Re: New 'GObject' as base for GtkObject?

[Bill Huey <billh burn ucsd edu>]

> OK, I'm lost here. Java, as far as I know allows no
> multiple-inheritance of implementation, while you are jumping through
> large hoops to achieve multiple inheritance of data and member
> functions.

Java has interface inheritence as a means of dealing with MI issues.

Wittness:

class ThreadInterface : Object
{
	void Run()
}

class DragNDropInterface : Object
{
	void dragMethodA();
	...
}

class TextFrame extends TextFrameParentClass		// inherits all sorts of from the parent object.
	implements DragNDropInterface, ThreadInterface	// include these interfaces and fill
							// in the object members.
{
	...
};

Knowning modern OO design *should* be important for the Gtk core folks
and not knowing that Java has a semi-form MI is a little peculiar to
say the least.

> I think what you mean by having only virtual inheritance, is that
> there is only one copy of each base class in the derived object, but I
> don't really see how this makes it Java-like.

> But my basic opinion is that while it is neat, it is certainly far too
> drastic a change to go into GTK+ in the near future ... it would
> require rewriting large amounts of code in a very non-gradual fashion.
 
That's correct. "Neat" for you is means "zero hack" and "proper design"
to me and others. From the looks of it (libgnome*) there's already some
rather bizzare maintenance issues with Gtk/GNOME already.

> Also, right now I have no particular interest in having full multiple
> inheritance of implementation within in GTK+, and I'm rather confident

MI is fairly important would normally indictate to me that folks the don't
know it's benifits haven't use a modern GUI in the 90's. That's just bad.

> that if all you want is multiple interfaces, then it is possible to
> design something that is simpler and faster then gos. (Note that that
> in the case where your object heirarchies are flat, the ->level
> optimization buys you nothing and you just get a fairly simple
> implementation of multiple interface lookup via a binary search in an
> array.)
 
Run time typing is powerful.

> Regards,
>                                         Owen

bill