FastColoredTextBoxNS.AutocompleteListView.ProcessKey C# (CSharp) Method

        private bool ProcessKey(Keys keyData, Keys keyModifiers)
        {
            if (keyModifiers == Keys.None)
                switch (keyData)
                {
                    case Keys.Down:
                        SelectNext(+1);
                        return true;

                    case Keys.PageDown:
                        SelectNext(+10);
                        return true;

                    case Keys.Up:
                        SelectNext(-1);
                        return true;

                    case Keys.PageUp:
                        SelectNext(-10);
                        return true;

                    case Keys.Enter:
                        OnSelecting();
                        return true;

                    case Keys.Tab:
                        if (!AllowTabKey)
                            break;
                        OnSelecting();
                        return true;

                    case Keys.Escape:
                        Menu.Close();
                        return true;
                }

            return false;
        }