組合模式(Composite Pattern),又叫部分整體模式,是用於把一組相似的對象當作一個單一的對象。組合模式依據樹形結構來組合對象,用來表示部分以及整體層次。
組合模式包含以下主要角色。
- 抽象構件(Component)角色:它的主要作用是爲樹葉構件和樹枝構件聲明公共接口,並實現它們的默認行爲。在透明式的組合模式中抽象構件還聲明訪問和管理子類的接口;在安全式的組合模式中不聲明訪問和管理子類的接口,管理工作由樹枝構件完成。
- 樹葉構件(Leaf)角色:是組合中的葉節點對象,它沒有子節點,用於實現抽象構件角色中 聲明的公共接口。
- 樹枝構件(Composite)角色:是組合中的分支節點對象,它有子節點。它實現了抽象構件角色中聲明的接口,它的主要作用是存儲和管理子部件,通常包含 Add()、Remove()、GetChild() 等方法。
#include <iostream>
#include <string>
#include <vector>
using namespace std;
class Company
{
protected:
string m_strName;
public:
Company(string strName)
{
m_strName = strName;
}
virtual void Add(Company* c) = 0;
virtual void Display(int nDepth) = 0;
virtual void LineOfDuty() = 0;
};
class ConcreteCompany : public Company
{
private:
vector<Company*> m_company;
public:
ConcreteCompany(string strName) :Company(strName) {}
virtual void Add(Company* c)
{
m_company.push_back(c);
}
virtual void Display(int nDepth)
{
string strtemp;
for (int i = 0; i < nDepth; i++)
{
strtemp += "-";
}
strtemp += m_strName;
cout << strtemp << endl;
vector<Company*>::iterator p = m_company.begin();
while (p != m_company.end())
{
(*p)->Display(nDepth + 2);
p++;
}
}
virtual void LineOfDuty()
{
vector<Company*>::iterator p = m_company.begin();
while (p != m_company.end())
{
(*p)->LineOfDuty();
p++;
}
}
};
class HrDepartment : public Company
{
public:
HrDepartment(string strname) : Company(strname) {}
virtual void Display(int nDepth)
{
string strtemp;
for (int i = 0; i < nDepth; i++)
{
strtemp += "-";
}
strtemp += m_strName;
cout << strtemp << endl;
}
virtual void Add(Company* c)
{
cout << "error" << endl;
}
virtual void LineOfDuty()
{
cout << m_strName << ":招聘人才" << endl;
}
};
//客戶端:
int main()
{
ConcreteCompany *pSchool = new ConcreteCompany("清華大學");
ConcreteCompany *pApartmentMath = new ConcreteCompany("數學系");
pApartmentMath->Add(new HrDepartment("清華大學數學學習組"));
ConcreteCompany *pApartmentPhysics = new ConcreteCompany("物理系");
pApartmentPhysics->Add(new HrDepartment("清華大學物理學習組"));
ConcreteCompany *pApartmentComputer = new ConcreteCompany("計算機系");
pApartmentComputer->Add(new HrDepartment("清華大學計算機學習組"));
pSchool->Add(pApartmentMath);
pSchool->Add(pApartmentPhysics);
pSchool->Add(pApartmentComputer);
pSchool->Display(2);
pSchool->LineOfDuty();
cin.get();
return 0;
}