设计模式18-备忘录模式

备忘录模式 我更想称它为快照模式，它的思想就是把对象的状态保存为快照，存储到其他地方，在需要的时候拿来加载上，就可以得到当时候存快照时的样子

比如我们游戏的存档点

#include <iostream>
#include <string>
#include <vector>

class ArchievePoint {
public:
    ArchievePoint(std::string pos, int level, int money) 
    : m_pos(pos)
    , m_level(level)
    , m_money(money)
    {}
    std::string m_pos;
    int m_level;
    int m_money;    
};

class Game {
public:
    void show() {
        std::cout << "当前在[" << m_pos << "] 等级：" << m_level << " 金币：" << m_money << std::endl;
    }

    void StageOne() {
        m_pos = "光之谷";
        m_level = 3;
        m_money = 1000;
        show();
    }

    void StageTwo() {
        m_pos = "岩穴";
        m_level = 10;
        m_money = 3000;
        show();
    }
    void StageThree() {
        m_pos = "冰城";
        m_level = 20;
        m_money = 8000;
        show();
    }

    ArchievePoint* Archive() {
        return new ArchievePoint(m_pos, m_level, m_money);
    }

    void LoadArchieve(ArchievePoint* acv) {
        m_pos = acv->m_pos;
        m_level = acv->m_level;
        m_money = acv->m_money;
        show();
    }

private:
    std::string m_pos;
    int m_level;
    int m_money;
};

class ArchieveManager {
public:
    void AddArchievePoint(ArchievePoint* acv) {
        m_acvs.push_back(acv);
    }

    ArchievePoint* getArchievePoint(int index) {
        if(index >= m_acvs.size()) {
            return nullptr;
        }
        return m_acvs[index];
    }

    ~ArchieveManager() {
        for(auto item : m_acvs) {
            delete item;
        }
    }
private:
    std::vector<ArchievePoint*> m_acvs;
};

int main() {
    ArchieveManager am;
    Game game;

    game.StageOne();
    auto acv = game.Archive();
    am.AddArchievePoint(acv);
    game.StageTwo();
    acv = game.Archive();
    am.AddArchievePoint(acv);

    std::cout << "==============================" << std::endl;
    Game newgame;
    newgame.LoadArchieve(am.getArchievePoint(1));
    newgame.StageThree();
    return 0;
}