@Override
public void handle(ActionEvent ae) {
Parent parent = SimpleCalendar.this.getParent();
// Popup will be shown at upper left corner of calenderbutton
Point2D point = calenderButton.localToScene(0, 0);
final double layoutX = parent.getScene().getWindow().getX() + parent.getScene().getX() + point.getX();
final double layoutY = parent.getScene().getWindow().getY() + parent.getScene().getY() + point.getY();
popup.show(SimpleCalendar.this, layoutX, layoutY);
}