anchor.diff:      function GetTop: Integer;
       function GetHeight: Integer;
       function GetWidth: Integer;
  +
  +    //Let the control know that it was clicked to do its internal magic
  +    procedure DoClick(X,Y: Integer; Shift: TShiftState; Button: TMouseButton); virtual;
   
       function GetVisible: Boolean;
       procedure SetAbsLeft(aValue: Integer);
  
positive.code:     procedure ControlMouseDown(Sender: TObject; Shift: TShiftState); virtual;
      procedure ControlMouseUp(Sender: TObject; Shift: TShiftState); virtual;
      procedure FocusChanged(aFocused: Boolean); virtual;
      //Let the control know that it was clicked to do its internal magic
      procedure DoClick(X,Y: Integer; Shift: TShiftState; Button: TMouseButton); virtual;
    public
      Hitable: Boolean; //Can this control be hit with the cursor?
      Focusable: Boolean; //Can this control have focus (e.g. TKMEdit sets this true)
  
negative.code: procedure TKMListHeader.DoClick(X,Y: Integer; Shift: TShiftState; Button: TMouseButton);
  var ColumnID: Integer;
  begin
    //do not invoke inherited here, to fully override parent DoClick method
    ColumnID := GetColumnIndex(X);
    if (ColumnID <> -1) and Assigned(OnColumnClick) then
    begin
  