Develop Reference

Adding dynamic buttons on GridPane FXML JavaFX

I've started a project requested by our instructor building an application in JavaFX.
I used SceneBuilder for FXML Part when I want to add buttons on gridpane, but it didn't work. The connection with the database is okay. On the first part of the application, the user logs in. After that he/she comes on UserWindow, but the buttons aren't displayed.
File Main.java:
package sample;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
Stage window;
Controller c;
ControllerB cB;
#Override
public void start(Stage primaryStage) throws Exception {
window = primaryStage;
FXMLLoader f = new FXMLLoader();
FXMLLoader f2 = new FXMLLoader();
f.setLocation(Main.class.getResource("sample.fxml"));
f2.setLocation(Main.class.getResource("UserWindow.fxml"));
Parent root = f.load();
Parent root2 = f2.load();
Scene s = new Scene(root, 500, 340);
// Controllers
c = f.getController();
c.setMain(this);
c.setScene2(new Scene(root2, 900, 500));
cB = f2.getController();
cB.setMain(this);
cB.setScene(s);
window.setTitle("Remote Works");
window.setScene(s);
window.show();
}
public static void main(String[] args) {
launch(args);
}
public void setUserData(Object o) {
window.setUserData(o);
}
public void setScene(Scene scene) {
window.setScene(scene);
window.show();
}
public void setScene2(Scene scene) {
window.setScene(scene);
window.show();
}
}
File ControllerB.java:
package sample;
import javafx.collections.*;
import javafx.event.ActionEvent;
import javafx.fxml.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.layout.GridPane;
import java.io.IOException;
import java.net.URL;
import java.sql.*;
import java.util.*;
public class ControllerB implements Initializable {
#FXML
private GridPane Box;
#FXML
private Label nameUser;
#FXML
private Label matriculeUser;
#FXML
private Label fonctionUser;
#FXML
private Button deconnect;
private Scene scene1;
private Main main;
ObservableList<String> ecoles;
#Override
public void initialize(URL url, ResourceBundle resourceBundle) {
try {
schoolretrieve();
int size = ecoles.size();
Node[] n = new Node[size];
for (int i = 0; i < n.length; i++) {
FXMLLoader loader = new FXMLLoader(getClass().getResource("Bloc.fxml"));
ControllerItem controller = new ControllerItem();
loader.setController(controller);
n[i] = loader.load();
controller.setButtonInst(ecoles.get(i)); // Until this part all works
Box.getChildren().add(n[i]); // But it doesn't add buttons to GridPane
}
} catch (IOException | NullPointerException | SQLException e) {
//System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
File ControllerItem.java:
package sample;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
public class ControllerItem {
#FXML
private Button buttonInst;
public Button getButtonInst() {
return buttonInst;
}
public void setButtonInst(String s) {
buttonInst.setText(s);
}
}
File Bloc.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<Button fx:id="buttonInst" mnemonicParsing="false" prefHeight="132.0" prefWidth="201.0" stylesheets="#../styles.css" xmlns="http://javafx.com/javafx/10.0.2-internal" xmlns:fx="http://javafx.com/fxml/1" />
File UserWindow.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.shape.*?>
<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="497.0" prefWidth="710.0" styleClass="pane" stylesheets="#../styles.css" xmlns="http://javafx.com/javafx/10.0.2-internal" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.ControllerB">
<left>
<Pane prefHeight="497.0" prefWidth="156.0" BorderPane.alignment="CENTER">
<children>
<ImageView fitHeight="150.0" fitWidth="151.0" layoutX="11.0" pickOnBounds="true" preserveRatio="true" />
<Circle fill="#e1ebf5" layoutX="78.0" layoutY="88.0" opacity="0.18" radius="74.0" stroke="BLACK" strokeType="INSIDE" />
<Label fx:id="nameUser" layoutX="10.0" layoutY="196.0" prefHeight="50.0" prefWidth="136.0" text="Nom Utilisateur :" />
<Label fx:id="fonctionUser" layoutX="11.0" layoutY="259.0" prefHeight="37.0" prefWidth="136.0" text="Statut : " />
<Label fx:id="matriculeUser" layoutX="10.0" layoutY="306.0" prefHeight="37.0" prefWidth="136.0" text="Identifiant : " />
<Button fx:id="deconnect" layoutX="20.0" layoutY="364.0" mnemonicParsing="false" onAction="#onAction" prefHeight="27.0" prefWidth="117.0" text="deconnexion" />
</children>
</Pane>
</left>
<center>
<Pane opacity="0.0" prefHeight="200.0" prefWidth="200.0" style="-fx-background-color: #f7cc3d;"
BorderPane.alignment="CENTER">
<GridPane fx:id="Box" alignment="TOP_CENTER" hgap="3.0" layoutX="70.0" layoutY="96.0"
nodeOrientation="LEFT_TO_RIGHT" opacity="0.95" prefHeight="305.0" prefWidth="415.0"
styleClass="gridpane" stylesheets="#../ss.css" vgap="3.0"/>
</Pane>
</center>
</BorderPane>

