include/tdbutil/stringKeyFactory.h

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/*******************************************************************************
** Copyright (c) 2007 MAK Technologies, Inc.
** All rights reserved.
*******************************************************************************/
/*******************************************************************************
** $RCSfile: stringKeyFactory.h,v $ $Revision: 1.1 $ $State: Exp $
*******************************************************************************/


#ifndef stringKeyFactory_h
#define stringKeyFactory_h

#include <map>
#include <vlutil/vlString.h>

// Template for creating factory classes that are keyed off a string type 
// identifier.
// Instances if this template are created by specifying the data type that
// is to be created by the factory.  A creator function prototype is then provided
// by the DtCreatorFcn typedef in the new class.
// The creation method for classes created from this factory must not take 
// any parameters.  For a version of this template where the creation method
// takes a parameters, see DtStringKeyFactoryWithParam.
template <typename T_CreationType>
class DtStringKeyFactory
{

public:
   // The creator function signature used by this factory.
   typedef T_CreationType* (*DtCreatorFcn)();
   typedef std::map<DtString, DtCreatorFcn> DtCreatorFunctionMap;

public:
   // constructor
   DtStringKeyFactory();

private:
   // Not implemented.
   DtStringKeyFactory(const DtStringKeyFactory& orig);
   // Not implemented.
   const DtStringKeyFactory& operator=(const DtStringKeyFactory& 
      orig);

public:
   // Destructor: deletes factory and any entries on the factory.
   virtual ~DtStringKeyFactory();

   // Add a creator function to the factory.
   virtual void addCreatorFcn(const DtString& type, DtCreatorFcn fcn);

   // Create and return a new instance of the type based on the creator
   // functions and the type specified.
   // Prints a warning if not found.  
   virtual T_CreationType* createItem(const DtString& type) const;

   // Static creator function for this factory, so it can be created
   // though a factory itself.
   static DtStringKeyFactory<T_CreationType>* create();
   const DtCreatorFunctionMap& functionMap() const
   {
      return myCreatorFunctionMap;
   }

protected:
   DtCreatorFunctionMap myCreatorFunctionMap;
   
};

// Template for creating factory classes that are keyed off a string type 
// identifier and take a single argument in the creation method.
// Instances if this template are created by specifying the data type that
// is to be created by the factory.  A creator function prototype is then provided
// by the DtCreatorFcn typedef in the new class.
// The creation method for classes created from this factory must take  
// a single parameter.  For a version of this template where the creation method
// takes no parameters, see DtStringKeyFactory.
template <typename T_CreationType, typename T_ConstructorParam>
class DtStringKeyFactoryWithParam
{
public:
   // The creator function signature used by this factory.
   typedef T_CreationType* (*DtCreatorFcn)(T_ConstructorParam);
   typedef std::map<DtString, DtCreatorFcn> DtCreatorFunctionMap;

public:
   // constructor
   DtStringKeyFactoryWithParam();

private:
   // Not implemented.
   DtStringKeyFactoryWithParam(const DtStringKeyFactoryWithParam& orig);
   // Not implemented.
   const DtStringKeyFactoryWithParam& operator=(const DtStringKeyFactoryWithParam& 
      orig);

public:
   // Destructor: deletes factory and any entries on the factory.
   virtual ~DtStringKeyFactoryWithParam();

   // Add a creator function to the factory.
   virtual void addCreatorFcn(const DtString& type, DtCreatorFcn fcn);

   // Create and return a new instance of the type based on the creator
   // functions and the type specified passing the specified parameter 
   // to the creation method.
   // Prints a warning if not found.  
   virtual T_CreationType* createItem(const DtString& type, 
      T_ConstructorParam param) const;

   // Static creator function for this factory, so it can be created
   // though a factory itself.
   static DtStringKeyFactoryWithParam<T_CreationType, T_ConstructorParam>* create();

   const DtCreatorFunctionMap& functionMap() const
   {
      return myCreatorFunctionMap;
   }

protected:
   DtCreatorFunctionMap myCreatorFunctionMap;

};

#define stringKeyFactory_inl_
#include "tdbutil/stringKeyFactory.inl"
#undef  stringKeyFactory_inl_

#endif