Develop Reference

Create a null-safe BooleanBinding with JavaFX 8

I need help creating a null-safe BooleanBinding. It has to be null-safe since I can not provide default values for all attributes in the model (one reason: the model contains enumerations). My first approach has been as follows:
executeButtonDisabled.bind(missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.CREATED)));
final BooleanBinding isNotExecutingBinding = missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.EXECUTING));
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding)
But that approach does not work because the complete expression is evaluated which results in a NullPointerException (but it correctly updates the buttons, when a property is provided). Now I am trying to use the Bindings class as suggested in JavaFX binding and null values, but I can't make it work. Here's my current approach:
final BooleanBinding isNotCreatedBinding = Bindings.createBooleanBinding(
() -> mission.isNull().getValue()
? true
: missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.CREATED).getValue());
final BooleanBinding isNotExecutingBinding = Bindings.createBooleanBinding(
() -> mission.isNull().getValue()
? true
: missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.EXECUTING).getValue());
executeButtonDisabled.bind(isNotCreatedBinding);
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding);
But this does not work and I do not understand why. It seems that the property binding for modelProperty() does not work here! Can you explain to me how-to convert the first working solution (at least without null) to a proper null-safe solution?
Edit 2016-04-26: The suggested solution does not work, therefore I created a simple fully-working example:
Mission.java:
package de.florianwolters.example.javafx.bindings;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Mission {
enum Status {
CREATED,
EXECUTING,
COMPLETED,
CANCELED;
}
private final StringProperty shortName = new SimpleStringProperty();
private final ObjectProperty<Status> status = new SimpleObjectProperty<>();
public Mission(final String shortName) {
this.setShortName(shortName);
this.setStatus(Status.CREATED);
}
public String getShortName() {
return shortNameProperty().get();
}
public void setShortName(final String shortName) {
shortNameProperty().set(shortName);
}
public StringProperty shortNameProperty() {
return shortName;
}
public Status getStatus() {
return statusProperty().get();
}
public void setStatus(final Status status) {
statusProperty().set(status);
}
public ObjectProperty<Status> statusProperty() {
return status;
}
}
MissionDetailsViewModel.java:
package de.florianwolters.example.javafx.bindings;
import javafx.beans.binding.Bindings;
import javafx.beans.binding.BooleanBinding;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.ReadOnlyBooleanProperty;
import javafx.beans.property.ReadOnlyBooleanWrapper;
import javafx.beans.property.SimpleObjectProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class MissionDetailsViewModel {
/**
* The logger used for logging in the `MissionDetailsViewModel` class.
*/
private static final Logger LOGGER = LoggerFactory.getLogger(
MissionDetailsViewModel.class);
private ObjectProperty<Mission> mission = new SimpleObjectProperty<>();
private final ReadOnlyBooleanWrapper executeButtonDisabled = new ReadOnlyBooleanWrapper(true);
private final ReadOnlyBooleanWrapper completeButtonDisabled = new ReadOnlyBooleanWrapper(true);
private final ReadOnlyBooleanWrapper cancelButtonDisabled = new ReadOnlyBooleanWrapper(true);
/**
* Constructs a `MissionDetailsViewModel`.
*/
public MissionDetailsViewModel(final ObjectProperty<Mission> mission) {
this.mission.bind(mission);
// partialWorkingBinding();
notWorkingBinding();
}
private void notWorkingBinding() {
final BooleanBinding isNotCreatedBinding = Bindings.createBooleanBinding(
() -> missionProperty().isNull().get()
? true
: missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.CREATED).get(),
missionProperty());
final BooleanBinding isNotExecutingBinding = Bindings.createBooleanBinding(
() -> mission.isNull().get()
? true
: missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.EXECUTING).get(),
missionProperty());
executeButtonDisabled.bind(isNotCreatedBinding);
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding);
}
private void partialWorkingBinding() {
executeButtonDisabled.bind(missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.CREATED)));
final BooleanBinding isNotExecutingBinding = missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.EXECUTING));
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding);
}
public boolean isExecuteButtonDisabled() {
return executeButtonDisabledProperty().get();
}
public ReadOnlyBooleanProperty executeButtonDisabledProperty() {
return executeButtonDisabled;
}
public boolean isCompleteButtonDisabled() {
return completeButtonDisabledProperty().get();
}
public ReadOnlyBooleanProperty completeButtonDisabledProperty() {
return completeButtonDisabled;
}
public boolean isCancelButtonDisabled() {
return cancelButtonDisabledProperty().get();
}
public ReadOnlyBooleanProperty cancelButtonDisabledProperty() {
return cancelButtonDisabled;
}
public Mission getMission() {
return missionProperty().get();
}
public void setMission(final Mission mission) {
missionProperty().set(mission);
}
public ObjectProperty<Mission> missionProperty() {
return mission;
}
}
MissionDetailsViewModelTest.java:
package de.florianwolters.example.javafx.bindings;
import static eu.lestard.assertj.javafx.api.Assertions.assertThat;
import javafx.beans.property.SimpleObjectProperty;
import org.junit.Before;
import org.junit.Test;
public final class MissionDetailsViewModelTest {
private Mission mission;
private MissionDetailsViewModel viewModel;
#Before
public void setUp() {
mission = new Mission("My Short Name");
viewModel = new MissionDetailsViewModel(new SimpleObjectProperty<Mission>(mission));
}
#Test
public void testInitialValues() {
assertThat(viewModel.executeButtonDisabledProperty()).isFalse();
assertThat(viewModel.completeButtonDisabledProperty()).isTrue();
assertThat(viewModel.cancelButtonDisabledProperty()).isTrue();
}
#Test
public void testMissionStatusSetToExecuting() {
mission.setStatus(Mission.Status.EXECUTING);
assertThat(viewModel.executeButtonDisabledProperty()).isTrue();
assertThat(viewModel.completeButtonDisabledProperty()).isFalse();
assertThat(viewModel.cancelButtonDisabledProperty()).isFalse();
}
#Test
public void testMissionStatusSetToCompleted() {
mission.setStatus(Mission.Status.COMPLETED);
assertThat(viewModel.executeButtonDisabledProperty()).isTrue();
assertThat(viewModel.completeButtonDisabledProperty()).isTrue();
assertThat(viewModel.cancelButtonDisabledProperty()).isTrue();
}
#Test
public void testMissionStatusSetToCanceled() {
mission.setStatus(Mission.Status.CANCELED);
assertThat(viewModel.executeButtonDisabledProperty()).isTrue();
assertThat(viewModel.completeButtonDisabledProperty()).isTrue();
assertThat(viewModel.cancelButtonDisabledProperty()).isTrue();
}
}
The unit test fails with the code above (the method notWorkingBinding() is used) but works with the method partialWorkingBinding(). What am I doing wrong?

