Show a notification when a braille display is connected.

chrome/browser/chromeos/accessibility/accessibility_manager.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
 
 #include <set>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/session_state_observer.h"
 #include "base/callback_list.h"
 #include "base/memory/weak_ptr.h"
 #include "base/prefs/pref_change_registrar.h"
+#include "base/scoped_observer.h"
 #include "base/time/time.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
 #include "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_system.h"
 
 namespace content {
 class RenderViewHost;
 }
 class Profile;
 
 namespace chromeos {
 
 enum AccessibilityNotificationType {
   ACCESSIBILITY_MANAGER_SHUTDOWN,
   ACCESSIBILITY_TOGGLE_HIGH_CONTRAST_MODE,
   ACCESSIBILITY_TOGGLE_LARGE_CURSOR,
   ACCESSIBILITY_TOGGLE_SCREEN_MAGNIFIER,
   ACCESSIBILITY_TOGGLE_SPOKEN_FEEDBACK,
-  ACCESSIBILITY_TOGGLE_VIRTUAL_KEYBOARD
+  ACCESSIBILITY_TOGGLE_VIRTUAL_KEYBOARD,
+  ACCESSIBILITY_BRAILLE_DISPLAY_CONNECTION_STATE_CHANGED
 };
 
 struct AccessibilityStatusEventDetails {
   AccessibilityStatusEventDetails(
       AccessibilityNotificationType notification_type,
       bool enabled,
       ash::AccessibilityNotificationVisibility notify);
 
   AccessibilityStatusEventDetails(
       AccessibilityNotificationType notification_type,
@@ skipping 12 matching lines @@
 
 typedef base::CallbackList<void(const AccessibilityStatusEventDetails&)>
     AccessibilityStatusCallbackList;
 
 typedef AccessibilityStatusCallbackList::Subscription
     AccessibilityStatusSubscription;
 
 // AccessibilityManager changes the statuses of accessibility features
 // watching profile notifications and pref-changes.
 // TODO(yoshiki): merge MagnificationManager with AccessibilityManager.
-class AccessibilityManager : public content::NotificationObserver,
-    extensions::api::braille_display_private::BrailleObserver,
-    public ash::SessionStateObserver {
+class AccessibilityManager
+    : public content::NotificationObserver,
+      public extensions::api::braille_display_private::BrailleObserver,
+      public ash::SessionStateObserver {
  public:
   // Creates an instance of AccessibilityManager, this should be called once,
   // because only one instance should exist at the same time.
   static void Initialize();
   // Deletes the existing instance of AccessibilityManager.
   static void Shutdown();
   // Returns the existing instance. If there is no instance, returns NULL.
   static AccessibilityManager* Get();
 
   // On a user's first login into a device, any a11y features enabled/disabled
@@ skipping 60 matching lines @@
   void SetAutoclickDelay(int delay_ms);
 
   // Returns the autoclick delay in milliseconds.
   int GetAutoclickDelay() const;
 
   // Enables or disables the virtual keyboard.
   void EnableVirtualKeyboard(bool enabled);
   // Returns true if the virtual keyboard is enabled, otherwise false.
   bool IsVirtualKeyboardEnabled();
 
+  // Returns true if a braille display is connected to the system, otherwise
+  // false.
+  bool IsBrailleDisplayConnected() const;
+
   // SessionStateObserver overrides:
   virtual void ActiveUserChanged(const std::string& user_id) OVERRIDE;
 
   void SetProfileForTest(Profile* profile);
 
   static void SetBrailleControllerForTest(
       extensions::api::braille_display_private::BrailleController* controller);
 
   // Enables/disables system sounds.
   void EnableSystemSounds(bool system_sounds_enabled);
@@ skipping 87 matching lines @@
   ash::AccessibilityNotificationVisibility spoken_feedback_notification_;
 
   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 
   bool should_speak_chrome_vox_announcements_on_user_screen_;
 
   bool system_sounds_enabled_;
 
   AccessibilityStatusCallbackList callback_list_;
 
+  bool braille_display_connected_;
+  ScopedObserver<extensions::api::braille_display_private::BrailleController,
+                 AccessibilityManager> scoped_braille_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_