FIFE  2008.0
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resource_ptr.h
00001 /***************************************************************************
00002  *   Copyright (C) 2005-2008 by the FIFE team                              *
00003  *   http://www.fifengine.de                                               *
00004  *   This file is part of FIFE.                                            *
00005  *                                                                         *
00006  *   FIFE is free software; you can redistribute it and/or                 *
00007  *   modify it under the terms of the GNU Lesser General Public            *
00008  *   License as published by the Free Software Foundation; either          *
00009  *   version 2.1 of the License, or (at your option) any later version.    *
00010  *                                                                         *
00011  *   This library is distributed in the hope that it will be useful,       *
00012  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
00013  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
00014  *   Lesser General Public License for more details.                       *
00015  *                                                                         *
00016  *   You should have received a copy of the GNU Lesser General Public      *
00017  *   License along with this library; if not, write to the                 *
00018  *   Free Software Foundation, Inc.,                                       *
00019  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA          *
00020  ***************************************************************************/
00021 
00022 #ifndef FIFE_RESOURE_PTR_H
00023 #define FIFE_RESOURE_PTR_H
00024 
00025 // Standard C++ library includes
00026 
00027 // 3rd party library includes
00028 
00029 // FIFE includes
00030 // These includes are split up in two parts, separated by one empty line
00031 // First block: files included from the FIFE root src directory
00032 // Second block: files included from the same folder
00033 #include "resource.h"
00034 #include "pool.h"
00035 
00036 namespace FIFE {
00037 
00040     class ResourcePtr {
00041     public:
00042         ResourcePtr(IResource* ptr = 0) : m_ptr(ptr),m_pool(0),m_index(Pool::INVALID_ID) {
00043             if( m_ptr )
00044                 m_ptr->addRef();
00045         }
00046 
00047         ResourcePtr(Pool* pool,int index) : m_ptr(0),m_pool(pool),m_index(index) {
00048         }
00049 
00050         ResourcePtr(const ResourcePtr& r)
00051         : m_ptr(r.m_ptr),m_pool(r.m_pool),m_index(r.m_index) {
00052             if(m_ptr) {
00053                  m_ptr->addRef();
00054             }
00055         }
00056 
00057         ResourcePtr& operator=(const ResourcePtr& r) {
00058             if( this == &r )
00059                 return *this;
00060             release();
00061             m_ptr = r.m_ptr;
00062             m_pool = r.m_pool;
00063             m_index = r.m_index;
00064             if(m_ptr) {
00065                  m_ptr->addRef();
00066             }
00067             return *this;
00068         }
00069 
00070         ~ResourcePtr() {
00071             release();
00072         }
00073 
00074         IResource& operator->() {
00075             load();
00076             return *m_ptr;
00077         }
00078 
00079         const IResource& operator->() const {
00080             constLoad();
00081             return *m_ptr;
00082         }
00083 
00084         operator bool() const {
00085             return isValid();
00086         }
00087 
00088         bool isValid() const {
00089             return m_ptr || isLoadable();
00090         }
00091 
00092         bool isLoadable() const {
00093             return m_pool && m_index != Pool::INVALID_ID;
00094         }
00095 
00096         bool operator==(const ResourcePtr& r) const {
00097             if( isLoadable() && r.isLoadable() )
00098                 return m_index == r.m_index && m_pool == r.m_pool;
00099             if( !isLoadable() && !r.isLoadable() )
00100                 return m_ptr == r.m_ptr;
00101             return false;
00102         }
00103 
00104         bool operator<(const ResourcePtr& r) const {
00105             if( isLoadable() && r.isLoadable() )
00106             {
00107                 if( m_pool == r.m_pool )
00108                     return m_index < r.m_index;
00109                 return m_pool < r.m_pool;
00110             }
00111             if( !isLoadable() && !r.isLoadable() )
00112                 return m_ptr < r.m_ptr;
00113             return isLoadable() < r.isLoadable();
00114         }
00115 
00116         void release() {
00117             if(m_ptr) {
00118                  m_ptr->decRef();
00119             }
00120             m_ptr = 0;
00121         }
00122 
00123         void load() {
00124             constLoad();
00125         }
00126 
00127         void unload() {
00128             release();
00129             if( isLoadable() ) {
00130                 m_pool->release(m_index);
00131             }
00132         }
00133 
00134         template<class T>
00135         T* get() {
00136             if( isValid() )
00137                 load();
00138             return dynamic_cast<T*>(m_ptr);
00139         }
00140 
00141     private:
00142         void constLoad() const {
00143             if( m_ptr )
00144                 return;
00145             m_ptr = &m_pool->get(m_index);
00146             m_ptr->addRef();
00147         }
00148         mutable IResource* m_ptr;
00149         Pool* m_pool;
00150         int m_index;
00151     };
00152 }
00153 #endif
00154