JavaFX 8: change colour of a specific circle with his own id - javafx

Question

I ve created this program that when you click on "create" button other two ButtonBar (called newNode) are created.. inside this Button bar there are a button and a circle. When all is created I would like to change the colour of these two circle when i click another Button. I ve coded something but I can just change the colour of the LAST circle.
public class Controller implements Initializable{
#FXML
private Button btnHaveFun;
#FXML
private ButtonBar ReadSMSBar;
#FXML
private ButtonBar GalleryBar;
#FXML
private ButtonBar FileExplorerBar;
#FXML
private ButtonBar SpyCamBar;
#FXML
private ButtonBar TakeAPictureBar;
#FXML
private ButtonBar TakeAScreenshotBar;
#FXML
private ButtonBar RecordAVideoBar;
#FXML
private ButtonBar SpyWhatsappBar;
#FXML
private ButtonBar KeyLoggerBar;
#FXML
private ButtonBar ScreenStreamBar;
#FXML
private ButtonBar SpyMicrophoneBar;
#FXML
private ButtonBar slaveBar;
#FXML
private VBox slaveVbox;
#FXML
private Circle statusSlave;
private ButtonBar newNode = new ButtonBar();
private Circle c= new Circle();
#Override
public void initialize(URL location, ResourceBundle resources) {
// TODO Auto-generated method stub
}
public void creat(String s){
newNode = new ButtonBar();
c= new Circle();
c.setRadius(11);
c.setStrokeWidth(1);
c.setStroke(Paint.valueOf("#ffffff"));
c.setFill(Paint.valueOf("#15ff00"));
c.setId(s);
newNode.getButtons().addAll(new Button("Mavero"),c);
slaveVbox.getChildren().addAll(newNode) ;
}
#FXML
public void newComp(){
creat("id1");
creat("id2");
}
#FXML
public void change(){
c.setFill(Color.BLACK);
}
}

Answer 1

You could use Node.lookup() to get the Circles using a css selector (or Node.lookupAll for multiple nodes):
void change(String oldId, String newId) {
change(oldId, Color.RED);
change(newId, Color.GREEN);
}
void change(String id, Color color){
Circle circle = (Circle) slaveVbox.lookup('#'+id);
circle.setFill(color);
}

Answer 2

Its simple:
Just add All Circles in a List ->
List<Circle> circles = new ArrayList<>();
public void creat(String s) {
newNode = new ButtonBar();
Circle c = new Circle();
c.setRadius(11);
c.setStrokeWidth(1);
c.setStroke(Paint.valueOf("#ffffff"));
c.setFill(Paint.valueOf("#15ff00"));
c.setId(s);
circles.add(c);
newNode.getButtons().addAll(new Button("Mavero"), c);
slaveVbox.getChildren().addAll(newNode);
}
#FXML
public void newComp() {
creat("id1");
creat("id2");
}
#FXML
public void change() {
for (Circle c : circles) {
c.setFill(Color.BLACK);
}
}