public void setActionBar(NonterminalActionBar tabIn)
        {
            Unregister();

            NontAb = tabIn;

            NontAb.ControlEvent += new NonterminalActionBar.ControlEventHandler(NonterminalControlEvent);
        }
        void setActionBar(object sender, GrammarEventArgs e)
        {
            if (sender is Terminal)
            {
                TerminalActionBar tab = new TerminalActionBar(sender as Terminal);
                actionBarHolder.Content = tab;
                controller.setActionBar(tab);
            }

            if (sender is NonterminalCollapsed)
            {
                NonterminalActionBar tab = new NonterminalActionBar(sender as NonterminalCollapsed);
                actionBarHolder.Content = tab;
                controller.setActionBar(tab);
            }

            if (sender is NonterminalExpanded)
            {
                NonterminalActionBar tab = new NonterminalActionBar(sender as NonterminalExpanded);
                actionBarHolder.Content = tab;
                controller.setActionBar(tab);
            }
        }