Re: GtkAda / Ada Newbie Question

["J Cusick" <JoeSmoke@hotmail.com>]

On Wed, 12 Nov 2003 02:10:14 +0100, Ludovic Brenta wrote:

> "J Cusick" <Joe@Smoke.not> writes:
> 
>> I'm new to both Ada and GtkAda and have a question regarding my first
>> basic hello world program.
>> 
>> These are the lines in question:
>> 
>> procedure Simple is
>>    S_Window : Gtk.Window;
>>    S_Button : Gtk.Button;
>> 
>> and this is the error I get when attempting gnatmake:
>> 
>> simple.adb:8:18: subtype mark required in this context 
>> every place that S_Window or S_Button shows up.

...

>> I have absolutely no clue what this error is telling me. What is a
>> "subtype mark" and how do I supply one?

...
 
> Loosely speaking, a subtype mark is the name of a type or subtype.  If you
> need a formal definition of this or other terms, see the Ada Reference
> Manual but this is not for the faint of heart.  Here, you supplied the
> names of two packages instead of names of types or subtypes.  You should
> have said:
> 
> S_Window : Gtk.Window.Gtk_Window_Record; S_Button :
> Gtk.Button.Gtk_Button_Record;
> 
>> As I have mentioned, I'm just starting to climb the learning curve for
>> both Ada and GtkAda, so any help or pointers are greatly
>> appreciated.Thanks for any answers regarding this question.

...
 
> Here are a few hints:
> 
> 1) Use glade2 to build your user interface using a point-and-click
>    interface, then use gate2 to generate Ada code from the .glade file. 
>    Then, study how the generated Ada code works.  There are also several
>    examples that come with GtkAda, one of which is hello world.
> 
> 2) Go to http://libre.act-europe.fr/GtkAda and subscribe to the
>    mailing lists there.  Questions specific to GtkAda are best answered
>    there.
> 
> 3) Study the *.ads files provided with GtkAda.  They include a wealth
>    of documentation in comments.  For example, the file "gtk-window.ads"
>    contains the specification for the package Gtk.Window.
> 
> HTH

Ludovic,

Thanks for the excellent pointers. This helps a great deal.
The ADA Ref. Man. is indeed not for the feint of heart :-),
I tried there first.

However, the other pointers are a good start for me.

Regards, and thanks again...

John C.