[gtkada] Add_From_File with null for Error.

[Pascal]

Hello Emmanuel,

In one hand, if you don't care about null then you can pass directly the parameter Error to GTK+ function, as:
   function Add_From_File
      (Builder  : not null access Gtk_Builder_Record;
       Filename : UTF8_String;
       Error    : access Glib.Error.GError) return Guint
   is
      function Internal
         (Builder   : System.Address;
          Filename  : Interfaces.C.Strings.chars_ptr;
          Acc_Error : access Glib.Error.GError) return Guint;
      pragma Import (C, Internal, "gtk_builder_add_from_file");
      — Acc_Error    : aliased Glib.Error.GError;
      Tmp_Filename : Interfaces.C.Strings.chars_ptr := New_String (Filename);
      Tmp_Return   : Guint;
   begin
      Tmp_Return := Internal (Get_Object (Builder), Tmp_Filename, Error); — Acc_Error
      Free (Tmp_Filename);
      — Error.all := Acc_Error;
      return Tmp_Return;
   end Add_From_File;

In other hand, if you care about null you can add "not null" on the GTKAda parameter Error, as:
   function Add_From_File
      (Builder  : not null access Gtk_Builder_Record;
       Filename : UTF8_String;
       Error    : not null access Glib.Error.GError) return Guint

Regards, Pascal.
http://blady.pagesperso-orange.fr


Le 3 mars 2014 à 15:31, Emmanuel Briot <briot at adacore.com> a écrit :

>> As in C GTK programming, I put null for Error parameter thus I got:
>> Exception name: CONSTRAINT_ERROR
>> Message: gtk-builder.adb:149 access check failed
> 
> This is an error in gtk+ itself, or rather in the .gir file they export.
> Your patch is incorrect since it manually modified a file that is generated
> automatically.
> 
> I have put a workaround in GtkAda, but the recommendation is not to
> pass null for the error, you really should not be ignoring errors in the
> first place.
> 
> regards
> Emmanuel