JavaFX Rectangle drag and drop

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

public class Main extends Application {  
  @Override/*  w w  w  .j  a v a2 s . c  o  m*/
  public void start(Stage primaryStage) {     
    Pane pane = new Pane();
    Rectangle rectangle = new Rectangle(40, 40, 50, 60);
    rectangle.setFill(Color.WHITE);
    rectangle.setStroke(Color.BLACK);

    rectangle.setOnMouseDragged(e -> {
      if (rectangle.contains(e.getX(), e.getY())) {
        rectangle.setX(e.getX() - 50 / 2);
        rectangle.setY(e.getY() - 60 / 2);
      }
    });
    
    pane.getChildren().add(rectangle);
    

    Scene scene = new Scene(pane, 400, 250);
    primaryStage.setTitle("java2s.com");
    primaryStage.setScene(scene);
    primaryStage.show();
  }


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