组合模式

  1 #include <iostream>
  2 #include <vector>
  3 #include <string>
  4 using namespace std;
  5 
  6 class Component
  7 {
  8 public:
  9     string name;
 10     Component(string name)
 11     {
 12         this->name = name;
 13     }
 14     virtual void add(Component *) = 0;
 15     virtual void remove(Component *) = 0;
 16     virtual void display(int) = 0;
 17 };
 18 
 19 class Leaf : public Component
 20 {
 21 public:
 22     Leaf(string name) : Component(name)
 23     {}
 24     void add(Component *c)
 25     {
 26         cout << "leaf cannot add" << endl;
 27     }
 28     void remove(Component *c)
 29     {
 30         cout << "leaf cannot remove" << endl;
 31     }
 32     void display(int depth)
 33     {
 34         string str(depth, ‘-‘);
 35         str += name;
 36         cout << str << endl;
 37     }
 38 };
 39 
 40 class Composite : public Component
 41 {
 42 private:
 43     vector<Component*> component;
 44 public:
 45     Composite(string name) : Component(name)
 46     {}
 47     void add(Component *c)
 48     {
 49         component.push_back(c);
 50     }
 51     void remove(Component *c)
 52     {
 53         vector<Component*>::iterator iter = component.begin();
 54         while (iter != component.end())
 55         {
 56             if (*iter == c)
 57             {
 58                 component.erase(iter++);
 59             }
 60             else
 61             {
 62                 iter++;
 63             }
 64         }
 65     }
 66     void display(int depth)
 67     {
 68         string str(depth, ‘-‘);
 69         str += name;
 70         cout << str << endl;
 71 
 72         vector<Component*>::iterator iter=component.begin();
 73         while (iter != component.end())
 74         {
 75             (*iter)->display(depth + 2);
 76             iter++;
 77         }
 78     }
 79 };
 80 
 81 
 82 int main()
 83 {
 84     Component *p = new Composite("小李"); 
 85     p->add(new Leaf("小王"));
 86     p->add(new Leaf("小强"));
 87 
 88     Component *sub = new Composite("小虎"); 
 89     sub->add(new Leaf("小王"));
 90     sub->add(new Leaf("小明"));
 91     sub->add(new Leaf("小柳"));
 92     
 93     p->add(sub);
 94     p->display(0);
 95 
 96     cout << "*******" << endl;
 97     sub->display(2);
 98 
 99     return 0;
100 }
101 //Result:
102 /*
103 小李
104 --小王
105 --小强
106 --小虎
107 ----小王
108 ----小明
109 ----小柳
110 *******
111 --小虎
112 ----小王
113 ----小明
114 ----小柳
115 */