I start exploring the JavaFX FXML application technology.
I use one main Stage accessed in Main class with Main.getStage() that is invoked in the start of application with the overriden method public void start(Stage stage). Having two public static Scene inside to keep the persistence while switching them.
#Override
public void start(Stage stage) throws Exception {
STAGE = stage;
LOGIN = new Scene(FXMLLoader.load(getClass().getResource("Login.fxml")));
REGISTER = new Scene(FXMLLoader.load(getClass().getResource("Register.fxml")));
STAGE.setScene(LOGIN);
STAGE.setTitle("FXApplication");
STAGE.show();
}
public static Stage getStage() {
return STAGE;
}
Both Scenes have the same controller class called MainController. Using:
Button with fx:id="buttonLoginRegister" to go to the REGISTER Scene
Button with fx:id="buttonRegisterBack" to go back to the LOGIN one.
and both having the same onClick event handleButtonAction(ActionEvent event). The TextFields are fields for a username to log in/register.
#FXML private Button buttonLoginRegister;
#FXML private Button buttonRegisterBack;
#FXML private TextField fieldLoginUsername;
#FXML private TextField fieldRegisterUsername;
#FXML
private void handleButtonAction(ActionEvent event) throws IOException {
Stage stage = Main.getStage();
if (event.getSource() == buttonLoginRegister) {
stage.setScene(Main.REGISTER);
stage.show();
// Setting the text, the working way
TextField node = (TextField) stage.getScene().lookup("#fieldRegisterUsername");
node.setText(fieldLoginUsername.getText());
// Setting the text, the erroneous way
// fieldRegisterUsername.setText(fieldLoginUsername.getText());
} else {
stage.setScene(Main.LOGIN);
stage.show();
}
}
My goal is to copy the value from the LOGIN TextField to the one in the REGISTER scene. It works well using the code above. However firstly I tried to access the element in the another Scene with:
fieldRegisterUsername.setText(fieldLoginUsername.getText());
And it's erroneous. To be exact, the fieldRegisterUsername is null.
Why are some elements found with the lookup(String id) method and not with #FXML annotation?
As mentioned in my comment, sharing a controller between different views is rarely a good idea, and I'd strongly advise you to make a separate controller for each view.
As to your problem itself - you have two instances of your controller class, one for each time you call FXMLLoader.load. Presumably, one view has the fieldLoginUsername TextField, while the other has fieldRegisterUsername.
If the condition of the if statement is met, it means the active scene was the Login scene, thus the controller handling it is the one which has fieldLoginUsername, so naturally fieldRegisterUsername will be null.
But on the first line inside the if clause you change the active scene to the Register one, so by the time you call scene#lookup you are referring to the scene whose controller is the Register controller, the one that does have fieldRegisterUsername.
If you were to call scene#lookup before changing the active scene you would find it returns null as well.
If you must use the same class for controller, you probably want to make sure you only have one instance of that class. That would necessitate using FXMLLoader#setController.
Related
I have a function that updates a ListView in my FXML Controller Class. I want this to run every time the user presses F5.
I'm not sure what the best way is to achieve this and tried following:
1. Get the scene from the controller
I tried to get the scene like here and added scene.onKeyPressed(e -> ...);. But I failed to find a way to get the scene reliably.
2. Call the function from outside
Furthermore I tried to handle this from my scene controller, not my preferred way, because I don't want to call this method when this particular file is not loaded. I load the FXML file with layout.setCenter(FXMLLoader.load(...)); I failed to get an instance of the Controller itself, where I could call the method.
What is wrong with my design? Or is there an #FXML annotation that allows me to handle a KeyEvent?
Example
ApplicationManager:
#Override
public void start(Stage stage){
BorderPane layout = new BorderPane();
Scene scene = new Scene(layout);
layout.setCenter(FXMLLoader.load(getClass().getResource("/designs/lobby.fxml");
}
LobbyFxmlController:
#FXML private ListView<Label> lobbyListView;
#FXML
public void initialize(){
//I can't get the scene here
}
private void loadLobbies(){
// I need to run this on F5 presses
lobbyListView.setItems("lobby 1", "lobby 2", "lobby 3");
}
I just needed to add onKeyPressed="#handleKeyPress" to the FXML layout item and handle this method in the Controller.
