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