accessibility_manager.h revision f8ee788a64d60abd8f2d742a5fdedde054ecd910 
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/session_state_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 "chromeos/ime/input_method_manager.h"
21#include "content/public/browser/notification_observer.h"
22#include "content/public/browser/notification_registrar.h"
23#include "extensions/browser/event_router.h"
24#include "extensions/browser/extension_system.h"
25
26namespace content {
27class RenderViewHost;
28}
29class Profile;
30
31namespace chromeos {
32
33enum 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
43struct AccessibilityStatusEventDetails {
44  AccessibilityStatusEventDetails(
45      AccessibilityNotificationType notification_type,
46      bool enabled,
47      ash::AccessibilityNotificationVisibility notify);
48
49  AccessibilityStatusEventDetails(
50      AccessibilityNotificationType notification_type,
51      bool enabled,
52      ash::MagnifierType magnifier_type,
53      ash::AccessibilityNotificationVisibility notify);
54
55  AccessibilityNotificationType notification_type;
56  bool enabled;
57  ash::MagnifierType magnifier_type;
58  ash::AccessibilityNotificationVisibility notify;
59};
60
61typedef base::Callback<void(const AccessibilityStatusEventDetails&)>
62    AccessibilityStatusCallback;
63
64typedef base::CallbackList<void(const AccessibilityStatusEventDetails&)>
65    AccessibilityStatusCallbackList;
66
67typedef 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.
73class AccessibilityManager
74    : public content::NotificationObserver,
75      public extensions::api::braille_display_private::BrailleObserver,
76      public input_method::InputMethodManager::Observer,
77      public ash::SessionStateObserver {
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                            ash::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(ash::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  virtual 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 protected:
194  AccessibilityManager();
195  virtual ~AccessibilityManager();
196
197 private:
198  void LoadChromeVox();
199  void LoadChromeVoxToUserScreen(const base::Closure& done_cb);
200  void LoadChromeVoxToLockScreen(const base::Closure& done_cb);
201  void UnloadChromeVox();
202  void UnloadChromeVoxFromLockScreen();
203  void PostLoadChromeVox(Profile* profile);
204  void PostUnloadChromeVox(Profile* profile);
205
206  void UpdateLargeCursorFromPref();
207  void UpdateStickyKeysFromPref();
208  void UpdateSpokenFeedbackFromPref();
209  void UpdateHighContrastFromPref();
210  void UpdateAutoclickFromPref();
211  void UpdateAutoclickDelayFromPref();
212  void UpdateVirtualKeyboardFromPref();
213
214  void CheckBrailleState();
215  void ReceiveBrailleDisplayState(
216      scoped_ptr<extensions::api::braille_display_private::DisplayState> state);
217  void UpdateBrailleImeState();
218
219  void SetProfile(Profile* profile);
220
221  void UpdateChromeOSAccessibilityHistograms();
222
223  // content::NotificationObserver
224  virtual void Observe(int type,
225                       const content::NotificationSource& source,
226                       const content::NotificationDetails& details) OVERRIDE;
227
228  // extensions::api::braille_display_private::BrailleObserver implementation.
229  // Enables spoken feedback if a braille display becomes available.
230  virtual void OnBrailleDisplayStateChanged(
231      const extensions::api::braille_display_private::DisplayState&
232          display_state) OVERRIDE;
233  virtual void OnBrailleKeyEvent(
234      const extensions::api::braille_display_private::KeyEvent& event) OVERRIDE;
235
236  // InputMethodManager::Observer
237  virtual void InputMethodChanged(input_method::InputMethodManager* manager,
238                                  bool show_message) OVERRIDE;
239
240
241  // Profile which has the current a11y context.
242  Profile* profile_;
243
244  // Profile which ChromeVox is currently loaded to. If NULL, ChromeVox is not
245  // loaded to any profile.
246  bool chrome_vox_loaded_on_lock_screen_;
247  bool chrome_vox_loaded_on_user_screen_;
248
249  content::NotificationRegistrar notification_registrar_;
250  scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
251  scoped_ptr<PrefChangeRegistrar> local_state_pref_change_registrar_;
252  scoped_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
253
254  PrefHandler large_cursor_pref_handler_;
255  PrefHandler spoken_feedback_pref_handler_;
256  PrefHandler high_contrast_pref_handler_;
257  PrefHandler autoclick_pref_handler_;
258  PrefHandler autoclick_delay_pref_handler_;
259  PrefHandler virtual_keyboard_pref_handler_;
260
261  bool large_cursor_enabled_;
262  bool sticky_keys_enabled_;
263  bool spoken_feedback_enabled_;
264  bool high_contrast_enabled_;
265  bool autoclick_enabled_;
266  int autoclick_delay_ms_;
267  bool virtual_keyboard_enabled_;
268
269  ash::AccessibilityNotificationVisibility spoken_feedback_notification_;
270
271  base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
272
273  bool should_speak_chrome_vox_announcements_on_user_screen_;
274
275  bool system_sounds_enabled_;
276
277  AccessibilityStatusCallbackList callback_list_;
278
279  bool braille_display_connected_;
280  ScopedObserver<extensions::api::braille_display_private::BrailleController,
281                 AccessibilityManager> scoped_braille_observer_;
282
283  bool braille_ime_current_;
284
285  DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
286};
287
288}  // namespace chromeos
289
290#endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
291