So you have file UserWindow.fxml and you have declared a GridPane in it. I suggest you to don't make a separate .fxml file for the button.
Just do it like this in your ControllerB:
#Override
public void initialize(URL url, ResourceBundle resourceBundle) {
schoolretrieve();
int size = ecoles.size();
//Node[] n = new Node[size];
for (int i = 0; i < size; i++) {
//FXMLLoader loader = new FXMLLoader(getClass().getResource("Bloc.fxml"));
//ControllerItem controller = new ControllerItem();
//loader.setController(controller);
//n[i] = loader.load();
//controller.setButtonInst(ecoles.get(i));
//Box.getChildren().add(n[i]);
Button btn = new Button(ecoles.get(i));
Box.add(btn, 0, i); // Button is added to next row every time.
}
}

How to get the controller of an included FXML?

I have a simple two tab application build around JavaFXML and scenebuilder. The tabs do nothing at present because I cannot get past a nullpointer exception when trying to load them.
The java and fxml files are arranged in a Netbeans project like this:
Main Application: The application main class MainApp.java sets the scene and is declared as follows:
package tabpane;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
public class MainApp extends Application {
private static Stage primaryStage;
private AnchorPane rootLayout;
public MainApp() {}
#Override
public void start(Stage primaryStage) {
primaryStage.initStyle(StageStyle.UNDECORATED);
MainApp.primaryStage = primaryStage;
MainApp.primaryStage.setTitle("Account Names");
initRootLayout();
}
public void initRootLayout() {
try {
FXMLLoader loader = new FXMLLoader();
loader.setLocation(MainApp.class.getResource("view/MainView.fxml"));
rootLayout = (AnchorPane) loader.load();
Scene scene = new Scene(rootLayout);
primaryStage.setScene(scene);
primaryStage.show();
} catch (IOException e) {
Logger.getLogger(MainApp.class.getName()).log(Level.SEVERE, null, e);
System.out.println("MainApp: IOException in method: initRootLayout" + e.getMessage());
System.exit(0);
}
}
public Stage getPrimaryStage() {
return primaryStage;
}
public static void main(String[] args) {
launch(args);
}
}
The MainController class declares the two tabs, the Input tab and Account tab, for the application and an exit button for closing the program. This is the MainView. fxml file:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Tab?>
<?import javafx.scene.control.TabPane?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane id="AnchorPane" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="tabpane1.view.MainController">
<children>
<TabPane fx:id="tabPane" prefHeight="345.0" prefWidth="600.0" style="-fx-background-color: blue;" tabClosingPolicy="UNAVAILABLE">
<tabs>
<Tab fx:id="inputTab" closable="false" text="Input">
<content>
<fx:include source="InputView.fxml" />
</content>
</Tab>
<Tab fx:id="detailTab" closable="false" text="Detail">
<content>
<fx:include source="DetailView.fxml" />
</content>
</Tab>
</tabs>
</TabPane>
<Button fx:id="exitBtn" layoutX="529.0" layoutY="355.0" mnemonicParsing="false" onAction="#handleExitBtn" text="Exit" />
</children>
</AnchorPane>
This is the java controller class for the main view contained in MainController.java:
package tabpane1.view;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
public class MainController implements Initializable {
#FXML public TabPane tabPane;
#FXML public Tab inputTab;
#FXML public Tab accountTab;
#FXML private Button exitBtn;
public DetailController detailController;
public InputController inputController;
#Override
public void initialize(URL location, ResourceBundle resources) {
detailController = new FXMLLoader(getClass().getResource("DetailView.fxml")).getController();
// System.out.println(detailController.getClass());
inputController = new FXMLLoader(getClass().getResource("InputView.fxml")).getController();
// System.out.println(inputController.getClass());
}
#FXML private void handleExitBtn() {
System.exit(0);
}
}
The two println statements are simply trying to get the references to the two tabs, which are detailController and inputController, to do something. However, when these are uncommented and run, the following dump is output:
MainApp: IOException in method: initRootLayout
SEVERE: null
file:/G:/J2EE/TabPane_1/dist/run1314937364/TabPane_1.jar!/tabpane1/view/MainView.fxml
javafx.fxml.LoadException:
file:/G:/J2EE/TabPane_1/dist/run1314937364/TabPane_1.jar!/tabpane1/view/MainView.fxml
