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 "ash/shell_observer.h"
  12 #include "base/callback_forward.h"
  13 #include "base/callback_list.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/prefs/pref_change_registrar.h"
  16 #include "base/scoped_observer.h"
  17 #include "base/time/time.h"
  18 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
  19 #include "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
  20 #include "content/public/browser/notification_observer.h"
  21 #include "content/public/browser/notification_registrar.h"
  22 #include "extensions/browser/event_router.h"
  23 #include "extensions/browser/extension_system.h"
  24 #include "ui/base/ime/chromeos/input_method_manager.h"
  25 #include "ui/chromeos/accessibility_types.h"
  26
  27 namespace content {
  28 class RenderViewHost;
  29 }
  30 class Profile;
  31
  32 namespace chromeos {
  33
  34 enum AccessibilityNotificationType {
  35   ACCESSIBILITY_MANAGER_SHUTDOWN,
  36   ACCESSIBILITY_TOGGLE_HIGH_CONTRAST_MODE,
  37   ACCESSIBILITY_TOGGLE_LARGE_CURSOR,
  38   ACCESSIBILITY_TOGGLE_SCREEN_MAGNIFIER,
  39   ACCESSIBILITY_TOGGLE_SPOKEN_FEEDBACK,
  40   ACCESSIBILITY_TOGGLE_VIRTUAL_KEYBOARD,
  41   ACCESSIBILITY_BRAILLE_DISPLAY_CONNECTION_STATE_CHANGED
  42 };
  43
  44 struct AccessibilityStatusEventDetails {
  45   AccessibilityStatusEventDetails(
  46       AccessibilityNotificationType notification_type,
  47       bool enabled,
  48       ui::AccessibilityNotificationVisibility notify);
  49
  50   AccessibilityStatusEventDetails(
  51       AccessibilityNotificationType notification_type,
  52       bool enabled,
  53       ui::MagnifierType magnifier_type,
  54       ui::AccessibilityNotificationVisibility notify);
  55
  56   AccessibilityNotificationType notification_type;
  57   bool enabled;
  58   ui::MagnifierType magnifier_type;
  59   ui::AccessibilityNotificationVisibility notify;
  60 };
  61
  62 typedef base::Callback<void(const AccessibilityStatusEventDetails&)>
  63     AccessibilityStatusCallback;
  64
  65 typedef base::CallbackList<void(const AccessibilityStatusEventDetails&)>
  66     AccessibilityStatusCallbackList;
  67
  68 typedef AccessibilityStatusCallbackList::Subscription
  69     AccessibilityStatusSubscription;
  70
  71 // AccessibilityManager changes the statuses of accessibility features
  72 // watching profile notifications and pref-changes.
  73 // TODO(yoshiki): merge MagnificationManager with AccessibilityManager.
  74 class AccessibilityManager
  75     : public content::NotificationObserver,
  76       public extensions::api::braille_display_private::BrailleObserver,
  77       public ash::SessionStateObserver,
  78       public ash::ShellObserver,
  79       public input_method::InputMethodManager::Observer {
  80  public:
  81   // Creates an instance of AccessibilityManager, this should be called once,
  82   // because only one instance should exist at the same time.
  83   static void Initialize();
  84   // Deletes the existing instance of AccessibilityManager.
  85   static void Shutdown();
  86   // Returns the existing instance. If there is no instance, returns NULL.
  87   static AccessibilityManager* Get();
  88
  89   // On a user's first login into a device, any a11y features enabled/disabled
  90   // by the user on the login screen are enabled/disabled in the user's profile.
  91   // This class watches for profile changes and copies settings into the user's
  92   // profile when it detects a login with a newly created profile.
  93   class PrefHandler {
  94    public:
  95     explicit PrefHandler(const char* pref_path);
  96     virtual ~PrefHandler();
  97
  98     // Should be called from AccessibilityManager::SetProfile().
