Re: Justifying the GTK+ 3.0 ABI break

["Havoc Pennington" <hp pobox com>]

Hi,

On Mon, Jul 14, 2008 at 11:37 AM, Johan Dahlin <jdahlin async com br> wrote:
>
> Why should the life of a GTK+ developer hard per definition?
>
> The main reason is exactly to make it easier for existing and new developers
> to contribute to GTK+, the rest are only secondary.

Is lack of sealed objects really what's using up most of the
maintainers time? I would be more sold on that if Matthias, etc.
posted and said this was using up their time. I have never heard them
say that. I don't know where their time goes, but when I was working
on gtk, this was definitely not it.

To me the point should be and hopefully is to enable new features and
enhancements. Though like Murray, I'm skeptical that sealed objects
really do that. There's more to ABI than struct fields; the hardest
part is keeping _semantics_ backward compatible. You can kill the
foo::label field but people can still rely on foo_get_child()
returning a label, for example.

I don't think any fundamental semantic changes - whether making GDK
less X11-like, or moving to a scene graph, or nuking child GdkWindow,
or fixing GtkStyle to be less crap, would be enabled by sealing object
fields. I agree (I think) with Murray on that. So by sealing first
instead of having those changes ready, we're postponing all those
semantic changes to GTK 4.0 (which is however long in future - 4-5
years I guess?), because they will be new ABI breaks not included in
3.0.

All this said, I'm glad someone is interested in GTK and some
decisions are being made.

Havoc