You set up the calculation function for isNotCreatedBinding, but you didn't set the dependencies for the binding. You need to add mision as dependency:
Bindings.createBooleanBinding(
() -> mission.isNull().getValue()
? true
: missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.CREATED).getValue(), mission);
EDIT
You need to listen to the statusProperty instead of missionProperty, which will not work with createBooleanBinding when missionProperty().get() == null.
But you can use a When binding:
(is causing a NullPointerException as already mentioned in the question)
BooleanBinding isNotCreatedBinding = new When(mission.isNotNull()).then(mission.get().statusProperty().isNotEqualTo(Mission.Status.CREATED)).otherwise(false);
Or a more low-level solution:
missionProperty().addListener((ov, m, m1) -> {
if (m1 != null) {
executeButtonDisabled.bind(m1.statusProperty().isNotEqualTo(Mission.Status.CREATED));
}else {
executeButtonDisabled.unbind();
executeButtonDisabled.set(false);
}
});

Tomas Mikula's ReactFX framework (v 2.0) has this functionality built in:
import org.reactfx.value.Val;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleObjectProperty;
public class NestedBindingTest {
public static void main(String[] args) {
BooleanProperty disable = new SimpleBooleanProperty();
disable.addListener((obs, wasDisabled, isNowDisabled) ->
System.out.println("disable: "+wasDisabled+" -> "+isNowDisabled));
ObjectProperty<Item> item = new SimpleObjectProperty<>();
Val<Item.Status> status = Val.flatMap(item, Item::statusProperty);
disable.bind(status.map(s -> s == Item.Status.PENDING).orElseConst(true));
Item i = new Item();
System.out.println("Setting item");
item.set(i);
System.out.println("Setting item status to PENDING");
i.setStatus(Item.Status.PENDING);
System.out.println("Setting item status to READY");
i.setStatus(Item.Status.READY);
System.out.println("Setting item to null");
item.set(null);
}
public static class Item {
public enum Status {PENDING, READY}
private final ObjectProperty<Status> status = new SimpleObjectProperty<>();
public final ObjectProperty<Status> statusProperty() {
return this.status;
}
public final NestedBindingTest.Item.Status getStatus() {
return this.statusProperty().get();
}
public final void setStatus(final NestedBindingTest.Item.Status status) {
this.statusProperty().set(status);
}
}
}

