JavaFX: can't call a Controller function from anoher class - function

Question

I have this simple controller:
#FXML
private VBox VVbox;
private ButtonBar newNode = new ButtonBar();
private Circle c= new Circle();
private Button b= new Button();
private Label lname = new Label();
private Label lIMEI = new Label();
private Label lroot = new Label();
#Override
public void initialize(URL location, ResourceBundle resources) {
// TODO Auto-generated method stub
}
public void create(String imei){
System.out.println(imei);
newNode = new ButtonBar();
b = setButtonSpec(imei + "btnHavefun");
c = setCircleSpec(imei + "statuOnline");
lname= setLNameSpec(imei + "name");
lIMEI = setLIMEISpec(imei + "Imei");
lroot = setLrootSpec(imei + "root");
newNode.getButtons().addAll(lname,lIMEI,lroot,b,c);
VVbox.getChildren().addAll(newNode) ;
}
this is my main:
#Override
public void start(Stage primaryStage) {
this.primaryStage = primaryStage;
this.primaryStage.setTitle("Thypheon Application");
Connection connessione = new Connection();
Thread t = new Thread(connessione);
initDesign();
t.start();
}
public static void main(String[] args) {
launch(args);
}
public void initDesign(){
try {
loader2= new FXMLLoader(getClass().getResource("Design.fxml"));
AnchorPane anchor = (AnchorPane) loader2.load();
rootLayout.setCenter(anchor);
controller = loader2.getController();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
As you can see in main I start a new thread in which I would like a Controller function.
public class Connection implements Runnable {
String result;
Controller controller = new Controller();
public void run() {
controller.create("TEST123");
}
Everything seems to be inside create function until The last line is executed: VVbox.getChildren().addAll(newNode) ;
Probably because it has a reference to the FXML file.. How can I solve this?

Answer 1

Yes you are right. The controller that you instantiate yourself does not get its fields injected by FXML. To obtain a reference to the controller the following is a possible solution:
public Controller initDesign(){
// some FXML loading code
return controller;
}
You will then need to modify your Connection to take a Controller object in the constructor:
class Connection ... {
Controller contoller;
public Connection(Controller controller) {
this.controller = controller;
}
}
Finally in start() you will need:
Controller controller = initDesign();
Connection connessione = new Connection(controller);
Thread t = new Thread(connessione);
t.start();
However, there is more than one issue with your design.
Your Connection instance is NOT run on JavaFX Application Thread. Therefore, any attempt to modify the scene graph from a different thread (e.g. your call to VVbox.getChildren().addAll(newNode);) will cause an error.
The start() method is called from JavaFX Thread. There is no need to create a new thread. I am unsure of the intentions, but you can call your create() from Controller in start() to be executed on JavaFX Thread.