Изменение позиций элементов ListBox с помощью Drag and Drop 3

...
private
  { Private declarations }
  GoingUp: Boolean;

procedure TForm1.ListBox1DragOver(Sender, Source: TObject;
  X, Y: Integer; State: TDragState; var Accept: Boolean);
begin
  Accept := (Sender = Source) and
    (TListBox(Sender).ItemAtPos(Point(X, Y), False) >= 0);
  {устанавливаем таймер для автопрокрутки}
  if Accept then
    with Sender as TListBox do
      if Y > Height - ItemHeight then
      begin
        GoingUp := False;
        Timer1.Enabled := True;
      end
      else if Y > ItemHeight then
      begin
        GoingUp := True;
        Timer1.Enabled := True;
      end
      else
        Timer1.Enabled := False;
end;

procedure TForm1.ListBox1DragDrop(Sender, Source: TObject;
  X, Y: Integer);
var
  NuPos: Integer;
begin
  with Sender as TListBox do
  begin
    NuPos := ItemAtPos(Point(X, Y), False);
    if NuPos >= Items.Count then
      Dec(NuPos);
    Label1.Caption := Format('Перемещено из %d в %d',
      [ItemIndex, NuPos]);
    Items.Move(ItemIndex, NuPos);
    {выделяем перемещенный элемент}
    ItemIndex := NuPos;
  end;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  with ListBox1 do
    if GoingUp then
      if TopIndex > 0 then
        TopIndex := TopIndex - 1
      else
        Timer1.Enabled := False
    else if TopIndex < Items.Count - 1 then
      TopIndex := TopIndex + 1
    else
      Timer1.Enabled := False;
end;

procedure TForm1.ListBox1EndDrag(Sender, Target: TObject;
  X, Y: Integer);
begin
  Timer1.Enabled := False;
end;