JavaFX Moving Window positio example

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class MovingWindowEx extends Application {

    int x = 0;
    int y = 0;
    Label lblx;
    Label lbly;
   
    @Override
    public void start(Stage stage) {

        initUI(stage);
    }

    private void initUI(Stage stage) {

        VBox root = new VBox(10);
        root.setPadding(new Insets(10));
       
        String txt1 = String.format("x: %d", x);
        lblx = new Label(txt1);
       
        String txt2 = String.format("y: %d", y);
        lbly = new Label(txt2);       
       
        root.getChildren().addAll(lblx, lbly);
       
        stage.xProperty().addListener(new ChangeListener<Number>() {

            @Override
            public void changed(ObservableValue<? extends Number> observable,
                    Number oldValue, Number newValue) {
               
                doChange(newValue);
            }
           
            private void doChange(Number newValue) {
               
                x = newValue.intValue();
                updateXLabel();               
            }
           
        });
       
        stage.yProperty().addListener(new ChangeListener<Number>() {

            @Override
            public void changed(ObservableValue<? extends Number> observable,
                    Number oldValue, Number newValue) {
               
                doChange(newValue);
            }
           
            private void doChange(Number newValue) {
               
                y = newValue.intValue();
                updateYLabel();               
            }
           
        });       

        Scene scene = new Scene(root, 300, 250);

        stage.setTitle("Moving window");
        stage.setScene(scene);
        stage.show();
    }
   
    private void updateXLabel() {
       
        String txt = String.format("x: %d", x);
        lblx.setText(txt);
    }
   
    private void updateYLabel() {
       
        String txt = String.format("y: %d", y);
        lbly.setText(txt);       
    }

    public static void main(String[] args) {
        launch(args);
    }
}