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/memory/weak_ptr.h"
  13 #include "base/prefs/pref_change_registrar.h"
  14 #include "base/time/time.h"
  15 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
  16 #include "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
  17 #include "chrome/browser/extensions/extension_system.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
  22 class Profile;
  23
  24 namespace chromeos {
  25
  26 struct AccessibilityStatusEventDetails {
  27   AccessibilityStatusEventDetails(
  28       bool enabled,
  29       ash::AccessibilityNotificationVisibility notify);
  30
  31   AccessibilityStatusEventDetails(
  32       bool enabled,
  33       ash::MagnifierType magnifier_type,
  34       ash::AccessibilityNotificationVisibility notify);
  35
  36   bool enabled;
  37   ash::MagnifierType magnifier_type;
  38   ash::AccessibilityNotificationVisibility notify;
  39 };
  40
  41 // AccessibilityManager changes the statuses of accessibility features
  42 // watching profile notifications and pref-changes.
  43 // TODO(yoshiki): merge MagnificationManager with AccessibilityManager.
  44 class AccessibilityManager : public content::NotificationObserver,
  45     public extensions::EventRouter::Observer,
  46     extensions::api::braille_display_private::BrailleObserver,
  47     public ash::SessionStateObserver {
  48  public:
  49   // Creates an instance of AccessibilityManager, this should be called once,
  50   // because only one instance should exist at the same time.
  51   static void Initialize();
  52   // Deletes the existing instance of AccessibilityManager.
  53   static void Shutdown();
  54   // Returns the existing instance. If there is no instance, returns NULL.
  55   static AccessibilityManager* Get();
  56
  57   // On a user's first login into a device, any a11y features enabled/disabled
  58   // by the user on the login screen are enabled/disabled in the user's profile.
  59   // This class watches for profile changes and copies settings into the user's
  60   // profile when it detects a login with a newly created profile.
  61   class PrefHandler {
  62    public:
  63     explicit PrefHandler(const char* pref_path);
  64     virtual ~PrefHandler();
  65
  66     // Should be called from AccessibilityManager::SetProfile().
  67     void HandleProfileChanged(Profile* previous_profile,
  68                               Profile* current_profile);
  69
  70    private:
  71     const char* pref_path_;
  72   };
  73
  74   // Returns true when the accessibility menu should be shown.
  75   bool ShouldShowAccessibilityMenu();
  76
  77   // Enables or disables the large cursor.
  78   void EnableLargeCursor(bool enabled);
  79   // Returns true if the large cursor is enabled, or false if not.
  80   bool IsLargeCursorEnabled();
  81
  82   // Enables or disable Sticky Keys.
  83   void EnableStickyKeys(bool enabled);
  84
  85   // Returns true if Incognito mode is allowed, or false if not.
  86   bool IsIncognitoAllowed();
  87
  88   // Returns true if the Sticky Keys is enabled, or false if not.
  89   bool IsStickyKeysEnabled();
  90
  91   // Enables or disables spoken feedback. Enabling spoken feedback installs the
  92   // ChromeVox component extension.
  93   void EnableSpokenFeedback(bool enabled,
  94                             ash::AccessibilityNotificationVisibility notify);
  95
  96   // Returns true if spoken feedback is enabled, or false if not.
  97   bool IsSpokenFeedbackEnabled();
  98
  99   // Toggles whether Chrome OS spoken feedback is on or off.
 100   void ToggleSpokenFeedback(ash::AccessibilityNotificationVisibility notify);
 101
 102   // Enables or disables the high contrast mode for Chrome.
 103   void EnableHighContrast(bool enabled);
 104
 105   // Returns true if High Contrast is enabled, or false if not.
 106   bool IsHighContrastEnabled();
 107
 108   // Enables or disables autoclick.
 109   void EnableAutoclick(bool enabled);
 110
 111   // Returns true if autoclick is enabled.
 112   bool IsAutoclickEnabled();
 113
 114   // Set the delay for autoclicking after stopping the cursor in milliseconds.
 115   void SetAutoclickDelay(int delay_ms);
 116
 117   // Returns the autoclick delay in milliseconds.
