Re: GtkAda callback and event

[DrPi <314@drpi.fr>]

Le 12/09/2021 à 10:52, Dmitry A. Kazakov a écrit :
> On 2021-09-12 09:08, AdaMagica wrote:
>> DrPi schrieb am Samstag, 11. September 2021 um 17:24:45 UTC+2:
>>> Even if I just started using GtkAda, I find it very powerful.
>>> The big problem is documentation. Of course, there are the reference
>>> manual and the (small) user guide but I miss a document explaining the
>>> use of all these functionalities.
>>
>> A good introduction into GtkAda is direly needed. Trial and error cost me
>> enormously much time.
>> The GtkAda UG and RM are a bad joke.
> 
> I think you rather mean GTK introduction because GtkAda follows GTK to 
> the letter. 
I don't fully agree with you.
I already found Gtk examples I've not been able to use directly with 
GtkAda because of Ada implementation. Or at least, it was not the best 
way to do things. Mostly due to the GtkAda OO implementation. Events and 
customized widgets are good examples.

I also loose big amount of time searching for how to do things.


There are few advanced topics of interplay between GtkAda
> objects and GObject etc, but that is not required in the beginning. 
> Basically, you know GTK, you know GtkAda.
> 
> Regarding GTK introduction, it would require a genius to write that. GTK 
> is incredibly messy and full of small details you must know before you 
> started. I have no idea how anybody could summarize that in a compact 
> form. There exist various GTK "getting started." All of them, while 
> describing important things, miss minor details essential to write an 
> actual application. There seems no such thing as overview in the case of 
> GTK.
>
They may be not perfect but they have the merit to exist.

I think the the tutorial I've found is a good one to start.
It starts from scratch which is not as easy as one could think it is : a 
basic application never ends. The main window closes but the exe never 
stops. Quite disturbing.
When you create a basic GtkAda project with GPS, you get an application 
with such a behavior. At first, I thought I did something wrong when 
installing GtkAda. I then found the tutorial and discovered this 
behavior is the correct one.


> And things are far worse for those who get lured by GLADE. GLADE further 
> obscures what is going on, what has to be done. Be happy you did not 
> step into that...
> 
I tried Glade once and quickly changed my mind. I don't say it's a bad 
tool. Just that, like you said, things are more obscure using it. As I 
like to understand what I do, this is not the way to go for me right now.
I did the same thing with WxPython. I learned to construct my GUI 
programmatically. Then, when I've been comfortable with it I switched to 
wxFormBuilder for some of my projects.



URL to the French tutorial I use : 
https://zestedesavoir.com/tutoriels/645/apprenez-a-programmer-avec-ada/555_ada-et-gtk-la-programmation-evenementielle/2676_gtkada-introduction-et-installation/

One problem with this tutorial is that it is outdated.