The overriden handle() and draw() in Fl_Group *ARE* still virtual, even if there is no "virtual" specification in front of them (which can be omitted in this case) because the base class (Fl_Widget) has them virtual. This is C++ syntax stuff: once virtual, always virtual. It is little bit ugly (I would prefer if C++ would give you syntax error if you forget about it) but that is C++ specification says :-(
R. Jose Marcelo Auler wrote: >> I was trying to do my components based on the FLTK lib, but I figured out >> that the major of the components don't have virtual methods, so there is not >> way to do a secure inheritance. If, for instance, I specialize Fl_Widget to >> intercept some events by overriding int handle(int) method, and the user >> somehow calls the method by using a pointer to the basic class(Fl-Widget), I >> will have a not desired behavior. Is there a reason to have the classes this >> way(call speed?) and how the people are doing to specialize these >> classes(besides rewriting the fltk code, that I don't think is a good idea >> for maintenance)? >> Thanks, >> J.Marcelo Auler > Sorry this wasn't a good example, actually the component I'm having trouble > is Fl_Group, Fl_Widget has virtual methods for draw and handle. The only > virtual method Fl_Group has is the destructor. > _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
