[fpc-pascal] FPC and GTK2: signal handlers

[Jan Je/lowicki]

Hello all,

I am porting some pascal code from gtk 1.2 to 2.x using fpc 1.9.8.

Is there any difference between meaning of return values 
of signal callbacks in GTK+ 1.2 and 2.x?

I have troubles when I try to to GtkEntry a sevice, that would check 
whether some special key values were pressed, proceed specified 
action for them and next allow the default key-press handler to do 
its job:

    g_signal_connect(entry, 'key_press_event', @myhandler, nil);

where

    function myhandler(w: pGTKWidget; e: pGDKEvent; 
                       data: pointer):    boolean; cdecl;
    begin
      case e^.keyval of
      ....
      end;
      result := false;
    end;

In my opinion, returnig with FALSE should allow next callbacks 
connected to the same widget/event to be called; nevertheless they
are not called in my tests, including the default handler 
(gtk_combo_entry_key_press(), I guess).
Setting TRUE or FALSE as result of myhandler cannot change anything.

On the other side, when using g_signal_connect_after, the default 
handler stops the cascade on some key values, that are important 
for me (like Enter) -- although it allows user services on other keys.
It looks like the result value influenced spreading the signal.

I would like to run all the cascade of callbacks attached to single 
widget/event pairwhen I need, including default services. 
Is there any way to do it in GTK2 as easily as it was in GTK1.2?

With regards,


                                       Jan Jelowicki
                                       jasj at ozi.ar.wroc.pl
                         
-------------------------------------------------------------------
Wroclaw University of Agriculture    Akademia Rolnicza we Wroclawiu
Department of Mathematics            Katedra Matematyki
-------------------------------------------------------------------