C++设计模式之备忘录模式

#include <iostream>
using namespace std;
 
struct State
{
     wchar_t wcsState[260];
};
 
class Memento
{
public:
     Memento(State *pState) : m_pState(pState){}
 
     State *GetState() { return m_pState; }
 
private:
     friend class Originator;
 
     State *m_pState;
};
 
class Originator
{
public:
     Originator() : m_pState(NULL) {}
     ~Originator()
     {
          // Delete the storage of the state
          if (m_pState)
          {
               delete m_pState;
               m_pState = NULL;
          }
     }
 
     void SetMemento(Memento *pMemento);
     Memento *CreateMemento();
 
     void SetValue(wchar_t *value)
     {
          memset(wcsValue, 0, 260 * sizeof(wchar_t));
          wcscpy_s(wcsValue, 260, value);
     }
 
     void PrintState() { wcout<<wcsValue<<endl; }
 
private:
     State *m_pState; // To store the object's state
 
     wchar_t wcsValue[260]; // This is the object's real data
};
 
Memento *Originator::CreateMemento()
{
     m_pState = new State;
     if (m_pState == NULL)
     {
          return NULL;
     }
 
     Memento *pMemento = new Memento(m_pState);
 
     wcscpy_s(m_pState->wcsState, 260, wcsValue); // Backup the value
     return pMemento;
}
 
void Originator::SetMemento(Memento *pMemento)
{
     m_pState = pMemento->GetState();
 
     // Recovery the data
     memset(wcsValue, 0, 260 * sizeof(wchar_t));
     wcscpy_s(wcsValue, 260, m_pState->wcsState);
}
 
// Manager the Memento
class Caretaker
{
public:
     Memento *GetMemento() { return m_pMemento; }
     void SetMemnto(Memento *pMemento)
     {
          // Free the previous Memento
          if (m_pMemento)
          {
               delete m_pMemento;
               m_pMemento = NULL;
          }
 
          // Set the new Memento
          m_pMemento = pMemento;
     }
 
private:
     Memento *m_pMemento;
};
 
int main()
{
     Originator *pOriginator = new Originator();
     pOriginator->SetValue(L"On");
     pOriginator->PrintState();
 
     // Now I backup the state
     Caretaker *pCaretaker = new Caretaker();
     pCaretaker->SetMemnto(pOriginator->CreateMemento());
 
     // Set the new state
     pOriginator->SetValue(L"Off");
     pOriginator->PrintState();
 
     // Recovery to the old state
     pOriginator->SetMemento(pCaretaker->GetMemento());
     pOriginator->PrintState();
 
     if (pCaretaker)
     {
          delete pCaretaker;
     }
 
     if (pOriginator)
     {
          delete pOriginator;
     }
 
     return 0;
}

#include <iostream>
using namespace std;
 
class RoleStateMemento
{
public:
     RoleStateMemento(unsigned iBlood, unsigned iAttack, unsigned iDefense) : m_iBlood(iBlood), m_iAttack(iAttack), m_iDefense(iDefense){}
 
private:
     friend class GameRole;
 
     unsigned GetBloodValue() { return m_iBlood; }
     unsigned GetAttackValue() { return m_iAttack; }
     unsigned GetDefenseValue() { return m_iDefense; }
 
     unsigned m_iBlood;   // 生命力
     unsigned m_iAttack;  // 攻击力
     unsigned m_iDefense; // 防御力
};
 
class GameRole
{
public:
     GameRole() : m_iBlood(100), m_iAttack(100), m_iDefense(100){}
 
     // 存档
     RoleStateMemento *SaveState() { return new RoleStateMemento(m_iBlood, m_iAttack, m_iDefense); }
 
     // 恢复存档
     void RecoveryState(RoleStateMemento *pRoleState)
     {
          m_iBlood = pRoleState->GetBloodValue();
          m_iAttack = pRoleState->GetAttackValue();
          m_iDefense = pRoleState->GetDefenseValue();
          cout<<"Recovery..."<<endl;
     }
 
     void ShowState()
     {
          cout<<"Blood:"<<m_iBlood<<endl;
          cout<<"Attack:"<<m_iAttack<<endl;
          cout<<"Defense:"<<m_iDefense<<endl;
     }
 
     void Fight()
     {
          m_iBlood -= 100;
          m_iAttack -= 10;
          m_iDefense -= 20;
 
          if (m_iBlood == 0)
          {
               cout<<"Game Over"<<endl;
          }
     }
 
private:
     unsigned m_iBlood;   // 生命力
     unsigned m_iAttack;  // 攻击力
     unsigned m_iDefense; // 防御力
};
 
class RoleStateCaretaker
{
public:
     void SetRoleStateMemento(RoleStateMemento *pRoleStateMemento) { m_pRoleStateMemento = pRoleStateMemento; }
     RoleStateMemento *GetRoleStateMemento() { return m_pRoleStateMemento; }
 
private:
     RoleStateMemento *m_pRoleStateMemento;
};
 
int main()
{
     GameRole *pLiXY = new GameRole(); // 创建李逍遥这个角色
     pLiXY->ShowState(); // 显示初始的状态
 
     // 存档
     RoleStateCaretaker *pRoleStateCaretaker = new RoleStateCaretaker();
     pRoleStateCaretaker->SetRoleStateMemento(pLiXY->SaveState());
 
     // 开始打大BOSS
     pLiXY->Fight();
     pLiXY->ShowState();
 
     // 读档，从新开始
     pLiXY->RecoveryState(pRoleStateCaretaker->GetRoleStateMemento());
     pLiXY->ShowState();
 
     return 0;
}