/*================================================================

• Copyright (C) 2017 Ltd. All rights reserved.
• FileName：fsm.cpp
• Author： shrekshen
• Create-time：2017-12-19 20:18:03
• Describle：study fsm, reference:http://blog.csdn.net/popy007/...

*
================================================================*/

include <iostream>

include <map>

using namespace std;

class Fsm;//前置声明
//首先创建一个gamestate类，它是其他状态类的基类
enum E_GAME_STATE
{

E_INTO_GAME = 0,
E_PLAY_GAME = 1,
E_LEFT_GAME = 2

};

class GameState
{

public:
    virtual ~GameState(){}
    virtual void drive() = 0;
    GameState(Fsm* fsm)
    {
        m_fsm = fsm;
    }
    Fsm *m_fsm;

};

//然后添加一个管理这些类的管理类，也就是状态机
class Fsm
{

public:
    void add_state(E_GAME_STATE gameState , GameState *state)
    {
        state_map.insert(pair<E_GAME_STATE, GameState *>(gameState, state));
    }
    
    void switch_state(E_GAME_STATE gameState)
    {
        std::map<E_GAME_STATE, GameState *>::iterator it = state_map.find(gameState);
        current_state = it->second;
        current_state->drive();
    }

protected:
    std::map<E_GAME_STATE, GameState *> state_map;
    GameState *current_state;

};

class IntoGameState : public GameState
{

public:
    IntoGameState(Fsm *fsm):GameState(fsm)
    {
    
    }
public:
    virtual void drive()
    {
        cout << "IntoGameState" << endl;
        m_fsm->switch_state(E_PLAY_GAME);
    }

};

class PlayGameState : public GameState
{

public:
    PlayGameState(Fsm *fsm):GameState(fsm)
    {
    
    }

public:
    virtual void drive()
    {
        cout << "PlayGameState" << endl;
        m_fsm->switch_state(E_LEFT_GAME);
    }

};

class LeftGameState : public GameState
{

public:
    LeftGameState(Fsm *fsm):GameState(fsm)
    {

    }

public:
    virtual void drive()
    {
        cout << "LeftGameState" << endl;
        m_fsm->switch_state(E_INTO_GAME);
    }

};

int main(){

Fsm *fsm = new Fsm;
GameState *intostate = new IntoGameState(fsm);
GameState *playstate = new PlayGameState(fsm);
GameState *leftstate = new LeftGameState(fsm);
fsm->add_state(E_INTO_GAME, intostate);
fsm->add_state(E_PLAY_GAME, playstate);
fsm->add_state(E_LEFT_GAME, leftstate);
fsm->switch_state(E_LEFT_GAME);

}

最近在学习设计模式，写的一个简单的状态机，遇到了这个问题，麻烦各位看看。

class Fsm;//前置声明
//首先创建一个gamestate类，它是其他状态类的基类
enum E_GAME_STATE
{

E_INTO_GAME = 0,
E_PLAY_GAME = 1,
E_LEFT_GAME = 2

};

class GameState
{

public:
    virtual ~GameState(){}
    virtual void cycle() = 0;
    virtual void drive()=0;
    GameState(Fsm* fsm)
    {
        m_fsm = fsm;
    }
    Fsm *m_fsm;

};

class IntoGameState : public GameState
{

public:
    virtual void drive(Fsm *fsm)
    {
        m_fsm = fsm;
        cout << "IntoGameState" << endl;
        m_fsm->switch_state(E_LEFT_GAME);
    }

};

class PlayGameState : public GameState
{

public:
    virtual void drive(Fsm *fsm)
    {
        m_fsm = fsm;
        cout << "PlayGameState" << endl;
        m_fsm->switch_state(E_LEFT_GAME);
    }

};

class LeftGameState : public GameState
{

public:
    virtual void drive(Fsm *fsm)
    {
        m_fsm = fsm;
        cout << "LeftGameState" << endl;
        m_fsm->switch_state(E_INTO_GAME);
    }

};

//然后添加一个管理这些类的管理类，也就是状态机
class Fsm
{

public:
    add_state(E_GAME_STATE gameState , GameState *state)
    {
        state_map.insert(gameState, state);
    }
    
    switch_state(E_GAME_STATE gameState)
    {
        std::map<E_GAME_STATE, GameState *> it = state_map.find(gameState);
        current_state = it->end();
        current_state->drive(Fsm);
    }

private:
    std::map<E_GAME_STATE, GameState *> state_map;
    GameState *current_state;

};

int main(){

Fsm *fsm = new Fsm;
GameState *intostate = new IntoGameState(fsm);
GameState *playstate = new PlayGameState(fsm);
GameState *leftstate = new LeftGameState(fsm);
fsm->add_state(E_INTO_GAME, intostate);
fsm->add_state(E_PLAY_GAME, playstate);
fsm->add_state(E_LEFT_GAME, leftstate);
fsm->switch_state(E_LEFT_GAME);

}