how to share data between two stages in javafx - javafx

Question

I have two fxml window login and main window.Their respective controllers are given below:
public class MainwindowController extends Stage implements Initializable {
#FXML private Button Send;
#FXML private TextField txtBcast;
#FXML private ListView listviewUsers;
#FXML Label lblDisplayName;
/**
* Initializes the controller class.
* #param url
* #param rb
*/
#Override
public void initialize(URL url, ResourceBundle rb) {
ObservableList<String> chat =FXCollections.observableArrayList ("default");
listviewUsers.setItems(chat);
}
public void setLblName(String msg){
lblDisplayName.setText(msg);
}
#FXML public void ActionSend(ActionEvent e){
send();
txtBcast.setText("");
}
private void send() {
if (txtBcast.getText().isEmpty())
return;
// chatManager.sendPublicMsg(format,txtBcast.getText());
}
/**
*
* #param e
* #throws Exception
*/
#FXML public void ActionUserSelected( MouseEvent e) throws Exception{
// String lineRest = e.getActionCommand();
if(e.getClickCount()==2)
{
if(!listviewUsers.getSelectionModel().isEmpty())
{
String str=(String)listviewUsers.getSelectionModel().getSelectedItem();
Parent main= FXMLLoader.load(getClass().getResource("/letschat/fxwindows/Usertab.fxml"));
Scene scene = new Scene(main);
Stage stage = new Stage();
stage.setTitle(str);
stage.setScene(scene);
stage.show();
}
else { JOptionPane.showMessageDialog(null, "Oops! it seems you are trying to click the list view"); }
}
//Stage pstage = (Stage)listUsers.getScene().getWindow();
//pstage.close();
}
}
And
public class LoginwindowController extends Stage implements Initializable {
#FXML private LoginwindowController loginwindowController;
#FXML private MainwindowController mainwindowController;
#FXML private Button btnSignIn;
#FXML private TextField txtDisplayName;
#FXML private ToggleGroup Gender;
#FXML private ComboBox comboStatus;
/**
* Initializes the controller class.
* #param url
* #param rb
*/
#Override
public void initialize(URL url, ResourceBundle rb) {
ObservableList<String> items =FXCollections.observableArrayList ("Online","Offline");
comboStatus.setItems(items);
writeToTextField();
}
public void writeToTextField() {
String username = System.getProperty("user.name");
txtDisplayName.setText(""+ username);
}
#FXML protected void ActionSignIn(ActionEvent event) throws Exception {
mainwindowController.setLblName(txtDisplayName.getText());
InetAddress addr = InetAddress.getLocalHost();
if(addr.isLoopbackAddress())
{
Dialogs.create().message("Oops! It seems you are not connected to any network..\n :(").showError();
}
else{
start(txtDisplayName.getText());// start chat manager
Parent root= FXMLLoader.load(getClass().getResource("/letschat/fxwindows/Mainwindow.fxml"));
Scene scene = new Scene(root);
Stage stage = new Stage();
stage.setTitle("LetsChat-Welcome "+ txtDisplayName.getText());
// Context.getInstance().setDisplayName(txtDisplayName.getText());
stage.setScene(scene);
stage.getIcons().add(new Image("/letschat/images/logo.png"));
Stage pstage = (Stage)btnSignIn.getScene().getWindow();
stage.show();
pstage.close();
}
}
private void start(String name) {
try {
ChatManager ic = new ChatManager(name);
ic.start();
} catch (Exception ex) {
Dialogs.create().message( "Could not start the chat session\nCheck that there no other instances running :(").showError();
}
}
}
I want the label lblDisplayName in main window updated with text from txtDisplay Name in login window when user clicks signin button.can someone help how to do so..soon plz

Answer 1

There are various ways to do this, in your case Login will create the other stage so an easy way is to create a new FXML loader (variable name: myLoader) and, if you want to pass the username of the user as constructor argument you can use myLoader.setControllerFactory and as return:
return clazz == MyController.class ? new MyController(userName) : null;
MyController is the name of the Controller where you want to read the username
If you want to use set methods, with getController you get the controller instance and call the set method (e.g, myController.setUsername());
To create a custom FXML
FXMLLoader myLoader = new FXMLLoader(<if you use relative paths, here you should pass the position);
remember to call the load() because the URI overload is static. (i.e, use getResourceAsStream).
If your application is large and complex, you could use EventBus (which I prefer everywhere..)

Answer 2

I'm not sure I completely understand the relationship between the two controllers, and which are the FXML files that correspond to the controllers, but it looks like the LoginWindowController loads MainWindow.fxml, and I'm guessing that MainWindowController is the controller for MainWindow.fxml.
In that case, you can just do
#FXML protected void ActionSignIn(ActionEvent event) throws Exception {
InetAddress addr = InetAddress.getLocalHost();
if(addr.isLoopbackAddress())
{
Dialogs.create().message("Oops! It seems you are not connected to any network..\n :(").showError();
}
else{
start(txtDisplayName.getText());// start chat manager
FXMLLoader loader = new FXMLLoader(getClass().getResource("/letschat/fxwindows/Mainwindow.fxml"));
Parent root= loader.load();
MainWindowController mainWindowController = loader.getController();
mainWindowController.setLblName(txtDisplayName.getText());
Scene scene = new Scene(root);
Stage stage = new Stage();
stage.setTitle("LetsChat-Welcome "+ txtDisplayName.getText());
// Context.getInstance().setDisplayName(txtDisplayName.getText());
stage.setScene(scene);
stage.getIcons().add(new Image("/letschat/images/logo.png"));
Stage pstage = (Stage)btnSignIn.getScene().getWindow();
stage.show();
pstage.close();
}
}