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
at tabpane1.MainApp.initRootLayout(MainApp.java:43)
at tabpane1.MainApp.start(MainApp.java:33)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at tabpane1.view.MainController.initialize(MainController.java:24)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 13 more
When the printlns are commented out, the outcome is as expected, that is the tab pane is correctly displayed:
As mentioned the detail and input controllers are empty, but for completeness they are as follows:
InputView.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane id="AnchorPane" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="tabpane1.view.InputController">
</AnchorPane>
The controller InputController.java:
package tabpane1.view;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.Initializable;
public class InputController implements Initializable {
#Override
public void initialize(URL location, ResourceBundle resources) {}
}
DetailView.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane id="AnchorPane" prefHeight="400.0" prefWidth="600.0" style="-fx-background-color: transparent;" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="tabpane1.view.DetailController" />
The controller DetailController.java:
package tabpane1.view;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.Initializable;
public class InputController implements Initializable {
#Override
public void initialize(URL location, ResourceBundle resources) {}
}

The way to get reference to the controller of an embedded FXML is described in this article.
You simply have to give an fx:id to the included resource:
<fx:include fx:id="IncludedView" source="InputView.fxml" />
Get a reference to IncludedView in the MainController:
#FXML private Parent IncludedView;
Get a reference to its controller simply by appending the word Controller in addition to the variable name of the embedded element:
#FXML private InputController IncludedViewController;
That is all.
Test it with:
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
public class MainController implements Initializable {
#FXML private Parent IncludedView;
#FXML private InputController IncludedViewController; // $IncludedView;+Controller
#Override
public void initialize(URL location, ResourceBundle resources) {
System.out.println(IncludedView.getClass());
System.out.println(IncludedViewController.getClass() );
}
#FXML private void handleExitBtn() {
System.exit(0);
}
}
An MRE for the sake of future readers:
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class GetEmbeddedController extends Application {
#Override
public void start(Stage primaryStage) {
try {
Pane root = (Pane) FXMLLoader.load(getClass().getResource("MainView.fxml"));
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(null);
}
}
MainView.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.AnchorPane?>
<AnchorPane id="AnchorPane" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/10.0.1"
xmlns:fx="http://javafx.com/fxml/1" fx:controller="MainController">
<children>
<fx:include fx:id="includedView" source="IncludedView.fxml" />
<Button layoutX="401.0" layoutY="354.0" onAction="#handleTestBtn" text="Test Included Controller" />
</children>
</AnchorPane>
MainController.java
import javafx.fxml.FXML;
import javafx.scene.Parent;
public class MainController{
#FXML private Parent includedView; //not used in this demo
/*
* Get a reference to IncludedView controller simply by appending
* the word Controller in addition to the variable name of the embedded
* element:$IncludedView;+Controller
*/
#FXML private IncludedViewController includedViewController;
#FXML private void handleTestBtn() {
includedViewController.showAlert();
}
}
IncludedView.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Text?>
<AnchorPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/10.0.1"
xmlns:fx="http://javafx.com/fxml/1" fx:controller="IncludedViewController">
<children>
<Text layoutX="277.0" layoutY="196.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Included Fxml" />
</children>
</AnchorPane>
IncludedViewController.java
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
public class IncludedViewController{
void showAlert(){
Alert alert = new Alert(AlertType.INFORMATION);
alert.setContentText("Alert invoked by IncludedViewController ");
alert.show();
}
}