  99     void HandleProfileChanged(Profile* previous_profile,
 100                               Profile* current_profile);
 101
 102    private:
 103     const char* pref_path_;
 104
 105     DISALLOW_COPY_AND_ASSIGN(PrefHandler);
 106   };
 107
 108   // Returns true when the accessibility menu should be shown.
 109   bool ShouldShowAccessibilityMenu();
 110
 111   // Returns true when cursor compositing should be enabled.
 112   bool ShouldEnableCursorCompositing();
 113
 114   // Enables or disables the large cursor.
 115   void EnableLargeCursor(bool enabled);
 116   // Returns true if the large cursor is enabled, or false if not.
 117   bool IsLargeCursorEnabled();
 118
 119   // Enables or disable Sticky Keys.
 120   void EnableStickyKeys(bool enabled);
 121
 122   // Returns true if Incognito mode is allowed, or false if not.
 123   bool IsIncognitoAllowed();
 124
 125   // Returns true if the Sticky Keys is enabled, or false if not.
 126   bool IsStickyKeysEnabled();
 127
 128   // Enables or disables spoken feedback. Enabling spoken feedback installs the
 129   // ChromeVox component extension.
 130   void EnableSpokenFeedback(bool enabled,
 131                             ui::AccessibilityNotificationVisibility notify);
 132
 133   // Returns true if spoken feedback is enabled, or false if not.
 134   bool IsSpokenFeedbackEnabled();
 135
 136   // Toggles whether Chrome OS spoken feedback is on or off.
 137   void ToggleSpokenFeedback(ui::AccessibilityNotificationVisibility notify);
 138
 139   // Enables or disables the high contrast mode for Chrome.
 140   void EnableHighContrast(bool enabled);
 141
 142   // Returns true if High Contrast is enabled, or false if not.
 143   bool IsHighContrastEnabled();
 144
 145   // Enables or disables autoclick.
 146   void EnableAutoclick(bool enabled);
 147
 148   // Returns true if autoclick is enabled.
 149   bool IsAutoclickEnabled();
 150
 151   // Set the delay for autoclicking after stopping the cursor in milliseconds.
 152   void SetAutoclickDelay(int delay_ms);
 153
 154   // Returns the autoclick delay in milliseconds.
 155   int GetAutoclickDelay() const;
 156
 157   // Enables or disables the virtual keyboard.
 158   void EnableVirtualKeyboard(bool enabled);
 159   // Returns true if the virtual keyboard is enabled, otherwise false.
 160   bool IsVirtualKeyboardEnabled();
 161
 162   // Returns true if a braille display is connected to the system, otherwise
 163   // false.
 164   bool IsBrailleDisplayConnected() const;
 165
 166   // SessionStateObserver overrides:
 167   void ActiveUserChanged(const std::string& user_id) override;
 168
 169   // ShellObserver overrides:
 170   void OnAppTerminating() override;
 171
 172   void SetProfileForTest(Profile* profile);
 173
 174   static void SetBrailleControllerForTest(
 175       extensions::api::braille_display_private::BrailleController* controller);
 176
 177   // Enables/disables system sounds.
 178   void EnableSystemSounds(bool system_sounds_enabled);
 179
 180   // Initiates play of shutdown sound and returns it's duration.
 181   base::TimeDelta PlayShutdownSound();
 182
 183   // Injects ChromeVox scripts into given |render_view_host|.
 184   void InjectChromeVox(content::RenderViewHost* render_view_host);
 185
 186   // Register a callback to be notified when the status of an accessibility
 187   // option changes.
 188   scoped_ptr<AccessibilityStatusSubscription> RegisterCallback(
 189       const AccessibilityStatusCallback& cb);
 190
 191   // Notify registered callbacks of a status change in an accessibility setting.
 192   void NotifyAccessibilityStatusChanged(
 193       AccessibilityStatusEventDetails& details);
 194
 195   // Notify accessibility when locale changes occur.
 196   void OnLocaleChanged();
 197
 198   // Plays an earcon. Earcons are brief and distinctive sounds that indicate
 199   // when their mapped event has occurred. The sound key enums can be found in
 200   // chromeos/audio/chromeos_sounds.h.