I got a controller which launchs a new window called file :
// MainController.java
Stage primaryStage = new Stage();
FXMLLoader fx = new FXMLLoader(Paths.get("../file.fxml").toUri().toURL());
Scene scene = new Scene(fx.load());
primaryStage.setScene(scene);
primaryStage.show();
primaryStage.centerOnScreen();
FileController control = (FileController ) fx.getController();
control.getValiderBE().setOnAction(event1 -> {
System.out.prinln("here 1");
});
I got a Button in the FXML file :
// file.fxml, fx:controller="FileController"
<Button fx:id="validerBE" onMouseClicked="#validerClickBE" text="Valider">
</Button>
In its controller (instance of FileController) I got :
FileController.java
#FXML
private Button validerBE;
#FXML
void validerClickBE(MouseEvent event) {
System.out.prinln("here 2");
}
public Button getValiderBE() {
return validerBE;
}
And print goes in this order : here 1 => here 2. And sometines method in FileController is even not called^^ Like if event is down in here 1 call
But I'd to have in the other order, because new window add an element to a list, and first source controller should refresh a TableView (so after adding operation)
First, note that you should be using onAction to handle button clicks, not onMouseClicked. The reason for this is that if the user navigates to the button and activates it (typically with the space bar), or otherwise fires the button without the mouse (e.g. with a mnemonic), the onMouseClicked handler won't be invoked.
So you should have
<Button fx:id="validerBE" onAction="#validerClickBE" text="Valider" />
and
#FXML
void validerClickBE(ActionEvent event) {
System.out.prinln("here 2");
}
For ordering the events: there is no general way to control the order in which event handlers are invoked. There are some special cases, which you may be able to take advantage of in some specific circumstances, but in general the order of handler invocation is not specified. Consequently, if you have two actions that are dependent on each other, they should be performed in the same handler.
At any rate, it is generally bad practice to expose the UI controls outside of the controller anyway - it violates the principal of encapsulation and will make your code much harder to maintain. Typically you should pass a data model to the controller, and then the controller can invoke any actions on the data model that it needs to invoke.
At the very least, you can define a field to represent an action to perform when the button is pressed, and invoke it from your existing handler, though of course a proper MVC approach is far preferable:
public class FileController {
private Runnable onValidate = () -> {} ;
public void setOnValidate(Runnable onValidate) {
this.onValidate = onValidate ;
}
#FXML
private void validerClickBE(ActionEvent event) {
// whichever order you need....
onValidate.run();
System.out.println("here 2");
}
}
and then of course
FXMLLoader fx = new FXMLLoader(Paths.get("../file.fxml").toUri().toURL());
Scene scene = new Scene(fx.load());
primaryStage.setScene(scene);
primaryStage.show();
primaryStage.centerOnScreen();
FileController control = (FileController ) fx.getController();
control.setOnValidate(() -> System.out.println("here 1"));
I have an app in JavaFX, which has main scene with menu and toolbar, and smaller scenes, which are injected into this main scene, after one of menu buttons are being pressed.
Now, HomeCntroller is responsible for either scene components: Home Scene (with toolbar and menu), and injected scene. This leads me to create massive, huge and very unprofessional controller if number of injected scenes is more than one.
How to split controller responsibility?
Now my Controller looks like this:
changeDashboardPane method injects smaller Pane into my main HomePane.
#Component
#RequiredArgsConstructor(onConstructor = #__(#Autowired) )
public class HomeController extends AbstractController {
private static final Logger LOG = Logger.getLogger(HomeController.class);
private final BudgetProfileService budgetProfileService;
#FXML
private Label usernameLabel;
#FXML
private ComboBox<String> budgetProfilesComboBox;
#FXML
private AnchorPane dashBoardPane;
#FXML
public void initialize() {
refreshUsernameLabel();
getAllBudgetProfiles();
changeDashboardPane(PaneFactoryKeys.FINANCES_PANE);
}
private void refreshUsernameLabel() {
String username = UserAccountProvider.getLoggedUser().getUsername();
usernameLabel.setText(username);
}
private void getAllBudgetProfiles() {
List<String> budgetProfileNames = budgetProfileService.getAllBudgetProfileNames();
if (!budgetProfileNames.isEmpty()) {
budgetProfilesComboBox.getItems().clear();
budgetProfilesComboBox.getItems().addAll(budgetProfileNames);
}
}
#FXML
public void handleFinancesButtonAction() {
changeDashboardPane(PaneFactoryKeys.FINANCES_PANE);
}
#FXML
public void handlePeriodButtonAction() {
changeDashboardPane(PaneFactoryKeys.PERIOD_PANE);
}
#FXML
public void handleStatisticsButtonAction() {
changeDashboardPane(PaneFactoryKeys.STATISTICS_PANE);
}
#FXML
public void handleSettingsButtonAction() {
changeDashboardPane(PaneFactoryKeys.SETTINGS_PANE);
}
private final void changeDashboardPane(String paneFactoryKey) {
double injectedPanePosition = 0.0;
Pane paneToChange = getPaneFromFactory(paneFactoryKey);
dashBoardPane.getChildren().clear();
AnchorPane.setTopAnchor(paneToChange, injectedPanePosition);
dashBoardPane.getChildren().add(paneToChange);
}
}
To get this more clear, screens:
without injected second pane
with injected second pane
Any ideas guys?