Using POJOs as model layer in JavaFX application

I'm creating simple JavaFX application. I want my model layer to be completely independent from JavaFX - no StringProperty, IntegerProperty and etc. as fields. I want it to be POJO. Main reason to do so is that I want it to be Serializable.
I've created DataRepository - simple CRUD-like interface and some implementations of it, so I can at anytime change where I store my data - XML file, SQLite database or anything else. I also have to somehow connect my data storage with JavaFX (to display its content in TableView), so I decided to create my implementation of ObservableList which wraps my repository. My question is - is there any other way? ObservableList contains about 30 methods to implement and it looks like I'm doing something wrong.
My (simplified) model:
public class Movie implements Serializable {
private String title;
private String director;
public Movie() {
}
public Movie(String title, String director) {
this.title = title;
this.director = director;
}
// Getters and setters, equals etc...
}
MovieRepository:
public interface MovieRepository {
public void add(Movie movie);
public void remove(String title);
public void remove(int index);
public Movie get(String title);
public Movie get(int index);
public List<Movie> getAll();
}
Controller for my main view:
public class MainController {
#FXML
private TableView<Movie> movieTable;
#FXML
private TableColumn<Movie, String> movieTitleColumn;
#FXML
private Label titleLabel;
private MovieRepository movies = new DBMovieRepository(); //MovieRepository implementation which uses SQLite DB to store data
private MainApp app;
#FXML
private void initialize() {
movieTable.setItems(new ObservableMovies(movies));
// ObservableMovies is my implementation of ObservableList
// It basically wraps methods from MovieRepository
// and notifies listeners
showMovieDetails(null);
movieTitleColumn.setCellValueFactory(cellData -> new ReadOnlyStringWrapper(cellData.getValue().getTitle()));
movieTable.getSelectionModel().selectedItemProperty()
.addListener((observable, oldValue, newValue) -> showMovieDetails(newValue));
}
private void showMovieDetails(Movie movie) {
if(movie != null) {
titleLabel.setText(movie.getTitle());
} else {
titleLabel.setText("");
}
}
#FXML
private void handleNew() {
Movie movie = new Movie();
app.showNewMovieDialog(movie);
movieTable.getItems().add(movie);
}
public void setApp(MainApp app) {
this.app = app;
}
}

You have a couple of options here (maybe more), which are covered in other questions on this site. However, for convenience, I'll summarize them here too.
1. Use JavaFX Properties and make the class Serializable
You can do this with a custom serialized form. Make the JavaFX properties transient and implement readObject and writeObject to store the values they wrap:
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Objects;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Movie implements Serializable {
private transient StringProperty title = new SimpleStringProperty();
private transient StringProperty director = new SimpleStringProperty();
public Movie() {
}
public Movie(String title, String director) {
setTitle(title);
setDirector(director);
}
#Override
public int hashCode() {
return Objects.hash(getDirector(), getTitle());
}
#Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Movie other = (Movie) obj;
return Objects.equals(getTitle(), other.getTitle())
&& Objects.equals(getDirector(), other.getDirector());
}
public final StringProperty titleProperty() {
return this.title;
}
public final String getTitle() {
return this.titleProperty().get();
}
public final void setTitle(final String title) {
this.titleProperty().set(title);
}
public final StringProperty directorProperty() {
return this.director;
}
public final String getDirector() {
return this.directorProperty().get();
}
public final void setDirector(final String director) {
this.directorProperty().set(director);
}
private void readObject(ObjectInputStream s) throws ClassNotFoundException, IOException {
s.defaultReadObject();
title = new SimpleStringProperty((String) s.readObject());
director = new SimpleStringProperty((String) s.readObject());
}
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
s.writeObject(getTitle());
s.writeObject(getDirector());
}
}
2. Use a POJO with "bound properties".
See JavaBean wrapping with JavaFX Properties for details. In brief:
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
public class Movie {
private String title ;
private String director ;
private final PropertyChangeSupport propertySupport ;
public Movie(String title, String director) {
this.title = title ;
this.director = director ;
this.propertySupport = new PropertyChangeSupport(this);
}
public Movie() {
this("", "");
}
public String getTitle() {
return title ;
}
public String setTitle(String title) {
String oldTitle = this.title ;
this.title = title ;
propertySupport.firePropertyChange("title", oldTitle, title);
}
// similarly for director...
public void addPropertyChangeListener(PropertyChangeListener listener) {
propertySupport.addPropertyChangeListener(listener);
}
// hashCode and equals...
}
For wanting to wrap your repository as an observable list, instead wrap it with a repository implementation that uses an observable list:
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
public class ObservableMovieRepository implements MovieRepository {
private final MovieRepository repository ;
private final ObservableList<Movie> movieList;
public ObservableMovieRepository(MovieRepository repository) {
this.repository = repository ;
this.movieList = FXCollections.observableArrayList(repository.getAll());
}
#Override
public void add(Movie movie) {
repository.add(movie);
movieList.add(movie);
}
#Override
public void remove(String title) {
Movie movie = get(title);
repository.remove(title);
movieList.remove(title);
}
#Override
public void remove(int index) {
repository.remove(index);
movieList.remove(index);
}
#Override
public Movie get(String title) {
return repository.get(title);
}
#Override
public Movie get(int index) {
return movieList.get(index);
}
#Override
public ObservableList<Movie> getAll() {
return movieList ;
}
}
This uses the standard ObservableList implementation that copies an existing list on creation, and the implementation keeps that list in sync with the list in the wrapped repository. Now your UI code can do
ObservableMovieRepository movies = new ObservableMovieRepository(new DBMovieRepository());
// ...
movieTable.setItems(movies.getAll());
With the Movie class above, you would just do
movieTitleColumn.setCellValueFactory(cellData -> cellData.getValue().titleProperty());
If you use the POJO version you can do
movieTitleColumn.setCellValueFactory(cellData -> {
try {
return new JavaBeanStringPropertyBuilder()
.bean(cellData.getValue())
.name("title")
.build();
} catch (Exception e) { throw new RuntimeException(e); }
}

