Fwd: Re: [jCharts-users] Swing app question

[Nathaniel G. A. <nat...@ya...>]

--- "Nathaniel G. Auvil" <nat...@ya...> wrote:
> Date: Tue, 15 Apr 2003 10:59:20 -0700 (PDT)
> From: "Nathaniel G. Auvil" <nat...@ya...>
> Subject: Re: [jCharts-users] Swing app question
> To: fra...@ag...
> 
> 
> hi.
> 
> Your problem is the Graphics2D Object coming from your JPanel is null.  This is because your app
> is not visible on the screen so the jvm does not create the underlying graphics components.  To
> fix this, simply call the 'setVisible( true );' method on your JFrame before you render the
> chart.
> 
> 
> 
> 
> --- fra...@ag... wrote:
> > Hi,
> > 
> > I have only downloaded jCharts today, so my experience with package is not great. I really
> want
> > to use the package to embed charting components in Swing applications. Within the distribution
> > I found an example of a Swing PieChart. I tried to follow that example to try and reconstruct
> > my own Swing bar chart based on the distributions bar chart example.
> > 
> > The code is given below. All seems to work, the frame gets drawn but finally I get an
> exception
> > when the "axisChart.render()" method is called:
> > 
> > $ source runharness
> > /cygdrive/d/mpowerdem/src/wdiscovery
> > java.lang.NullPointerException
> >         at org.jCharts.Chart.render(Unknown Source)
> >         at com.agilent.wdiscovery.MainFrame.initComponents(MainFrame.java:81)
> >         at com.agilent.wdiscovery.MainFrame.<init>(MainFrame.java:34)
> >         at com.agilent.wdiscovery.LaunchWirelessApp.<init>(LaunchWirelessApp.jav
> > a:20)
> >         at com.agilent.wdiscovery.LaunchWirelessApp.main(LaunchWirelessApp.java:
> > 49)
> > 
> > I have tried other things in despair but I'm not getting very far. Can anyone help or point
> > me to some other Swing based examples?
> > 
> > Thanks,
> > 
> > Francisco
> > 
> >
>
--------------------------------------------------------------------------------------------------------------------------------------
> > 
> > package com.agilent.wdiscovery;
> > 
> > import org.jCharts.chartData.ChartDataException;
> > import org.jCharts.properties.*;
> > import org.jCharts.chartData.*;
> > import org.jCharts.axisChart.*;
> > import org.jCharts.types.*;
> > import org.jCharts.imageMap.*;
> > 
> > import java.awt.*;
> > import java.awt.event.*;
> > import java.awt.image.*;
> > import javax.swing.*;
> > 
> > /**
> >  * <p>Title: </p>
> >  * <p>Description: </p>
> >  * <p>Copyright: Copyright (c) 2003</p>
> >  * <p>Company: </p>
> >  * @author unascribed
> >  * @version 1.0
> >  */
> > 
> > public class MainFrame extends JFrame {
> >   private JPanel contentPane;
> >   private BorderLayout borderLayout1 = new BorderLayout();
> >   private JPanel jPanel1 = new JPanel(true);
> > 
> >   //Construct the frame
> >   public MainFrame() {
> >     enableEvents(AWTEvent.WINDOW_EVENT_MASK);
> >     try {
> >       jbInit();
> >       initComponents();
> >     }
> >     catch(Exception e) {
> >       e.printStackTrace();
> >     }
> >   }
> >   //Component initialization
> >   private void jbInit() throws Exception {
> >     //setIconImage(Toolkit.getDefaultToolkit().createImage(MainFrame.class.getResource("[Your
> > Icon]")));
> >     contentPane = (JPanel) this.getContentPane();
> >     contentPane.setLayout(borderLayout1);
> >     this.setSize(new Dimension(400, 300));
> >     this.setTitle("802.11 Wireless Discovery");
> >     jPanel1.setBorder(BorderFactory.createEtchedBorder());
> >     contentPane.add(jPanel1,  BorderLayout.CENTER);
> >   }
> >   //Overridden so we can exit when window is closed
> >   protected void processWindowEvent(WindowEvent e) {
> >     super.processWindowEvent(e);
> >     if (e.getID() == WindowEvent.WINDOW_CLOSING) {
> >       System.exit(0);
> >     }
> >   }
> > 
> >   private void initComponents() throws ChartDataException, PropertyException {
> >     String[] xAxisLabels= { "1998", "1999", "2000", "2001", "2002", "2003", "2004" };
> >     String xAxisTitle= "Years";
> >     String yAxisTitle= "Problems";
> >     String title= "Micro$oft at Work";
> >     DataSeries dataSeries = new DataSeries( xAxisLabels, xAxisTitle, yAxisTitle, title );
> > 
> >     double[][] data= new double[][]{ { 250, 45, -36, 66, 145, 80, 55 } };
> >     String[] legendLabels= { "Bugs" };
> >     Paint[] paints= new Paint[]{ Color.blue.darker() };
> >     BarChartProperties barChartProperties= new BarChartProperties();
> >     AxisChartDataSet axisChartDataSet= new AxisChartDataSet( data, legendLabels, paints,
> > ChartType.BAR, barChartProperties );
> >     dataSeries.addIAxisPlotDataSet( axisChartDataSet );
> > 
> >     ChartProperties chartProperties= new ChartProperties();
> > 
> >     //---to make this plot horizontally, pass true to the AxisProperties Constructor
> >     //AxisProperties axisProperties= new AxisProperties( true );
> >     AxisProperties axisProperties= new AxisProperties();
> >     LegendProperties legendProperties= new LegendProperties();
> >     AxisChart axisChart= new AxisChart( dataSeries, chartProperties, axisProperties,
> > legendProperties, 200, 200 );
> > 
> >     axisChart.setGraphics2D( (Graphics2D) this.jPanel1.getGraphics() );
> >     axisChart.render();
> >   }
> > }
> > 
> > 
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> 
> 
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