JavaFX - How to check if mouse is has entered and or exited a Pane?

Question

I have a pane in Javafx that a want to animate whenever the mouse has entered its boundaries and I want the animation to stop once the mouse has exited the pane. I understand this calls for a listener but all the answers I find only seem to concern java.awt

Answer 1

You can use the methods Node.setOnMouseEntered() and Node.setOnMouseExited() to register event handlers, which start or stop your animation. Here is a simple example:

public class MainTest extends Application {
    public void start(Stage primaryStage) {
        Pane pane = new Pane();
        pane.setStyle("-fx-background-color: #ff0000");
        pane.setLayoutX(100);
        pane.setLayoutY(100);
        pane.setPrefSize(300,300);
        pane.setOnMouseEntered(event -> startAnimation());
        pane.setOnMouseExited(event -> stopAnimation());

        Scene scene = new Scene(new Pane(pane), 500, 500);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private void stopAnimation() {
        System.out.println("stop");
        // do whatever you need to start your animation
    }

    private void startAnimation() {
        System.out.println("start");
        // do whatever you need to stop your animation
    }
}

Answer 2

Or you can make it with chain of *.fxml file and your controller class:

1. Add into your in fxml file into Pane string two events onMouseEntered="#onMouseInto" onMouseExited="#onMouseOut" to make it like

<AnchorPane fx:id="rootPane" onMouseEntered="#onMouseInto" onMouseExited="#onMouseOut" prefHeight="400.0" prefWidth="400.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="yourPackage.YourControllerClass">

2. Add method events into controller class. For example I will change background color of my pane, but you can do whatever you want for sure ;)

    @FXML
    public AnchorPane rootPane;

    public void onMouseInto(MouseEvent mouseEvent) {
        //Your own event when cursor is gonna into the rootPane
        rootPane.setStyle("-fx-background-color: #1F292E");
    }

    public void onMouseOut(MouseEvent mouseEvent) {
        //Your own event when cursor is gonna out the rootPane
        rootPane.setStyle("-fx-background-color: #C792EA");
    }