Gnash  0.8.10
GnashFactory.h
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00001 // GnashFactory.h   A generic class template
00002 // 
00003 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
00004 //   Free Software Foundation, Inc
00005 // 
00006 // This program is free software; you can redistribute it and/or modify
00007 // it under the terms of the GNU General Public License as published by
00008 // the Free Software Foundation; either version 3 of the License, or
00009 // (at your option) any later version.
00010 // 
00011 // This program 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
00014 // GNU General Public License for more details.
00015 // 
00016 // You should have received a copy of the GNU General Public License
00017 // along with this program; if not, write to the Free Software
00018 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00019 //
00020 
00021 #ifndef GNASH_FACTORY_H
00022 #define GNASH_FACTORY_H
00023 
00024 #ifdef HAVE_CONFIG_H
00025 # include "gnashconfig.h"
00026 #endif
00027 
00028 #include <map>
00029 #include <string>
00030 #include <algorithm>
00031 #include <iterator>
00032 #include <boost/type_traits.hpp>
00033 #include <boost/utility/enable_if.hpp>
00034 
00035 #include "dsodefs.h"
00036 #include "GnashAlgorithm.h"
00037 
00038 namespace gnash {
00039 
00040 
00042 //
00046 //
00049 //
00055 template<typename T, typename Init = void, typename Key = std::string>
00056 class DSOEXPORT GnashFactory
00057 {
00058 public:
00059 
00060     typedef T value_type;
00061     typedef Key key_type;
00062 
00063     template<typename Derived>
00064     struct RegisterHandler
00065     {
00066         static T* createHandler() {
00067             return new Derived();
00068         }
00069 
00070         RegisterHandler(const Key& name) {
00071             GnashFactory::instance().registerHandler(name, createHandler);
00072         }
00073     };
00074 
00075     typedef T*(*CreateHandler)();
00076     typedef std::map<std::string, CreateHandler> Handlers;
00077 
00079     static GnashFactory& instance() {
00080         static GnashFactory m;
00081         return m;
00082     }
00083 
00085     //
00087     template<typename Iterator>
00088     void listKeys(Iterator i, typename boost::enable_if<boost::is_same<
00089               typename std::iterator_traits<Iterator>::iterator_category,
00090               std::output_iterator_tag> >::type* dummy = 0) {
00091         Init();
00092         static_cast<void>(dummy);
00093         std::transform(_handlers.begin(), _handlers.end(), i,
00094                 boost::bind(&Handlers::value_type::first, _1));
00095     }
00096 
00098     //
00103     T* get(const Key& name) {
00104         Init();
00105         if (name.empty()) {
00106             return _handlers.empty() ? 0 : _handlers.begin()->second();
00107         }
00108 
00109         typename Handlers::const_iterator it = _handlers.find(name);
00110         if (it == _handlers.end()) return 0;
00111         return it->second();
00112     }
00113 
00115     //
00120     void registerHandler(const Key& name, CreateHandler r) {
00121         _handlers[name] = r;
00122     }
00123 
00124 private:
00125 
00126     GnashFactory() {}
00127 
00128     Handlers _handlers;
00129 
00130 };
00131  
00132 } // namespace gnash
00133 
00134 #endif