/// <summary>
        /// Selection up.
        /// </summary>
        private void SelectionUp()
        {
            int row = HelperListView.SelectedRow - 1;

            if (ActiveList.ContainsKey(row))
            {
                HelperListView.SelectRow(row);

                if (HelperListView.VerticalScrollControl.Value - HelperListView.VerticalScrollControl.StepIncrement >= 0)
                {
                    HelperListView.VerticalScrollControl.Value -= HelperListView.VerticalScrollControl.StepIncrement;
                }
            }
        }
        /// <summary>
        /// Selection down.
        /// </summary>
        private void SelectionDown()
        {
            int row = HelperListView.SelectedRow + 1;

            if (ActiveList.ContainsKey(row))
            {
                HelperListView.SelectRow(row);

                if (HelperListView.VerticalScrollControl.Value + HelperListView.VerticalScrollControl.StepIncrement <
                    HelperListView.VerticalScrollControl.UpperValue)
                {
                    HelperListView.VerticalScrollControl.Value += HelperListView.VerticalScrollControl.StepIncrement;
                }
            }
        }
        /// <summary>
        /// Set items to data store.
        /// </summary>
        private void SetItems(List <String> items)
        {
            ActiveList = new Dictionary <int, String>();
            HelperListView.UnselectAll();
            HelperStore.Clear();
            foreach (var s in items)
            {
                int row = HelperStore.AddRow();
                HelperStore.SetValue(row, Values, s);
                ActiveList.Add(row, s);
            }


            if (items.Count > 0)
            {
                HelperListView.SelectRow(0);
            }
        }