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Missing GUI elements when adding from different files

I am trying to add GUIs, created from individual files and add them into my main code.
While it seems to be working, kind of, however, it is missing some elements. For example, in my GridPane, there are a label and a text, both of which are missing. Likewise, for my treeview, there is a treeitem within, however, that is missing as well.
What I am trying to attempt is to reduce the amount of code in the main field and as well as to call relevant events between the Guis, eg. if I select something in the TreeView, that selected TreeItem information will be populated in the GridPane.
Client.java
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
public class Client extends Application
{
private treeviewGui tvGui;
private gridpaneGui inputFieldsGui;
public void init()
{
tvGui = new treeviewGui();
inputFieldsGui = new gridpaneGui();
}
#Override
public void start(Stage topView)
{
topView.setTitle("Test Application");
HBox mainLayout = new HBox(10);
mainLayout.getChildren().addAll(tvGui, inputFieldsGui);
Scene scene = new Scene(mainLayout);
topView.centerOnScreen();
topView.setScene(scene);
topView.show();
}
public static void main(String[] argv)
{
launch(argv);
}
}
treeviewGui.java
import javafx.scene.control.*;
public class treeviewGui extends TreeView
{
private TreeView treeview;
public treeviewGui()
{
treeview = new TreeView();
preload();
}
private void preload()
{
TreeItem<String> newTI = new TreeItem<>("blah");
treeview.setRoot(newTI);
}
}
gridPane.java
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.geometry.Pos;
import javafx.scene.text.Text;
public class gridpaneGui extends GridPane
{
private GridPane gridPane;
public Text fnameTxt;
public gridpaneGui()
{
gridPane = new GridPane();
gridPane.setAlignment(Pos.CENTER);
gridPane.setHgap(5);
gridPane.setVgap(5);
// First Name
Label fnameLbl = new Label("First Name");
fnameTxt = new Text("-");
gridPane.addRow(0, fnameLbl, fnameTxt);
}
public void setFname(String nameStr)
{
fnameTxt.setText(nameStr);
}
}

JavaFX: Listen to Scene changes

How can I make a custom Event that triggers on Stage.setScene()?
In my code, the button switches the Scenes and that works fine. However, I would like to extend the Stage to have an additional Event that is triggered when a button or possibly any other Element triggers a setScene.
Example:
package sample;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.stage.Stage;
public class Main extends Application {
public static void main(String[] args) {
Application.launch(args);
}
#Override
public void start(Stage stage) {
Group g1 = new Group();
Button b1 = new Button("2");
g1.getChildren().setAll(b1);
Scene scene1 = new Scene(g1, 50, 50);
Group g2 = new Group();
Button b2 = new Button("1");
g2.getChildren().setAll(b2);
Scene scene2 = new Scene(g2, 50, 50);
stage.setScene(scene1);
stage.setTitle("JavaFX Application Life Cycle");
b1.setOnAction(actionEvent -> {
System.out.println("1");
stage.setScene(scene2);
});
b2.setOnAction(actionEvent -> {
System.out.println("2");
stage.setScene(scene1);
});
stage.show();
}
}

You can add a ChangeListener<Scene> to your Stage like this:
stage.sceneProperty().addListener((observable, oldScene, newScene) -> {
System.out.println("New scene: " + newScene);
System.out.println("Old scene: " + oldScene);
});

