Connecting two Choice Boxes or Combo Boxes

Question

Is there a way to connect two Choice boxes or Combo boxes. It doesn't really matter which. I want to change the items in box two(Integers), depending on what's been chosen on box one(Strings).

ex:
Box one:
cupcakes
cookies

Box two:
if cupcakes, then the numbers 1,2,3, .... ,28,29,30.
if cookies, then the numbers 1,2,3, .... ,27,28.
else empty box.

The numbers can be put in through an array. What I have a problem with is how to use the event handler to change whats in the second box.

Answer 1

There can be different approaches depending on your requirements. One can be:

@Override
public void start( Stage stage )
{

    final Map<String, ObservableList<Integer>> map = new HashMap<>();
    map.put( "cupcakes", FXCollections.observableArrayList( 1,2,3,4,5,6));
    map.put( "cookies",  FXCollections.observableArrayList(11,12,13,14,15,16));

    final ComboBox<String> comboOne = new ComboBox<>();
    comboOne.getItems().addAll(
            "cupcakes",
            "cookies",
            "empty box"
    );
    final ComboBox<Integer> comboTwo = new ComboBox<>();

    comboOne.getSelectionModel().selectedItemProperty().addListener( new ChangeListener<String>()
    {
        @Override
        public void changed( ObservableValue<? extends String> observable, String oldValue, String newValue )
        {
            comboTwo.setItems( 
                    map.containsKey( newValue ) ? map.get( newValue ) : FXCollections.emptyObservableList()
            );
        }
    } );

    VBox grid = new VBox( 20 );
    grid.getChildren().addAll( comboOne, comboTwo );

    Scene scene = new Scene( grid, 450, 250 );
    stage.setScene( scene );
    stage.show();
}