《C++新经典设计模式》之第9章命令模式

- - - 命令模式.cpp

命令模式.cpp

#include <iostream>
#include <list>
#include <memory>
using namespace std;// 5种角色
// Receiver（接收者），Cook，提供请求业务的处理接口
// Invoker（调用者），Waiter，发送请求，通过命令对象执行请求
// Command（抽象命令），声明执行操作的接口
// ConcreteCommand（具体命令），通过调用Receiver相关操作执行请求
// Client（客户端），创建具体命令并设定接收者，创建调用者并驱动执行命令动作// 将请求或命令封装为对象，通过参数进行传递，对象化的对象可以排队执行或者撤销namespace ns1
{class Cook // 厨师类{public:void cook_fish() { cout << "fish" << endl; } // 做红烧鱼void cook_meat() { cout << "meat" << endl; } // 做锅包肉};class Command // 厨师做的每样菜品对应的抽象类{protected:shared_ptr<Cook> m_pcook;public:Command(const shared_ptr<Cook> &pcook) : m_pcook(pcook) {}virtual ~Command() {}virtual void Execute() = 0;};class CommandFish : public Command // 做红烧鱼菜品命令（顾客下的红烧鱼菜品便签）{public:CommandFish(const shared_ptr<Cook> &pcook) : Command(pcook) {}void Execute() override { m_pcook->cook_fish(); }};class CommandMeat : public Command // 做锅包肉菜品命令（顾客下的锅包肉菜品便签）{public:CommandMeat(const shared_ptr<Cook> &pcook) : Command(pcook) {}void Execute() override { m_pcook->cook_meat(); }};class Waiter0 // 服务员类{shared_ptr<Command> m_pcommand; // 服务员手中握着顾客书写的菜品便签public:void SetCommand(const shared_ptr<Command> &pcommand) { m_pcommand = pcommand; } // 顾客将便签交给服务员void Notify() { m_pcommand->Execute(); }                                        // 服务员将便签交到厨师手里让厨师开始做菜};class Waiter{private:// 一个便签中可以包含多个菜品甚至可以一次收集多个顾客的便签，达到一次性通知厨师做多道菜的效果list<shared_ptr<Command>> m_commlist; // 菜品列表，每道菜品作为一项，如果一个便签中有多个菜品，则这里将包含多项public:// 将顾客的便签增加到便签列表中，即便一个便签中包含多道菜品，这也相当于一道一道菜品加入到列表中void AddCommand(const shared_ptr<Command> &pcommand){m_commlist.push_back(pcommand);}void DelCommand(const shared_ptr<Command> &pcommand) // 如果顾客想撤单则将便签从列表中删除{m_commlist.remove(pcommand);}void Notify() // 服务员将所有便签一次性交到厨师手里让厨师开始按顺序做菜{for (auto iter = m_commlist.cbegin(); iter != m_commlist.cend(); ++iter) // 依次让厨师做每一道菜品(*iter)->Execute();}};
}namespace ns2
{class Cook // 厨师类{public:void cook_fish() { cout << "fish" << endl; } // 做红烧鱼void cook_meat() { cout << "meat" << endl; } // 做锅包肉};class Command // 厨师做的每样菜品对应的抽象类{protected:shared_ptr<Cook> m_pcook;public:Command(const shared_ptr<Cook> &pcook) : m_pcook(pcook) {}virtual ~Command() {}virtual void Execute() = 0;};class CommandFish : public Command // 做红烧鱼菜品命令（顾客下的红烧鱼菜品便签）{public:CommandFish(const shared_ptr<Cook> &pcook) : Command(pcook) {}void Execute() override { m_pcook->cook_fish(); }};class CommandMeat : public Command // 做锅包肉菜品命令（顾客下的锅包肉菜品便签）{public:CommandMeat(const shared_ptr<Cook> &pcook) : Command(pcook) {}void Execute() override { m_pcook->cook_meat(); }};class Traineewaiter // 实习服务员类{shared_ptr<Command> m_pcommand; // 实习服务员手中握着顾客书写的菜品便签public:Traineewaiter(const shared_ptr<Command> &pcommand) : m_pcommand(pcommand) {}void Notify() // 实习服务员将便签交到厨师手里让厨师开始做菜{if (m_pcommand != nullptr)m_pcommand->Execute();}};
}namespace ns3
