Problems with Glade 3, and Ada drawing

["ldries46" <bertus.dries@planet.nl>]

I am trying to draw a grid on  Gtk_Drawing Area. I want that drawing to 
appear when then program starts before anything is done.
I can draw that grid  and see it but whenever the program redraws the window 
it disappears as a whole or in some cases partly. As various sources I found 
out that I have to act on the draw signal. As I build my GUI with Glade 3 I 
thought I could connect the drawing signal with:

Register_Handler
  (Builder      => Builder,
   Handler_Name => "On_Area_Draw", -- from XML file <signal handler=..>
   Handler      => Sudoku_Callbacks.On_Area_Draw'Access);

Where I coupled  "On_Area_Draw" in Glade with the draw signal in the 
Gtk_Drawing_Area. Although This was carried out case Sensitive the program 
aborted. The most likely reason therefor is that the handler procedure was:

procedure On_Area_Draw (Object : access Gtkada_Builder_Record'Class);

where it should have been

function On_Area_Draw (Object : access Gtkada_Builder_Record'Class; Context 
: Cairo.Cairo_Context) return boolean;

Using the last results in aborting the compilation.

The question now is how should I connect the draw signal to which 
function/procedure to get a correct working program?