FastColoredTextBoxNS.AutocompleteListView.OnSelecting C# (CSharp) Method

        internal virtual void OnSelecting()
        {
            if (FocussedItemIndex < 0 || FocussedItemIndex >= visibleItems.Count)
                return;
            tb.TextSource.Manager.BeginAutoUndoCommands();
            try
            {
                AutocompleteItem item = FocussedItem;
                SelectingEventArgs args = new SelectingEventArgs
                {
                    Item = item,
                    SelectedIndex = FocussedItemIndex
                };

                Menu.OnSelecting(args);

                if (args.Cancel)
                {
                    FocussedItemIndex = args.SelectedIndex;
                    Invalidate();
                    return;
                }

                if (!args.Handled)
                {
                    var fragment = Menu.Fragment;
                    DoAutocomplete(item, fragment);
                }

                Menu.Close();
                //
                SelectedEventArgs args2 = new SelectedEventArgs
                {
                    Item = item,
                    Tb = Menu.Fragment.tb
                };
                item.OnSelected(Menu, args2);
                Menu.OnSelected(args2);
            }
            finally
            {
                tb.TextSource.Manager.EndAutoUndoCommands();
            }
        }

 public virtual void OnSelecting()
 {
     listView.OnSelecting();
 }