 201   void PlayEarcon(int sound_key);
 202
 203   // Profile having the a11y context.
 204   Profile* profile() { return profile_; }
 205
 206  protected:
 207   AccessibilityManager();
 208   ~AccessibilityManager() override;
 209
 210  private:
 211   void LoadChromeVox();
 212   void LoadChromeVoxToUserScreen(const base::Closure& done_cb);
 213   void LoadChromeVoxToLockScreen(const base::Closure& done_cb);
 214   void UnloadChromeVox();
 215   void UnloadChromeVoxFromLockScreen();
 216   void PostLoadChromeVox(Profile* profile);
 217   void PostUnloadChromeVox(Profile* profile);
 218
 219   void UpdateLargeCursorFromPref();
 220   void UpdateStickyKeysFromPref();
 221   void UpdateSpokenFeedbackFromPref();
 222   void UpdateHighContrastFromPref();
 223   void UpdateAutoclickFromPref();
 224   void UpdateAutoclickDelayFromPref();
 225   void UpdateVirtualKeyboardFromPref();
 226
 227   void CheckBrailleState();
 228   void ReceiveBrailleDisplayState(
 229       scoped_ptr<extensions::api::braille_display_private::DisplayState> state);
 230   void UpdateBrailleImeState();
 231
 232   void SetProfile(Profile* profile);
 233
 234   void UpdateChromeOSAccessibilityHistograms();
 235
 236   // content::NotificationObserver
 237   void Observe(int type,
 238                const content::NotificationSource& source,
 239                const content::NotificationDetails& details) override;
 240
 241   // extensions::api::braille_display_private::BrailleObserver implementation.
 242   // Enables spoken feedback if a braille display becomes available.
 243   void OnBrailleDisplayStateChanged(
 244       const extensions::api::braille_display_private::DisplayState&
 245           display_state) override;
 246   void OnBrailleKeyEvent(
 247       const extensions::api::braille_display_private::KeyEvent& event) override;
 248
 249   // InputMethodManager::Observer
 250   void InputMethodChanged(input_method::InputMethodManager* manager,
 251                           Profile* profile,
 252                           bool show_message) override;
 253
 254   // Profile which has the current a11y context.
 255   Profile* profile_;
 256
 257   // Profile which ChromeVox is currently loaded to. If NULL, ChromeVox is not
 258   // loaded to any profile.
 259   bool chrome_vox_loaded_on_lock_screen_;
 260   bool chrome_vox_loaded_on_user_screen_;
 261
 262   content::NotificationRegistrar notification_registrar_;
 263   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
 264   scoped_ptr<PrefChangeRegistrar> local_state_pref_change_registrar_;
 265   scoped_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
 266
 267   PrefHandler large_cursor_pref_handler_;
 268   PrefHandler spoken_feedback_pref_handler_;
 269   PrefHandler high_contrast_pref_handler_;
 270   PrefHandler autoclick_pref_handler_;
 271   PrefHandler autoclick_delay_pref_handler_;
 272   PrefHandler virtual_keyboard_pref_handler_;
 273
 274   bool large_cursor_enabled_;
 275   bool sticky_keys_enabled_;
 276   bool spoken_feedback_enabled_;
 277   bool high_contrast_enabled_;
 278   bool autoclick_enabled_;
 279   int autoclick_delay_ms_;
 280   bool virtual_keyboard_enabled_;
 281
 282   ui::AccessibilityNotificationVisibility spoken_feedback_notification_;
 283
 284   bool should_speak_chrome_vox_announcements_on_user_screen_;
 285
 286   bool system_sounds_enabled_;
 287
 288   AccessibilityStatusCallbackList callback_list_;
 289
 290   bool braille_display_connected_;
 291   ScopedObserver<extensions::api::braille_display_private::BrailleController,
 292                  AccessibilityManager> scoped_braille_observer_;
 293
 294   bool braille_ime_current_;
 295
 296   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 297
 298   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
 299 };
 300
 301 }  // namespace chromeos
 302
 303 #endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_