LuaWindow class

[xoft]

I think it'd be better to have a single cItemGrid represent the virtual window contents. We have quite a nice interface for that class, it knows how to do lots of things, so why duplicate the technology. I'd still keep the Window:SetSlot() and Window:GetSlot() functions, but other than that, you should do a Window:GetItemGrid() and perform more complex operations on it.

Now that we have the contents settled, how about those callbacks? Some example code?