Is it correct, following object orientation, to use pointers to C++ functions?

Question

I am creating classes that represent items in a menu, each item performs an action and I am assigning the action by a function pointer to each instantiated menu item, is this valid by following POO? or there is an easier and more practical way to do this?

Follows code:

class MenuItem{
public:
     MenuItem(GLsizei x, GLsizei y, string texto, bool enabled = false);
     ~MenuItem();

     void display();

     void setAction(void (*action)());
     void runAction();
private:
     GLsizei x, y;
     string texto;
     bool enabled;
     void (*action)();
};

void MenuItem::setAction(void (*action)())
{
     this->action=action;
}

void MenuItem::runAction()
{
    action();
}

Class that instance Menuitem:

class Menu{
public:
     Menu(vector<string> itens, GLsizei width, GLsizei heigth);
     ~Menu();

     void selectNext();
     void selectPrevious();

     MenuItem* getSelectedItem() const;

     void display();
private:
     MenuItem **itens;
     int selectedItem;
     int contItens;
     GLsizei width, heigth;
};


void function(void){
     cout<<"faz alguma coisa"<<endl;
}

Menu::Menu(vector<string> itens, GLsizei width, GLsizei heigth)
     :width(width), heigth(heigth)
{
     contItens=0;
     this->itens=new MenuItem*[itens.size()];
     for(string s: itens){
         this->itens[contItens++]=new MenuItem(width/2, heigth/2-contItens*30, s);
     }
     this->itens[selectedItem=0]->setEnabled(true);

     this->itens[0]->setAction(function);//aqui eu coloco a ação no primeiro item
}

calling function:

void keyboard(unsigned char key, int x, int y){
    if(key=='s')
        menu->getSelectedItem()->runAction();
    if(key=='d')
        menu->selectNext();
    if(key=='a')
        menu->selectPrevious();
    glutPostRedisplay();
}

I only created function for testing. My idea is to put a method in Menu which places by means of function pointer the action referenced to each item. But the code itself works, I’m just in doubt if it follows POO and if it’s not so complex?

Answer 1

Correct can only be said by seeing a concrete case. In this respect the question cannot be answered. The actual case has not been put forward, so even if I say you can do it, if you do it wrong it doesn’t matter what I said.

This has nothing to do with object orientation. Even if it had, what matters is to solve the problem well, not meet what the paradigm says.

Pointers for functions are perfectly valid in various situations.

Of course in C++ it is more common to use functors or more (not so) recently Amble. You can also make creative uses of templates or the simple polymorphism. If you think you need this indirect the ideal is to use a more idiomatic mechanism of C++ and more modern (because it brings advantages).