Overview
I am working on a simple JavaFX application with multiple scenes using the MVC Architectural pattern. I have the design in place but I am having trouble persisting the User model across the different scenes. At the moment I do not have any backend. I am looking to just instantiate the User model when the application starts and display that single instance across my application. Any changes to that user model will up updated across the scenes. I am not looking to persist after the application closes.
I believe the issue arises from a design choice I had early on in development. I use a Controller named SceneNavigatorControl that calls the class Navigator which handles the presentation of different scenes in the application. These scenes are .fxml files.
SceneNavigatorControl
public class SceneNavigatorControl implements Initializable {
@FXML
private BorderPane mainStage;
@FXML
private void displayHomeScene() {
Navigator object = new Navigator();
Pane view = object.getScene("Home");
handleButtonChange("Home");
mainStage.setCenter(view);
}
@FXML
private void displayProfileScene() {
Navigator object = new Navigator();
Pane view = object.getScene("Profile");
handleButtonChange("Profile");
mainStage.setCenter(view);
}
@Override
public void initialize(URL location, ResourceBundle resources) {
// Called when the application starts, should this be where I instantiate User?
//User user = new User();
//user.setName("Bob");
displayHomeScene();
}
}
The above code handles which scene to take the user to. Depending on which button is tapped. One of the above functions is called and the scene is displayed by using the Navigator Class. I would think this is where I instantiate User and pass it to all other controllers
Navigator Class
public class Navigator {
private Pane view;
public Pane getScene(String fileName) {
try {
URL fileUrl = ActivityTracker.class.getResource("/ActivityTracker/Views/" + fileName + ".fxml");
if (fileUrl == null) {
throw new java.io.FileNotFoundException("FXML File cannot be found");
}
view = new FXMLLoader().load(fileUrl);
} catch (Exception e) {
System.out.print("No page " + fileName + " please check FXMLLoader");
}
return view;
}
}
The navigator class simple checks if a .fxml file with a given name exists. If it does, it replaces the current scene on the stage with the one given.
HomeView
<AnchorPane fx:id="Home" prefHeight="500.0" prefWidth="500.0" xmlns="http://javafx.com/javafx/8.0.172-ea" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ActivityTracker.Controllers.HomeController">
<children>
<Label fx:id="clockLabel" layoutX="90.0" layoutY="32.0" textFill="WHITE" AnchorPane.leftAnchor="90.0" AnchorPane.topAnchor="32.0">
<font>
<Font name="Lucida Grande" size="100.0" />
</font></Label>
<Pane layoutX="410.0" layoutY="-1.0" prefHeight="500.0" prefWidth="90.0" style="-fx-background-color: #1d1d1d;" />
</children>
This is our view which is created using an .fxml file. On the first line is where we declare what view is associated with what controller.
HomeController
public class HomeController implements Initializable {
@FXML
private Pane Home;
@Override
public void initialize(URL location, ResourceBundle resources) {
// Print users details
}
}
ActivityTracker (Main)
public class ActivityTracker extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) {
try {
Parent root = FXMLLoader.load(ActivityTracker.class.getResource("Views/Stage.fxml"));
Scene scene = new Scene(root);
primaryStage.setScene(scene);
primaryStage.setResizable(false);
primaryStage.show();
} catch (Exception ex) {
Logger.getLogger(ActivityTracker.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
User Model
public class User {
// Define all user stat variables for the model
private String userName;
/**
* Method that returns the users name
* @return users name of type String
*/
public String getUsersName() {
return userName;
}
/**
* Method that takes in a string value and sets it as the current users name
* @param name the current users weight
*/
public void setUsersName(String name) {
this.userName = name;
}
}
