anchor.diff:      //e.g. scrollbar on a listbox
       procedure SetHeight(aValue: Integer); override;
       procedure SetWidth(aValue: Integer); override;
  +
  +    function GetDrawRect: TKMRect; override;
       procedure ControlMouseMove(Sender: TObject; X, Y: Integer; Shift: TShiftState); override;
       procedure ControlMouseDown(Sender: TObject; Shift: TShiftState); override;
       procedure ControlMouseUp(Sender: TObject; Shift: TShiftState); override;
  
positive.code:     procedure SetTop(aValue: Integer); override;
      procedure SetHeight(aValue: Integer); override;
      procedure SetWidth(aValue: Integer); override;
    public
      constructor Create(aParent: TKMPanel; aLeft, aTop, aWidth, aHeight: Integer; aScrollAxisSet: TKMScrollAxisSet;
                         aStyle: TKMButtonStyle; aScrollStyle: TKMScrollStyle);
  
negative.code: begin
    Result := (Hitable or aIncludeNotHitable)
              and (fEnabled or aIncludeDisabled)
              and KMInRect(KMPoint(X,Y), GetDrawRect);
  end;
  
  
  