Loki/examples/Factory.cpp

////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2005 by Peter Kuemmel
//
// Code covered by the MIT License
// The authors make no representations about the suitability of this software
// for any purpose. It is provided "as is" without express or implied warranty.
////////////////////////////////////////////////////////////////////////////////

// $Header$

//#define CLASS_LEVEL_THERADING

#include <iostream>
#include "loki/Factory.h"
#include "loki/Functor.h"

using Loki::Functor;
using Loki::Factory;
using Loki::SingletonHolder;
using std::cout;
using std::endl;

 
////////////////////////////////////////////
// Object to create: Product
// Constructor with 0 and 2 arguments
////////////////////////////////////////////
 
class AbstractProduct{};
 
class Product : public AbstractProduct
{
public:
    Product(){}
    Product( int, int ){}
};
 
///////////////////////////////////////////////////////////
// Factory for creation a Product object without parameters
///////////////////////////////////////////////////////////
 
typedef SingletonHolder 
<
    Factory< AbstractProduct, int >
>
PFactoryNull;
 
/////////////////////////////////////////////////////////////
// Factory for creation a Product object with 2 parameters
/////////////////////////////////////////////////////////////
 
typedef SingletonHolder
<
    Factory< AbstractProduct, int, TYPELIST_2( int, int ) >
>
PFactory;
 
////////////////////////////////////////////////////
// Creator functions with different names
////////////////////////////////////////////////////
 
Product* createProductNull()             
{ 
    cout << "createProductNull()" << endl;
    return new Product;     
}
Product* createProductParm( int a, int b ) 
{ 
    cout << "createProductParm( int a, int b ) " << endl;
    return new Product( a, b ); 
}

///////////////////////////////////////////////////
// Overloaded creator functions 
///////////////////////////////////////////////////
Product* createProductOver()             
{ 
    cout << "createProductOver()" << endl;
    return new Product;     
}
Product* createProductOver( int a, int b ) 
{ 
    cout << "createProductOver( int a, int b )" << endl;
    return new Product( a, b ); 
}

 
 
///////////////////////////////////////////////////
// Creator functions are polymorphic member functions
///////////////////////////////////////////////////
 
class AbstractCreator{
public:
    virtual AbstractProduct* create() = 0;
    virtual AbstractProduct* createParm( int, int ) = 0;
};

class Creator : public AbstractCreator{
public:
    Creator(){};
    AbstractProduct* create()                 
    {
        cout << "Creator::create()" << endl;
        return new Product;     
    }
    AbstractProduct* createParm( int a, int b ) 
    {
        cout << "Creator::create( int a, int b )" << endl;
        return new Product( a,b );
    }
};
 
///////////////////////////////////////////////////////////////
// Creator functions are member functions of a template class
///////////////////////////////////////////////////////////////
 
template< class T>
class CreatorT{
public:
    CreatorT(){};
    T* create()                 
    {
        cout << "CreatorT<T>::create()" << endl;
        return new T;     
    }
    T* createParm( int a, int b ) 
    {
        cout << "CreatorT<T>::create( int a, int b )" << endl;
        return new T( a,b );
    }
};
 
 ///////////////////////////////////////////////////////////////
// get creator functions on runntime
///////////////////////////////////////////////////////////////

typedef Functor<Product*,TYPELIST_2(int,int)> CreateFunctor;

typedef 
SingletonHolder
<
    Factory< AbstractProduct, int,TYPELIST_3(CreateFunctor,int,int) >
>
PFactoryFunctorParm;

Product* createProductRuntime(CreateFunctor func, int a, int b) 
{ 
    Product *p = func( a, b );
    cout << "    called by createProductRuntime(CreateFunctor func, int a, int b) " << endl;
    return p; 
}
 




///////////////////////////////////////
// Register creator functions 
// No additional typdefs are necessary!
//////////////////////////////////////
 
AbstractCreator* c = new Creator;
CreatorT<Product> cT;
 
bool reg()
{
    bool const ok1 = PFactoryNull::Instance().Register( 1, createProductNull );
    bool const ok2 = PFactoryNull::Instance().Register( 2, (Product*(*)()) createProductOver );
    bool const ok3 = PFactoryNull::Instance().Register( 3, c, &AbstractCreator::create );
    bool const ok4 = PFactoryNull::Instance().Register( 4, &cT, &CreatorT<Product>::create );
 
    bool const ok5 = PFactory::Instance().Register( 1, createProductParm );
    bool const ok6 = PFactory::Instance().Register( 2, (Product*(*)(int,int))createProductOver );
    bool const ok7 = PFactory::Instance().Register( 3, c, &AbstractCreator::createParm );
    bool const ok8 = PFactory::Instance().Register( 4, &cT, &CreatorT<Product>::createParm );

    bool const ok9 = PFactoryFunctorParm::Instance().Register( 1, createProductRuntime );
    
    return ok1 && ok2 && ok3 && ok4 && ok5 && ok6 && ok7 && ok8 && ok9;
}
 
int main(int argc, char *argv[])
{
    reg();
    
     AbstractProduct* p;
 
    cout << endl << "creator function is a simple function:" << endl;
    p= PFactoryNull::Instance().CreateObject( 1 ); 
    delete p;
    p= PFactory::Instance().CreateObject( 1, 64,64 );
    delete p;
    
    cout << endl << "creator function is a overloaded function:" << endl;
    p= PFactoryNull::Instance().CreateObject( 2 );
    delete p;
    p= PFactory::Instance().CreateObject( 2, 64,64 );
    delete p;
    
    cout << endl << "creator function is a member function:" << endl;
    p= PFactoryNull::Instance().CreateObject( 3 );
    delete p;
    p= PFactory::Instance().CreateObject( 3, 64,64 );
    delete p;
    
    cout << endl << "creator function is a template member function" << endl;
    p= PFactoryNull::Instance().CreateObject( 4 );
    delete p;
    p= PFactory::Instance().CreateObject( 4, 64,64 );
    delete p;

    CreateFunctor func1(createProductParm);
    CreateFunctor func2(&cT, &CreatorT<Product>::createParm);
    cout << endl << "creator function is a functor parameter" << endl;
    p= PFactoryFunctorParm::Instance().CreateObject( 1, func1, 64,64 );
    delete p;
    p= PFactoryFunctorParm::Instance().CreateObject( 1, func2, 64,64 );
    delete p;
    
    cout << endl;
    cout << endl;
    system("PAUSE");
    return EXIT_SUCCESS;
}

// $Log$
// Revision 1.1  2005/07/28 14:27:12  syntheticpp
// add Factory example
//