Printing with Gtk runs but produces only empty pages

Printing with Gtk runs but produces only empty pages

[ldries46]

I am trying to crate a Gtk print procedure,
 From the point I start creating Print_Op and Print_Set the code I use is:

          Print_Op := new Gtkada_Print_Operation_Record;
          Gtkada.Printing.Initialize (Print_Op);
          Gtk_New(Print_Set);
          Set_Current_Page (Print_Op, 1);
          Number := long_float(last_line) / long_float(delta_lines);
          Number := long_float'Ceiling(Number);
          nr_Pages := Gint(Number);
          Set_N_Pages (Print_Op, nr_Pages + 1);

I just put a breakpoint at the line after Set_N_Pages. I also found the 
following parameters. If I delete the + 1 in the last line get message 
that possily point to adres 0*0

nr                 100
delta_lines    56
last_line         14
nr_Pages          1

On the Debugging Console I got the following messages:

(gdb) show lang
&"show lang\n"
~"The current source language is \"auto; currently ada\".\n"
^done
(gdb)
ptype &Print_Op
&"ptype &Print_Op\n"
~"type = access access new 
gtk.print_operation.gtk_print_operation_record with record null; end 
record\n"
^done
(gdb)
-data-evaluate-expression "Print_Op"
^done,value="0xf8eb730"
(gdb)
(

The folowing code is:

          Set_Use_Full_Page(Print_Op, true);
          Set_Unit (Print_Op, points);
          Print_Op.Set_Print_Settings(Print_Set);
          On_Draw_Page(Print_Op, Draw);
          Result := Connect_and_Run(Print_Op ,Action_Print_Dialog, 
Main_Window);

The overall result is that the program does not show a failure but also 
does not print any thing except an empty page.
As I try to debug something not all parameters displayed in the 
variables window when I am running the debugger.

Can anyone tell me wher to find a working example?

Re: Printing with Gtk runs but produces only empty pages

[ldries46]

Op 24-1-2023 om 17:01 schreef ldries46:
> I am trying to crate a Gtk print procedure,
> From the point I start creating Print_Op and Print_Set the code I use is:
>
>          Print_Op := new Gtkada_Print_Operation_Record;
>          Gtkada.Printing.Initialize (Print_Op);
>          Gtk_New(Print_Set);
>          Set_Current_Page (Print_Op, 1);
>          Number := long_float(last_line) / long_float(delta_lines);
>          Number := long_float'Ceiling(Number);
>          nr_Pages := Gint(Number);
>          Set_N_Pages (Print_Op, nr_Pages + 1);
>
> I just put a breakpoint at the line after Set_N_Pages. I also found 
> the following parameters. If I delete the + 1 in the last line get 
> message that possily point to adres 0*0
>
> nr                 100
> delta_lines    56
> last_line         14
> nr_Pages          1
>
> On the Debugging Console I got the following messages:
>
> (gdb) show lang
> &"show lang\n"
> ~"The current source language is \"auto; currently ada\".\n"
> ^done
> (gdb)
> ptype &Print_Op
> &"ptype &Print_Op\n"
> ~"type = access access new 
> gtk.print_operation.gtk_print_operation_record with record null; end 
> record\n"
> ^done
> (gdb)
> -data-evaluate-expression "Print_Op"
> ^done,value="0xf8eb730"
> (gdb)
> (
>
> The folowing code is:
>
>          Set_Use_Full_Page(Print_Op, true);
>          Set_Unit (Print_Op, points);
>          Print_Op.Set_Print_Settings(Print_Set);
>          On_Draw_Page(Print_Op, Draw);
>          Result := Connect_and_Run(Print_Op ,Action_Print_Dialog, 
> Main_Window);
>
> The overall result is that the program does not show a failure but 
> also does not print any thing except an empty page.
> As I try to debug something not all parameters displayed in the 
> variables window when I am running the debugger.
>
> Can anyone tell me wher to find a working example?
>
The problem is solved by rearranging the program and because the 
debugger in GNAT 23.0W works not correctl. Only one problem has not been 
solved see a new question