1 // Copyright 2012 The Chromium Authors 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 COMPONENTS_PREFS_DEFAULT_PREF_STORE_H_ 6 #define COMPONENTS_PREFS_DEFAULT_PREF_STORE_H_ 7 8 #include <memory> 9 #include <string> 10 11 #include "base/observer_list.h" 12 #include "base/strings/string_piece.h" 13 #include "base/values.h" 14 #include "components/prefs/pref_store.h" 15 #include "components/prefs/pref_value_map.h" 16 #include "components/prefs/prefs_export.h" 17 18 // Used within a PrefRegistry to keep track of default preference values. 19 class COMPONENTS_PREFS_EXPORT DefaultPrefStore : public PrefStore { 20 public: 21 typedef PrefValueMap::const_iterator const_iterator; 22 23 DefaultPrefStore(); 24 25 DefaultPrefStore(const DefaultPrefStore&) = delete; 26 DefaultPrefStore& operator=(const DefaultPrefStore&) = delete; 27 28 // PrefStore implementation: 29 bool GetValue(base::StringPiece key, 30 const base::Value** result) const override; 31 base::Value::Dict GetValues() const override; 32 void AddObserver(PrefStore::Observer* observer) override; 33 void RemoveObserver(PrefStore::Observer* observer) override; 34 bool HasObservers() const override; 35 36 // Sets a |value| for |key|. Should only be called if a value has not been 37 // set yet; otherwise call ReplaceDefaultValue(). 38 void SetDefaultValue(const std::string& key, base::Value value); 39 40 // Replaces the the value for |key| with a new value. Should only be called 41 // if a value has alreday been set; otherwise call SetDefaultValue(). 42 void ReplaceDefaultValue(const std::string& key, base::Value value); 43 44 const_iterator begin() const; 45 const_iterator end() const; 46 47 private: 48 ~DefaultPrefStore() override; 49 50 PrefValueMap prefs_; 51 52 base::ObserverList<PrefStore::Observer, true>::Unchecked observers_; 53 }; 54 55 #endif // COMPONENTS_PREFS_DEFAULT_PREF_STORE_H_ 56