I believe using a listener, as shown in the answer by #M.S., is probably the best and simplest way to react to scene changes. However, you ask about how to make a "custom event" that you can fire when the scene changes; by "event" I assume you mean a subclass of javafx.event.Event. So while I recommend sticking with a simple listener, here's an example of a custom event.
First, you need a custom event class:
import javafx.event.Event;
import javafx.event.EventType;
import javafx.scene.Scene;
import javafx.stage.Window;
public class SceneChangedEvent extends Event {
public static final EventType<SceneChangedEvent> SCENE_CHANGED =
new EventType<>(Event.ANY, "SCENE_CHANGED");
public static final EventType<SceneChangedEvent> ANY = SCENE_CHANGED;
private transient Window window;
private transient Scene oldScene;
private transient Scene newScene;
public SceneChangedEvent(Window window, Scene oldScene, Scene newScene) {
super(window, window, SCENE_CHANGED);
this.window = window;
this.oldScene = oldScene;
this.newScene = newScene;
}
public Window getWindow() {
return window;
}
public Scene getOldScene() {
return oldScene;
}
public Scene getNewScene() {
return newScene;
}
}
I'm not sure what information you want to carry with the event so I just added the source Window as well as the old and new Scenes. If you're wondering about the ANY = SCENE_CHANGED, I'm just following the pattern used by javafx.event.ActionEvent (which also only has a single event-type).
Then you simply need to fire the event when the scene changes. To implement this you're still going to need a change listener. As you mention wanting to extend Stage here's an example of that:
import javafx.beans.NamedArg;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.event.EventHandler;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
public class CustomStage extends Stage {
private final ObjectProperty<EventHandler<? super SceneChangedEvent>> onSceneChanged =
new SimpleObjectProperty<>(this, "onSceneChanged") {
#Override
protected void invalidated() {
setEventHandler(SceneChangedEvent.SCENE_CHANGED, get());
}
};
public final void setOnSceneChanged(EventHandler<? super SceneChangedEvent> handler) {
onSceneChanged.set(handler);
}
public final EventHandler<? super SceneChangedEvent> getOnSceneChanged() {
return onSceneChanged.get();
}
public final ObjectProperty<EventHandler<? super SceneChangedEvent>> onSceneChangedProperty() {
return onSceneChanged;
}
public CustomStage() {
this(StageStyle.DECORATED);
}
public CustomStage(#NamedArg(value = "style", defaultValue = "DECORATED") StageStyle style) {
super(style);
sceneProperty().addListener((obs, ov, nv) -> fireEvent(new SceneChangedEvent(this, ov, nv)));
}
}
This would let you react to the scene changing using any of the following:
CustomStage stage = new CustomStage();
// addEventFilter/addEventHandler
stage.addEventFilter(SceneChangedEvent.SCENE_CHANGED, e -> { ... });
stage.addEventHandler(SceneChangedEvent.SCENE_CHANGED, e -> { ... });
// setOnSceneChanged
stage.setOnSceneChanged(e -> { ... });
Keep in mind that the event will only target the CustomStage instance. In other words, only event handlers added to the CustomStage instance will be notified of the event. And as you can see, this is much more complicated than simply adding a change listener to the scene property of the Stage.

JavaFX LineChart Exception at ControllerClass [duplicate]

I have following code:
package pl.javastart.youtufy.controller;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.application.Platform;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ToggleButton;
import javafx.scene.web.WebEngine;
import javafx.stage.Stage;
public class ConnectionErrorController implements Initializable {
#FXML
private Label infoLabel;
#FXML
private Button tryButton;
#FXML
private Button exitButton;
#Override
public void initialize(URL location, ResourceBundle resources) {
MainController mc = new MainController();
infoLabel.setText("Connection lost, please try again");
tryButton.setText("try again");
exitButton.setText("exit");
tryButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
WebEngine webEngine = mc.getContentPaneController().getVideoWebView().getEngine(); // 1
ToggleButton playButton = mc.getControlPaneController().getPlayButton(); // 2
Node source = (Node) event.getSource();
Stage stage = (Stage) source.getScene().getWindow();
if (mc.testInet()) {
stage.close();
mc.play(webEngine, playButton);
} else {
stage.close();
MainController.exist = false;
}
}
});
exitButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
Platform.exit();
}
});
}
}
I am trying to use WebEngine and ToggleButton Objects from controllers in MainController (I generated getters and setters to them in MainController):
public class MainController implements Initializable {
#FXML
private ContentPaneController contentPaneController;
#FXML
private ControlPaneController controlPaneController;
#FXML
private MenuPaneController menuPaneController;
#FXML
private SearchPaneController searchPaneController;
private Youtube youtubeInstance;
public static boolean exist = false;
public ControlPaneController getControlPaneController() {
return controlPaneController;
}
public void setControlPaneController(ControlPaneController controlPaneController) {
this.controlPaneController = controlPaneController;
}
public ContentPaneController getContentPaneController() {
return contentPaneController;
}
public void setContentPaneController(ContentPaneController contentPaneController) {
this.contentPaneController = contentPaneController;
}
But its still returns NullPointerException. I had same problem, when I tried simply make references to the controllers in ConnectionErrorController. How to refer to the ToggleButton i WebEngine Objects from controllers in ConnectionErrorController properly?
Regards

