SourceCategoryDataset dst = (SourceCategoryDataset)plot.getDataset();
dst.setDataSourceCollection((DataSourceCollection)o);
chart.setTitle(dst.getName());
for (int i=0; i<mappers.size(); ++i) {
DataSource ds = (DataSource)mapperSources.get(i);
if (ds!=null) ds.removeListener(this);
ColorMapper cm = (ColorMapper)mappers.get(i);
if (cm!=null) cm.removeListener(this);
}
for (int i=0; i<((DataSourceCollection)o).size(); ++i) {
mappers.add(null); mapperSources.add(null); // no mapper by default