JavaFX Use Chart Legend to toggle show/hide Series possible?

Is it possible to use a chart’s legend to toggle show/hide a series?

I got a LineChart with a legend and there are too many Series so you can’t read out the information well. I was wondering if there is a possibility to use the legend to toggle the series to show/hide?

Most of the names of my Series are pretty long and it looks very weird if they are written twice once in the legend so you know which color belongs to which Series and a second time besides a CheckBox to toggle them.

Edit1: Maybe I was unclear, even if there is no built in function for this, I could use some input for how a workaround could look like, because I can’t come up with anything.

Answer

Here is how I solved this – I am not aware of any simpler built-in solution

LineChart<Number, Number> chart;

for (Node n : chart.getChildrenUnmodifiable()) {
    if (n instanceof Legend) {
        Legend l = (Legend) n;
        for (Legend.LegendItem li : l.getItems()) {
            for (XYChart.Series<Number, Number> s : chart.getData()) {
                if (s.getName().equals(li.getText())) {
                    li.getSymbol().setCursor(Cursor.HAND); // Hint user that legend symbol is clickable
                    li.getSymbol().setOnMouseClicked(me -> {
                        if (me.getButton() == MouseButton.PRIMARY) {
                            s.getNode().setVisible(!s.getNode().isVisible()); // Toggle visibility of line
                            for (XYChart.Data<Number, Number> d : s.getData()) {
                                if (d.getNode() != null) {
                                    d.getNode().setVisible(s.getNode().isVisible()); // Toggle visibility of every node in the series
                                }
                            }
                        }
                    });
                    break;
                }
            }
        }
    }
}

You need to run this code once on your chart (LineChart in this example, but you can probably adapt it to any other chart). I find the Legend child, and then iterate over all of its’ items. I match the legend item to the correct series based on the name – from my experience they always match, and I couldn’t find a better way to match them. Then it’s just a matter of adding the correct event handler to that specific legend item.