JavaFx Set Label Text on Scene Open - java

I have an FXML file with an empty Label named welcomeText.
It's the main Scene of my program and I would like to set the label text to something like that: Hello "username" when I start the program on Windows or Linux.
public class MainAdminController implements Initializable {
#FXML
private Label welcomeText;
final String username = System.getProperty("user.name");
#FXML
private void SetWelcome() {
welcomeText.setText("Hello " +username);
}
}
But it isn't show anything. Any idea how can I set the Label properly when I open the scene? Thanks.

The SetWelcome method is superfluous.
Define an initialize() method for your controller and it will automatically be invoked when the FXMLLoader loads a new document linked to the controller.
public void initialize() {
welcomeText.setText("Hello " +username);
}

Related

JavaFX: Adding a new tab from a tab controller

I am trying to make it such that I can create a new tab for my TabPane from within another tab but I am having some difficulty. Currently I have the TabPane set up in the "main-window.fxml" with the corresponding MainWindowController. I have a tab within this TabPane which, via fx:include, displays "mainTab.fxml" to the scene graph, controlled by MainTabController. Now from within the "mainTab" I want a button to be able to add an additional tab to the TabPane, but since this is requires a reference to the TabPane in "main-window", I have created a static method in "main-window". When the run the code below I get a NullPointerException on this line in the MainWindowController:
mainTabPane.getTabs().add(new Tab(team.getTeamName()));
Could someone please tell me as to why it is giving this exception and how I can begin to work around it?
main-window.fxml:
<TabPane fx:id="mainTabPane">
<tabs>
<Tab fx:id="mainTab" text="Main" closable="false">
<fx:include source="mainTab.fxml" fx:id="mainWindowTab" alignment="CENTER"/>
</Tab>
</tabs>
</TabPane>
mainTab.fxml (the event handler for the button):
#FXML
public void handleSubmit() {
String teamName = teamNameTextField.getText();
Roster roster = rosterComboBox.getValue();
int startWeek = spinner.getValue();
Team newTeam = new Team(teamName, startWeek, roster);
TeamData.addTeam(newTeam);
MainWindowController controller = new MainWindowController();
controller.createTeamTab(newTeam);
}
MainWindowController:
public class MainWindowController {
#FXML
private TabPane mainTabPane;
public void createTeamTab(Team team) {
mainTabPane.getTabs().add(new Tab(team.getTeamName()));
}
}
Your code doesn't work because you are not calling createTeamTab(...) on the controller: you are calling it on another instance of MainWindowController that you created. (The fields annotated #FXML are initialized in the controller instance by the FXMLLoader when the FXML is loaded: for fairly obvious reasons they will not be set to the same values in arbitrary other instances of the same class.) You need to get a reference to the controller you are using for the main tab, and pass it a reference to the main controller.
You didn't tell us the class name for the controller of mainTab.fxml: I will assume it is MainTabController (so just change it to whatever class name you actually use).
In MainWindowController, do:
public class MainWindowController {
#FXML
private TabPane mainTabPane;
#FXML
// fx:id of the fx:include with "Controller" appended
private MainTabController mainWindowTabController ;
public void initialize() {
mainWindowTabController.setMainWindowController(this);
}
public void createTeamTab(Team team) {
mainTabPane.getTabs().add(new Tab(team.getTeamName()));
}
}
and then in MainTabController do
public class MainWindowController {
private MainWindowController mainWindowController ;
public void setMainWindowController(MainWindowController mainWindowController) {
this.mainWindowController = mainWindowController ;
}
#FXML
public void handleSubmit() {
String teamName = teamNameTextField.getText();
Roster roster = rosterComboBox.getValue();
int startWeek = spinner.getValue();
Team newTeam = new Team(teamName, startWeek, roster);
TeamData.addTeam(newTeam);
mainWindowController.createTeamTab(newTeam);
}
}

