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| 1 | +//Composite（组合模式-对象结构型） |
| 2 | +//将对象组合成树形结构以表示“部分-整体”的层次结构。 |
| 3 | +//Composite使得用户对单个对象和组合对象的使用具有一致性。 |
| 4 | +#include <iostream> |
| 5 | +#include <list> |
| 6 | + |
| 7 | +//书中定义了Leaf功能节点和Composite容器节点， |
| 8 | +//在有的资料上Leaf和Composite接口融合的叫透明组合模式， |
| 9 | +//Leaf和Composite一样也有增删接口但没有内部实现； |
| 10 | +//只在Composite有子节点管理接口的叫安全组合模式。 |
| 11 | + |
| 12 | +//基类 |
| 13 | +class Component |
| 14 | +{ |
| 15 | +public: |
| 16 | + explicit Component(Component* parent = nullptr) |
| 17 | + : parentPtr(parent) { |
| 18 | + } |
| 19 | + virtual ~Component() {} |
| 20 | + |
| 21 | + Component* parent() const { |
| 22 | + return parentPtr; |
| 23 | + } |
| 24 | + |
| 25 | + void setParent(Component* parent) { |
| 26 | + parentPtr = parent; |
| 27 | + } |
| 28 | + |
| 29 | + virtual void add(Component* sub) {} |
| 30 | + virtual void remove(Component* sub) {} |
| 31 | + //一致性的操作接口 |
| 32 | + virtual void doing() = 0; |
| 33 | + |
| 34 | +private: |
| 35 | + Component* parentPtr; |
| 36 | +}; |
| 37 | + |
| 38 | +class Composite : public Component |
| 39 | +{ |
| 40 | +public: |
| 41 | + using Component::Component; |
| 42 | + //析构时释放对象树上的子节点 |
| 43 | + ~Composite() { |
| 44 | + for (auto&& child : childrenList) |
| 45 | + { |
| 46 | + delete child; |
| 47 | + } |
| 48 | + childrenList.clear(); |
| 49 | + } |
| 50 | + |
| 51 | + void add(Component* child) override { |
| 52 | + if (!child) return; |
| 53 | + child->setParent(this); |
| 54 | + childrenList.push_back(child); |
| 55 | + } |
| 56 | + void remove(Component* child) override { |
| 57 | + if (!child) return; |
| 58 | + child->setParent(nullptr); |
| 59 | + childrenList.remove(child); |
| 60 | + } |
| 61 | + void doing() override { |
| 62 | + std::cout << "composite doing. for children..." << std::endl; |
| 63 | + for (auto&& child : childrenList) |
| 64 | + { |
| 65 | + child->doing(); |
| 66 | + } |
| 67 | + } |
| 68 | + |
| 69 | +private: |
| 70 | + std::list<Component*> childrenList; |
| 71 | +}; |
| 72 | + |
| 73 | +class Leaf : public Component |
| 74 | +{ |
| 75 | +public: |
| 76 | + using Component::Component; |
| 77 | + void doing() override { |
| 78 | + std::cout << "leaf doing." << std::endl; |
| 79 | + } |
| 80 | +}; |
| 81 | + |
| 82 | + |
| 83 | +//测试 |
| 84 | +void testCompositePattern() |
| 85 | +{ |
| 86 | + //如果leaf和composite合二为一，就可以把children管理放到基类了 |
| 87 | + Composite* c01 = new Composite; |
| 88 | + Leaf* l01 = new Leaf; |
| 89 | + Leaf* l02 = new Leaf; |
| 90 | + c01->add(l01); |
| 91 | + c01->add(l02); |
| 92 | + |
| 93 | + Composite* c11 = new Composite; |
| 94 | + Leaf* l11 = new Leaf; |
| 95 | + Leaf* l12 = new Leaf; |
| 96 | + c11->add(l11); |
| 97 | + c11->add(l12); |
| 98 | + |
| 99 | + c01->add(c11); |
| 100 | + c01->doing(); |
| 101 | + delete c01; |
| 102 | +} |
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