Having tooltip trouble

Question

I'm having some tootip issues. The scenario is I'm returning some data from an EJB (which is working). You're supposed hover over a mark on a scatter chart, and it gives you some information about that mark. I can't get it to work. Maybe I'm being too simple about the way I've coded it? Anyway, here's my code:
("array" comes from the EJB, and each entry in that array is another array)
        XYChart.Series<Number, Number> normalSeries = new XYChart.Series<>();
        XYChart.Series<Number, Number> negativeOutlierSeries = new XYChart.Series<>();
        XYChart.Series<Number, Number> positiveOutlierSeries = new XYChart.Series<>();
        for (int i = 0; i < array.size(); i++) {
            ArrayList arr = (ArrayList) array.get(i);
            // intercept, slope
            XYChart.Data data = new XYChart.Data(arr.get(0), arr.get(1));
            System.out.println("tooltip: " + arr.get(3));
            // tooltip
            Tooltip.install(data.getNode(), new Tooltip(arr.get(3).toString()));
            // check outlier
            if (Integer.parseInt(arr.get(2).toString()) == 0) {
                normalSeries.getData().add(data);
            // if the outlier isn't zero, check slope
            } else if (Float.parseFloat(arr.get(1).toString()) < 0) {
                negativeOutlierSeries.getData().add(data);
            } else {
                positiveOutlierSeries.getData().add(data);
        sc.getData().addAll(normalSeries, negativeOutlierSeries, positiveOutlierSeries);
        sc.setLegendVisible(false);The chart displays okay, but when I hover over one of the marks, it doesn't show me anything. I must be doing something wrong, but what?
Thanks!

Answer 1

The other mechanism in that thread seems to work ok:
import java.util.Random;
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.ScatterChart;
import javafx.scene.control.Tooltip;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import static javafx.scene.chart.XYChart.*;
public class ScatterChartTest extends Application {
  @Override
  public void start(Stage primaryStage) throws Exception {
    BorderPane root = new BorderPane();
    NumberAxis xaxis = new NumberAxis();
    NumberAxis yaxis = new NumberAxis();
    ScatterChart<Number, Number> scatterPlot = new ScatterChart<>(xaxis, yaxis);
    Series<Number, Number> series = new Series<>();
    series.setName("Random Data");
    Random rng = new Random();
    for (int i=0; i<10; i++) {
      final double x = rng.nextDouble();
      final double y = rng.nextDouble();
      final Data<Number, Number> datum = new Data<Number, Number>(x, y, String.format("x=%.3f%ny=%.3f",x,y));
      series.getData().add(datum);
      // When node is installed on datum, register a Tooltip on it:
      datum.nodeProperty().addListener(new ChangeListener<Node>() {
        @Override
        public void changed(ObservableValue<? extends Node> observable,
            Node oldValue, Node newValue) {
          if (newValue != null) {
            Tooltip.install(newValue, new Tooltip(datum.getExtraValue().toString()));
            datum.nodeProperty().removeListener(this);
    scatterPlot.getData().add(series);
    root.setCenter(scatterPlot);
    primaryStage.setScene(new Scene(root, 600, 600));
    primaryStage.show();
  public static void main(String[] args) {launch(args);}
}