Focus on next item in container

Question

Is there a way to programmatically focus on the next focusable node in a container without directly calling on a specific component's requestFocus() method? This functionality would be similar to pressing the tab button to traverse focus between components where disabled nodes are skipped.

Answer 1

There is no public method for this. Only hacks and workarounds.

You could use the node's

impl_traverse(Direction.NEXT);

method. But this one is deprecated and could be removed at any time and your code breaks with a new java version.

Alternatively you could catch the enter key and fire a tab key event. But that's equally ugly.

Or if you are in a textfield you could do it like this:

if( textfield.getSkin() instanceof BehaviorSkinBase) {
    ((BehaviorSkinBase) textfield.getSkin()).getBehavior().traverseNext();  
}

But that's also discouraged since it isn't api.

And even if you'd use reflection to access the scene's traverse method like this:

Method[] allMethods = scene.getClass().getDeclaredMethods();
for (Method m : allMethods) {
    String mname = m.getName();
    if (mname.startsWith("traverse")) {
        m.setAccessible(true);
        m.invoke(scene, new Object[] { textfield, Direction.NEXT });
    }
}

you'd end up with having to provide a Direction parameter which is also discouraged.

The best thing you can do is to comment and vote on this issue.

Answer 2

According to your use case, you may also filter and convert Enter keys to Tab on parent pane:

@Override
public void start( final Stage primaryStage )
{
    TextField field1 = new TextField();
    TextField field2 = new TextField();
    TextField field3 = new TextField();
    VBox vbox = new VBox( field1, field2, field3 );

    vbox.addEventFilter( KeyEvent.KEY_PRESSED, ( KeyEvent event ) ->
    {
        if ( event.getCode() == KeyCode.ENTER )
        {
            KeyEvent newEvent
                    = new KeyEvent(
                            null,
                            null,
                            KeyEvent.KEY_PRESSED,
                            "",
                            "\t",
                            KeyCode.TAB,
                            event.isShiftDown(),
                            event.isControlDown(),
                            event.isAltDown(),
                            event.isMetaDown()
                    );

            Event.fireEvent( event.getTarget(), newEvent );
            event.consume();
        }
    } );
    final Scene scene = new Scene( vbox, 800, 600 );
    primaryStage.setScene( scene );
    primaryStage.show();

}