Reenabled ChromeOS system setting for timezone selection....

chrome/browser/chromeos/cros_settings.h

 // Copyright (c) 2010 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_CROS_SETTINGS_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_SETTINGS_H_
 #pragma once
 
 #include <string>
 #include <vector>
+
+#include "base/hash_tables.h"
+#include "base/non_thread_safe.h"
+#include "base/observer_list.h"
 #include "base/singleton.h"
-
 #include "chrome/browser/chromeos/cros_settings_names.h"
+#include "chrome/common/notification_observer.h"
 
 class Value;
 
 namespace chromeos {
 
 class CrosSettingsProvider;
 
 // A class manages per-device/global settings.
-class CrosSettings {
+class CrosSettings : public NonThreadSafe {
  public:
   // Class factory.
   static CrosSettings* Get();
 
   // Helper function to test if given path is a value cros settings name.
   static bool IsCrosSettings(const std::string& path);
 
   // Sets |in_value| to given |path| in cros settings.
   // Note that this takes ownership of |in_value|.
   void Set(const std::string& path, Value* in_value);
 
+  // Fires system setting change notification.
+  void FireObservers(const char* path);
+
   // Gets settings value of given |path| to |out_value|.
   // Note that |out_value| is still owned by this class.
   bool Get(const std::string& path, Value** out_value) const;
 
   // Convenience forms of Set().  These methods will replace any existing
   // value at that path, even if it has a different type.
   void SetBoolean(const std::string& path, bool in_value);
   void SetInteger(const std::string& path, int in_value);
   void SetReal(const std::string& path, double in_value);
   void SetString(const std::string& path, const std::string& in_value);
 
   // These are convenience forms of Get().  The value will be retrieved
   // and the return value will be true if the path is valid and the value at
   // the end of the path can be returned in the form specified.
   bool GetBoolean(const std::string& path, bool* out_value) const;
   bool GetInteger(const std::string& path, int* out_value) const;
   bool GetReal(const std::string& path, double* out_value) const;
   bool GetString(const std::string& path, std::string* out_value) const;
 
+  // adding/removing of providers
+  bool AddSettingsProvider(CrosSettingsProvider* provider);
+  bool RemoveSettingsProvider(CrosSettingsProvider* provider);
+
+  // If the pref at the given path changes, we call the observer's Observe
+  // method with NOTIFY_PREF_CHANGED.
+  void AddSettingsObserver(const char* path, NotificationObserver* obs);
+  void RemoveSettingsObserver(const char* path, NotificationObserver* obs);
+
  private:
-  // adding/removing of providers
-  bool AddProvider(CrosSettingsProvider* provider);
-  bool RemoveProvider(CrosSettingsProvider* provider);
+  // List of ChromeOS system settings providers.
+  std::vector<CrosSettingsProvider*> providers_;
 
-  std::vector<CrosSettingsProvider*> providers_;
+  // A map from settings names to a list of observers. Observers get fired in
+  // the order they are added.
+  typedef ObserverList<NotificationObserver> NotificationObserverList;
+  typedef base::hash_map<std::string, NotificationObserverList*>
+      SettingsObserverMap;
+  SettingsObserverMap settings_observers_;
 
   CrosSettings();
   ~CrosSettings();
   CrosSettingsProvider* GetProvider(const std::string& path) const;
   friend struct DefaultSingletonTraits<CrosSettings>;
+
   DISALLOW_COPY_AND_ASSIGN(CrosSettings);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_SETTINGS_H_