@Override
    public void navigate(NavigationEvent event) {
        String command = event.getDestination();
        
        if(command == "Novo"){
            formState = FormState.CREATING;
            abrirFormulario(null);
        }
        else if(command == "Editar"){
            formState = FormState.UPDATING;
            abrirFormulario(event.getArg("Item"));
        }
        else if (command == "Excluir"){
            executarCommand(Operation.EXCLUIR, event.getArg("Item"));
            
        }
        else{//error!
            System.err.println("Comando " + command + " não identificado!");
        }
    }