anchor.diff:  begin
     inherited HandleLMouseUp(x, y, shiftstate);
     FSliderDragging   := False;
  -  HandlePaint;
  +  RePaint;
   end;
   
   procedure TfpgTrackBar.HandleMouseMove(x, y: integer; btnstate: word; shiftstate: TShiftState);
  
positive.code:   if newp <> FPosition then
    begin
      Position := newp;
      if Assigned(FOnChange) then
        FOnChange(self, FPosition);
    end;
  
negative.code:   if FSliderPos > area then
      FSliderPos := area;
  
    if area <> FMin then
      newp := FMin + Trunc((FMax - FMin)  * (FSliderPos / area))
    else
  