Adapter Design Pattern Example

Click here to see the Description of Adapter Design Pattern

Source Code with Example:

/*
* File:adapter.cpp
* This file is described the adapter Design Pattern with help of example
* Author: Aplha
* Date: 29 Dec 2020
*/

//Header file
#include<iostream>

//Target interface
class ITarget
{
public:
    virtual void Start()=0;
    virtual void Stop()=0;
    virtual void SetMotorType(std::string) = 0;

};

//Motor Interface
class IMotor
{
public:
   virtual void StartMotor()=0;
   virtual void StopMotor()=0;
};

//Actual Motor Class
class ActualMotor:public IMotor
{
   void StartMotor()
   {std::cout<<"Actual Motor Start, call driver app"<<std::endl;}
   void StopMotor()
   {std::cout<<"Actual Motor Stop, call driver app"<<std::endl;}
};

// Motor Simulator Class
class MotorSimulator:public IMotor
{
   void StartMotor()
   {std::cout<<"Motor Simulator  Start for testing"<<std::endl;}
   void StopMotor()
   {std::cout<<"Motor Simulator Stop for testing"<<std::endl;}
};


//Adapter Class
class Adapter:public ITarget
{
    IMotor* mp;
    Adapter(const Adapter &other) = delete;  // Disallow copying
    void operator=(const Adapter &) = delete;// Disallow copying
public:
    Adapter();
    ~Adapter();
    void Start(); //Get interface from Base class
    void Stop();  //Get interface from Base class
    void SetMotorType(std::string str);
};


//Adapter definition
    Adapter::Adapter():mp(nullptr){}
    Adapter::~Adapter()
    {
        if(mp)
	 delete mp;
    }
    void Adapter::Start()
    {
	if(mp)
        {
	   mp->StartMotor();
        }
        else
	std::cout<<"Motor is not set"<<std::endl;
    }
    void Adapter::Stop()
    {
        if(mp)
        {
           mp->StopMotor();
        }
        else
        std::cout<<"Motor is not set"<<std::endl;
    }

    void Adapter::SetMotorType(std::string str)
    {
        if(str == "ActualMotor")
  	{
	    if(mp)
	        delete mp;
	    mp = new ActualMotor;
	}
	else if(str == "SimulatorMotor")
	{ 
            if(mp)
                delete mp;
            mp = new MotorSimulator;
	}
	else
        {
	    std::cout<<"Motor type is not available"<<std::endl;
	    if(mp)
	       delete mp;
	}
    }

//Client
int main()
{
    std::cout<<"In Main"<<std::endl;
    //Create the Target
    ITarget * tar = new Adapter;
    //Set the Actual Motor
    tar->SetMotorType("ActualMotor");
    tar->Start();
    tar->Stop();
    //Set the Simulator Motor
    tar->SetMotorType("SimulatorMotor");
    tar->Start();
    tar->Stop();
    delete tar;
    return 0;
}

Compilation command:

g++ -std=c++11 adapter.cpp

Output:

In Main
Actual Motor Start, call driver app
Actual Motor Stop, call driver app
Motor Simulator Start for testing
Motor Simulator Stop for testing