组合模式

#include <iostream>
#include <list>
#include <string>
using namespace std;

//component
class IFile {
public:
    virtual void displaye() = 0;
    virtual int add(IFile* iFile) = 0;
    virtual int remove(IFile *iFile) = 0;
    virtual list<IFile*>* getChild() = 0;
};

//Leaf
class File :public IFile {
public:
    File(string name):m_name(name){}
    virtual void displaye() {
        cout << m_name << endl;
    }

    virtual int add(IFile* ifile) {
        return -1;
    }

    virtual int remove(IFile* ifile) {
        return -1;
    }

    virtual list<IFile*>* getChild() {
        return NULL;
    }
private:
    string m_name;

};

//目录：Composite
class Dir :public IFile {
public:
    Dir(string name) :m_name(name) {
        m_list = new list<IFile*>;
    }

    virtual void displaye() {
        cout << m_name << endl;
    }
    
    virtual int add(IFile* ifile) {
        m_list->push_back(ifile);
        return 0;
    }

    virtual int remove(IFile* ifile) {
        m_list->remove(ifile);
        return 0;
    }

    virtual list<IFile*> * getChild() {
        return m_list;
    }
private:
    string m_name;
    list<IFile*> *m_list;
};

void showTree(IFile* root, int level) {
    if (root == NULL)
        return;
    int i = 0;
    for (i = 0;i < level;i++) {
        printf("\t");
    }

    root->displaye();
    list<IFile*> *list1 = root->getChild();
    if (list1 != NULL) {
        for (list<IFile*>::iterator iter = list1->begin();iter != list1->end();iter++) {
            if ((*iter)->getChild() == NULL) {
                //这是文件
                for (i = 0;i < level;i++) {
                    printf("\t");
                }
                (*iter)->displaye();
            }
            else {
                showTree(*iter, level + 1);
            }
        }
    }
}