第6章 创建型模式—建造者模式

//创建型模式：建造者模式
//神舟飞船的组装
#include <stdio.h>
#include <string>

using namespace std;
//*************************辅助类：各个部件************************
//轨道舱
class OrbitalModule
{
private:
    string name;
public:
    OrbitalModule(string name)
    {
        this->name = name;
    }
    
    void setName(string name)
    {
        this->name = name;
    }
    
    string getName(){return name;}
};

//发动机
class Engine
{
private:
    string name;
public:
    Engine(string name)
    {
        this->name = name;
    }
    
    void setName(string name)
    {
        this->name = name;
    }
    
    string getName(){return name;}
};

//逃逸塔
class EscapeTower
{
private:
    string name;
public:
    EscapeTower(string name)
    {
        this->name = name;
    }
    
    void setName(string name)
    {
        this->name =name;
    }
    
    string getName(){return name;}
};

//最终产品Product
class Airship
{
private:
    OrbitalModule* orbitalModule;  //轨道舱
    Engine* engine;                //发动机
    EscapeTower* escapeTower;      //逃逸塔
public:
    OrbitalModule* getOrbitalModule(){return orbitalModule;}
    void setOrbitalModule(OrbitalModule* orbitalModule)
    {
        this->orbitalModule =orbitalModule;
    }    
    
    Engine* getEngine(){return engine;}
    void setEngine(Engine* engine)
    {
        this->engine =engine;
    } 

    EscapeTower* getEscapeTower(){return escapeTower;}
    void setEscapeTower(EscapeTower* escapeTower)
    {
        this->escapeTower =escapeTower;
    }

    void launch()
    {
        //检测发动机是否正常
        printf("%s\n",engine->getName().c_str()); 
        //检测轨道舱是否正常
        printf("%s\n",orbitalModule->getName().c_str());
        //检测逃逸塔是否正常
        printf("%s\n",escapeTower->getName().c_str());
        
        //发射
        printf("launch...\n");        
    }    
};

//*******************************************Builder：建造者*****************************
//抽象建造者
class AirshipBuilder
{
public:
    //构建发动机
    virtual void builderEngine() = 0;
    //构建轨道舱
    virtual void builderOrbitalModule() = 0;
    //构建逃逸塔
    virtual void builderEscapeTower() = 0;
};

//具体建造者
class ConcreteAirshipBuilder : public AirshipBuilder
{
private:
    Airship airship;
public:

    //Engine部件的构建
    void builderEngine()
    {
        Engine* engine =airship.getEngine();
        if (engine != NULL)
            delete engine;
        
        engine = new Engine("Airship‘s Engine!");
        
        //组装工作
        airship.setEngine(engine);       
    }
    
    //OrbitalModule部件的构建
    void builderOrbitalModule()
    {
        OrbitalModule* orbitalModule =airship.getOrbitalModule();
        if (orbitalModule != NULL)
            delete orbitalModule;
        
        orbitalModule = new OrbitalModule("Airship‘s OrbitalModule!");
        
        //组装工作
        airship.setOrbitalModule(orbitalModule);        
    }
    
    //EscapeTower部件的构建
    void builderEscapeTower()
    {
        EscapeTower* escapeTower =airship.getEscapeTower();
        if (escapeTower != NULL)
            delete escapeTower;
        
        escapeTower = new EscapeTower("Airship‘s EscapeTower!");
        
        //组装工作
        airship.setEscapeTower(escapeTower);          
    }
    
    //返回最终的整个产品（神舟飞船）
    Airship& getResult(){return airship;}
    
    ~ConcreteAirshipBuilder()
    {
        OrbitalModule* orbitalModule = airship.getOrbitalModule();
        if (orbitalModule != NULL)
            delete orbitalModule;
        
        Engine* engine =airship.getEngine();
        if (engine != NULL)
            delete engine;
        
        EscapeTower* escapeTower = airship.getEscapeTower();
        if (escapeTower != NULL)
            delete escapeTower;        
    }
};

//********************************Director：指导者******************************
class Director
{
private:
    AirshipBuilder* builder;
public:
    Director(AirshipBuilder* builder)
    {
        this->builder = builder;
    }
    
    //构建过程
    //1、建造者所构建的各部分是可以是先后顺序的，但本例这个顺序不明显或无关紧要。
    //2、本类中只有构建的过程（流程，也就算法），组装过程放在Builder类中。
    void construct()
    {
        //1.先构建发动机
        builder->builderEngine();
        //2.再构建轨道舱
        builder->builderOrbitalModule();
        //3.最后构建逃逸塔
        builder->builderEscapeTower();
    }
};


int main()
{
    //客户端调用例子
    
    //构建者
    AirshipBuilder* builder = new ConcreteAirshipBuilder();
    
    //指导者
    Director* director = new Director(builder);
    director->construct(); //生成最终产品
    
    //测试
    Airship& airship = ((ConcreteAirshipBuilder*)builder)->getResult();
    airship.launch();
      
    delete builder;
    delete director;    
    
    return 0;
}