There seem to be multiple question in here, so I'm not really sure, if I understood you correctly, but I will try to split it up a bit.
I want my model layer to be completely independent from JavaFX - no
StringProperty, IntegerProperty and etc. as fields. I want it to be
POJO.
You could mark your properties as transient. Then you just need to wrap them around your values and it will be both JavaFX compliant and Serializable. You just have to propagate changes back to your backing attributes.
I also have to somehow connect my data storage with JavaFX (to display
its content in TableView), so I decided to create my implementation of
ObservableList which wraps my repository. My question is - is there
any other way?
Very limited information on this and I really don't know, why you would need to create your own implementation of ObservableList, but to keep it POJO, you could maintain plain java.util.Collections in your bean and provide transient ObservableLists, which you can create on creation by wrapping your java.util.Lists in your POJO. You can find those methods in the FXCollections utility class.
ObservableList contains about 30 methods to implement and it looks
like I'm doing something wrong.
If you really need to implement it, you can inherit from ObservableListBase.

JavaFx: can data binding (textfield) be used in production mode?

I use java 8.0.45. I have implemented my first javafx application (very simple) with data binding. However, biding from user input-> pojo seems to work with bugs. I've checked about 200 times. I entered new values in text fields and after that I checked model values. The same code, the same my behaviour. Sometimes everything works fine (in most cases - about 80-90%) sometimes model value!=textfield value. I've noticed the following. Data binding for some certain text field works,works and then at some point of time that binding stops working and all new values for this certain textfield are not passed to model. Nor exceptions. Nor any warnings. Nothing. Just binding doesn't work.
I have 4 textfiled which are created via fxml. Two for string model type. One for integer. One for bigdecimal. The problem happens to all these fields(sometimes to one, sometimes to several). As my number fields can have null values, I use for example PropertyObject but not IntegerProperty (people from openjfx advised so).
So is this JavaFx bug or what? P.S. I use felix osgi, weld cdi, and pax - I don't know if it matters...
My code is the following:
DTO - POJO Model
public class Task {
private String name;
private Integer order;
private BigDecimal weight;
private String comment;
private final PropertyChangeSupport propertyChangeSupport;
public Task() {
this.propertyChangeSupport = new PropertyChangeSupport(this);
}
public String getName() {
return name;
}
public void setName(String name) {
String pv = this.name ;
this.name = name;
propertyChangeSupport.firePropertyChange("name", pv, name);
}
public Integer getOrder() {
return order;
}
public void setOrder(Integer order) {
Integer pv = this.order;
this.order = order;
propertyChangeSupport.firePropertyChange("order", pv, this.order);
}
public BigDecimal getWeight() {
return weight;
}
public void setWeight(BigDecimal weight) {
BigDecimal pv = this.weight;
this.weight = weight;
propertyChangeSupport.firePropertyChange("weight", pv, weight);
}
public String getComment() {
return comment;
}
public void setComment(String comment) {
String pv = this.comment;
this.comment = comment;
propertyChangeSupport.firePropertyChange("comment", pv, this.comment);
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
propertyChangeSupport.addPropertyChangeListener(listener);
}
}
Adapter
public class TaskAdapter {
private StringProperty nameProperty;
private ObjectProperty<Integer> orderProperty;
private ObjectProperty<BigDecimal> weightProperty;
private StringProperty commentProperty;
public TaskAdapter(Task task) {
try {
nameProperty=new JavaBeanStringPropertyBuilder().bean(task).name("name").build();
orderProperty=new JavaBeanObjectPropertyBuilder<Integer>().bean(task).name("order").build();
weightProperty=new JavaBeanObjectPropertyBuilder<BigDecimal>().bean(task).name("weight").build();
commentProperty=new JavaBeanStringPropertyBuilder().bean(task).name("comment").build();
} catch (NoSuchMethodException ex) {
Logger.getLogger(this.getClass().getName()).log(Level.SEVERE, null, ex);
}
}
public StringProperty getNameProperty() {
return nameProperty;
}
public ObjectProperty<Integer> getOrderProperty() {
return orderProperty;
}
public ObjectProperty<BigDecimal> getWeightProperty() {
return weightProperty;
}
