[gtkada] Signal handler

[Dmitry A. Kazakov]

On Fri, 10 Jun 2011 16:01:19 +0200, you wrote:

> In package Gtk.Entry_Completion:
>    --  - "match_selected"
>    --    procedure Handler
>    --       (Completion : access Gtk_Entry_Completion_Record'Class;
>    --        Model      : Gtk_Tree_Model;
>    --        Iter       : Gtk_Tree_Iter);
>    --    Gets emitted when a match from the list is selected. The default
>    --    behaviour is to replace the contents of the entry with the contents of
>    --    the text column in the row pointed to by Iter.
>    --    Return value: %TRUE if the signal has been handled
> 
> How can I instantiate a package from Gtk.Handlers to connect this handler?

You instantiate Gtk.Handlers.User_Callback or Gtk.Handlers.Callback as
usual. Then you declare handler as follows:

procedure Entry_Completion_Handler
          (  Object  : access Gtk_Entry_Completion_Record'Class;
             Params  : GValues
          );         
            
Within the handler you access parameters as follows:

procedure Entry_Completion_Handler
          (  Object  : access Gtk_Entry_Completion_Record'Class;
             Params  : GValues
          )  is
   Iter : Gtk_Tree_Iter;
begin
   Get_Tree_Iter (Nth (Params, 1), Iter);

See Gtk.Tree_Model.Get_Tree_Iter. Getting the model is a bit more
complicated, but models are normally accessible implicitly through other
ways. If you still want to get it from GValue use GLib.Values.Get_Object on
Nth (Params, 0).

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