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 <QSettings> 24 #include <QHash> 25 26 class Persistable; 27 28 // Singleton class managing the saving of persistent data to permanent storage 29 // Clients must implement Persistable and register with this object, they can 30 // then be saved/loaded. 31 class PersistentInfo { 32 public: 33 // Initialise the storage backend for the Persistable, migrating the settings 34 // if needed. Must be called before any other function. 35 void migrateAndInit(); 36 // Register a Persistable 37 void registerPersistable( Persistable* object, const QString& name ); 38 // Get a Persistable (or NULL if it doesn't exist) 39 Persistable* getPersistable( const QString& name ); 40 // Save a persistable to its permanent storage 41 void save( const QString& name ); 42 // Retrieve a persistable from permanent storage 43 void retrieve( const QString& name ); 44 45 private: 46 // Can't be constructed or copied (singleton) 47 PersistentInfo(); 48 PersistentInfo( const PersistentInfo& ); 49 ~PersistentInfo(); 50 51 // Has migrateAndInit() been called? 52 bool initialised_; 53 54 // List of persistables 55 QHash<QString, Persistable*> objectList_; 56 57 // Qt setting object 58 QSettings* settings_; 59 60 // allow this function to create one instance 61 friend PersistentInfo& GetPersistentInfo(); 62 }; 63 64 PersistentInfo& GetPersistentInfo(); 65 66 // Global function used to get an object from the PersistentInfo store 67 template<typename T> 68 T& Persistent( const char* name ) 69 { 70 Persistable* p = GetPersistentInfo().getPersistable( QString( name ) ); 71 return dynamic_cast<T&>(*p); 72 } 73 74 #endif 75