Draw a polygon in javafx

I'm trying to draw a polygon in javafx adding to its array of point the mouse coordinates. My problem is that I don't know how to make it stop when I click something else from the mouse left click.

Polygon polygon = new Polygon();
rootPane.setOnMouseClicked((MouseEvent mouseEvent) -> {
    do {
        polygon.getPoints().addAll(mouseEvent.getX(),mouseEvent.getY());
    } while(mouseEvent.getButton().equals(mouseEvent.isSecondaryButtonDown()));    
});
rootPane.getChildren().add(polygon);