结构型设计模式---组合模式(Composite)

组合模式：将对象组合成树形结构以表示“部分-整体”的层次结构。

Composite使得用户对单个对象和组合对象的使用具有一致性。

适用场景：

(1)所要表示的对象具有部分-整体的层次结构

(2)用户可以忽略组合对象与单个对象的不同，统一地使用组合结构中的所有对象

Composite.h

#ifndef _COMPOSITE_H_

#define _COMPOSITE_H_

#include <string>

#include <vector>

using std::string;

using std::vector;

class Component

{

public:

    virtual ~Component() {};

    Component(string , int);

    virtual void print(int ) = 0;

protected:

    string name_;

    int salary_;

};

class Worker : public Component

{

public:

    Worker(string, int);

    virtual void print(int);

};

class Manager : public Component

{

public:

     Manager(string, int);

     void add(Component *);

     virtual void print(int);

private:

     vector<Component *> children_;

};

#endif

Composite.cpp

#include <iostream>

#include "Composite.h"

using std::cout;

using std::endl;

Component::Component(string name, int salary) : name_(name), salary_(salary)

{

}

Worker::Worker(string name, int salary) : Component(name, salary)

{

}

void Worker::print(int level)

{

     for (int i = 0; i < level; ++i)

         cout << "\t";

     cout << "Worker : " << name_ << " salary : " << salary_ << endl;

}

Manager::Manager(string name, int salary) : Component(name, salary)

{

}

void Manager::add(Component *com)

{

     children_.push_back(com);

}

void Manager::print(int level)

{

     for (int i = 0; i < level; ++i)

         cout << "\t";

     cout << "Manager : " << name_ << " salary : " << salary_ << endl;

     if (!children_.empty())

     {

         for (int j = 0; j < level; ++j)

             cout << "\t";

         cout << "Subordinates of " << name_ << ": " << endl;

         ++level;

         int size = children_.size();

         for (int k = 0; k < size; ++k)

             children_[k]->print(level);

     }

}

main.cpp

#include "Composite.h"

int main()

{

    Manager direct("Jim", 1000);

    Manager mgrDev("Jun", 100);

    Manager mgrQA("Na", 80);

    Worker qa("tao", 80);

    Worker qe("ou", 60);

    Worker pdev("zhen", 70);

    Worker sdev("denny", 60);

    direct.add(&mgrDev);

    direct.add(&mgrQA);

    mgrDev.add(&pdev);

    mgrDev.add(&sdev);

    mgrQA.add(&qa);

    mgrQA.add(&qe);

    direct.print(0);

    return 0;

}

Makefile

cc=g++

exe=main

obj= main.o Composite.o

$(exe): $(obj)

        $(cc) -o $(exe) $(obj)

main.o: main.cpp Composite.h

        $(cc) -c main.cpp

Composite.o: Composite.cpp Composite.h

        $(cc) -c Composite.cpp

clean:

        rm -rf *o $(exe)

output:

Manager : Jim salary : 1000

Subordinates of Jim:

 Manager : Jun salary : 100

 Subordinates of Jun:

  Worker : zhen salary : 70

  Worker : denny salary : 60

 Manager : Na salary : 80

 Subordinates of Na:

  Worker : tao salary : 80

  Worker : ou salary : 60