public StringProperty getCommentProperty() {
return commentProperty;
}
}
BigDecimal Converter
public class SimpleBigDecimalStringConverter extends StringConverter<BigDecimal>{
#Override
public String toString(BigDecimal i) {
if (i == null) {
return "" ;
} else {
return i.toString();
}
}
#Override
public BigDecimal fromString(String string) {
if (string.trim().length() == 0) {
return null ;
} else {
try {
return new BigDecimal(string);
} catch (NumberFormatException nfe) {
return null ;
}
}
}
}
IntegerConverter
public class SimpleIntegerStringConverter extends StringConverter<Integer>{
#Override
public String toString(Integer i) {
if (i == null) {
return "" ;
} else {
return i.toString();
}
}
#Override
public Integer fromString(String string) {
if (string.trim().length() == 0) {
return null ;
} else {
try {
return Integer.valueOf(string);
} catch (NumberFormatException nfe) {
return null ;
}
}
}
}
Initializing code
Task task=new Task();
TaskAdapter adapter=new TaskAdapter(task);
nameTextField.textProperty().bindBidirectional(adapter.getNameProperty());
orderTextField.textProperty().bindBidirectional(adapter.getOrderProperty(),new SimpleIntegerStringConverter());
weightTextField.textProperty().bindBidirectional(adapter.getWeightProperty(),new BigDecimalStringConverter());
commentTextField.textProperty().bindBidirectional(adapter.getCommentProperty());

What is happening
JavaFX Bindings use WeakChangeListeners behind the scenes to implement the binding. This means that the binding itself can be garbage collected if no other references to it are in scope. In your code, the adapter is defined as a local variable, so it gets prematurely garbage collected at some arbitrary time when the gc runs.
Demo
Here's a demo using your code that shows the issue. It has the same text fields you define, plus two buttons. One button dumps the value of the task to the console, the other forces the garbage collector to run. You'll see that the binding stops working as soon as you run the gc.
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
import javafx.util.converter.BigDecimalStringConverter;
public class POJOBindingExample extends Application {
private TextField nameTextField = new TextField();
private TextField orderTextField = new TextField();
private TextField weightTextField = new TextField();
private TextField commentTextField = new TextField();
#Override
public void start(Stage primaryStage) {
Task task = new Task();
TaskAdapter adapter = new TaskAdapter(task);
nameTextField.textProperty().bindBidirectional(adapter.getNameProperty());
orderTextField.textProperty().bindBidirectional(adapter.getOrderProperty(),new SimpleIntegerStringConverter());
weightTextField.textProperty().bindBidirectional(adapter.getWeightProperty(),new BigDecimalStringConverter());
commentTextField.textProperty().bindBidirectional(adapter.getCommentProperty());
GridPane grid = new GridPane();
grid.addRow(0, new Label("Name:"), nameTextField);
grid.addRow(1, new Label("Order:"), orderTextField);
grid.addRow(2, new Label("Weight:"), weightTextField);
grid.addRow(3, new Label("Comment:"), commentTextField);
Button showButton = new Button("Show Task");
showButton.setOnAction(e -> {
System.out.println(task.getName());
System.out.println(task.getOrder());
System.out.println(task.getWeight());
System.out.println(task.getComment());
System.out.println();
});
Button gcButton = new Button("Run GC");
gcButton.setOnAction(e -> System.gc());
HBox buttons = new HBox(10, showButton, gcButton);
BorderPane.setAlignment(grid, Pos.CENTER);
BorderPane.setAlignment(buttons, Pos.CENTER);
BorderPane.setMargin(grid, new Insets(10));
BorderPane.setMargin(buttons, new Insets(10));
BorderPane root = new BorderPane(grid, null, null, buttons, null);
Scene scene = new Scene(root);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Fix
To fix the problem, you need to ensure a reference to the TaskAdapter persists as long as you need it. In the above code, if you move the reference to the TaskAdapter so that it is an instance field, everything will work as required:
public class POJOBindingExample extends Application {
private TextField nameTextField = new TextField();
private TextField orderTextField = new TextField();
private TextField weightTextField = new TextField();
private TextField commentTextField = new TextField();
private TaskAdapter adapter;
#Override
public void start(Stage primaryStage) {
Task task = new Task();
adapter = new TaskAdapter(task);
// ... etc
}
}
You might also be interested in reading Tomas Mikula's blog, though I don't think you can use his library directly to implement binding to a POJO.