 118   int GetAutoclickDelay() const;
 119
 120   // SessionStateObserver overrides:
 121   virtual void ActiveUserChanged(const std::string& user_id) OVERRIDE;
 122
 123   void SetProfileForTest(Profile* profile);
 124
 125   static void SetBrailleControllerForTest(
 126       extensions::api::braille_display_private::BrailleController* controller);
 127
 128   // Enables/disables system sounds.
 129   void EnableSystemSounds(bool system_sounds_enabled);
 130
 131   // Initiates play of shutdown sound and returns it's duration.
 132   base::TimeDelta PlayShutdownSound();
 133
 134  protected:
 135   AccessibilityManager();
 136   virtual ~AccessibilityManager();
 137
 138  private:
 139   void LoadChromeVox();
 140   void LoadChromeVoxToUserScreen();
 141   void LoadChromeVoxToLockScreen();
 142   void UnloadChromeVox();
 143   void UnloadChromeVoxFromLockScreen();
 144   void SetUpPreLoadChromeVox(Profile* profile);
 145   void TearDownPostUnloadChromeVox(Profile* profile);
 146
 147   void UpdateLargeCursorFromPref();
 148   void UpdateStickyKeysFromPref();
 149   void UpdateSpokenFeedbackFromPref();
 150   void UpdateHighContrastFromPref();
 151   void UpdateAutoclickFromPref();
 152   void UpdateAutoclickDelayFromPref();
 153   void LocalePrefChanged();
 154
 155   void CheckBrailleState();
 156   void ReceiveBrailleDisplayState(
 157       scoped_ptr<extensions::api::braille_display_private::DisplayState> state);
 158
 159
 160   void SetProfile(Profile* profile);
 161
 162   void UpdateChromeOSAccessibilityHistograms();
 163
 164   // content::NotificationObserver implementation:
 165   virtual void Observe(int type,
 166                        const content::NotificationSource& source,
 167                        const content::NotificationDetails& details) OVERRIDE;
 168
 169   // extensions::api::braille_display_private::BrailleObserver implementation.
 170   // Enables spoken feedback if a braille display becomes available.
 171   virtual void OnDisplayStateChanged(
 172       const extensions::api::braille_display_private::DisplayState&
 173           display_state) OVERRIDE;
 174
 175   // EventRouter::Observer implementation.
 176   virtual void OnListenerAdded(
 177       const extensions::EventListenerInfo& details) OVERRIDE;
 178   virtual void OnListenerRemoved(
 179       const extensions::EventListenerInfo& details) OVERRIDE;
 180
 181   // Profile which has the current a11y context.
 182   Profile* profile_;
 183
 184   // Profile which ChromeVox is currently loaded to. If NULL, ChromeVox is not
 185   // loaded to any profile.
 186   bool chrome_vox_loaded_on_lock_screen_;
 187   bool chrome_vox_loaded_on_user_screen_;
 188
 189   // Set of profiles ChromeVox is loaded to.
 190   std::set<Profile*> chromevox_profiles_;
 191
 192   content::NotificationRegistrar notification_registrar_;
 193   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
 194   scoped_ptr<PrefChangeRegistrar> local_state_pref_change_registrar_;
 195   scoped_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
 196
 197   PrefHandler large_cursor_pref_handler_;
 198   PrefHandler spoken_feedback_pref_handler_;
 199   PrefHandler high_contrast_pref_handler_;
 200   PrefHandler autoclick_pref_handler_;
 201   PrefHandler autoclick_delay_pref_handler_;
 202
 203   bool large_cursor_enabled_;
 204   bool sticky_keys_enabled_;
 205   bool spoken_feedback_enabled_;
 206   bool high_contrast_enabled_;
 207   bool autoclick_enabled_;
 208   int autoclick_delay_ms_;
 209
 210   ash::AccessibilityNotificationVisibility spoken_feedback_notification_;
 211
 212   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 213
 214   bool should_speak_chrome_vox_announcements_on_user_screen_;
 215
 216   bool system_sounds_enabled_;
 217
 218   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
 219 };
 220
 221 }  // namespace chromeos
 222
 223 #endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_