90 lines
1.3 KiB
C++
90 lines
1.3 KiB
C++
#ifndef __DEMO_H__
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#define __DEMO_H__
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#ifndef __DEMO_H__
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// 前向声明
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class Memento;
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// 原发器 典型实现
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class Originator
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{
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public:
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Originator(){
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state = "";
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}
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Originator(String iState){
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state = iState;
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}
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// 创建备忘录对象
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Memento* createMemento(){
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return new Memento(this);
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}
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// 利用备忘录对象恢复原发器状态
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void restoreMemento(Memento* m){
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state = m->getState();
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}
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void setState(string iState){
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state = iState;
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}
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string getState(){
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return state;
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}
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private:
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string state;
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};
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// 备忘录 典型实现（仿照原生器的设计）
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class Memento
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{
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public:
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Memento(){
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state = "";
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}
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Memento(Originator* o){
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state = o->getState();
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}
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void setState(String iState){
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state = iState;
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}
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string getState(){
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return state;
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}
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private:
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String state;
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};
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// 负责人 典型实现
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class Caretaker
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{
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public:
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Caretaker(){}
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Memento* getMemento(){
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return memento;
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}
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void setMemento(Memento *m){
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memento = m;
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}
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private:
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Memento* memento;
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};
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// 客户端 示例代码
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int main()
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{
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// 创建原发器对象
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Originator o = new Originator("状态1");
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// 创建负责人对象
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Caretaker *c = new Caretaker();
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c->setMemento(o->createMemento());
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o->setState("状态2");
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// 从负责人对象中取出备忘录对象，实现撤销
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o->restoreMemento(c->getMemento());
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return 0;
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}
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#endif
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#endif // __DEMO_H__
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