The table cells are empty in my tableview. JavaFX + Scenebuilder

I am trying to get the table cells to show the string when i create new rows. But all the rows are just empty. Do anyone know what i am doing wrong?
Here is the main class:
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Cursor;
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("/fxml/BasketCase_GUI_0.3.fxml"));
Scene scene = new Scene(root,1110,740);
scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
primaryStage.setResizable(false);
primaryStage.setScene(scene);
primaryStage.setTitle("Basket Case_Beta");
primaryStage.show();
scene.setCursor(Cursor.DEFAULT);
}
public static void main(String[] args) throws Exception {
launch(args);
}
}
This is normal and working so i dont think you need to worry about that one.
Here is the controller class. Where I think the problem might be.
package application;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
public class MainController implements Initializable {
#FXML
TableView<Table> TableID;
#FXML
TableColumn<Table, Integer> aPlayerID;
#FXML
TableColumn<Table, String> aLeague;
#FXML
TableColumn<Table, String> aName;
private int aNumber = 1;
SimpleStringProperty str = new SimpleStringProperty();
public MainController() {
str.set("Hello");
}
final ObservableList<Table> data = FXCollections.observableArrayList(
new Table(aNumber++, "hehe", "hoho"),
new Table(aNumber++, "hehe", "hoho"),
new Table(aNumber++, "hehe", "hoho")
);
public void buttonClick(ActionEvent event) {
data.add(new Table(aNumber++, "hehe", "hoho"));
TableID.getColumns().addAll(aPlayerID, aLeague, aName);
}
#Override
public void initialize(URL arg0, ResourceBundle arg1) {
aPlayerID.setCellValueFactory( new PropertyValueFactory<Table, Integer>("bPlayerID"));
aLeague.setCellValueFactory( new PropertyValueFactory<Table, String>("bLeague"));
aName.setCellValueFactory( new PropertyValueFactory<Table, String>("bName"));
TableID.setItems(data);
}
}
And here is also the table class thats needed for the tableviewer
package application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
public class Table {
private final SimpleIntegerProperty bPlayerID;
private final SimpleStringProperty bLeague;
private final SimpleStringProperty bName;
public Table(int cPlayerID, String cLeague, String cName) {
this.bPlayerID = new SimpleIntegerProperty(cPlayerID);
this.bLeague = new SimpleStringProperty(cLeague);
this.bName = new SimpleStringProperty(cName);
}
public int getbPlayerID() {
return bPlayerID.get();
}
public void setbPlayerID(int v) {
bPlayerID.set(v);
}
public String getbLeague() {
return bLeague.get();
}
public void setbLeague(String v) {
bLeague.set(v);
}
public String getbName() {
return bName.get();
}
public void setbName(String v) {
bName.set(v);
}
}
Do you guys know what could be wrong or maybe suggest how I could add just the tableviewer with code that still works with the rest of the fxml file from the scenebuilder?

