[gtkada] Limit Storage Size of Gtk_Text

[Bade, Frank]

Hi !
On Friday 17 May 2002 10:40, you wrote:
> "Bade, Frank" <Frank.Bade at astrium-space.com> writes:
> > This window should display logging information in an application which
> > must be able to run several days without being stopped. Therefore, the
> > amount of data stored by the window should be limited to do not eat up
> > all the memory.
>
> Just remove from the beginning of the gtk_text when it gets too big.

I did it and it worked. But I had problems to correct the vertical 
adjustment. 

I coded the following statement to force the window to display the last 
message always:

         Freeze(Log_Window_Ptr.Scrolled_Text);

         -- limit the content of the window
         Loc_Limit_Stored_Text(Text     => Log_Window_Ptr.Scrolled_Text,
                               Max_Size => Max_Logged_Text_Size);

         Insert(Text  => Log_Window_Ptr.Scrolled_Text,
                Chars => Get_Time & "> " & Msg & Ascii.Lf);

         -- jump to the end of the scrolling area
         Set_Value(Adjustment => Get_Vadj(Log_Window_Ptr.Scrolled_Text),
                   Value      => 
Get_Upper(Get_Vadj(Log_Window_Ptr.Scrolled_Text)));

         Thaw(Log_Window_Ptr.Scrolled_Text);

Here is the above called procedure:

   procedure Loc_Limit_Stored_Text(Text     : in Gtk.Text.Gtk_Text;
                                   Max_Size : in Glib.Guint) is
      use Gtk.Text;
      use Glib;
       Loc_Old_Len   : constant Guint    := Get_Length(Text);
      Loc_Reduce_By : constant Guint    := Max_Size / 10;
   begin
 
      if Loc_Old_Len >= Max_Size then

         -- reduce it
         -- check the size and delete chars if necessary
         if Get_Length(Text) >= Max_Size then

            Set_Point(Text,0);

            if Forward_Delete(Text,Loc_Reduce_By) then

               -- set the insertion point to the end of the text
               Set_Point (Text  => Text,
                          Index => Get_Length(Text));

            else
               Loc_New_Err_Msg("Unable to Forward_Delete Text",true);
            end if; -- if Forward_Delete(Text,Loc_Reduce_By) then
         end if;

      end if; --  if Loc_Old_Len >= Max_Size then
  
   end Loc_Limit_Stored_Text;

The result is that it stops working with an exception after having written a 
few thousand messages:
Gtk-ERROR **: file gtktext.c: line 4712 (find_line_params): assertion failed: 
(lp.end.property)

I didn't want to bother you with those details that's why I asked for an 
example ....

Any ideas ??
	Frank
-- 
..........................  Astrium SI  ..............................
Frank Bade                                      Tel:   +49-421-5395648
Dep.: IO 62                                     Fax:   +49-421-5394378