JavaFX Windows needs resize to display content

I have this problem with my JavaFX windows, where I added a Scrollpan containing a graph. When I launch the app I need to resize the windows so that the content appears.
Here is the Model:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<VBox xmlns:fx="http://javafx.com/fxml/1" prefHeight="544.0" prefWidth="788.0" xmlns="http://javafx.com/javafx/8.0.121"
fx:controller="Solution.SolutionController">
<MenuBar fx:id="menuBar">
<menus>
<Menu text="File">
<items>
<MenuItem text="Save"/>
</items>
</Menu>
</menus>
</MenuBar>
<VBox fx:id="contenu" alignment="CENTER">
<HBox alignment="CENTER">
<ScrollPane style="-fx-background: WHITE" fx:id="pane" focusTraversable="false" prefHeight="608.0"
prefWidth="700">
</ScrollPane>
</HBox>
<Label fx:id="counter">
</Label>
<VBox.margin>
<Insets top="17.0"/>
</VBox.margin>
</VBox>
<HBox alignment="CENTER" prefWidth="690.0">
<Button onAction="#handleGauche" text="Gauche"/>
<Button onAction="#handleDroite" text="Droite"/>
</HBox>
</VBox>
Here is the controller:
package Solution;
import Main.Individual;
import javafx.embed.swing.SwingNode;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Label;
import javafx.scene.control.MenuBar;
import javafx.scene.control.ScrollPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javax.swing.*;
import java.awt.*;
import java.util.ArrayList;
public class SolutionController {
public VBox contenu;
public Label counter;
public MenuBar menuBar;
public ScrollPane pane;
ArrayList<Individual> graph;
JPanel panel;
int i;
public void init() {
i = 0;
panel = new JPanel();
panel.setBackground(Color.WHITE);
panel.add(graph.get(i).chopper.getContentPane());
panel.validate();
panel.repaint();
counter.setText((i+1) + "/" + graph.size());
SwingNode sn = new SwingNode();
sn.setContent(panel);
pane.setContent(sn);
}
#FXML
void handleDroite(ActionEvent event) {
i = (i + 1) % graph.size();
changeContent();
}
#FXML
void handleGauche(ActionEvent event) {
i = (graph.size() + (i - 1)) % graph.size();
changeContent();
}
public void changeContent(){
counter.setText((i+1) + "/" + graph.size());
panel.add(graph.get(i).chopper.getContentPane());
panel.repaint();
SwingNode sn = new SwingNode();
sn.setContent(panel);
pane.setContent(sn);
}
}
And here is the view:
package Solution;
import Main.Individual;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import java.io.IOException;
import java.util.ArrayList;
public class SolutionApplication extends Application{
ArrayList<Individual> graphI;
public SolutionApplication(ArrayList<Individual> graph) {
graphI = new ArrayList<>(graph);
}
public void start(Stage primaryStage) throws IOException {
FXMLLoader loader = new FXMLLoader(getClass().getResource("Solution.fxml"));
Parent root = loader.load();
SolutionController controller = loader.getController();
controller.graph = new ArrayList<>(graphI);
controller.init();
primaryStage.setTitle("Main Window");
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
}
I did stumble on this post
javafx SwingNode not working until window is resized
However they say its a bug with the JDK? I use version 10
I'd like to know how I can fix this.
Thanks for reading.