I would recommend you to divide your main scene in smaller ones, for example you can have a tools scene, a header scene, a content scene and so on. Then you should have one controller for every scene.
After that I would use a publisher-subscriber pattern to deal with behaviors, like when you press a button on settings scene, it triggers an event that other scenes listen to and then they handle it changing their state accordingly.
I hope it was clear and can help!
Create multiple controllers , multiple FXML files - to continue on my answer that i provided you before, JavaFX how to inject new FXML content to current Scene each of those views that have separate fxml file also has
fx:controller="appplication.ExampleViewController"
attached to it.So what you do is create main controller as was mentioned , that is basically the FRAME CONTAINER that encapsulates controls to change your dynamic container.If your application is really ui rich and have a lot of functionality in one controller , you can break down your view even further:
For instance take out menu and put it into separated controller , and insert it into your main view with main controller
/same way as in method setView()/
, what you are doing is just taking it away to keep controller code smaller, YOU DONT DECREASE/INCREASE SCENE GRAPH THIS WAY, doesnt have a drawback its just a personal preference.
You gonna end up with more fxml files and controllers in the end.Its all the same thing as from your previous question there is no additional code needed you can actually reuse what was already provided.
Data between controllers are passed thru MODEL. - look more into MVC dont work with application data in controllers only care about view or passing them from/into model
To avoid a huge contoller class, as I am using multiple tabs, I split the tabs to single java files.
My solution was to create a cascade of classes:
Base: Containing all defs for FX types
Tab1 extends Base: Tab one implementation
Tab2 extends Tab1: Tab two implementation
Controller extends Tab2 implements Initializable: Implements initialize(URL url, ResourceBundle resourceBundle)
Important:
Any accessed object must be definded in the current tab or before.
Any Objects in Base are available in Controller whereas no object of Controller is accessable in Base, Tab1 or Tab2.
Feel free to add your opinion as comment or submit a improvement.
I have written a controller for two windows /stages.
The first window is opened in the MainClass. The second in the Controller, if the user clicks onto a button.
How can I get the TextFields from second.fxml in the applyFor()-method?
Thanks.
#FXML
protected void requestNewAccount(ActionEvent event) {
try {
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("second.fxml")); // TextFields in there
Parent root = (Parent) fxmlLoader.load();
Stage stage = new Stage();
stage.initModality(Modality.APPLICATION_MODAL);
stage.setTitle("Second Window");
Scene scene = new Scene(root);
String css = MainOnlineCustomer.class.getResource("/style.css").toExternalForm();
scene.getStylesheets().clear();
scene.getStylesheets().add(css);
stage.setScene(scene);
stage.show();
} catch (IOException e) {
logger.error(e);
}
}
/**
* closes the "second"-Window
* #param event
*/
#FXML
protected void cancel(ActionEvent event) {
final Node source = (Node) event.getSource();
final Stage stage = (Stage) source.getScene().getWindow();
stage.close();
}
#FXML
protected void applyFor(ActionEvent event) {
// get values from TextField in second.fxml here!!!
}
It's not good to share controllers between fxmls unless they serve the same purpose. Here both fxml seem to serve a different purpose (account management, login or something similar for one of them and creating a new account for the other). What is even worse is that those classes do not share the same controller instance, which means the small (and probably only) benefit you could get from using the same controller, is not used here. You should better use different controllers.
Since you use Modality.APPLICATION_MODAL as modality, I'd recommend using showAndWait instead of show to open the new stage. This will enter a nested event loop, which allows the UI to remain responsive and continues after the invocation of showAndWait once the stage is closed.
