Interaction managed in separated class

Hello everybody !
I would like to know if I can call the callback functions (keyboard, mouse, etc.) from separate classes.

For example I have a main renderer (handled by a GLFW window in my case), and I would like to call for mouse events :


given that the renderer has an attribute :

Interaction* interaction;

which is the class that manages all the inputs, and has a function :

void Interaction::mouseButtonCallback(int button, int action) {...}

This leads me to an error like :
error: argument of type ‘void (Interaction::)(int, int)’ does not match ‘void (*)(int, int)’

Is there a way to do it or am I condemned to handle the inputs in the same class as my renderer ?

Any advice is really welcome !


Ok, I’m replying to my owm post… Silly thing, I just should have created my callback functions static…

Well, at least now I know I should not reply so fast… Obviously making a function static implies that all the data it handles must be static… Which I have to avoid.
So does anyone have an idea about how to use a mouseButtonCallback function that belongs to an external class ?

One thing that works is creating a “mouseInteraction()” function that belongs to the external class which is called in the callback function, but it’s not so clean…

Instance methods cannot be used as function pointers. There are several reasons for this, including issues with inheritance (virtual methods resolved through v-tables) and the hidden ‘this’ parameter.

Now, it’s been a long time since I last used C++, but IIRC you can solve this issue using ‘functors’ (google is your friend).

How about…(probably typos)

class InteractionCallback {
    static Interaction* pInteraction;
    static void setInteraction(Interation* pI) { pInteraction = pI; }
    static void mouseButton(int button, int action)
       pInteraction->mouseButtonCallback(button, action);

Hi, sorry for the late reply I had not seen your posts.
What I eventually did is wrapping the functions like :

void mouseButtonCallback(int button, int action) 
	r->mouseButtonInteraction(button, action);

Where r is the class managing the interaction. It works, and doesn’t make such a mess finally…
I haven’t tried what you’re suggesting Stuart McDonald, but in some other context where I’m not too afraid of using static functions, I will give it a try !
Thanks for your answers guys.