Source/System/FileIO/OSB/OSGOSBElementFactory.cpp

   1 /*---------------------------------------------------------------------------*\
   2  *                                OpenSG                                     *
   3  *                                                                           *
   4  *                                                                           *
   5  *                   Copyright (C) 2006 by the OpenSG Forum                  *
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   7  *                            www.opensg.org                                 *
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  15  * This library is free software; you can redistribute it and/or modify it   *
  16  * under the terms of the GNU Library General Public License as published    *
  17  * by the Free Software Foundation, version 2.                               *
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  19  * This library is distributed in the hope that it will be useful, but       *
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  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  22  * Library General Public License for more details.                          *
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  28 \*---------------------------------------------------------------------------*/
  29 /*---------------------------------------------------------------------------*\
  30  *                                Changes                                    *
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  37 \*---------------------------------------------------------------------------*/
  38
  39 #include "OSGOSBElementFactory.h"
  40
  41 #include "OSGSingletonHolder.ins"
  42
  43 OSG_BEGIN_NAMESPACE
  44
  45 OSG_SINGLETON_INST(OSG::OSBElementFactorySingleton, addPostFactoryExitFunction)
  46
  47 template class SingletonHolder<OSG::OSBElementFactorySingleton>;
  48
  49 /*-------------------------------------------------------------------------*/
  50 /* OSBElementCreatorBase                                                  */
  51 /*-------------------------------------------------------------------------*/
  52
  53 /*-------------------------------------------------------------------------*/
  54 /* Destructor                                                              */
  55
  56 OSBElementCreatorBase::~OSBElementCreatorBase(void)
  57 {
  58 }
  59
  60 /*-------------------------------------------------------------------------*/
  61 /* OSBElementFactorySingleton                                             */
  62 /*-------------------------------------------------------------------------*/
  63
  64 /*! \class OSG::OSBElementFactory
  65
  66     Singleton registry of the read and write objects for specific object types.
  67     Maps a type name (usually a field container type name) to an object derived
  68     from OSBElementCreatorBase. The object is then used to create an object
  69     derived from OSBElementBase that handles the reading/writing.
  70
  71     \dev
  72     OSBElementFactory is only a typedef for
  73     SingletonHolder\<OSBElementFactorySingleton\> which generates the
  74     boilerplate code for the singleton.
  75     \enddev
  76  */
  77
  78 /*-------------------------------------------------------------------------*/
  79 /* Registration                                                            */
  80
  81 bool
  82 OSBElementFactorySingleton::registerElement(
  83     const std::string &typeName, OSBElementCreatorBase *creator)
  84 {
  85     bool          returnValue = true;
  86     RegistryMapIt it          = _registry.find(typeName);
  87
  88     if(it != _registry.end())
  89     {
  90         FWARNING(("OSBElementFactorySingleton::registerElement: "
  91                   "typeName: '%s' Registration failed, "
  92                   "an entry for this type already exists.\n",
  93                   typeName.c_str()                                ));
  94         returnValue = false;
  95     }
  96     else
  97     {
  98         _registry.insert(it, RegistryMap::value_type(typeName, creator));
  99     }
 100
 101     return returnValue;
 102 }
 103
 104 bool
 105 OSBElementFactorySingleton::unregisterElement(const std::string &typeName)
 106 {
 107     bool          returnValue = true;
 108     RegistryMapIt it          = _registry.find(typeName);
 109
 110     if(it != _registry.end())
 111     {
 112         delete it->second;
 113         _registry.erase(it);
 114     }
 115     else
 116     {
 117         FWARNING(("OSBElementFactorySingleton::unregisterElement: "
 118                   "typeName: '%s' Attempt to unregister an unknown type.\n",
 119                   typeName.c_str()                                          ));
 120         returnValue = false;
 121     }
 122
 123     return returnValue;
 124 }
 125
 126 bool
 127 OSBElementFactorySingleton::registerDefault(OSBElementCreatorBase *creator)
 128 {
 129     bool returnValue = true;
 130
 131     if(_defaultCreator != 0)
 132     {
 133         FWARNING(("OSBElementFactorySingleton::registerDefault: "
 134                   "Registration failed, a default creator exists already.\n"));
 135         returnValue = false;
 136     }
 137     else
 138     {
 139         _defaultCreator = creator;
 140     }
 141
 142     return returnValue;
 143 }
 144
 145 bool
 146 OSBElementFactorySingleton::unregisterDefault(void)
 147 {
 148     bool returnValue = true;
 149
 150     if(_defaultCreator == 0)
 151     {
 152         FWARNING(("OSBElementFactorySingleton::unregisterDefault: "
 153                   "Attempt to unregister empty default creator.\n"));
 154         returnValue = false;
 155     }
 156     else
 157     {
 158         delete _defaultCreator;
 159         _defaultCreator = 0;
 160     }
 161     return returnValue;
 162 }
 163
 164 const OSBElementFactorySingleton::RegistryMap &
 165 OSBElementFactorySingleton::getRegistryMap(void) const
 166 {
 167     return _registry;
 168 }
 169
 170 OSBElementFactorySingleton::RegistryMap &
 171 OSBElementFactorySingleton::editRegistryMap(void)
 172 {
 173     return _registry;
 174 }
 175
 176 /*-------------------------------------------------------------------------*/
 177 /* Constructor                                                             */
 178
 179 OSBElementFactorySingleton::OSBElementFactorySingleton(void)
 180     : _registry      ( ),
 181       _defaultCreator(0)
 182 {
 183 }
 184
 185 /*-------------------------------------------------------------------------*/
 186 /* Destructor                                                              */
 187
 188 OSBElementFactorySingleton::~OSBElementFactorySingleton(void)
 189 {
 190     // deleting 0 is harmless
 191     delete _defaultCreator;
 192
 193     RegistryMapIt regIt  = _registry.begin();
 194     RegistryMapIt regEnd = _registry.end  ();
 195
 196     while(regIt != regEnd)
 197     {
 198         delete (*regIt).second;
 199
 200         ++regIt;
 201     }
 202 }
 203
 204 OSG_END_NAMESPACE