[结构型模式] 组合模式的理解

头文件

//CompositePattern.h

#ifndef COMPOSITE_PATTERN_H
#define COMPOSITE_PATTERN_H

#include <Windows.h>
#include <iostream>
#include <string>
#include <vector>
using namespace std;

namespace CompositePattern
{
    //
    //////////////////////////////////////////////////////////////////////////
    class Component
    {
    public:
        Component(string name);
        virtual ~Component();
        virtual void Operation() = 0;
        virtual void Add(Component *) = 0;
        virtual void Remove(Component *) = 0;
        virtual Component *GetChild(int) = 0;
        virtual string GetName();
        virtual void Print() = 0;
    protected:
        string m_strCompname;
    };

    class Leaf : public Component
    {
    public:
        Leaf(string name);
        virtual void Operation();
        virtual void Add(Component *pComponent);
        virtual void Remove(Component *pComponent);
        virtual Component *GetChild(int index);
        virtual void Print();
    };
    class Composite : public Component
    {
    public:
        Composite(string name);
        virtual ~Composite();
        virtual void Operation();
        virtual void Add(Component *pComponent);
        virtual void Remove(Component *pComponent);
        virtual Component *GetChild(int index);
        virtual void Print();

    private:
        vector<Component*> m_vecComp;
    };

    //////////////////////////////////////////////////////////////////////////
    void CompositePattern_Test();
}

#endif

实现

#include "CompositePattern.h"
#include <iostream>
using namespace std;

namespace CompositePattern
{
    //////////////////////////////////////////////////////////////////////////
    Component::Component(string name)
        : m_strCompname(name)
    { }

    Component::~Component(){}

    //////////////////////////////////////////////////////////////////////////
    string Component::GetName()
    {
        return m_strCompname;
    }

    Leaf::Leaf(string name) : Component(name)
    {}
    void Leaf::Operation()
    {
        cout<<"I'm "<<m_strCompname<<endl;
    }
    void Leaf::Add(Component *pComponent){}
    void Leaf::Remove(Component *pComponent){}
    Component* Leaf::GetChild(int index)
    {
        return NULL;
    }
    void Leaf::Print(){}


    //////////////////////////////////////////////////////////////////////////
    Composite::Composite(string name)
        : Component(name)
    {}

    Composite::~Composite()
    {
        vector<Component *>::iterator it = m_vecComp.begin();
        while (it != m_vecComp.end())
        {
            if (*it != NULL)
            {
                cout<<"----delete "<<(*it)->GetName()<<"----"<<endl;
                delete *it;
                *it = NULL;
            }
            m_vecComp.erase(it);
            it = m_vecComp.begin();
        }
    }
    void Composite::Operation()
    {
        cout<<"I'm "<<m_strCompname<<endl;
    }
    void Composite::Add(Component *pComponent)
    {
        m_vecComp.push_back(pComponent);
    }
    void Composite::Remove(Component *pComponent)
    {
        for (vector<Component *>::iterator it = m_vecComp.begin(); it != m_vecComp.end(); ++it)
        {
            if ((*it)->GetName() == pComponent->GetName())
            {
                if (*it != NULL)
                {
                    delete *it;
                    *it = NULL;
                }
                m_vecComp.erase(it);
                break;
            }
        }
    }
    Component* Composite::GetChild(int index)
    {
        if (index > m_vecComp.size())
        {
            return NULL;
        }
        return m_vecComp[index - 1];
    }
    void Composite::Print()
    {
        for (vector<Component *>::iterator it = m_vecComp.begin(); it != m_vecComp.end(); ++it)
        {
            cout<<(*it)->GetName()<<endl;
        }
    }


    //////////////////////////////////////////////////////////////////////////
    void CompositePattern_Test()
    {
        Component *pNode = new Composite("Beijing Head Office");
        Component *pNodeHr = new Leaf("Beijing Human Resources Department");
        Component *pSubNodeSh = new Composite("Shanghai Branch");
        Component *pSubNodeCd = new Composite("Chengdu Branch");
        Component *pSubNodeBt = new Composite("Baotou Branch");
        pNode->Add(pNodeHr);
        pNode->Add(pSubNodeSh);
        pNode->Add(pSubNodeCd);
        pNode->Add(pSubNodeBt);
        pNode->Print();
        Component *pSubNodeShHr = new Leaf("Shanghai Human Resources Department");
        Component *pSubNodeShCg = new Leaf("Shanghai Purchasing Department");
        Component *pSubNodeShXs = new Leaf("Shanghai Sales department");
        Component *pSubNodeShZb = new Leaf("Shanghai Quality supervision Department");
        pSubNodeSh->Add(pSubNodeShHr);
        pSubNodeSh->Add(pSubNodeShCg);
        pSubNodeSh->Add(pSubNodeShXs);
        pSubNodeSh->Add(pSubNodeShZb);
        pNode->Print();

        // 公司不景气，需要关闭上海质量监督部门
        pSubNodeSh->Remove(pSubNodeShZb);
        if (pNode != NULL)
        {
            delete pNode;
            pNode = NULL;
        }
    }
}

客户端

#include "CompositePattern.h"


#include <iostream>
using namespace std;
using namespace CompositePattern;

void main()
{
    CompositePattern_Test();
}

运行结果