I have a LegendItemEntity, how do I get the LegendItem? - jfreechart

Question

I have code that hides/shows a series when the LegendItemEntity is clicked. The code works, except I use the index of the series as the index of the LegendItem in the LegendItemCollection. The problem is that sometimes there are more series than LegendItems and their respective indices are not the same. How do I get the LegendItem given that I have the LegendItemEntity?
private final ChartMouseListener chartMouseListener = new ChartMouseListener() {
public void chartMouseClicked(ChartMouseEvent cme) {
ChartEntity entity = cme.getEntity();
if (entity instanceof LegendItemEntity) {
LegendItemEntity itemEntity = (LegendItemEntity) entity;
int index = dataset.getSeriesIndex(itemEntity.getSeriesKey());
XYPlot plot = (XYPlot) chart.getPlot();
XYItemRenderer renderer = plot.getRenderer();
renderer.setSeriesVisible(index, !renderer.isSeriesVisible(index));
LegendItem legendItem = plot.getLegendItems().get(index);
if (renderer.isSeriesVisible(index)) {
legendItem.setLinePaint(renderer.getSeriesPaint(index));
} else {
legendItem.setLinePaint(Color.WHITE);
}
}
}
public void chartMouseMoved(ChartMouseEvent cme) {
}
};

Answer 1

You can use renderer.getLegendItem(). The result will be null for a non-visible series. Given a JFreeChart chart, a chartMouseClicked() implementation might look like this:
#Override
public void chartMouseClicked(ChartMouseEvent e) {
ChartEntity entity = e.getEntity();
if (entity instanceof LegendItemEntity) {
LegendItemEntity itemEntity = (LegendItemEntity) entity;
Comparable key = itemEntity.getSeriesKey();
XYDataset dataset = (XYDataset) itemEntity.getDataset();
int seriesIndex = dataset.indexOf(key);
XYPlot plot = (XYPlot) chart.getPlot();
int datasetIndex = plot.indexOf(dataset);
XYItemRenderer renderer = plot.getRenderer();
LegendItem legendItem = renderer.getLegendItem(datasetIndex, seriesIndex);
System.out.println(key + " " + datasetIndex + " " + seriesIndex);
System.out.println(legendItem);
}
}