The names of your get methods are wrong. According to the PropertyValueFactory documentation, if you pass in a property name of "xyz", the property value factory will first look for a method xyzProperty() belonging to the object in the table row. If it doesn't find that, it will fall back on looking for a method called getXyz() (carefully look at the capitalization there), wrapping the result in a ReadOnlyObjectWrapper.
So the following would work:
package application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
public class Table {
private final SimpleIntegerProperty bPlayerID;
private final SimpleStringProperty bLeague;
private final SimpleStringProperty bName;
public Table(int cPlayerID, String cLeague, String cName) {
this.bPlayerID = new SimpleIntegerProperty(cPlayerID);
this.bLeague = new SimpleStringProperty(cLeague);
this.bName = new SimpleStringProperty(cName);
}
public int getBPlayerID() {
return bPlayerID.get();
}
public void setBPlayerID(int v) {
bPlayerID.set(v);
}
public String getBLeague() {
return bLeague.get();
}
public void setBLeague(String v) {
bLeague.set(v);
}
public String getBName() {
return bName.get();
}
public void setBName(String v) {
bName.set(v);
}
}
However, as stated in the PropertyValueFactory documentation, the properties in this case would not be "live": in other words if the values change, the table will not automatically update. Additionally, if you wanted to make the table editable, it wouldn't update the properties without some explicit wiring to call the set methods.
It's better to define your table model using the outline in the Properties and Bindings tutorial:
package application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Table {
private final IntegerProperty bPlayerID;
private final StringProperty bLeague;
private final StringProperty bName;
public Table(int cPlayerID, String cLeague, String cName) {
this.bPlayerID = new SimpleIntegerProperty(cPlayerID);
this.bLeague = new SimpleStringProperty(cLeague);
this.bName = new SimpleStringProperty(cName);
}
public int getBPlayerID() {
return bPlayerID.get();
}
public void setBPlayerID(int v) {
bPlayerID.set(v);
}
public IntegerProperty bPlayerIDProperty() {
return bPlayerID ;
}
public String getBLeague() {
return bLeague.get();
}
public void setBLeague(String v) {
bLeague.set(v);
}
public StringProperty bLeagueProperty() {
return bLeague ;
}
public String getBName() {
return bName.get();
}
public void setBName(String v) {
bName.set(v);
}
public StringProperty bNameProperty() {
return bName ;
}
}
If you do that, then (in Java 8) you can use the following cell value factories, instead of the PropertyValueFactory:
aPlayerID.setCellValueFactory(cellData -> cellData.getValue().bPlayerIDProperty());
which will allow the compiler to catch any errors, instead of it just failing silently at runtime.

in stringproperty you gotto add asobjects() method after cellData.getValue().bPlayerIDProperty())... so I hope that would help

ListView is not reflecting changes

I created a TableView a while back and registered Properties to each of the TableColumns. Editing of the internal data reflected itself back in the TableView just fine.
With a ListView, however, it is a different story. The changes are not being shown right away unless I close the frame and open it again.
My ListView consists of ActionSteps. Note that I used the Javafx beans properties.
package application.objects;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.function.IntPredicate;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class ActionStep {
private StringProperty actionStepID;
private ObjectProperty<LocalDate> dateSet, dateFinished;
private StringProperty stepName;
private IntegerProperty completion;
private ArrayList<StepComment> comments;
public ActionStep(String name) {
actionStepID = new SimpleStringProperty();
stepName = new SimpleStringProperty();
dateSet = new SimpleObjectProperty<LocalDate>();
dateFinished = new SimpleObjectProperty<LocalDate>();
completion = new SimpleIntegerProperty();
stepName.setValue(name);
}
public void setName(String name) {
stepName.setValue(name);
}
public String getName() {
return stepName.getValue();
}
public StringProperty stepNameProperty() {
return actionStepID;
}
public void setID(String id) {
actionStepID.setValue(id);
}
public String getID() {
return actionStepID.get();
}
public StringProperty actionStepIDProperty() {
return actionStepID;
}
public void setCompletion(int percent) {
if (percent < 0 || percent > 100)
return;
completion.set(percent);
}
public int getCompletion() {
return completion.get();
}
public IntegerProperty completionProperty() {
return completion;
}
public void setDateSet(LocalDate date) {
dateSet.set(date);
}
public LocalDate getDateSet() {
return dateSet.get();
}
public ObjectProperty<LocalDate> dateSetProperty() {
return dateSet;
}
public void setDateFinished(LocalDate date) {
dateFinished.set(date);
}
public LocalDate getDateFinished() {
return dateFinished.get();
}
public ObjectProperty<LocalDate> dateFinishedProperty() {
return dateFinished;
}
public String toString() {
return stepNameProperty().get();
}
}
My ListView uses an ObservableList as well.
#FXML
private ListView<ActionStep> actionStepsListView;
private ObservableList<ActionStep> listOfSteps;
listOfSteps = FXCollections.observableArrayList();
actionStepsListView.setItems(listOfSteps);
if (plan != null) {
ArrayList<ActionStep> arrayOfSteps = plan.getStepsArrayList();
for (int i = 0; i < arrayOfSteps.size(); i++)
listOfSteps.add(arrayOfSteps.get(i));
} else
plan = new ActionPlan();
How come changes made to the ObservableList do not reflect themselves in the ListView? I noticed that the ListView called upon every object's toString() to display their values in the ListView, rather than binding it to their Properties.
What am I doing wrong? Am I supposed to override a cell factory or something?

