Show a notification when a braille display is connected.

chrome/browser/chromeos/accessibility/accessibility_manager.cc

 // 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.
 
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 
 #include "ash/audio/sounds.h"
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/high_contrast/high_contrast_controller.h"
 #include "ash/metrics/user_metrics_recorder.h"
@@ skipping 290 matching lines @@
       large_cursor_enabled_(false),
       sticky_keys_enabled_(false),
       spoken_feedback_enabled_(false),
       high_contrast_enabled_(false),
       autoclick_enabled_(false),
       autoclick_delay_ms_(ash::AutoclickController::kDefaultAutoclickDelayMs),
       virtual_keyboard_enabled_(false),
       spoken_feedback_notification_(ash::A11Y_NOTIFICATION_NONE),
       weak_ptr_factory_(this),
       should_speak_chrome_vox_announcements_on_user_screen_(true),
-      system_sounds_enabled_(false) {
+      system_sounds_enabled_(false),
+      braille_display_connected_(false),
+      scoped_braille_observer_(this) {
   notification_registrar_.Add(this,
                               chrome::NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE,
                               content::NotificationService::AllSources());
   notification_registrar_.Add(this,
                               chrome::NOTIFICATION_SESSION_STARTED,
                               content::NotificationService::AllSources());
   notification_registrar_.Add(this,
                               chrome::NOTIFICATION_PROFILE_DESTROYED,
                               content::NotificationService::AllSources());
   notification_registrar_.Add(this,
                               chrome::NOTIFICATION_SCREEN_LOCK_STATE_CHANGED,
                               content::NotificationService::AllSources());
 
-  GetBrailleController()->AddObserver(this);
-
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   media::SoundsManager* manager = media::SoundsManager::Get();
   manager->Initialize(SOUND_SHUTDOWN,
                       bundle.GetRawDataResource(IDR_SOUND_SHUTDOWN_WAV));
   manager->Initialize(
       SOUND_SPOKEN_FEEDBACK_ENABLED,
       bundle.GetRawDataResource(IDR_SOUND_SPOKEN_FEEDBACK_ENABLED_WAV));
   manager->Initialize(
       SOUND_SPOKEN_FEEDBACK_DISABLED,
       bundle.GetRawDataResource(IDR_SOUND_SPOKEN_FEEDBACK_DISABLED_WAV));
@@ skipping 395 matching lines @@
 
 #if defined(USE_ASH)
   keyboard::SetAccessibilityKeyboardEnabled(enabled);
   if (enabled)
     ash::Shell::GetInstance()->CreateKeyboard();
   else if (!keyboard::IsKeyboardEnabled())
     ash::Shell::GetInstance()->DeactivateKeyboard();
 #endif
 }
 
+bool AccessibilityManager::IsBrailleDisplayConnected() const {
+  return braille_display_connected_;
+}
+
 void AccessibilityManager::CheckBrailleState() {
+  BrailleController* braille_controller = GetBrailleController();
+  if (!scoped_braille_observer_.IsObserving(braille_controller))
+    scoped_braille_observer_.Add(braille_controller);
   BrowserThread::PostTaskAndReplyWithResult(
-      BrowserThread::IO, FROM_HERE, base::Bind(
-          &BrailleController::GetDisplayState,
-          base::Unretained(GetBrailleController())),
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&BrailleController::GetDisplayState,
+                 base::Unretained(braille_controller)),
       base::Bind(&AccessibilityManager::ReceiveBrailleDisplayState,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 void AccessibilityManager::ReceiveBrailleDisplayState(
     scoped_ptr<extensions::api::braille_display_private::DisplayState> state) {
   OnDisplayStateChanged(*state);
 }
 
 
@@ skipping 47 matching lines @@
             base::Unretained(this)));
   }
 
   large_cursor_pref_handler_.HandleProfileChanged(profile_, profile);
   spoken_feedback_pref_handler_.HandleProfileChanged(profile_, profile);
   high_contrast_pref_handler_.HandleProfileChanged(profile_, profile);
   autoclick_pref_handler_.HandleProfileChanged(profile_, profile);
   autoclick_delay_pref_handler_.HandleProfileChanged(profile_, profile);
   virtual_keyboard_pref_handler_.HandleProfileChanged(profile_, profile);
 
-  if (!profile_ && profile)
+  bool had_profile = (profile_ != NULL);
+  profile_ = profile;
+
+  if (!had_profile && profile)
     CheckBrailleState();
 
-  profile_ = profile;
   UpdateLargeCursorFromPref();
   UpdateStickyKeysFromPref();
   UpdateSpokenFeedbackFromPref();
   UpdateHighContrastFromPref();
   UpdateAutoclickFromPref();
   UpdateAutoclickDelayFromPref();
   UpdateVirtualKeyboardFromPref();
 }
 
 void AccessibilityManager::ActiveUserChanged(const std::string& user_id) {
@@ skipping 127 matching lines @@
           LoadChromeVoxToUserScreen();
         }
       }
       break;
     }
   }
 }
 
 void AccessibilityManager::OnDisplayStateChanged(
     const DisplayState& display_state) {
-  if (display_state.available)
+  braille_display_connected_ = display_state.available;
+  if (braille_display_connected_)
     EnableSpokenFeedback(true, ash::A11Y_NOTIFICATION_SHOW);
+
+  AccessibilityStatusEventDetails details(
+      ACCESSIBILITY_BRAILLE_DISPLAY_CONNECTION_STATE_CHANGED,
+      braille_display_connected_,
+      ash::A11Y_NOTIFICATION_SHOW);
+  NotifyAccessibilityStatusChanged(details);
 }
 
 void AccessibilityManager::PostLoadChromeVox(Profile* profile) {
   // Do any setup work needed immediately after ChromeVox actually loads.
   if (system_sounds_enabled_)
     ash::PlaySystemSoundAlways(SOUND_SPOKEN_FEEDBACK_ENABLED);
 
   ExtensionAccessibilityEventRouter::GetInstance()->
       OnChromeVoxLoadStateChanged(profile_,
           IsSpokenFeedbackEnabled(),
           chrome_vox_loaded_on_lock_screen_ ||
               should_speak_chrome_vox_announcements_on_user_screen_);
 
   should_speak_chrome_vox_announcements_on_user_screen_ =
       chrome_vox_loaded_on_lock_screen_;
 }
 
 void AccessibilityManager::PostUnloadChromeVox(Profile* profile) {
   // Do any teardown work needed immediately after ChromeVox actually unloads.
   if (system_sounds_enabled_)
     ash::PlaySystemSoundAlways(SOUND_SPOKEN_FEEDBACK_DISABLED);
 }
 
 }  // namespace chromeos