Design-Pattern/Structural-Decorator Design Pattern2 at master · rajakumar-ops/Design-Pattern · GitHub

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// CPP program to demonstrate
// Decorator pattern
#include <iostream>
#include <string>
using namespace std;

// Component
class MilkShake
{
public:
    virtual string Serve() = 0;
    virtual float price() = 0;
};


// Concrete Component
class BaseMilkShake : public MilkShake
{
public:
    string Serve()
    {
        return "MilkShake";
    }

    float price()
    {
        return 30;
    }
};

// Decorator
class MilkShakeDecorator: public MilkShake
{
protected:
    MilkShake *m_MilkShake;
public:

    MilkShakeDecorator(MilkShake *baseMilkShake): m_MilkShake(baseMilkShake){}

    string Serve()
    {
        return m_MilkShake->Serve();
    }

    float price()
    {
        return m_MilkShake->price();
    }
};


// Concrete Decorator
class MangoMilkShake: public MilkShakeDecorator
{
public:
    MangoMilkShake(MilkShake *baseMilkShake): MilkShakeDecorator(baseMilkShake){}

    string Serve()
    {
        return m_MilkShake->Serve() + " decorated with Mango ";
    }
    float price()
    {
        return m_MilkShake->price() + 40;
    }
};


class VanillaMilkShake: public MilkShakeDecorator
{
public:
    VanillaMilkShake(MilkShake *baseMilkShake): MilkShakeDecorator(baseMilkShake){}

    string Serve()
    {
        return m_MilkShake->Serve() + " decorated with Vanilla ";
    }
    float price()
    {
        return m_MilkShake->price() + 80;
    }
};

int main()
{
  MilkShake *baseMilkShake = new BaseMilkShake();
  cout << "Basic Milk shake \n";
  cout << baseMilkShake -> Serve() << endl;
  cout << baseMilkShake -> price() << endl;

  MilkShake *decoratedMilkShake = new MangoMilkShake(baseMilkShake);
  cout << "Mango decorated Milk shake \n";
  cout << decoratedMilkShake -> Serve() << endl;
  cout << decoratedMilkShake -> price() << endl;

  delete decoratedMilkShake;

  decoratedMilkShake = new VanillaMilkShake(baseMilkShake);
  cout << "Vanilla decorated Milk shake \n";
  cout << decoratedMilkShake -> Serve() << endl;
  cout << decoratedMilkShake -> price() << endl;

 delete decoratedMilkShake;
 delete baseMilkShake;
  return 0;
}