1 /* 2 * Copyright (C) 2011 Nicolas Bonnefon and other contributors 3 * 4 * This file is part of glogg. 5 * 6 * glogg is free software: you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation, either version 3 of the License, or 9 * (at your option) any later version. 10 * 11 * glogg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with glogg. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #ifndef PERSISTENTINFO_H 21 #define PERSISTENTINFO_H 22 23 #include <memory> 24 25 #include <QSettings> 26 #include <QHash> 27 28 class Persistable; 29 30 // Singleton class managing the saving of persistent data to permanent storage 31 // Clients must implement Persistable and register with this object, they can 32 // then be saved/loaded. 33 class PersistentInfo { 34 public: 35 // Initialise the storage backend for the Persistable, migrating the settings 36 // if needed. Must be called before any other function. 37 void migrateAndInit(); 38 // Register a Persistable 39 void registerPersistable( std::shared_ptr<Persistable> object, 40 const QString& name ); 41 // Get a Persistable (or NULL if it doesn't exist) 42 std::shared_ptr<Persistable> getPersistable( const QString& name ); 43 // Save a persistable to its permanent storage 44 void save( const QString& name ); 45 // Retrieve a persistable from permanent storage 46 void retrieve( const QString& name ); 47 48 private: 49 // Can't be constructed or copied (singleton) 50 PersistentInfo(); 51 PersistentInfo( const PersistentInfo& ); 52 ~PersistentInfo(); 53 54 // Has migrateAndInit() been called? 55 bool initialised_; 56 57 // List of persistables 58 QHash<QString, std::shared_ptr<Persistable>> objectList_; 59 60 // Qt setting object 61 QSettings* settings_; 62 63 // allow this function to create one instance 64 friend PersistentInfo& GetPersistentInfo(); 65 }; 66 67 PersistentInfo& GetPersistentInfo(); 68 69 // Global function used to get a reference to an object 70 // from the PersistentInfo store 71 template<typename T> 72 std::shared_ptr<T> Persistent( const char* name ) 73 { 74 std::shared_ptr<Persistable> p = 75 GetPersistentInfo().getPersistable( QString( name ) ); 76 return std::dynamic_pointer_cast<T>(p); 77 } 78 79 template<typename T> 80 std::shared_ptr<T> PersistentCopy( const char* name ) 81 { 82 std::shared_ptr<Persistable> p = 83 GetPersistentInfo().getPersistable( QString( name ) ); 84 return std::make_shared<T>( *( std::dynamic_pointer_cast<T>(p) ) ); 85 } 86 #endif 87