{class Cook // 厨师类{public:void cook_fish() { cout << "fish" << endl; } // 做红烧鱼void cook_meat() { cout << "meat" << endl; } // 做锅包肉};class Command // 厨师做的每样菜品对应的抽象类{protected:shared_ptr<Cook> m_pcook;public:Command(const shared_ptr<Cook> &pcook = nullptr) : m_pcook(pcook) {}virtual ~Command() {}virtual void Execute() = 0;};class CommandFish : public Command // 做红烧鱼菜品命令（顾客下的红烧鱼菜品便签{public:CommandFish(const shared_ptr<Cook> &pcook = nullptr) : Command(pcook) {}void Execute() override{if (m_pcook != nullptr)m_pcook->cook_fish();}};class CommandMeat : public Command // 做锅包肉菜品命令（顾客下的锅包肉菜品便签）{public:CommandMeat(const shared_ptr<Cook> &pcook = nullptr) : Command(pcook) {}void Execute() override{if (m_pcook != nullptr)m_pcook->cook_meat();}};class CommandMacro : public Command // 宏命令：把多个命令组合{list<shared_ptr<Command>> m_commlist;public:void AddCommand(const shared_ptr<Command> &pcommand){m_commlist.push_back(pcommand);}virtual void Execute(){for (auto iter = m_commlist.cbegin(); iter != m_commlist.cend(); ++iter)(*iter)->Execute();}};class Traineewaiter // 实习服务员类{shared_ptr<Command> m_pcommand; // 实习服务员手中握着顾客书写的菜品便签public:Traineewaiter(const shared_ptr<Command> &pcommand = nullptr) : m_pcommand(pcommand) {}void Notify() // 实习服务员将便签交到厨师手里让厨师开始做菜{if (m_pcommand != nullptr)m_pcommand->Execute();}};
}namespace ns4
{class TC{public:void operator()(int tv){cout << "TC::operator(int tv), tv=" << tv << endl;}public:int operator()(int tv1, int tv2){cout << "TC::operator(int tv1, int tv2), tv1=" << tv1 << ", tv2=" << tv2 << endl;return tv1 + tv2;}};template <class T>          // T代表可调用对象的类型void functmptest(T callobj) // callobj是个可调用对象{callobj(100);}
}int main()
{
#if 0using namespace ns1;shared_ptr<Cook> pcook(new Cook());pcook->cook_fish();pcook->cook_meat();
#endif#if 0using namespace ns1;shared_ptr<Cook> cook(new Cook());shared_ptr<Command> pcmd1(new CommandFish(cook));pcmd1->Execute(); // 做红烧鱼shared_ptr<Command> pcmd2(new CommandMeat(cook));pcmd2->Execute(); // 做锅包肉
#endif#if 0using namespace ns1;shared_ptr<Cook> cook(new Cook());shared_ptr<Command> pcmd1(new CommandFish(cook));shared_ptr<Command> pcmd2(new CommandMeat(cook));shared_ptr<Waiter0> pwaiter(new Waiter0());pwaiter->SetCommand(pcmd1);pwaiter->Notify(); // 做红烧鱼pwaiter->SetCommand(pcmd2);pwaiter->Notify(); // 做锅包肉
#endif#if 0using namespace ns1;shared_ptr<Cook> cook(new Cook());shared_ptr<Command> pcmd1(new CommandFish(cook));shared_ptr<Command> pcmd2(new CommandMeat(cook));shared_ptr<Waiter> pwaiter(new Waiter());// 把多道菜品分别加入到菜品列表中pwaiter->AddCommand(pcmd1);pwaiter->AddCommand(pcmd2);// 服务员一次性通知厨师做多道菜pwaiter->Notify();
#endif#if 0using namespace ns2;shared_ptr<Cook> cook(new Cook());shared_ptr<Command> pcmd1(new CommandFish(cook));shared_ptr<Command> pcmd2(new CommandMeat(cook));shared_ptr<Traineewaiter> pwaitersx1(new Traineewaiter(pcmd1));pwaitersx1->Notify(); // 做红烧鱼shared_ptr<Traineewaiter> pwaitersx2(new Traineewaiter(pcmd2));pwaitersx2->Notify(); // 做锅包肉
#endif#if 0using namespace ns3;shared_ptr<Cook> cook(new Cook());shared_ptr<Command> pcmd1(new CommandFish(cook));shared_ptr<Command> pcmd2(new CommandMeat(cook));shared_ptr<CommandMacro> pcmd(new CommandMacro());shared_ptr<Traineewaiter> pwaiter(new Traineewaiter(pcmd));pcmd->AddCommand(pcmd1);pcmd->AddCommand(pcmd2);pwaiter->Notify();
#endif#if 1using namespace ns4;TC tc;tc(20); // 调用的是()操作符，这就是个可调用对象。等价于tc.operator()(20);cout << tc(30, 50) << endl;functmptest(tc);
#endifcout << "Over!\n";return 0;
}