[행동 패턴] - 중재자(Mediator)

구조

#pragma once

#include <iostream>
#include <algorithm>

class Colleague;

class Mediator
{
public:
    virtual void request() {}

protected:
    Colleague* colleague1;
    Colleague* colleague2;
};

class Colleague
{
public:
    virtual std::string request() {}
    virtual std::string request(std::string str) {}

protected:
    Mediator* mediator_;
};

class ConcreteColleague1 : public Colleague
{
public:
    ConcreteColleague1(Mediator* mediator)
    {
        mediator_ = mediator;
    }

    std::string request() {
        return "Apple";
    }
};

class ConcreteColleague2 : public Colleague
{
public:
    ConcreteColleague2(Mediator* mediator)
    {
        mediator_ = mediator;
    }

    std::string request(std::string str)
    {
        std::transform(str.begin(), str.end(), str.begin(), ::toupper);
        return str;
    }
};

class ConcreteMediator : public Mediator
{
public:
    ConcreteMediator()
    {
        colleague1 = new ConcreteColleague1(this);
        colleague2 = new ConcreteColleague2(this);
    }

    void request() override
    {
        std::string str = colleague1->request();
        std::string result = colleague2->request(str);
        std::cout << result;
    }
};

 

사용

int main()
{
    Mediator* mediator = new ConcreteMediator;
    mediator->request();

    system("pause");

    return 0;
}

 

여러가지의 객체들을 사용해야 할 때, 그 구조가 복잡해지니까

하나의 객체가(A) 모든 객체(a,b,c,d...)들을 멤버변수로 갖고, 그 멤버변수들 끼리 관계를 조절한다.