Magnifier: Prevent useless operation in enabling/disabling magnifier.

chrome/browser/chromeos/system/ash_system_tray_delegate.cc

 // Copyright (c) 2012 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/system/ash_system_tray_delegate.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/audio/audio_observer.h"
 #include "ash/system/bluetooth/bluetooth_observer.h"
@@ skipping 14 matching lines @@
 #include "ash/volume_control_delegate.h"
 #include "ash/wm/session_state_controller.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/chromeos/chromeos_version.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
+#include "chrome/browser/chromeos/accessibility/magnification_manager.h"
 #include "chrome/browser/chromeos/audio/audio_handler.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "chrome/browser/chromeos/cros/network_library.h"
 #include "chrome/browser/chromeos/drive/drive_system_service.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
 #include "chrome/browser/chromeos/input_method/input_method_util.h"
 #include "chrome/browser/chromeos/input_method/xkeyboard.h"
 #include "chrome/browser/chromeos/kiosk_mode/kiosk_mode_settings.h"
 #include "chrome/browser/chromeos/login/base_login_display_host.h"
 #include "chrome/browser/chromeos/login/login_display_host.h"
@@ skipping 111 matching lines @@
                            public NetworkMenuIcon::Delegate,
                            public NetworkMenu::Delegate,
                            public NetworkLibrary::NetworkManagerObserver,
                            public NetworkLibrary::NetworkObserver,
                            public google_apis::DriveServiceObserver,
                            public content::NotificationObserver,
                            public input_method::InputMethodManager::Observer,
                            public system::TimezoneSettings::Observer,
                            public device::BluetoothAdapter::Observer,
                            public SystemKeyEventListener::CapsLockObserver,
-                           public ash::NetworkTrayDelegate {
+                           public ash::NetworkTrayDelegate,
+                           public MagnificationObserver {
  public:
   SystemTrayDelegate()
       : ui_weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(
             new base::WeakPtrFactory<SystemTrayDelegate>(this))),
         network_icon_(ALLOW_THIS_IN_INITIALIZER_LIST(
                       new NetworkMenuIcon(this, NetworkMenuIcon::MENU_MODE))),
         network_icon_dark_(ALLOW_THIS_IN_INITIALIZER_LIST(
                       new NetworkMenuIcon(this, NetworkMenuIcon::MENU_MODE))),
         network_menu_(ALLOW_THIS_IN_INITIALIZER_LIST(new NetworkMenu(this))),
         clock_type_(base::k24HourClock),
@@ skipping 35 matching lines @@
     crosnet->AddNetworkManagerObserver(this);
     OnNetworkManagerChanged(crosnet);
 
     input_method::InputMethodManager::GetInstance()->AddObserver(this);
 
     system::TimezoneSettings::GetInstance()->AddObserver(this);
 
     if (SystemKeyEventListener::GetInstance())
       SystemKeyEventListener::GetInstance()->AddCapsLockObserver(this);
 
+    if (chromeos::MagnificationManager::Get())
+      chromeos::MagnificationManager::Get()->AddObserver(this);
+
     spoken_feedback_enabled_.Init(
         prefs::kSpokenFeedbackEnabled,
         g_browser_process->local_state(),
         base::Bind(&SystemTrayDelegate::OnAccessibilityModeChanged,
                    base::Unretained(this)));
 
     high_contrast_enabled_.Init(
         prefs::kHighContrastEnabled,
         g_browser_process->local_state(),
         base::Bind(&SystemTrayDelegate::OnAccessibilityModeChanged,
@@ skipping 15 matching lines @@
     DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
     NetworkLibrary* crosnet = CrosLibrary::Get()->GetNetworkLibrary();
     if (crosnet)
       crosnet->RemoveNetworkManagerObserver(this);
     input_method::InputMethodManager::GetInstance()->RemoveObserver(this);
     system::TimezoneSettings::GetInstance()->RemoveObserver(this);
     if (SystemKeyEventListener::GetInstance())
       SystemKeyEventListener::GetInstance()->RemoveCapsLockObserver(this);
     bluetooth_adapter_->RemoveObserver(this);
 
+    if (chromeos::MagnificationManager::Get())
+      chromeos::MagnificationManager::Get()->RemoveObserver(this);
+
     // Stop observing gdata operations.
     DriveSystemService* system_service = FindDriveSystemService();
     if (system_service) {
       system_service->drive_service()->RemoveObserver(this);
     }
   }
 
   // Overridden from ash::SystemTrayDelegate:
   virtual bool GetTrayVisibilityOnStartup() OVERRIDE {
     // In case of OOBE / sign in screen tray will be shown later.
@@ skipping 514 matching lines @@
                    base::Unretained(this)));
     pref_registrar_->Add(
         prefs::kLanguageRemapSearchKeyTo,
         base::Bind(&SystemTrayDelegate::OnLanguageRemapSearchKeyToChanged,
                    base::Unretained(this)));
     pref_registrar_->Add(
         prefs::kShowLogoutButtonInTray,
         base::Bind(&SystemTrayDelegate::UpdateShowLogoutButtonInTray,
                    base::Unretained(this)));
     pref_registrar_->Add(
-        prefs::kMagnifierType,
-        base::Bind(&SystemTrayDelegate::OnAccessibilityModeChanged,
-                   base::Unretained(this)));
-    pref_registrar_->Add(
         prefs::kShouldAlwaysShowAccessibilityMenu,
         base::Bind(&SystemTrayDelegate::OnAccessibilityModeChanged,
                    base::Unretained(this)));
 
     UpdateClockType();
     UpdateShowLogoutButtonInTray();
     search_key_mapped_to_ =
         profile->GetPrefs()->GetInteger(prefs::kLanguageRemapSearchKeyTo);
   }
 
@@ skipping 457 matching lines @@
     }
 
     if (!deal_url_to_open.empty()) {
       Browser* browser = GetAppropriateBrowser();
       if (!browser)
         return;
       chrome::ShowSingletonTab(browser, GURL(deal_url_to_open));
     }
   }
 
+  // Overridden from MagnificationObserver
+  void OnMagnifierTypeChanged(ash::MagnifierType new_type) {
+    OnAccessibilityModeChanged();
+  }
+
   scoped_ptr<base::WeakPtrFactory<SystemTrayDelegate> > ui_weak_ptr_factory_;
   scoped_ptr<NetworkMenuIcon> network_icon_;
   scoped_ptr<NetworkMenuIcon> network_icon_dark_;
   scoped_ptr<NetworkMenu> network_menu_;
   content::NotificationRegistrar registrar_;
   scoped_ptr<PrefChangeRegistrar> pref_registrar_;
   std::string cellular_device_path_;
   std::string active_network_path_;
   PowerSupplyStatus power_supply_status_;
   base::HourClockType clock_type_;
@@ skipping 16 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(SystemTrayDelegate);
 };
 
 }  // namespace
 
 ash::SystemTrayDelegate* CreateSystemTrayDelegate() {
   return new chromeos::SystemTrayDelegate();
 }
 
 }  // namespace chromeos