You are creating a controller instance "by hand" with
MainController mc = new MainController();
#FXML-annotated fields are initialized by the FXMLLoader when it creates the controller for you as part of the process of loading the FXML file. Since the controller you created is not the controller instance created by the FXMLLoader, its #FXML-annotated fields are uninitialized (i.e. they are null), and hence you get a null pointer exception.
You can get a reference to the controller created by the FXMLLoader by calling getController() on the FXMLLoader instance after calling load().
If you want one controller to communicate with another, then pass the reference to one controller to the other controller, by defining appropriate methods in the second controller:
public class ConnectionErrorController implements Initializable {
private MainController mainController ;
public void setMainController(MainController mainController) {
this.mainController = mainController ;
}
// ...
#Override
public void initialize(URL location, ResourceBundle resources) {
infoLabel.setText("Connection lost, please try again");
tryButton.setText("try again");
exitButton.setText("exit");
tryButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
WebEngine webEngine = mainController.getContentPaneController().getVideoWebView().getEngine(); // 1
ToggleButton playButton = mainController.getControlPaneController().getPlayButton(); // 2
if (mainController.testInet()) {
mainController.play(webEngine, playButton);
} else {
// obviously you can now do something better than the "public static field hack" here:
MainController.exist = false;
}
tryButton.getScene().getWindow().hide();
}
});
// ...
}
}
Assuming you are loading the second fxml file in a method in MainController, you can then just do something like:
public class MainController {
// ...
public void showConnectionErrorWindow(String fileName) {
FXMLLoader loader = new FXMLLoader(getClass().getResource("path/to/ConnectionError.fxml"));
Parent root = loader.load();
ConnectionErrorController connectionErrorController = loader.getController();
connectionErrorController.setMainController(this);
Scene scene = new Scene(root);
Stage stage = new Stage();
// etc...
}
// ...
}
Note that there are much more elegant ways of solving this problem, such as passing the ConnectionErrorController a callback function (in the form of a lambda expression) to process the call to play(...), which avoid the tight coupling between the ConnectionErrorController and the MainController. However, as you seem to be new to Java, this simpler approach might be more suitable.
See Passing Parameters JavaFX FXML for more information on passing values to controllers.

JavaFX button reacting on second click not first

I am trying to create my very first application in JavaFX and I have a problem with Button that calls a method (for example to open another window) - I always have to click it twice in order to trigger action.
Here's my code from the Controller:
import javafx.fxml.FXML;
import javafx.scene.control.Button;
public class ControllerSignIn {
#FXML
private Button forgot;
#FXML
private Button back;
#FXML
private Button signin;
public void forgetPasswordClicked() {
forgot.setOnAction(e -> ForgotPassword.setUpWindow()); //works on 2nd click
}
public void backClicked() {
back.setOnAction(e -> ForgotPassword.closeWindow()); //works on 2nd click
}
public void signInClicked() {
System.out.println("Sign In CLICKED"); //works on first click
}
}
My methods are implemented here:
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Modality;
import javafx.stage.Stage;
import java.io.IOException;
public class ForgotPassword {
static Stage window;
static Scene scene;
static Parent root;
private static void loadFXML() {
try {
root = FXMLLoader.load(ForgotPassword.class.getResource("ForgotPassword.fxml"));
} catch (IOException e) {
e.printStackTrace();
}
}
public static void setUpWindow() {
loadFXML();
scene = new Scene(root);
scene.getStylesheets().add("signin/SignIn.css");
window = new Stage();
window.initModality(Modality.APPLICATION_MODAL);
window.setTitle("Forgot Password?");
window.setScene(scene);
window.showAndWait();
}
public static void closeWindow() {
window.close();
}
}

