Flyweight(享元）--对象结构型模式

//Flyweight.h



#include <string>

class FlweightGraphicBase
{
public:
    virtual void PrintColor()=0;
protected:
    std::string m_Color;
};

class FlweightWhiteGraphic : public FlweightGraphicBase
{
public:
    FlweightWhiteGraphic();
    void PrintColor();
};

class FlweightBlackGraphic : public FlweightGraphicBase
{
public:
    FlweightBlackGraphic();
    void PrintColor();
};

//FlyweigtFactory.h



#include <string>
#include <memory>
#include <map>

class FlweightGraphicBase;

class FlyweightFactory
{
public:
    std::shared_ptr<FlweightGraphicBase> GetFlyweight(std::string sColor);
    void SetFlyweight(std::string sColor,
        std::shared_ptr<FlweightGraphicBase> pFlyweight);

private:
    std::map <std::string,std::shared_ptr<FlweightGraphicBase>> m_mapFlyweight;
};

//Flyweight.cpp

#include "Flyweight.h"
#include <iostream>

FlweightWhiteGraphic::FlweightWhiteGraphic()
{
    m_Color = "White";
}


void FlweightWhiteGraphic :: PrintColor()
{
    std::cout<<"Color is :" << m_Color << std::endl;
}


FlweightBlackGraphic::FlweightBlackGraphic()
{
    m_Color = "Black";
}


void FlweightBlackGraphic :: PrintColor()
{
    std::cout<<"Color is :" << m_Color << std::endl;
}

//FlyweightFactory.cpp


#include "FlyweightFactory.h"


std::shared_ptr<FlweightGraphicBase> FlyweightFactory::GetFlyweight(std::string sColor)
{
    auto iter = m_mapFlyweight.find(sColor);
    if(iter == m_mapFlyweight.end())
    {
        return nullptr;
    }

    return iter->second;
}

void FlyweightFactory::SetFlyweight(std::string sColor,
        std::shared_ptr<FlweightGraphicBase> pFlyweight)
{
    m_mapFlyweight[sColor] = pFlyweight;
}

//Client.cpp



#include "Flyweight.h"
#include "FlyweightFactory.h"
#include <iostream>

void Insert(std::string sColor,
    int index,std::shared_ptr<FlweightGraphicBase> pFlweightGraphic)
{
    std::cout<<"Posion " << index << " Insert: " << sColor << std::endl ;
}

int main()
{
    std::shared_ptr<FlyweightFactory> pFlyweightFactory(new FlyweightFactory);
    std::shared_ptr<FlweightWhiteGraphic> pFlweightWhiteGraphic(new FlweightWhiteGraphic);
    std::shared_ptr<FlweightBlackGraphic> pFlweightBlackGraphic(new FlweightBlackGraphic);

    pFlyweightFactory->SetFlyweight("White",pFlweightWhiteGraphic);
    pFlyweightFactory->SetFlyweight("Black",pFlweightBlackGraphic);

    auto pFlyweight = pFlyweightFactory->GetFlyweight("White");
    Insert("White",0,pFlyweight);

    pFlyweight = pFlyweightFactory->GetFlyweight("Black");
    Insert("Black",1,pFlyweight);

    pFlyweight = pFlyweightFactory->GetFlyweight("White");
    Insert("White",2,pFlyweight);

    pFlyweight = pFlyweightFactory->GetFlyweight("Black");
    Insert("Black",3,pFlyweight);

    while(1);

}