclick(bool enabled);
 137
 138   // Returns true if autoclick is enabled.
 139   bool IsAutoclickEnabled();
 140
 141   // Set the delay for autoclicking after stopping the cursor in milliseconds.
 142   void SetAutoclickDelay(int delay_ms);
 143
 144   // Returns the autoclick delay in milliseconds.
 145   int GetAutoclickDelay() const;
 146
 147   // Enables or disables the virtual keyboard.
 148   void EnableVirtualKeyboard(bool enabled);
 149   // Returns true if the virtual keyboard is enabled, otherwise false.
 150   bool IsVirtualKeyboardEnabled();
 151
 152   // SessionStateObserver overrides:
 153   virtual void ActiveUserChanged(const std::string& user_id) OVERRIDE;
 154
 155   void SetProfileForTest(Profile* profile);
 156
 157   static void SetBrailleControllerForTest(
 158       extensions::api::braille_display_private::BrailleController* controller);
 159
 160   // Enables/disables system sounds.
 161   void EnableSystemSounds(bool system_sounds_enabled);
 162
 163   // Initiates play of shutdown sound and returns it's duration.
 164   base::TimeDelta PlayShutdownSound();
 165
 166   // Injects ChromeVox scripts into given |render_view_host|.
 167   void InjectChromeVox(content::RenderViewHost* render_view_host);
 168
 169   // Register a callback to be notified when the status of an accessibility
 170   // option changes.
 171   scoped_ptr<AccessibilityStatusSubscription> RegisterCallback(
 172       const AccessibilityStatusCallback& cb);
 173
 174   // Notify registered callbacks of a status change in an accessibility setting.
 175   void NotifyAccessibilityStatusChanged(
 176       AccessibilityStatusEventDetails& details);
 177
 178   // Notify accessibility when locale changes occur.
 179   void OnLocaleChanged();
 180
 181  protected:
 182   AccessibilityManager();
 183   virtual ~AccessibilityManager();
 184
 185  private:
 186   void LoadChromeVox();
 187   void LoadChromeVoxToUserScreen();
 188   void LoadChromeVoxToLockScreen();
 189   void UnloadChromeVox();
 190   void UnloadChromeVoxFromLockScreen();
 191   void PostLoadChromeVox(Profile* profile);
 192   void PostUnloadChromeVox(Profile* profile);
 193
 194   void UpdateLargeCursorFromPref();
 195   void UpdateStickyKeysFromPref();
 196   void UpdateSpokenFeedbackFromPref();
 197   void UpdateHighContrastFromPref();
 198   void UpdateAutoclickFromPref();
 199   void UpdateAutoclickDelayFromPref();
 200   void UpdateVirtualKeyboardFromPref();
 201
 202   void CheckBrailleState();
 203   void ReceiveBrailleDisplayState(
 204       scoped_ptr<extensions::api::braille_display_private::DisplayState> state);
 205
 206   void SetProfile(Profile* profile);
 207
 208   void UpdateChromeOSAccessibilityHistograms();
 209
 210   // content::NotificationObserver implementation:
 211   virtual void Observe(int type,
 212                        const content::NotificationSource& source,
 213                        const content::NotificationDetails& details) OVERRIDE;
 214
 215   // extensions::api::braille_display_private::BrailleObserver implementation.
 216   // Enables spoken feedback if a braille display becomes available.
 217   virtual void OnDisplayStateChanged(
 218       const extensions::api::braille_display_private::DisplayState&
 219           display_state) OVERRIDE;
 220
 221   // Profile which has the current a11y context.
 222   Profile* profile_;
 223
 224   // Profile which ChromeVox is currently loaded to. If NULL, ChromeVox is not
 225   // loaded to any profile.
 226   bool chrome_vox_loaded_on_lock_screen_;
 227   bool chrome_vox_loaded_on_user_screen_;
 228
 229   content::NotificationRegistrar notification_registrar_;
 230   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
 231   scoped_ptr<PrefChangeRegistrar> local_state_pref_change_registrar_;
 232   scoped_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
 233
 234   PrefHandler large_cursor_pref_handler_;
 235   PrefHandler spoken_feedback_pref_handler_;
 236   PrefHandler high_contrast_pref_handler_;
 237   PrefHandler autoclick_pref_handler_;
 238   PrefHandler autoclick_delay_pref_handler_;
 239   PrefHandler virtual_keyboard_pref_handler_;
 240
 241   bool large_cursor_enabled_;
 242   bool sticky_keys_enabled_;
 243   bool spoken_feedback_enabled_;
 244   bool high_contrast_enabled_;
 245   bool autoclick_enabled_;
 246   int autoclick_delay_ms_;
 247   bool virtual_keyboard_enabled_;
 248
 249   ash::AccessibilityNotificationVisibility spoken_feedback_notification_;
 250
 251   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 252
 253   bool should_speak_chrome_vox_announcements_on_user_screen_;
 254
 255   bool system_sounds_enabled_;
 256
 257   AccessibilityStatusCallbackList callback_list_;
 258
 259   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
 260 };
 261
 262 }  // namespace chromeos
 263
 264 #endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_