Note that you're trying to do something more complex with the cells in your ListView than you were with the cells in the TableView. In the TableView, the objects displayed in the cells were changing, so it was easy for the cells to observe this. In the ListView, you want the cells to notice when properties that belong to the objects displayed in the cells change; this is one further step removed, so you have to do a bit of extra coding (though not much, as you'll see).
You could create a custom cell factory to bind to the stepNameProperty(), but it's tricky (you have to make sure to unbind/remove listeners from old items in the updateItem() method).
The easier way, though, which isn't well documented is to use an ObservableList with an extractor defined.
First, fix your method names: you have some weird mismatches in the code you posted. The getX/setX/xProperty method names should all match correctly. I.e. instead of
public void setName(String name) {
stepName.setValue(name);
}
public String getName() {
return stepName.getValue();
}
public StringProperty stepNameProperty() {
return actionStepID;
}
you should have
public final void setName(String name) {
stepName.setValue(name);
}
public final String getName() {
return stepName.getValue();
}
public StringProperty nameProperty() {
return stepName;
}
and similarly for the other property accessor methods. (Obviously, the names of the fields can be anything you like, as they're private.) Making the get/set methods final is good practice.
Then, create the list with an extractor. The extractor is a function that maps each element in the list to an array of Observables which the list will observe. If those values change, it will fire list updates to the list's observers. Since your ActionStep's toString() method references the nameProperty(), I assume you want the ListView to update if the nameProperty() changes. So you want to do
listOfSteps = FXCollections.observableArrayList(
actionStep -> new Observable[] { actionStep.nameProperty() } // the "extractor"
);
actionStepsListView.setItems(listOfSteps);
Note that in earlier versions of JavaFX 2.2 the ListView did not properly observe the list for update events; this was fixed (if I remember correctly) shortly prior to the release of Java 8. (Since you tagged the question JavaFX8, I assume you're using Java 8 and so you should be fine here.)
If you are not using Java 8, you can use the following (equivalent but more verbose) code:
listOfSteps = FXCollections.observableArrayList(
new Callback<ActionStep, Observable[]>() {
#Override
public Observable[] call(ActionStep actionStep) {
return new Observable[] { actionStep.nameProperty() } ;
}
});
actionStepListView.setItems(listOfSteps);

Here is sample how make listview with custom objects:
public class JavaFX_ListView extends Application {
class MyObject {
String day;
int number;
MyObject(String d, int n) {
day = d;
number = n;
}
String getDay() {
return day;
}
int getNumber() {
return number;
}
#Override
public String toString() {
return number + " " + day;
}
}
ObservableList<MyObject> myList;
// Create dummy list of MyObject
private void prepareMyList() {
myList = FXCollections.observableArrayList();
myList.add(new MyObject("Sunday", 50));
myList.add(new MyObject("Monday", 60));
myList.add(new MyObject("Tuesday", 20));
}
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("sample");
prepareMyList();
ListView<MyObject> listView = new ListView<>();
listView.setItems(myList);
Pane root = new Pane();
root.getChildren().add(listView);
primaryStage.setScene(new Scene(root, 300, 250));
primaryStage.show();
// testing
Timer timer = new Timer();
timer.schedule(new UpdateListTask(), 1000, 1000);
}
public static void main(String[] args) {
launch(args);
}
// testing
public class UpdateListTask extends TimerTask {
#Override
public void run() {
Platform.runLater(new Runnable() {
#Override
public void run() {
myList.add(new MyObject("sample", Calendar.getInstance()
.getTime().getSeconds()));
}
});
}
}
}