anchor.diff:    
   type
   
  -  { TMainWindow }
  -
     TMainWindow = class(TfpgWindow)
     private
       procedure   MsgPaint(var msg: TfpgMessageRec); message FPGM_PAINT;
       procedure   MsgClose(var msg: TfpgMessageRec); message FPGM_CLOSE;
       procedure   MsgResize(var msg: TfpgMessageRec); message FPGM_RESIZE;
  -  protected
  -    procedure   HandlePaint; virtual;
     public
       constructor Create(AOwner: TComponent); override;
       procedure   Show;
     end;
     
  -
  -procedure TMainWindow.HandlePaint;
  -begin
  -end;
   
   constructor TMainWindow.Create(AOwner: TComponent);
   begin
  
positive.code:   Classes
    ,fpGFX
    ,GFXBase
    ,gfx_widget
    ,gui_form
    ;
  
  const
  
negative.code:   r: TfpgRect;
    i: Integer;
  begin
    Canvas.BeginDraw;  // begin double buffering
  
    Color     := 0;
    r.Left    := 0;
  