[gtkada] End of life for gtk+extra and GTK+2

[Ludovic Brenta]

Hello, world.

As you all know, development of GTK+ 3.0 is in progress with a target release
date around March 2010.  GTK+ 3.0 will remove some functions that are
presently deprecated in GTK+ 2.16.  GtkAda uses gtk+extra2 (in src/gtkextra),
which is dead upstream and uses these deprecated symbols heavily.

I would like to give you an advance warning that Debian plans to drop GTK+ 2
and gtk+extra at some point in the future after GTK+ 3.0 is introduced.  My
estimate is that this removal might happen in June 2010.  When gtk+extra and
GTK+ 2 are removed from Debian, it will no longer be possible to build GtkAda,
or to run GtkAda applications on Debian; this applies both to Debian's
packages and to the GPS in GNAT GPL Edition, since it is linked dynamically
against GTK+ 2.

It is time to walk, not run, to the exit.

I can think of several possible solutions:
- adopt maintainership of gtk+extra2 and port it to to GTK+ 3.  This is a
major
undertaking according to the current Debian maintainer of gtk+extra2.
- reimplement the GtkAda widgets that currently depend on gtk+extra2 with
equivalent widgets from GTK+ 3 and drop gtk+extra2.  This reimplementation
could be done in Ada, too :)
- Drop the GtkAda widgets that depend on gtk+extra2 altogether.  I do not
think
this is desirable, especially if paying customers rely on those widgets.

Note that neither of the first two solutions depend on GTK+ 3 being released.
It is possible to do the porting early (i.e. right now) by using GTK+ 2.16 and
making sure not
to use any of the deprecated symbols; GTK+ 2.16 provides C preprocessor
defines that detect and warn against uses of deprecated symbols.  GTK+ 2.16
guarantees upward compatibility with 3.0 provided no deprecated symbols are
used.

I do not know which of the three solutions is more realistic.  I suggest you
guys do an assessment and tell me what you decide.

For more information, please see the recent thread on debian-devel starting
at:

http://lists.debian.org/debian-devel/2009/06/msg00884.html

This issue is not specific to Debian. I anticipate that community
distributions
(Fedora, Gentoo, etc.) will drop GTK+ 2 first, followed by the other
"long-term support" distributions (Red Hat, SuSE, FreeBSD, etc).

-- 
Ludovic Brenta.