Most likely you have the following in your FXML:
<Button fx:id="forgot" onAction="#forgetPasswordClicked" />
This makes your button forgot call your method forgetPasswordClicked(). But instead of defining your logic to be executed when your button is clicked, the first time you say: "When this button is clicked, place an action event on my button which will call setUpWindow()"
forgot.setOnAction(e -> ForgotPassword.setUpWindow());
Therefore, your first click "sets up" the logic of your button. The second click, actually executes it. To solve this, either immediately use your logic as such:
public void forgetPasswordClicked() {
ForgotPassword.setUpWindow();
}
or don't define the method to be called in your fxml, and move the initialization of your button (setting the action listener) to your initialization as following:
public class ControllerSignIn implements Initializable {
#FXML
private Button forgot;
#FXML
private Button back;
#Override
public void initialize(URL location, ResourceBundle resources) {
forgot.setOnAction(e -> ForgotPassword.setUpWindow());
back.setOnAction(e -> ForgotPassword.closeWindow());
}
}
This is also why your signInClicked() method works from the first click, because it actually executes the logic instead of setting up the handler first.

JavaFX use parsed variables during initialize

I know how to parse variables to controllers in JavaFX with fxml. But i need to use them in the initialize method of my controller. Is there a ways to do this? The background is, that i have a interface, where you can define different settings. Now you can safe them and have to be able to reopen them. So now when i open a rule, i need to set the values in the new option view. I know, that it works on text fields (UI-Elements) to set Text during initialize but not for variables. I tried different approaches. Like binding with properties (works for visibility property of button (UI-Element) but not for variables to set. Do you know a way or maybe an other approach?
Here is my example:
Controller1:
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.stage.Stage;
/**
*
* #author Sandro
*/
public class FXMLDocumentController implements Initializable {
#FXML
private Button btn_openWindow;
#FXML
private void handleButtonAction(ActionEvent event) {
try {
Stage stage = new Stage();
FXMLLoader loader = new FXMLLoader();
Parent root = loader.load(getClass().getResource("fxml_second.fxml").openStream());
Fxml_secondController cont = (Fxml_secondController)loader.getController();
cont.setFlag(0x00000002);
cont.setIsChange(false);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
} catch (IOException ex) {
Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);
}
}
#Override
public void initialize(URL url, ResourceBundle rb) {
btn_openWindow.setOnAction(this::handleButtonAction);
}
Controller 2:
/**
* FXML Controller class
*
* #author Sandro
*/
public class Fxml_secondController implements Initializable {
#FXML private Button btn_printOut;
private boolean isChange = true;
private int flag = 0x00000001;
private void printOut(ActionEvent event){
System.out.println("isChange: "+isChange);
System.out.println("flag: "+flag);
}
public boolean isIsChange() {
return isChange;
}
public void setIsChange(boolean isChange) {
this.isChange = isChange;
}
public int getFlag() {
return flag;
}
public void setFlag(int flag) {
this.flag = flag;
}
#Override
public void initialize(URL url, ResourceBundle rb) {
btn_printOut.setOnAction(this::printOut);
System.out.println(flag);
}
In controller 2 you see the problem. The console-output in initialize shows 1 but it need to show 2. If i klick on printOut (Button) it prints out the right values which i have set in Controller 1.

Set the controller in the Java code, instead of in FXML.
Remove the fx:controller attribute from fxml_second.fxml, and change the code in FXMLDocumentController as follows:
#FXML
private void handleButtonAction(ActionEvent event) {
try {
Stage stage = new Stage();
FXMLLoader loader = new FXMLLoader(getClass().getResource("fxml_second.fxml"));
Fxml_secondController cont = new Fxml_secondController();
cont.setFlag(0x00000002);
cont.setIsChange(false);
loader.setController(cont);
Parent root = loader.load();
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
} catch (IOException ex) {
Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);
}
}
Another option would be to use a custom component approach for the second fxml.