1 // Copyright (c) 2011 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 BASE_PREFS_PREF_NOTIFIER_IMPL_H_ 6 #define BASE_PREFS_PREF_NOTIFIER_IMPL_H_ 7 8 #include <list> 9 #include <string> 10 11 #include "base/callback.h" 12 #include "base/compiler_specific.h" 13 #include "base/containers/hash_tables.h" 14 #include "base/observer_list.h" 15 #include "base/prefs/base_prefs_export.h" 16 #include "base/prefs/pref_notifier.h" 17 #include "base/prefs/pref_observer.h" 18 #include "base/threading/thread_checker.h" 19 20 class PrefService; 21 22 // The PrefNotifier implementation used by the PrefService. 23 class BASE_PREFS_EXPORT PrefNotifierImpl 24 : public NON_EXPORTED_BASE(PrefNotifier) { 25 public: 26 PrefNotifierImpl(); 27 explicit PrefNotifierImpl(PrefService* pref_service); 28 virtual ~PrefNotifierImpl(); 29 30 // If the pref at the given path changes, we call the observer's 31 // OnPreferenceChanged method. 32 void AddPrefObserver(const char* path, PrefObserver* observer); 33 void RemovePrefObserver(const char* path, PrefObserver* observer); 34 35 // We run the callback once, when initialization completes. The bool 36 // parameter will be set to true for successful initialization, 37 // false for unsuccessful. 38 void AddInitObserver(base::Callback<void(bool)> observer); 39 40 void SetPrefService(PrefService* pref_service); 41 42 protected: 43 // PrefNotifier overrides. 44 virtual void OnPreferenceChanged(const std::string& pref_name) OVERRIDE; 45 virtual void OnInitializationCompleted(bool succeeded) OVERRIDE; 46 47 // A map from pref names to a list of observers. Observers get fired in the 48 // order they are added. These should only be accessed externally for unit 49 // testing. 50 typedef ObserverList<PrefObserver> PrefObserverList; 51 typedef base::hash_map<std::string, PrefObserverList*> PrefObserverMap; 52 53 typedef std::list<base::Callback<void(bool)> > PrefInitObserverList; 54 55 const PrefObserverMap* pref_observers() const { return &pref_observers_; } 56 57 private: 58 // For the given pref_name, fire any observer of the pref. Virtual so it can 59 // be mocked for unit testing. 60 virtual void FireObservers(const std::string& path); 61 62 // Weak reference; the notifier is owned by the PrefService. 63 PrefService* pref_service_; 64 65 PrefObserverMap pref_observers_; 66 PrefInitObserverList init_observers_; 67 68 base::ThreadChecker thread_checker_; 69 70 DISALLOW_COPY_AND_ASSIGN(PrefNotifierImpl); 71 }; 72 73 #endif // BASE_PREFS_PREF_NOTIFIER_IMPL_H_ 74
