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/session/session_state_observer.h"
  11 #include "base/callback_forward.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/scoped_observer.h"
  16 #include "base/time/time.h"
  17 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
  18 #include "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
  19 #include "content/public/browser/notification_observer.h"
  20 #include "content/public/browser/notification_registrar.h"
  21 #include "extensions/browser/event_router.h"
  22 #include "extensions/browser/extension_system.h"
  23 #include "ui/base/ime/chromeos/input_method_manager.h"
  24 #include "ui/chromeos/accessibility_types.h"
  25
  26 namespace content {
  27 class RenderViewHost;
  28 }
  29 class Profile;
  30
  31 namespace chromeos {
  32
  33 enum AccessibilityNotificationType {
  34   ACCESSIBILITY_MANAGER_SHUTDOWN,
  35   ACCESSIBILITY_TOGGLE_HIGH_CONTRAST_MODE,
  36   ACCESSIBILITY_TOGGLE_LARGE_CURSOR,
  37   ACCESSIBILITY_TOGGLE_SCREEN_MAGNIFIER,
  38   ACCESSIBILITY_TOGGLE_SPOKEN_FEEDBACK,
  39   ACCESSIBILITY_TOGGLE_VIRTUAL_KEYBOARD,
  40   ACCESSIBILITY_BRAILLE_DISPLAY_CONNECTION_STATE_CHANGED
  41 };
  42
  43 struct AccessibilityStatusEventDetails {
  44   AccessibilityStatusEventDetails(
  45       AccessibilityNotificationType notification_type,
  46       bool enabled,
  47       ui::AccessibilityNotificationVisibility notify);
  48
  49   AccessibilityStatusEventDetails(
  50       AccessibilityNotificationType notification_type,
  51       bool enabled,
  52       ui::MagnifierType magnifier_type,
  53       ui::AccessibilityNotificationVisibility notify);
  54
  55   AccessibilityNotificationType notification_type;
  56   bool enabled;
  57   ui::MagnifierType magnifier_type;
  58   ui::AccessibilityNotificationVisibility notify;
  59 };
  60
  61 typedef base::Callback<void(const AccessibilityStatusEventDetails&)>
  62     AccessibilityStatusCallback;
  63
  64 typedef base::CallbackList<void(const AccessibilityStatusEventDetails&)>
  65     AccessibilityStatusCallbackList;
  66
  67 typedef AccessibilityStatusCallbackList::Subscription
  68     AccessibilityStatusSubscription;
  69
  70 // AccessibilityManager changes the statuses of accessibility features
  71 // watching profile notifications and pref-changes.
  72 // TODO(yoshiki): merge MagnificationManager with AccessibilityManager.
  73 class AccessibilityManager
  74     : public content::NotificationObserver,
  75       public extensions::api::braille_display_private::BrailleObserver,
  76       public ash::SessionStateObserver,
  77       public input_method::InputMethodManager::Observer {
  78  public:
  79   // Creates an instance of AccessibilityManager, this should be called once,
  80   // because only one instance should exist at the same time.
  81   static void Initialize();
  82   // Deletes the existing instance of AccessibilityManager.
  83   static void Shutdown();
  84   // Returns the existing instance. If there is no instance, returns NULL.
  85   static AccessibilityManager* Get();
  86
  87   // On a user's first login into a device, any a11y features enabled/disabled
  88   // by the user on the login screen are enabled/disabled in the user's profile.
  89   // This class watches for profile changes and copies settings into the user's
  90   // profile when it detects a login with a newly created profile.
  91   class PrefHandler {
  92    public:
  93     explicit PrefHandler(const char* pref_path);
  94     virtual ~PrefHandler();
  95
  96     // Should be called from AccessibilityManager::SetProfile().
  97     void HandleProfileChanged(Profile* previous_profile,
  98                               Profile* current_profile);
  99
 100    private:
 101     const char* pref_path_;
 102
 103     DISALLOW_COPY_AND_ASSIGN(PrefHandler);
 104   };
 105
 106   // Returns true when the accessibility menu should be shown.