JavaFX how to inject new FXML content to current Scene

I have an app, which has HomeScene.fxml file with headers and menu. HomeScene has also dashboardPane, which should be changed dynamically after menu button is being pressed. Dashboard pane content should be loaded from another fxml file, lets say 'FinancesPane.fxml' or 'SettingsPane.fxml'.
Im trying to replace content of dashboardPane in HomeController:
#FXML
public void handleFinancesButtonAction() {
FinancesPaneFactory paneFactory = new FinancesPaneFactory();
dashBoardPane.getChildren().clear();
dashBoardPane.getChildren().add(paneFactory.createPane());
}
My FinancesPaneFactory looks like this:
public class FinancesPaneFactory extends PaneFactory {
private static final String PANE_TEMPLATE_PATH = "/sceneTemplates/FinancesPane.fxml";
public FinancesPaneFactory() {
super(PANE_TEMPLATE_PATH );
}
#Override
protected Pane generatePane(FXMLLoader loader) {
try {
return (Pane) loader.load();
} catch (IOException e) {
throw new FatBirdRuntimeException("Unable to load FinancesPane", e);
}
}
}
To be more clear, this is how HomeScene looks like: HomeScene .
This empty space is a dashboardPane, and should be replaced with another content when user press the left menu button.
How to inject this content dynamically?
Yes, you should do this to keep scene graph low and you will benefit from better performance , what i do is create dynamic container :
#FXML
private ScrollPane dynamicNode;
Scroll pane is a good choice.
This is put to MainController.
I have main controller different from others , main controller is actually the only one i initialize, so in your main program class whatever you call it :
private static MainViewController mainViewController;
...
private static BorderPane loadMainPane() throws IOException {
FXMLLoader loader = new FXMLLoader();
loader.setController(mainViewController);
BorderPane mainPane = (BorderPane) loader.load(
CsgoRr.class
.getResourceAsStream(Info.Resource.FXML_FILE_MAIN));
mainPane.getStylesheets().add(CsgoRr.class.getResource("path...style.css").toString());
return mainPane;
}
Dont forget to create static accessor, other controllers that i have are usually not created this way , i use fx:controller in fxml to specify what controller should be for which fxml , its usually handy to have mainController accessable.
So to change your views create in your main controller methods that are connected to your menu with whose you change views
#FXML
private void setViewPreferences() {
setView(Info.Resource.FXML_FILE_PREFERENCES);
}
#FXML
private void setViewProductPage() {
setView(Info.Resource.FXML_FILE_PRODUCT_PAGE);
}
Currently in dynamicNode is helper to see what exactly is the current selected, its
private String currentlyInDynamicPane;//not important
Here is setView
public void setView(String fxmlPath) {
dynamicNode.setContent(getView(fxmlPath));
currentlyInDynamicPane = fxmlPath;
}
public Node getView(String fxmlPath) {
try {
return new FXMLLoader(getClass().getResource(fxmlPath)).load();
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
}
So when you click left menu you swap FXML files, you can make sure that you have some default FXML shown at the start or when nothing in menu is selected as well.
This is the way i do it, roughly.
So think about YOUR DASHBOARD as DynamicPane,

JavaFX FXML access succeed with lookup() method but not with #FXML annotation

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.

Java FX changing value of Label from different scene

I have two scenes. The first scene invokes second scene using the following code.
#FXML
private void confirmation(ActionEvent event) throws IOException{
Stage confirmation_stage;
Parent confirmation;
confirmation_stage=new Stage();
confirmation=FXMLLoader.load(getClass().getResource("Confirmation.fxml"));
confirmation_stage.setScene(new Scene(confirmation));
confirmation_stage.initOwner(generate_button.getScene().getWindow());
confirmation_stage.show();
}
There is a label in "Confirmation.fxml" called "Proceed".
I need to change the content of that label from within this function and return the result(true/false). Help?
Create a ConfirmationController for the FXML. From the controller, expose a method which allows you to pass data (string) to set to the label.
public class ConfirmationController implements Initializable {
...
#FXML
private Label proceed;
...
public void setTextToLabel (String text) {
proceed.setText(text);
}
...
}
Inside your method where you are loading the FXML, you can have :
...
FXMLLoader loader = new FXMLLoader(getClass().getResource("Confirmation.fxml"));
confirmation = loader.load();
ConfirmationController controller = (ConfirmationController)loader.getController();
controller.setTextToLabel("Your Text"); // Call the method we wrote before
...
Labels in FXML have a setText method. So for your case the "Proceed" label will look something like:
Proceed.setText("The new text");
As for the second part of the question, I'm not 100% sure as to what you are asking. I don't really see any case for the function to return true or false.
Assuming that you have a controller called:confirmation_controller.java'. inside that controller, you have a public method getProceedLabel() that returns a reference for the label called Proceed. you can try the following code:
Stage confirmation_stage;
Parent confirmation;
confirmation_stage=new Stage();
FXMLLoader loader = new FXMLLoader(getClass().getResource("Confirmation.fxml"));
confirmation = loader.load();
confirmation_controller controller = loader.getController();
Label label = controller.getProceedLabel();
label.setText("..."):
confirmation_stage.setScene(new Scene(confirmation));
confirmation_stage.initOwner(generate_button.getScene().getWindow());
confirmation_stage.show();

Java Form problems

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.

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