Re: Ada Library, called, returns and continues ?

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

On Tue, 18 Dec 2012 08:14:20 -0800 (PST), Patrick wrote:

> Yes we can make meta widgets in Ada-GTK but adding a lower level widget
> would likely involve C with Ada-GTK.

Not at all. C is not required for adding new widgets. You can create
composite widgets and, surprise, you can add new Ada proxies
(Gtk_XXX_Record types) to Gtk widgets missing in GtkAda without writing a
single line in C. For example, GtkAda contributions, which purpose is
largely mainly just this, does not have *any* C code.

> If all the widgets were coded in Ada
> and the primitives in the C/C++ core were nicely wrapped and isolated,
> then a new programmer could just learn Ada and not have to worry about
> C/C++.

Well, certainly it would be very nice to have 100% Ada cross-system
graphical framework. The problem is that Ada community is far too small to
accomplish such a Mammut task. Furthermore, there is no chance a firm would
develop it as commercial product. Because you cannot make any money selling
general-purpose libraries. This market was ruined decades ago.

> Again I have very limited experience with threading but I am
> guessing that if certain widgets were also protected, it would make
> writing a multi-threading GUI APP much nicer.

It is rather a long story. In short yes, Ada's tasking primitives could
help making GUI interfaces simpler. But there are many problems to solve,
like that task and protected types are not tagged, lack of multiple
inheritance to name few.

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