Furthermore add a method to the controller of second.fxml that allows you to retrieve the result.
Example
This creates a Person object with given name and family name.
"primary window (opening the "inner" stage)
FXMLLoader loader = new FXMLLoader(getClass().getResource("second.fxml"));
Stage subStage = new Stage();
subStage.initModality(Modality.APPLICATION_MODAL);
subStage.setTitle("Second Window");
Scene scene = new Scene(loader.load());
subStage.setScene(scene);
subStage.showAndWait();
Optional<Person> result = loader.<Supplier<Optional<Person>>>getController().get();
if (result.isPresent()) {
// do something with the result
}
controller for "inner" content
public class SecondController implements Supplier<Optional<Person>> {
#FXML
private TextField givenName;
#FXML
private TextField familyName;
private boolean submitted = false;
// handler for submit action
#FXML
private void submit() {
submitted = true;
givenName.getScene().getWindow().hide();
}
// handler for cancel action
#FXML
private void cancel() {
givenName.getScene().getWindow().hide();
}
#Override
public Optional<Person> get() {
return submitted ? Optional.of(new Person(givenName.getText(), familyName.getText())) : Optional.empty();
}
}
Note that you can gain access to any data available to the controller this way. I wouldn't recommend accessing any nodes (like TextFields) directly though, since this makes changing the UI harder.
Using the Supplier interface here is not necessary, but I chose to do this to achieve a loose coupling between SecondController and the main window.
I've recently delved into JavaFX as a C# developer. One thing I noticed in Java is that you're not spoon fed the way Visual Studio/Microsoft spoonfeed us.
So. When I was creating a form using the scene builder for IntelliJ Idea on JavaFX. I inherited "Stage" for my controller class and created a void called load that will load the instance of the scene from the FXML file. Therefore when I call load() from the Main entry point or anywhere it will load the fxml file and show.
LoginController frmLogin = new LoginController();
frmLogin.load();
The problem is that it works and it does't work.
Here's my code.
Main.Java
public class Main extends Application
{
#Override
public void start(Stage primaryStage) throws Exception
{
LoginController frmLogin = new LoginController();
frmLogin.load();
}
public static void main(String[] args)
{
Application.launch(args);
}
}
LoginController.Java
public class LoginController extends Stage
{
#FXML
private TextField txtUsername;
#FXML
private TextField txtPassword;
#FXML
private void btnLogin_Clicked(ActionEvent e) throws Exception
{
if (txtUsername.getText().equals("admin") && txtPassword.getText().equals("pass"))
{
Messagebox.Show("Correct Login!");
this.show(); //The problem occurs here!
}
else
{
Messagebox.Show("Incorrect Login");
}
}
public void load() throws Exception
{
Parent root = FXMLLoader.load(getClass().getResource("frmLogin.fxml"));
this.setScene(new Scene(root));
this.setTitle("JavaFX GUI");
this.setResizable(false);
this.initModality(Modality.APPLICATION_MODAL);
this.show();
}
}
Here's a GIF of the problem.
http://i.imgur.com/0hOG76M.gif
I want to know why when I call .show() it shows a blank for?
Any help would be appreicated.
Solution
Don't inherit Stage in your Controller.
JavaFX will implicitly create a Stage for your application and pass it to your application (the primaryStage parameter in your application start method).
Sample
Here is a quick update which should work. Another alternative for this is to factor out the stage management as in James's answer.
public class Main extends Application
{
#Override
public void start(Stage primaryStage) throws Exception
{
Parent root = FXMLLoader.load(getClass().getResource("frmLogin.fxml"));
primaryStage.setScene(new Scene(root));
primaryStage.setTitle("JavaFX GUI");
primaryStage.setResizable(false);
primaryStage.show();
}
public static void main(String[] args)
{
Application.launch(args);
}
}
. . .
public class LoginController
{
#FXML
private TextField txtUsername;
#FXML
private TextField txtPassword;
#FXML
private void btnLogin_Clicked(ActionEvent e) throws Exception
{
if (txtUsername.getText().equals("admin") && txtPassword.getText().equals("pass"))
{
Messagebox.Show("Correct Login!");
}
else
{
Messagebox.Show("Incorrect Login");
}
}
}
Aside: I am not sure what your MessageBox class is, but JavaFX 8u40 has a built-in Alert dialog box for standard message box style functionality, so that would be the preferred method to do that.
