protected AbstractListView() : base()
        {
            // Init Window and references
            this.SetPolicy(Gtk.PolicyType.Automatic, Gtk.PolicyType.Never);
            dbAdapter        = DatabaseAdapter.GetInstance();
            editFrameAdapter = EditFrameAdapter.GetInstance();
            tabView          = new Gtk.Notebook();
            // template init methods
            PopulateTabView();
            AddWithViewport(tabView);

            // Set TabHead Behavior: only active tab has a visible button
            tabView.SwitchPage += delegate
            {
                int i = 0;
                foreach (var head in tabList)
                {
                    if (i == tabView.CurrentPage)
                    {
                        head.button.Show();
                    }
                    else
                    {
                        head.button.Hide();
                    }
                    i++;
                }
            };
        }
        public ProgrammChooserTBItem() : base()
        {
            dbAdapter   = DatabaseAdapter.GetInstance();
            listAdapter = ListFrameAdapter.GetInstance();
            editAdapter = EditFrameAdapter.GetInstance();

            cbVeranstaltung = new ComboBox();
            cbInstanz       = new ComboBox();

            PrepareComboBoxes();

            this.PackStart(cbVeranstaltung, false, true, 0);
            this.PackStart(cbInstanz, false, true, 0);
        }