Java Fx, Edit the textarea of a specific tab

Well, my question is simple.
I am building an application with Java Fx, and I have a TabPane.
When I open a new Tab, that Tab gets it's content by a fxml file.
tab.setContent((Node)FXMLLoader.load(this.getClass().getResource("/main/textEditor.fxml")))
Fine, that works well, it always loads the same file on all Tabs, so, all textarea on all tabs have the same id.
The problem is, with java, I can only get the information of the textarea of the first Tab.
How can i edit specifically the textarea of one tab in particular?
An example of what i want to do :
Main
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.geometry.Rectangle2D;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Screen;
import javafx.stage.Stage;
public class Main extends Application{
public static void main(String[] args) {
Application.launch(Main.class, args);
}
#Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("/tabPane/test.fxml"));
Screen screen = Screen.getPrimary();
Rectangle2D bounds = screen.getVisualBounds();
stage.setScene(new Scene(root));
stage.show();
}
}
test.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import java.net.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.layout.AnchorPane?>
<VBox prefHeight="400.0" prefWidth="640.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="tabPane.controller">
<children>
<MenuBar VBox.vgrow="NEVER">
<menus>
<Menu mnemonicParsing="false" onAction="#test" text="File">
<items>
<MenuItem fx:id="insert" mnemonicParsing="false" onAction="#test" text="Insert" />
</items>
</Menu>
</menus>
</MenuBar>
<AnchorPane maxHeight="-1.0" maxWidth="-1.0" prefHeight="-1.0" prefWidth="-1.0" VBox.vgrow="ALWAYS">
<children>
<Label alignment="CENTER" layoutX="155.0" layoutY="177.0" style="
" text="Drag components from Library here…" textAlignment="CENTER" textFill="#9f9f9f" wrapText="false">
<font>
<Font size="18.0" />
</font>
</Label>
<TabPane fx:id="tabPane" prefHeight="375.0" prefWidth="640.0" tabClosingPolicy="UNAVAILABLE">
<tabs>
<Tab text="Untitled Tab 1">
<content>
<TextArea fx:id="textarea" prefHeight="200.0" prefWidth="200.0" text="a" />
</content>
</Tab>
<Tab text="Untitled Tab 2">
<content>
<TextArea fx:id="textarea1" prefHeight="200.0" prefWidth="200.0" text="a" />
</content>
</Tab>
</tabs>
</TabPane>
</children>
</AnchorPane>
</children>
<stylesheets>
<URL value="#../../../../BasicApplicatio11n_css/BasicApplication.css" />
controller.java
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TextArea;
public class controller implements Initializable{
#FXML
private TextArea textarea;
#Override
public void initialize(URL arg0, ResourceBundle arg1) {
}
public void test(ActionEvent event){
textarea.appendText("Text");
}
}
There are two tabs on this example, when the button is pressed, I want to add the text on the current selected tab.

