Sorry if the following response is of no help to you:

Before thinking about how to implement it, you should rather think about the whole process.
I mean, how to you link a panel to that struct?
Panel collision can just be done by checking one panels position and size again other panels (or is there a new feature I'm unaware of?)
Now, how do you find out which struct to "use"?

<edit>
Another problem: afaik you cannot use "function pointers". Thus saving a link to a function in some property is not possible. But I might be wrong.
</edit>

I'm not quite sure if the way you want to go is the best way for this kind of problem.