 107   bool ShouldShowAccessibilityMenu();
 108
 109   // Returns true when cursor compositing should be enabled.
 110   bool ShouldEnableCursorCompositing();
 111
 112   // Enables or disables the large cursor.
 113   void EnableLargeCursor(bool enabled);
 114   // Returns true if the large cursor is enabled, or false if not.
 115   bool IsLargeCursorEnabled();
 116
 117   // Enables or disable Sticky Keys.
 118   void EnableStickyKeys(bool enabled);
 119
 120   // Returns true if Incognito mode is allowed, or false if not.
 121   bool IsIncognitoAllowed();
 122
 123   // Returns true if the Sticky Keys is enabled, or false if not.
 124   bool IsStickyKeysEnabled();
 125
 126   // Enables or disables spoken feedback. Enabling spoken feedback installs the
 127   // ChromeVox component extension.
 128   void EnableSpokenFeedback(bool enabled,
 129                             ui::AccessibilityNotificationVisibility notify);
 130
 131   // Returns true if spoken feedback is enabled, or false if not.
 132   bool IsSpokenFeedbackEnabled();
 133
 134   // Toggles whether Chrome OS spoken feedback is on or off.
 135   void ToggleSpokenFeedback(ui::AccessibilityNotificationVisibility notify);
 136
 137   // Enables or disables the high contrast mode for Chrome.
 138   void EnableHighContrast(bool enabled);
 139
 140   // Returns true if High Contrast is enabled, or false if not.
 141   bool IsHighContrastEnabled();
 142
 143   // Enables or disables autoclick.
 144   void EnableAutoclick(bool enabled);
 145
 146   // Returns true if autoclick is enabled.
 147   bool IsAutoclickEnabled();
 148
 149   // Set the delay for autoclicking after stopping the cursor in milliseconds.
 150   void SetAutoclickDelay(int delay_ms);
 151
 152   // Returns the autoclick delay in milliseconds.
 153   int GetAutoclickDelay() const;
 154
 155   // Enables or disables the virtual keyboard.
 156   void EnableVirtualKeyboard(bool enabled);
 157   // Returns true if the virtual keyboard is enabled, otherwise false.
 158   bool IsVirtualKeyboardEnabled();
 159
 160   // Returns true if a braille display is connected to the system, otherwise
 161   // false.
 162   bool IsBrailleDisplayConnected() const;
 163
 164   // SessionStateObserver overrides:
 165   void ActiveUserChanged(const std::string& user_id) override;
 166
 167   void SetProfileForTest(Profile* profile);
 168
 169   static void SetBrailleControllerForTest(
 170       extensions::api::braille_display_private::BrailleController* controller);
 171
 172   // Enables/disables system sounds.
 173   void EnableSystemSounds(bool system_sounds_enabled);
 174
 175   // Initiates play of shutdown sound and returns it's duration.
 176   base::TimeDelta PlayShutdownSound();
 177
 178   // Injects ChromeVox scripts into given |render_view_host|.
 179   void InjectChromeVox(content::RenderViewHost* render_view_host);
 180
 181   // Register a callback to be notified when the status of an accessibility
 182   // option changes.
 183   scoped_ptr<AccessibilityStatusSubscription> RegisterCallback(
 184       const AccessibilityStatusCallback& cb);
 185
 186   // Notify registered callbacks of a status change in an accessibility setting.
 187   void NotifyAccessibilityStatusChanged(
 188       AccessibilityStatusEventDetails& details);
 189
 190   // Notify accessibility when locale changes occur.
 191   void OnLocaleChanged();
 192
 193   // Plays an earcon. Earcons are brief and distinctive sounds that indicate
 194   // when their mapped event has occurred. The sound key enums can be found in
 195   // chromeos/audio/chromeos_sounds.h.
