java - JFreechart Boxplot changing size of boxes when coloring the boxes -

i using jfreechart make boxplot (code @ bottom). when don't add a coloring per box drawn wide , correctly centered (as want them):

however, when color them x-axis label, smaller , not centered correctly anymore:

how can coloring of second figure box sizes of first?

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package test;  import java.io.file; import java.util.arraylist; import java.util.arrays; import java.util.hashmap;  import org.jfree.chart.chartpanel; import org.jfree.chart.chartutilities; import org.jfree.chart.jfreechart; import org.jfree.chart.axis.categoryaxis; import org.jfree.chart.axis.numberaxis; import org.jfree.chart.labels.boxandwhiskertooltipgenerator; import org.jfree.chart.plot.categoryplot; import org.jfree.chart.renderer.category.boxandwhiskerrenderer; import org.jfree.data.statistics.defaultboxandwhiskercategorydataset;  public class test {     public static void main(string[] args) throws exception {     defaultboxandwhiskercategorydataset dataset = new defaultboxandwhiskercategorydataset();      // example data     hashmap<string, arraylist<double>> test = new hashmap<string, arraylist<double>>();     test.put("a",new arraylist<double>(arrays.aslist(0.8, 1.4, 0.8, 1.9, 1.2)));     test.put("b",new arraylist<double>(arrays.aslist(0.8, 1.4, 0.8, 1.9, 1.2)));     test.put("c",new arraylist<double>(arrays.aslist(0.8, 1.4, 0.8, 1.9, 1.2)));     test.put("d",new arraylist<double>(arrays.aslist(0.8, 1.4, 0.8, 1.9, 1.2)));     test.put("e",new arraylist<double>(arrays.aslist(0.8, 1.4, 0.8, 1.9, 1.2)));     (string k : test.keyset()){         /* change           *     string xaxislabel = "";          * wide plot          */         string xaxislabel = k;         dataset.add(test.get(k), xaxislabel, k);// + beta of interactionterm");     }     final categoryaxis xaxis = new categoryaxis("example x-axis");     final numberaxis yaxis = new numberaxis("example y-axis");     yaxis.setautorangeincludeszero(false);     final boxandwhiskerrenderer renderer = new boxandwhiskerrenderer();     renderer.setfillbox(true);     renderer.setseriestooltipgenerator(1, new boxandwhiskertooltipgenerator());     renderer.setmeanvisible(false);     final categoryplot plot = new categoryplot(dataset, xaxis, yaxis, renderer);      final jfreechart chart = new jfreechart(             "example",             plot             );     final chartpanel chartpanel = new chartpanel(chart);     chartpanel.setpreferredsize(new java.awt.dimension(3000,1800));     chartutilities.savechartaspng(new file("test.png"), chart, 1000, 600);     } } 

the difference first picture has 1 series, second picture has 5 series. instead of adding lots of series, add 1 series 5 items top picture. can use custom boxandwhiskerrenderer overrides getitempaint() different colors show here xylineandshaperenderer.

edit: matching legend, need new drawingsupplier this.