CommandMode

最新推荐文章于 2024-03-31 09:41:30 发布

原创最新推荐文章于 2024-03-31 09:41:30 发布 · 495 阅读

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文章标签：

#command #class #vector

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本文介绍了一种常用的设计模式——命令模式，并通过示例代码详细解释了如何在C++中实现这一模式，包括基本的命令执行及扩展到支持撤销操作的功能。

//一个很好的CommandMode

//提炼一个Command接口
class Command
{
public:
virtual ~Command(){}
virtual void Execute() = 0;
protected:
Command(){}
};
class LightOnCommand : public Command
{
public:
void Execute()
{
  //一般来说这里多是借助其它对象来完成，这个例子从简了
  cout << "开始发光" << endl;
}
};
class LightOffCommand : public Command
{
public:
void Execute()
{
  cout << "停止发光" << endl;
}

};
class FireOnCommand : public Command
{
public:
void Execute()
{
cout << "开始喷火" << endl;
}
};
class FireOffCommand : public Command
{
public:
void Execute()
{
cout << "结束喷火" << endl;
}
};

//公牛类
class Bulls
{
private:
//Command数组
vector<void*> m_Commands;
//void *m_Commands[4];
public:
Bulls()
{
  m_Commands.push_back(new LightOnCommand());
  m_Commands.push_back(new LightOffCommand());
  m_Commands.push_back(new FireOnCommand());
  m_Commands.push_back(new FireOffCommand());
}
//点击张开嘴
void ClickMouthOpen()
{
  m_Commands[0]->Execute();
}
void ClickMouthClose()
{
  m_Commands[1]->Execute();
}
void ClickEyeOpen()
{
  m_Commands[2]->Execute();
}
void ClickEyeClose()
{
  m_Commands[3]->Execute();
}
};

//提炼一个Command接口
class Command
{
public:
virtual ~Command(){}
virtual void Execute() = 0;
//撤消操作
virtual void UnExecute() = 0;
protected:
Command(){}
};
class LightOnCommand : public Command
{
public:
void Execute()
{
  //一般来说这里多是借助其它对象来完成，这个例子从简了
  cout << "开始发光" << endl;
}
void UnExecute()
{
  cout << "撤销发光操作" << endl;
}
};

//公牛类
class Bulls
{
private:
vector m_Commands;
//添加一个堆栈作为撤消操作的容器
stack m_UndoCommands;
public:
Bulls()
{
  m_Commands.push_back(new LightOnCommand());
  m_Commands.push_back(new LightOffCommand());
  m_Commands.push_back(new FireOnCommand());
  m_Commands.push_back(new FireOffCommand());
}
void ClickMouthOpen()
{
  m_Commands[0]->Execute();
  //每次操作后，把该操作放入堆栈中
  m_UndoCommands.push(m_Commands[0]);
}
void ClickMouthClose()
{
  m_Commands[1]->Execute();
  m_UndoCommands.push(m_Commands[1]);
}
void ClickEyeOpen()
{
  m_Commands[2]->Execute();
  m_UndoCommands.push(m_Commands[2]);
}
void ClickEyeClose()
{
  m_Commands[3]->Execute();
  m_UndoCommands.push(m_Commands[3]);
}
void Undo()
{
  //撤消通过调用m_UndoCommands来完成
  if ( !m_UndoCommands.empty())
  {
   m_UndoCommands.top()->UnExecute();
   m_UndoCommands.pop();
  }
}
};