[gtkada] Problem with drawing

[Michael Gonzalez]

Emmanuel:

> One more thing you might want to try:
> 
> Try writting the loop somewhat like:
> 
>    declare
>       Event : Gdk_Event;
>    begin
>       while Events_Pending loop
>           Gdk.Event.Get (Event);
>           if Event /= null then
>               Do_Event (Event);
>           end if;
>       end loop;
>    end;
> 
> It might help.

This made things worse because now the window blocks and is not drawn.
However, it gave me some clues. I found that the infinite sequence of
events is made of null events. These null events are somehow processed
by Main_Iteration or Main_Loop and that causes the window to be drawn.

I then tried using Peek(Event) to read the events without processing
them and I found a workaround. If I get a few consecutive null events I
exit the loop. It is something like:

      last_null : integer:=0;
      ...
      while Gtk.Main.Events_Pending loop
         Gdk.Event.Peek(Event);
         if event/= null then
            last_null:=0;
         else
            last_null:=last_null+1;
         end if;
         Dead := Gtk.Main.Main_Iteration(False);
         exit when last_null>5;
      end loop;

This workaround seems to work fine. I still don't understand the reason
for the infinite sequence of null events in windows (but not in linux).

Thanks for your help.

Best regards,

Michael.
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Michael Gonzalez Harbour                      E-mail: mgh at unican.es
Dpto. de Electronica y Computadores
Universidad de Cantabria                      Phone : +34-942-201483
Avda. de los Castros s/n
E-39005 Santander                             Fax   : +34-942-201402
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