int series = entity.getSeriesIndex();
int item = entity.getItem();
lastObSelected = obsModel.getValidObservation(series, item);
if (event.getTrigger().getClickCount() == 2) {
new ObservationDetailsDialog(lastObSelected);
}
} else {
// ...else if not XYItemEntity as subject of the event, select a
// valid observation by asking: which XYItemEntity is closest to the
// cross hairs?