public class Main extends Application {

@Override
public void start(Stage primaryStage) throws Exception{
    Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
    primaryStage.setTitle("Hello World");
    primaryStage.setScene(new Scene(root));
    primaryStage.show();
}


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

public class Controller {

@FXML
Rectangle tube = new Rectangle();


public void onClick() throws InterruptedException {
    int x = 0;
    while(x < 100){
        Double a = tube.getX();
        Double b = tube.getY();
        tube.setX(a-5);
        x++;
        Thread.sleep(10);
    }

}


}