C / C++ / MFC

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

class CBaseClass<br />
{<br />
.....<br />
....<br />
....<br />
<br />
private:<br />
int m_ClassID;<br />
enum<br />
{<br />
Worker,<br />
Salesman,<br />
Staff<br />
};<br />
}

CWorker::CWorker()<br />
{<br />
m_ClassID = CBaseClass::Worker;<br />
}<br />

#include <iostream>
#include <vector>

using namespace std;

class Visitor;

class CEmployee 
{
public:
    virtual void accept(Visitor& v);

    virtual void foo() 
    { 
        cout << "employee" << endl; 
    }
};

class CSalesman : public CEmployee
{
public:
    virtual void accept(Visitor& v);

    virtual void getCommision() 
    {  
        cout << "commision" << endl;
    }

    virtual void foo()
    {
        cout << "salesman" << endl;
    }
};

class CStaff : public CEmployee
{
public:
    virtual void accept(Visitor& v);

    virtual void foo()
    {
        cout << "staff" << endl;
    }
};

class Visitor
{
public:
    virtual void visit(CEmployee* pA) = 0;
    virtual void visit(CSalesman* pB) = 0;
    virtual void visit(CStaff* pC) = 0;
};

void CEmployee::accept(Visitor& v)
{
    v.visit(this);
}

void CStaff::accept(Visitor& v)
{
    v.visit(this);
}

void CSalesman::accept(Visitor& v)
{
    v.visit(this);
}

class CommisionVis : public Visitor
{
public:
    virtual void visit(CEmployee* pEmp)
    {
        // do nothing
    }

    virtual void visit(CSalesman* pEmp)
    {
        pEmp->getCommision();
    }

    virtual void visit(CStaff* pEmp)
    {
        // do nothing
    }
};


int main()
{
    std::vector<CEmployee*> empList;
    empList.push_back(new CEmployee());
    empList.push_back(new CSalesman());
    empList.push_back(new CStaff());
    for(size_t i = 0; i < empList.size(); i++)
    {
        empList.at(i)->foo();
    }
    cout << "**************************" << endl;
    CommisionVis vis;
    for(size_t i = 0; i < empList.size(); i++)
    {
        empList.at(i)->accept(vis);
    }
    // ... more code
}

std::vector<CEmployee*> empList;

class CEmployee
{
protected:
    virtual double getCommission( void ) { return 0.0; }
};
 
class CSalesman : public CEmployee
{
protected:
    virtual double getCommission( void ) { return 1.5; }
};
 
class CStaff : public CEmployee
{
    // no getCommission() here, use base class implementation
};

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

CMenu m_menu;

HMENU SetNewMenu(UINT nMenu);

HMENU CMainFrame::SetNewMenu(UINT nMenu)
{
    // Load the menu from the resources
    m_menu.LoadMenu(nMenu);
    m_menu.LoadToolbar(nMenu);  // if you will need a toolbar also

    return (m_menu.Detach());
}

CMenu* pMenu = AfxGetMainWnd()->GetMenu();

if (pMenu)
	pMenu->DestroyMenu();
	
CMainFrame* pFrame = reinterpret_cast<CMainFrame*>(m_pMainWnd)->SetNewMenu(IDR_MENU1);
ASSERT(pFrame != NULL);

HMENU hMenu = pFrame->NewMenu();
CMenu* pNewMenu = CMenu::FromHandle( hMenu );
ASSERT(pNewMenu != NULL);

AfxGetMainWnd()->SetMenu(pNewMenu);