Grafico ad area con valori negativi

Abbiamo già visto la configurazione utilizzata per disegnare questo grafico nel capitolo Sintassi della configurazione di Highcharts . Consideriamo ora il seguente esempio per comprendere ulteriormente un grafico ad area di base.

Esempio

HelloWorld.java

package com.tutorialspoint.client;

import org.moxieapps.gwt.highcharts.client.Chart;
import org.moxieapps.gwt.highcharts.client.Series.Type;
import org.moxieapps.gwt.highcharts.client.ToolTip;
import org.moxieapps.gwt.highcharts.client.ToolTipData;
import org.moxieapps.gwt.highcharts.client.ToolTipFormatter;

import org.moxieapps.gwt.highcharts.client.XAxis;
import org.moxieapps.gwt.highcharts.client.YAxis;
import org.moxieapps.gwt.highcharts.client.labels.AxisLabelsData;
import org.moxieapps.gwt.highcharts.client.labels.AxisLabelsFormatter;
import org.moxieapps.gwt.highcharts.client.labels.YAxisLabels;

import org.moxieapps.gwt.highcharts.client.plotOptions.AreaPlotOptions;
import org.moxieapps.gwt.highcharts.client.plotOptions.Marker;
import org.moxieapps.gwt.highcharts.client.plotOptions.PlotOptions.Stacking;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.ui.RootPanel;

public class HelloWorld implements EntryPoint {
   public void onModuleLoad() {
      Chart chart = new Chart()
         .setType(Type.AREA)
         .setChartTitleText("Historic and Estimated Worldwide Population Growth by Region")
         .setChartSubtitleText("Source: Wikipedia.org")
         .setToolTip(new ToolTip()
         .setFormatter(new ToolTipFormatter() {							
            @Override
            public String format(ToolTipData toolTipData) {
               return toolTipData.getXAsString() + ": " +  
                  NumberFormat.getFormat("#,###").format(toolTipData.getYAsDouble()) + " millions";
            }
         }));

         XAxis xAxis = chart.getXAxis();
         xAxis.setCategories("1750", "1800", "1850", "1900", "1950", "1999", "2050");
         xAxis.setTickmarkPlacement(XAxis.TickmarkPlacement.ON);  
         xAxis.setAxisTitleText(null);  

         YAxis yAxis = chart.getYAxis();
         yAxis.setAxisTitleText("Billions");
         yAxis.setLabels(new YAxisLabels()
            .setFormatter(new AxisLabelsFormatter() {
               @Override
               public String format(AxisLabelsData axisLabelsData) {
                  return String.valueOf(axisLabelsData.getValueAsLong() / 1000);
               }
            }));

         chart.addSeries(chart.createSeries()  
            .setName("Asia")  
            .setPoints(new Number[] { 502, 635, 809, 947, 1402, 3634, 5268 })  
         );  
         chart.addSeries(chart.createSeries()  
            .setName("Africa")  
            .setPoints(new Number[] { 106, 107, 111, 133, 221, 767, 1766 })  
         );  
         chart.addSeries(chart.createSeries()  
            .setName("Europe")  
            .setPoints(new Number[] { 163, 203, 276, -408, 547, 729, 628 })  
         );  
         chart.addSeries(chart.createSeries()  
            .setName("America")  
            .setPoints(new Number[] { 18, 31, 54, 156, -339, 818, 1201 })  
         );  
         chart.addSeries(chart.createSeries()  
            .setName("Oceania")  
            .setPoints(new Number[] { -2, 2, 2, 16, -13, -30, 46 })  
         );  
      RootPanel.get().add(chart);
   }
}

Risultato

Verifica il risultato.