It looks like you have confused the different pieces that make up the application.
The FXML typically represents the "view"; i.e. the portion of the UI that is visible. It defines what controls are displayed and how they are laid out.
The controller implements the logic that is connected to (controls) the view. So it typically processes user input and updates the view in various ways.
A Stage is a window.
So, I don't think it really makes sense that your controller is a Stage. There are some scenarios where you might make a controller a subclass of a UI element, but those are somewhat advanced uses of JavaFX, and even then you would typically subclass a layout pane, not a Stage.
Here's roughly what happens when you call load on an FXMLLoader:
The FXMLLoader creates a hierarchy of Nodes (UI elements) corresponding to the elements defined in the FXML file
If the FXML file defines a fx:controller attribute in its root element, the FXMLLoader constructs a new instance of that class. It then injects any elements with fx:id attributes into fields in that controller instance with names matching the fx:id values. It also registers any event handlers mapping to methods in the controller instance.
The FXMLLoader's load() method returns the object corresponding to the root element of the FXML file.
So, in your code, you actually end up with two LoginController instances. You create one yourself in the start() method. You then call load() on that instance. That method calls load(...) on an FXMLLoader (via the really ugly static load method). Calling FXMLLoader.load(...) then causes the FXMLLoader to create an instance of the class declared in fx:controller. I'm guessing (you didn't show the FXML code) that class is also LoginController. So that is the second instance.
Now what happens, is that you get a reference to the UI element from FXMLLoader.load(). You put that in a Scene, and set the Scene in the LoginController, which - unusually - is a Stage. Then you make the Stage appear on the screen with show(). Note this happens in the instance you created in the start method.
When the user presses the button that has btnLogin_Clicked registered as its handler, the handler method is invoked on the controller instance: the one created by the FXMLLoader. That instance never had a Scene set, so when you then call this.show() it shows that instance of the LoginController (which, again, is a Stage). Since it never had its scene set, you see a blank window.
It's not actually clear to me what you intend with the call to this.show() in btnLogin_Clicked anyway. Assuming you thought this was the same Stage you had created from the start(...) method, that Stage is already showing.
The typical pattern is that you use the primaryStage that is passed to the start(...) method, and set a scene in that and show it. So you'd do something like:
public class Main extends Application
{
#Override
public void start(Stage primaryStage) throws Exception
{
Parent root = FXMLLoader.load(getClass().getResource("frmLogin.fxml"));
primaryStage.setScene(new Scene(root));
primaryStage.setTitle("JavaFX GUI");
primaryStage.setResizable(false);
primaryStage.initModality(Modality.APPLICATION_MODAL);
primaryStage.show();
}
public static void main(String[] args)
{
Application.launch(args);
}
}
and then the controller is just a controller: it just handles the logic:
public class LoginController
{
#FXML
private TextField txtUsername;
#FXML
private TextField txtPassword;
#FXML
private void btnLogin_Clicked(ActionEvent e) throws Exception
{
if (txtUsername.getText().equals("admin") && txtPassword.getText().equals("pass"))
{
Messagebox.Show("Correct Login!");
// I don't really know what you were trying to do here
// but if you need a reference to the window containing the
// associated fxml elements, you can get it from one of those
// elements:
Stage stage = (Stage) txtUsername.getScene().getWindow();
//this.show(); //The problem occurs here!
}
else
{
Messagebox.Show("Incorrect Login");
}
}
}
Typically what you want to do when the user has successfully logged in, is to display something new in the current window. The simplest way to do this is just to set the root of the current scene to the content of a different FXML file. For example:
public class LoginController
{
#FXML
private TextField txtUsername;
#FXML
private TextField txtPassword;
#FXML
private void btnLogin_Clicked(ActionEvent e) throws Exception
{
if (txtUsername.getText().equals("admin") && txtPassword.getText().equals("pass"))
{
Messagebox.Show("Correct Login!");
Scene currentScene = txtUsername.getScene();
Parent root = FXMLLoader.load(getClass().getResource("Main.fxml"));
currentScene.setRoot(root);
// resize window:
currentScene.getWindow().sizeToScene();
}
else
{
Messagebox.Show("Incorrect Login");
}
}
}
Here Main.fxml defines the main application the user sees, having successfully logged in, and defines its own controller class, etc.