anchor.diff:        ATabCloseBorder, ATabCloseXMark: TColor);
       procedure DoPaintDropMark(C: TCanvas);
       procedure DoPaintScrollMark(C: TCanvas);
  -    procedure DoScrollAnimation(APosTo: integer);
       function GetIndexOfButton(AData: TATTabButtons; ABtn: TATTabButton): integer;
       function GetInitialVerticalIndent: integer;
  +    function GetButtonsEmpty: boolean;
       function IsScrollMarkNeeded: boolean;
       function GetMaxEdgePos: integer;
       function GetMaxScrollPos: integer;
  
positive.code:   RL, RR: TRect;
  begin
    if FOptPosition in [atpLeft, atpRight] then
      if FOptButtonLayout<>'' then
      begin
        RL:= GetRectOfButtonIndex(0, true);
        RR:= GetRectOfButtonIndex(0, false);
  
negative.code:     procedure MoveTab(AFrom, ATo: integer; AActivateThen: boolean);
      procedure DoScrollLeft;
      procedure DoScrollRight;
      procedure DoScrollAnimation(APosTo: integer);
  
    protected
      procedure Paint; override;
  