 196   void PlayEarcon(int sound_key);
 197
 198  protected:
 199   AccessibilityManager();
 200   ~AccessibilityManager() override;
 201
 202  private:
 203   void LoadChromeVox();
 204   void LoadChromeVoxToUserScreen(const base::Closure& done_cb);
 205   void LoadChromeVoxToLockScreen(const base::Closure& done_cb);
 206   void UnloadChromeVox();
 207   void UnloadChromeVoxFromLockScreen();
 208   void PostLoadChromeVox(Profile* profile);
 209   void PostUnloadChromeVox(Profile* profile);
 210
 211   void UpdateLargeCursorFromPref();
 212   void UpdateStickyKeysFromPref();
 213   void UpdateSpokenFeedbackFromPref();
 214   void UpdateHighContrastFromPref();
 215   void UpdateAutoclickFromPref();
 216   void UpdateAutoclickDelayFromPref();
 217   void UpdateVirtualKeyboardFromPref();
 218
 219   void CheckBrailleState();
 220   void ReceiveBrailleDisplayState(
 221       scoped_ptr<extensions::api::braille_display_private::DisplayState> state);
 222   void UpdateBrailleImeState();
 223
 224   void SetProfile(Profile* profile);
 225
 226   void UpdateChromeOSAccessibilityHistograms();
 227
 228   // content::NotificationObserver
 229   void Observe(int type,
 230                const content::NotificationSource& source,
 231                const content::NotificationDetails& details) override;
 232
 233   // extensions::api::braille_display_private::BrailleObserver implementation.
 234   // Enables spoken feedback if a braille display becomes available.
 235   void OnBrailleDisplayStateChanged(
 236       const extensions::api::braille_display_private::DisplayState&
 237           display_state) override;
 238   void OnBrailleKeyEvent(
 239       const extensions::api::braille_display_private::KeyEvent& event) override;
 240
 241   // InputMethodManager::Observer
 242   void InputMethodChanged(input_method::InputMethodManager* manager,
 243                           bool show_message) override;
 244
 245   // Profile which has the current a11y context.
 246   Profile* profile_;
 247
 248   // Profile which ChromeVox is currently loaded to. If NULL, ChromeVox is not
 249   // loaded to any profile.
 250   bool chrome_vox_loaded_on_lock_screen_;
 251   bool chrome_vox_loaded_on_user_screen_;
 252
 253   content::NotificationRegistrar notification_registrar_;
 254   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
 255   scoped_ptr<PrefChangeRegistrar> local_state_pref_change_registrar_;
 256   scoped_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
 257
 258   PrefHandler large_cursor_pref_handler_;
 259   PrefHandler spoken_feedback_pref_handler_;
 260   PrefHandler high_contrast_pref_handler_;
 261   PrefHandler autoclick_pref_handler_;
 262   PrefHandler autoclick_delay_pref_handler_;
 263   PrefHandler virtual_keyboard_pref_handler_;
 264
 265   bool large_cursor_enabled_;
 266   bool sticky_keys_enabled_;
 267   bool spoken_feedback_enabled_;
 268   bool high_contrast_enabled_;
 269   bool autoclick_enabled_;
 270   int autoclick_delay_ms_;
 271   bool virtual_keyboard_enabled_;
 272
 273   ui::AccessibilityNotificationVisibility spoken_feedback_notification_;
 274
 275   bool should_speak_chrome_vox_announcements_on_user_screen_;
 276
 277   bool system_sounds_enabled_;
 278
 279   AccessibilityStatusCallbackList callback_list_;
 280
 281   bool braille_display_connected_;
 282   ScopedObserver<extensions::api::braille_display_private::BrailleController,
 283                  AccessibilityManager> scoped_braille_observer_;
 284
 285   bool braille_ime_current_;
 286
 287   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 288
 289   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
 290 };
 291
 292 }  // namespace chromeos
 293
 294 #endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_