Example application showing how changing an item in a ListView changes its index

ListViewIndexChangesWhenItemUpdated .java

import java.io.IOException;
import java.util.Arrays;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.Observable;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.ListView;
import javafx.stage.Stage;
import javafx.util.Callback;

/**
 * Demonstrate a bug in ListView where changing an item property modified the
 * index. The {@link ObservableList} must have been created by calling
 * {@link FXCollections#observableArrayList(Callback)} where the callback
 * returns the property that is changed.
 * 
 * @author Andy Till
 * 
 */
public class ListViewIndexChangesWhenItemUpdated extends Application {

    /**
     * Change this to speed up the change, although it is important to see the
     * UI before the list item is modified.
     */
    private static final int ITEM_CHANGE_DELAY = 2000;

    public static void main(String[] args) throws IOException {
        Application.launch(args);
    }

    @Override
    public void start(Stage stage) throws Exception {
        final ObservableList<Person> observableArrayList = FXCollections.observableArrayList(new Callback<Person, Observable[]>() {
                @Override
                public Observable[] call(Person myTreeData) {
                    return new Observable[] { myTreeData.nameProperty() };
                }});

        observableArrayList.addAll(Arrays.asList(new Person("Test"), new Person("Test2")));
        
        ListView<Person> listView = new ListView<Person>();
        listView.setItems(observableArrayList);
        listView.getSelectionModel().select(0);
        
        Scene scene = new Scene(listView, 800, 600);
        stage.setScene(scene);
        stage.show();

        // modify the first list item after a delay without blocking the current
        // thread
        new Thread() {
            @Override
            public void run() {
                try {
                    sleep(ITEM_CHANGE_DELAY);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                Platform.runLater(new Runnable() {
                    @Override
                    public void run() {
                        observableArrayList.get(0).nameProperty().set("Changing");
                    }});
            }
        }.start();
    }

    private static class Person {

        public Person(String name) {
            this.name.set(name);
        }

        private final StringProperty name = new SimpleStringProperty();

        public StringProperty nameProperty() {
            return name;
        }

        @Override
        public String toString() {
            return nameProperty().get();
        }
    }
}