Hover popup on LineChart

Question

I am building a line chart graph and what to create a small modal/popup/tooltip to display the exact data points for the graph point that they are mousing over.
It looks like I would need to do this by attaching an event handler to the XYChart.Data<x,y> object that is added. But I can't find any information on how to attach the event handler that will work.
I originally tried it this way
List<XYChart.Data> data = new ArrayList<XYChart.Data>();
for (int i = 0; i < 12; i++) {
XYChart.Data<String, BigDecimal> dataPoint = new XYChart.Data<>(i + "", BigDecimal.valueOf(new Random().nextDouble() * 10000));
dataPoint.getNode().addEventHandler(MouseEvent.MOUSE_ENTERED, new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
System.out.println(event.getSource().toString());
data.add(dataPoint);
But that threw error as the getNode() method returned null. I am sure that I am doing this is a somewhat backwards way, but I can't find a better example. The JavaFX site says that a chart example (including hovers was in the sample code) but I can't find it if it's there.
Can someone point out to me what I need to do here?

Answer 1

Hi,
Please refer to the following document.
http://download.oracle.com/javafx/2.0/charts/pie-chart.htm
(Scroll down to Processing Events for a Pie Chart)
It performs almost what you're trying to implement.
Just adapt the sample to the LineChart and replace MOUSE_PRESSED with MOUSE_ENTERED.
Regards,
Alla