Re: New Ada portable GUI Library?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Sat, 12 Jan 2008 15:01:43 -0800 (PST), Lucretia wrote:

> Like I said, a thin C layer abstraction which is then imported into an
> Ada library and turned into a proper Ada GUI with native controls,
> this is the best way. For example:
> 
>  Ada GUI Thick bindings
> ------------------------
>  Ada GUI Thin bindings
> ------------------------
>   C abstraction layer   <- Can be provided via C or Ada depending on
> lowest layer
> ------------------------
>    X11 | GtkAda | QT
> 
> I know three is an X11 binding to Ada but it is old and uses
> preprocessing and if you want this library to be portable, you've no
> hope where that's concerned. Hence the use of a set of C calls whether
> these are written in C or Ada (with export(C, ...) pragmas).

Gtk and Qt are themselves thick bindings. It makes no sense to use them as
a low-level rendering platform. An all-Ada GUI design should IMO look like:

Ada GUI library
----------------------------------------
Ada rendering platform abstraction layer
           |
   Ada   | Ada native bindings, engine-specific
-------- | -----------------------------
   X11   | Win32 GUI API

The major problem is a good abstraction layer with a working concept of
inter-tasking signal handler composition. This is a weakness of most known
Ada GUI libraries.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de