There are a few different ways to do this. One way is to let the controller for the tab content expose the textProperty from the text area. Then in your "main controller", create a StringProperty field. When you create a new tab, just observe its selected property and update the string property field to point to the one from the current controller. Then you can easily load text into the "current" pane.
Here's a simple example of this:
EditorController:
import javafx.beans.property.StringProperty;
import javafx.fxml.FXML;
import javafx.scene.control.TextArea;
public class EditorController {
#FXML
private TextArea textArea ;
public StringProperty textProperty() {
return textArea.textProperty() ;
}
}
with textEditor.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.control.TextArea?>
<BorderPane xmlns:fx="http://javafx.com/fxml/1" fx:controller="EditorController">
<center>
<TextArea fx:id="textArea"/>
</center>
</BorderPane>
And then the MainController could look like:
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import javafx.beans.property.StringProperty;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.stage.FileChooser;
public class MainController {
#FXML
private TabPane tabPane ;
private StringProperty currentText ;
public void initialize() throws IOException {
// load an initial tab:
newTab();
}
#FXML
private void newTab() throws IOException {
Tab tab = new Tab("Untitled text");
FXMLLoader loader = new FXMLLoader(getClass().getResource("textEditor.fxml"));
tab.setContent(loader.load());
EditorController controller = loader.getController() ;
tab.selectedProperty().addListener((obs, wasSelected, isNowSelected) -> {
if (isNowSelected) {
currentText = controller.textProperty();
}
});
tabPane.getTabs().add(tab);
tabPane.getSelectionModel().select(tab);
}
#FXML
private void load() {
FileChooser chooser = new FileChooser();
File file = chooser.showOpenDialog(tabPane.getScene().getWindow());
if (file != null) {
Path path = file.toPath();
try {
currentText.set(String.join("\n", Files.readAllLines(path)));
} catch (IOException e) {
Alert alert = new Alert(AlertType.ERROR);
alert.setContentText("Unable to load file "+path);
alert.setTitle("Load error");
alert.showAndWait();
}
tabPane.getSelectionModel().getSelectedItem().setText(path.getFileName().toString());
}
}
}
with main.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.control.TabPane?>
<?import javafx.scene.control.Button?>
<?import javafx.geometry.Insets?>
<BorderPane xmlns:fx="http://javafx.com/fxml/1" fx:controller="MainController">
<center>
<TabPane fx:id="tabPane"/>
</center>
<bottom>
<HBox alignment="CENTER" spacing="5">
<padding>
<Insets top="5" right="5" left="5" bottom="5" />
</padding>
<Button text="Load..." onAction="#load" />
<Button text="New" onAction="#newTab"/>
</HBox>
</bottom>
</BorderPane>
For completeness, a simple application class:
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws IOException {
Parent root = FXMLLoader.load(getClass().getResource("main.fxml"));
Scene scene = new Scene(root, 800, 800);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
There are other approaches, e.g. you could just change the button's onAction property when the tab selection changes, etc.

JavaFX showing view make in scene builder with controller

I have this controller:
package cz.vutbr.feec.bmds.cv2;
import java.awt.Button;
import java.awt.TextField;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Slider;
public class TestGuiController {
private int buttonPressed = 0;
#FXML
private Button tlacitko;
#FXML
private TextField textovePole;
#FXML
private Slider slider;
public void buttonPressed(ActionEvent e) {
buttonPressed++;
textovePole.setText(Integer.toString(buttonPressed));
}
}
this fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.BorderPane?>
<AnchorPane prefHeight="200.0" prefWidth="200.0" xmlns:fx="http://javafx.com/fxml" fx:controller="cz.vutbr.feec.bmds.cv2.TestGuiController">
<children>
<Button fx:id="tlacitko" layoutX="30.0" layoutY="40.0" mnemonicParsing="false" onTouchPressed="#buttonPressed" text="Button" />
<Slider fx:id="slider" layoutX="157.0" layoutY="17.0" orientation="VERTICAL" />
<TextField fx:id="textovePole" layoutX="14.0" layoutY="89.0" prefWidth="134.0" />
</children>
</AnchorPane>
and this is my main class:
package cz.vutbr.feec.bmds.cv2;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("TestGui.fxml"));
primaryStage.setTitle("Titulek");
primaryStage.setScene(new Scene(root,300,275));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
When I run this through ant I get message box with error (exception during running application). I tried simple fxml without controller and it works so I am guesing I do something wrong with controller. What I must change to have it working?

I must answer my own question. Problem was in TestGuiController where I used java.awt.Button and java.awt.TextField instead of javafx.scene.control.Button and javafx.scene.control.TextField.

I'm not 100% sure but try:
in FXML: Button: onAction instead of onTouchPressed
Please provide the exact Exception message.