[学习][笔记]设计模式（基于C/C++实现）＜五＞装饰器模式

//beverage.h
#ifndef BEVERAGE_H
#define BEVERAGE_H
#include <string>
using namespace std;
class Bervage{
public:
    virtual string getDescription(){
        return description;
    }
    virtual double cost()=0;
protected:
    string description;
};
#endif // BEVERAGE_H
//beverage_espresso.h
#ifndef BEVERAGE_ESPRESSO_H
#define BEVERAGE_ESPRESSO_H
#include "beverage.h"
/**** 具体的饮料类 ****/
class Espresso:public Bervage{
public:
    Espresso(){
        description = " Espresso ";
    }
    double cost(){
        return 1.99;
    }
};
#endif // BEVERAGE_ESPRESSO_H
//beverage_tea.h
#ifndef BEVERAGE_TEA_H
#define BEVERAGE_TEA_H
#include "beverage.h"
class Tea:public Bervage{
public:
    Tea(){
        description = " Tea ";
    }
    double cost(){
        return 1.05;
    }
};
#endif // BEVERAGE_TEA_H
//condiment_mocha.h
#ifndef CONDIMENT_MOCHA_H
#define CONDIMENT_MOCHA_H
#include "decorator_condiment.h"
/**** 具体的调料类 ****/
class Mocha:public CondimentDecorator{
public:
    Mocha(Bervage *ptr){
        pBervage = ptr;
    }
    string getDescription(){
        return " Mocha "+pBervage->getDescription();
    }
    double cost(){
        return 0.2+pBervage->cost();
    }
};
#endif // CONDIMENT_MOCHA_H
//condiment_whip.h
#ifndef CONDIMENT_WHIP_H
#define CONDIMENT_WHIP_H
#include "decorator_condiment.h"
class Whip:public CondimentDecorator{
public:
    Whip(Bervage *ptr){
        pBervage = ptr;
    }
    string getDescription(){
        return " Whip "+pBervage->getDescription();
    }
    double cost(){
        return 0.5+pBervage->cost();
    }
};
#endif // CONDIMENT_WHIP_H
//decorator_condiment.h
#ifndef DECORATOR_CONDIMENT_H
#define DECORATOR_CONDIMENT_H
#include "beverage.h"
class CondimentDecorator:public Bervage{
protected:
    Bervage *pBervage;
};
#endif // DECORATOR_CONDIMENT_H
//main.cpp
#include <iostream>
#include "beverage_espresso.h"
#include "beverage_tea.h"
#include "condiment_mocha.h"
#include "condiment_whip.h"
using namespace std;
int main()
{
    Espresso esp;
    Mocha mocha(&esp);
    cout<<mocha.cost()<<endl;
    cout<<mocha.getDescription()<<endl;
    Mocha dmocha(&mocha);
    cout<<dmocha.cost()<<endl;
    cout<<dmocha.getDescription()<<endl;
    Whip wdmocha(&dmocha);
    cout<<wdmocha.cost()<<endl;
    cout<<wdmocha.getDescription()<<endl;
    return 0;
}
输出：
2.19
 Mocha  Espresso 
2.39
 Mocha  Mocha  Espresso 
2.89
 Whip  Mocha  Mocha  Espresso