Adaptor Pattern

• Structural Design Patterns

UML Diagram

Example of Adapter Design Pattern

Cat Header (Cat.h)

#ifndef CAT_H_
#define CAT_H_

class Cat
{
	public:
		virtual ~Cat() {}
		virtual void Meow() = 0; // Virtual 
};

#endif // CAT_H_

Living Cat (LivingCat.h)

#ifndef LIVINGCAT_H_
#define LIVINGCAT_H_

#include "Cat.h"

#include <string>
#include <iostream>

class LivingCat : public Cat {

	private:
		std::string _name;
	public:
		LivingCat(std::string name);
		virtual ~LivingCat();

		virtual void Meow();

};


LivingCat::LivingCat(std::string name) : _name(name) {}  // Constructor

LivingCat::~LivingCat() {}  // Deconstructor

void LivingCat::Meow() {
	std::cout << _name << " is Meowing!\n";
}


#endif // LIVINGCAT_H_

Robot Cat (RobotCat.h)

#ifndef ROBOTCAT_H_
#define ROBOTCAT_H_

#include <string>
#include <iostream>

class RobotCat {

	private:
		std::string _name;
		
	public:
		RobotCat(std::string name);
		virtual ~RobotCat();

		void PlayMeowingSound();

};


RobotCat::RobotCat(std::string name): _name(name) {}

RobotCat::~RobotCat() {}

void RobotCat::PlayMeowingSound()
{
	std::cout << _name << " is playing meowing sound\n";
}

#endif  // ROBOTCAT_H_

Roboto Cat Adapter (RobotCatAdaptor.h)

#ifndef ROBOTCATADAPTER_H_
#define ROBOTCATADAPTER_H_

#include "Cat.h"

#include "RobotCatAdapter.h"

#include "RobotCat.h"

class RobotCat;

class RobotCatAdapter : public Cat {
	private:
		RobotCat * _RobotCat;
		
	public:
		RobotCatAdapter(RobotCat * robotCat);
		virtual ~RobotCatAdapter();

		virtual void Meow();

};


RobotCatAdapter::RobotCatAdapter(RobotCat * robotCat) : _RobotCat(robotCat){}

RobotCatAdapter::~RobotCatAdapter() {}

void RobotCatAdapter::Meow()
{
   _RobotCat->PlayMeowingSound();
}

#endif // ROBOTCATADAPTER_H_

Cat Main File (CatMain.cpp)

#include "LivingCat.h"
#include "RobotCat.h"
#include "RobotCatAdapter.h"

int main()
{
    Cat * livingCat = new LivingCat(std::string("Koko"));
    livingCat->Meow();

    RobotCat * robotCat = new RobotCat(std::string("Oliver"));
    Cat * robotCatAdapter = new RobotCatAdapter(robotCat);
    robotCatAdapter->Meow();

    // Delete allocated memory from the Heap
    delete livingCat;
    delete robotCatAdapter;
    delete robotCat;
}

Output

Koko is Meowing!
Oliver is playing meowing sound