技術標籤：# 設計模式設計模式

責任鏈設計模式：

// 定義抽象的處理者
class LeaderHandler{
public:
    virtual bool handleRequest(int leave_days, LeaderHandlerChain* chain) = 0;
};

// 定義責任鏈
class LeaderHandlerChain{
public:
    LeaderHandlerChain& addHandler(LeaderHandler* handler){
        handlerList.push_back(handler);
        return
 
 *this;
    }

    bool handleRequest(int leave_days);

    LeaderHandler* getNextHandler(){
        int tmp_index = index + 1;
        if(tmp_index >= handlerList.size())
            return nullptr;
        return handlerList[tmp_index];
    }

    void setIndexAdd(){
        index++;
    }

private:
 

    QList<LeaderHandler*> handlerList;
    int index;
};

bool LeaderHandlerChain::handleRequest(int leave_days)
{
    if(handlerList.size() == 0)
        return false;

    handlerList[0]->handleRequest(leave_days, this);
}

// 定義具體的處理者

// 具體處理者1：班主任類
class ClassAdviser : public LeaderHandler{
 

public:
    ClassAdviser(int days){
        this->days = days;
    }

    virtual bool handleRequest(int leave_days, LeaderHandlerChain* chain){
        if(leave_days <= days){
            qDebug() << "ClassAdviser handle...";
            return true;
        }
        else
        {
            LeaderHandler* next = chain->getNextHandler();
            if(next == nullptr)
            {
                qDebug() << "no body handle this msg...";
            }
            else
            {
                chain->setIndexAdd();
                next->handleRequest(leave_days, chain);
            }
        }
    }

private:
    int days;
};

//具體處理者2：系主任類
class DepartmemHead : public LeaderHandler{
public:
    DepartmemHead(int days){
        this->days = days;
    }

    virtual bool handleRequest(int leave_days, LeaderHandlerChain* chain){
        if(leave_days <= days){
            qDebug() << "DepartmemHead handle...";
            return true;
        }
        else
        {
            LeaderHandler* next = chain->getNextHandler();
            if(next == nullptr)
            {
                qDebug() << "no body handle this msg...";
            }
            else
            {
                chain->setIndexAdd();
                next->handleRequest(leave_days, chain);
            }
        }
    }

private:
    int days;
};

//具體處理者3：院長類
class Dean : public LeaderHandler{
public:
    Dean(int days){
        this->days = days;
    }

    virtual bool handleRequest(int leave_days, LeaderHandlerChain* chain){
        if(leave_days <= days){
            qDebug() << "Dean handle...";
            return true;
        }
        else
        {
            LeaderHandler* next = chain->getNextHandler();
            if(next == nullptr)
            {
                qDebug() << "no body handle this msg...";
            }
            else
            {
                chain->setIndexAdd();
                next->handleRequest(leave_days, chain);
            }
        }
    }

private:
    int days;
};

//具體處理者4：教務處長類
class DeanOfStudies : public LeaderHandler{
public:
    DeanOfStudies(int days){
        this->days = days;
    }

    virtual bool handleRequest(int leave_days, LeaderHandlerChain* chain){
        if(leave_days <= days){
            qDebug() << "DeanOfStudies handle...";
            return true;
        }
        else
        {
            LeaderHandler* next = chain->getNextHandler();
            if(next == nullptr)
            {
                qDebug() << "no body handle this msg...";
                return false;
            }
            else
            {
                chain->setIndexAdd();
                next->handleRequest(leave_days, chain);
            }
        }
    }

private:
    int days;
};

// 客戶端
LeaderHandlerChain chain;
chain.addHandler(new ClassAdviser(3)).addHandler(new DepartmemHead(5)).addHandler(new Dean(7)).addHandler(new DeanOfStudies(10));
chain.handleRequest(11);