Key Listener in JavaFX that changes on button press

Question

My controller class has a moveButton method that on button click moves the button to a new location. This works fine and is called by a number of buttons which do the same thing. I want to add a key listener so when a button has been clicked once, until a different button is clicked, the user can use the up arrow to move the button (ie call the same moveButton function). The below is how I have tried to implement it, I also tried putting the key listener in the initialize method but neither seem to be working. Any advice would be greatly appreciated!

public void moveButton(ActionEvent actionEvent) {
    Button buttonPressed = (Button) actionEvent.getSource();
    double newAnchor = getNewAnchor(AnchorPane.getBottomAnchor(buttonPressed)) // separate method that returns new anchor location
    AnchorPane.setBottomAnchor(buttonPressed, newAnchor);

    buttonPressed.getScene().setOnKeyPressed(new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent event) {
                if(event.getCode() == KeyCode.UP){
                    moveButton(actionEvent);
                }
            }
     });
}

Answer 1

Don't treat the events like data that you need to pass around. Use them as triggers to do work. Generally, don't write generic event handlers that are called from multiple events and multiple nodes. Write short event handlers that just call methods to do something, and pass them the minimum from the event that they need to do the job.

If you do this, then it changes your thinking about how all of this stuff works and then it's just plain old Java, with no magic. And it's simple:

public class MoveButton extends Application {

    private Node activeButton;
    private Pane pane;

    @Override
    public void start(Stage primaryStage) throws Exception {
        pane = new Pane();
        Scene scene = new Scene(pane, 1200, 800);
        primaryStage.setScene(scene);
        primaryStage.show();
        Button button1 = new Button("Button 1");
        Button button2 = new Button("Button 2");
        button2.setTranslateX(80);
        button1.setOnAction(evt -> buttonClick(button1));
        button2.setOnAction(evt -> buttonClick(button2));
        pane.getChildren().addAll(button1, button2);
        pane.setOnKeyPressed(evt -> moveButton(evt.getCode()));
    }

    private void moveButton(KeyCode keyCode) {
        switch (keyCode) {
            case UP -> activeButton.setTranslateY(activeButton.getTranslateY() - 30);
            case RIGHT -> activeButton.setTranslateX(activeButton.getTranslateX() + 30);
            case DOWN -> activeButton.setTranslateY(activeButton.getTranslateY() + 30);
            case LEFT -> activeButton.setTranslateX(activeButton.getTranslateX() - 30);
        }
    }

    private void buttonClick(Node button) {
        activeButton = button;
        pane.requestFocus();
    }
}