Headfirst设计模式的C++实现——抽象工厂(Abstract Factory)

Dough.h

 #ifndef _DOUGH_H
 #define _DOUGH_H

 class Dough
 {
 };
 #endif

ThinCrustDough.h

 #ifndef _THIN_CRUST_DOUGH_H
 #define _THIN_CRUST_DOUGH_H

 #include "Dough.h"

 class ThinCrustDough : public Dough
 {
 };
 #endif

Sauce.h

 #ifndef _SAUCE_H
 #define _SAUCE_H

 class Sauce
 {
 };
 #endif

MarinaraSauce.h

 #ifndef _MARINARA_SAUCE_H
 #define _MARINARA_SAUCE_H

 #include "Sauce.h"

 class MarinaraSauce : public Sauce
 {
 };
 #endif

Pizza.h

 #ifndef _PIZZA_H
 #define _PIZZA_H
 #include <iostream>
 #include <string>
 #include "Dough.h"
 #include "Sauce.h"
 class Pizza
 {
 public:
     Pizza() : m_name(), m_p_dough(NULL), m_p_sauce(NULL) {}
     virtual ~Pizza() {}
     virtual void prepare() = ;
     virtual void bake() { std::cout << "Bake for 25 mins at 350" << std::endl; }
     virtual void cut() { std::cout << "Cutting the pizza into diagonal slices" << std::endl; }
     virtual void box() { std::cout << "Place pizza in official PizzaStore box" << std::endl; }
     void set_name(const std::string &name) { m_name = name; }
     std::string get_name() { return m_name; }
     Dough *m_p_dough;
     Sauce *m_p_sauce;
 private:
     std::string m_name;
 };
 #endif

CheesePizza.h

 #ifndef _CHEESE_PIZZA_H
 #define _CHEESE_PIZZA_H

 #include "Pizza.h"
 #include "PizzaIngredientFactory.h"

 class CheesePizza : public Pizza
 {
 private:
     PizzaIngredientFactory *m_p_ingredient_factory;
 public:
     CheesePizza(PizzaIngredientFactory *p) : m_p_ingredient_factory(p) {}
     void prepare()
     {
         std::cout << "Preparing " << get_name() << std::endl;
         m_p_sauce = m_p_ingredient_factory->create_sauce();
     }
 };

 #endif

GreekPizza.h

 #ifndef _GREEK_PIZZA_H
 #define _GREEK_PIZZA_H

 #include "Pizza.h"
 #include "PizzaIngredientFactory.h"

 class GreekPizza : public Pizza
 {
 private:
     PizzaIngredientFactory *m_p_ingredient_factory;
 public:
     GreekPizza(PizzaIngredientFactory *p) : m_p_ingredient_factory(p) {}
     void prepare()
     {
         std::cout << "Preparing " << get_name() << std::endl;
         m_p_dough = m_p_ingredient_factory->create_dough();
     }
 };

 #endif

PizzaStore.h

 #ifndef _PIZZA_STORE_H
 #define _PIZZA_STORE_H

 #include "Pizza.h"

 class PizzaStore
 {
 private:
     virtual Pizza* CreatePizza(const std::string &type) = ;
 public:
     Pizza* OrderPizza(const std::string &type)
     {
         Pizza *p_pizza = CreatePizza(type);
         if (p_pizza)
         {
             p_pizza->prepare();
             p_pizza->bake();
             p_pizza->cut();
             p_pizza->box();
         }
         return p_pizza;
     }
 };
 #endif

NYPizzaStore.h

 #ifndef _NY_PIZZA_STORE_H
 #define _NY_PIZZA_STORE_H

 #include "PizzaStore.h"
 #include "CheesePizza.h"
 #include "GreekPizza.h"
 #include "NYPizzaIngredientFactory.h"
 class NYPizzaStore : public PizzaStore
 {
 private:
     Pizza* CreatePizza(const std::string &type)
     {
         PizzaIngredientFactory *p_factory = new NYPizzaIngredientFactory();
         if ( "cheese" == type )
         {
             Pizza *p_pizza = new CheesePizza( p_factory );
             p_pizza->set_name("New York Style Cheese Pizza");
             return p_pizza;
         }
         if ( "greek" == type )
         {
             Pizza *p_pizza = new GreekPizza( p_factory );
             p_pizza->set_name("New York Style Greek Pizza");
             return p_pizza;
         }
         return NULL;
     }
 };
 #endif

PizzaIngredientFactory.h

 #ifndef _PIZZA_INGREDIENT_FACTORY_H
 #define _PIZZA_INGREDIENT_FACTORY_H

 #include "Dough.h"
 #include "Sauce.h"

 class PizzaIngredientFactory
 {
 public:
     virtual Dough* create_dough() = ;
     virtual Sauce* create_sauce() = ;
 };

 #endif

NYPizzaIngredientFactory.h

 #ifndef _NY_PIZZA_INGREDIENT_FACTORY_H
 #define _NY_PIZZA_INGREDIENT_FACTORY_H

 #include "ThinCrustDough.h"
 #include "MarinaraSauce.h"

 class NYPizzaIngredientFactory : public PizzaIngredientFactory
 {
 public:
     Dough* create_dough() { std::cout << "Creating Thin Crust Dough" << std::endl; return new ThinCrustDough(); }
     Sauce* create_sauce() { std::cout << "Creating Marinara Sauce" << std::endl; return new MarinaraSauce(); }
 };

 #endif

main.cpp

 #include "NYPizzaStore.h"
 int main()
 {
     NYPizzaStore pizza_store;
     Pizza *p_pizza = pizza_store.OrderPizza("greek");
     if ( p_pizza )
     {
         delete p_pizza;
     }
     return ;
 }