Is it legal to add a graph to a JPanel?

Question

Hi, I am working on a gui for one of my classes that needs to display a graph that shows the number of failed and passed questions on a test. My bar graph works perfectly when I test it separately, but when I try to implement it in the rest of my GUI, I get the following error:
Exception in thread "main" java.lang.IllegalArgumentException: adding a window to a container
Here is the relevant code with this issue:
import javax.swing.JFrame;
public class TestStudentStatistics {
     public static void main(String[] args) {
          studentStatistics f = new studentStatistics();
          f.setTitle("Student History");
         f.setSize(1000,1000);
         f.setVisible(true);
         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
public studentStatistics ()
          //adding the JPanels declared earlier in the code to a new container.
          Container c = this.getContentPane();
          c.add(jp1);
          c.add(jp2);
          c.add(jp3);
          c.add(jp4);
          c.add(jp5);
          /*creating an instance of the graph for the student's last three tests
           * This is currently designed for the prototype. These bars will be used in the
           * final product to show percentage failed overall per test and also per subject
           * area.
          bars graph = new bars(12,23,23,34,34,45);
          //adding the JList to the second JPanel
          jp2.add(jl1);
          //adding the graph to the third JPanel
          jp3.add(graph);
          //adding the Exit JButton declared earlier to the fourth JPanel
          jp4.add(jbtExit);
import java.awt.*;
import javax.swing.*;
public class bars extends JFrame
     private int true1, true2, true3, false1, false2, false3;
     public bars (double b1, double t1, double b2, double t2, double b3, double t3)
          true1 = (int)(b1/t1 * 300);
          false1 = 300-true1;
     public void paint(Graphics g2)
          double pass1;
          double fail1;
          fail1 = (double)false1/300*100;
          fail1 = Math.round(fail1);
          pass1 = (double)true1/300*100;
          pass1 = Math.round(pass1);
          //Drawing the first bar graph
          g2.setColor(Color.GREEN);
          g2.fillRect(10, 100, true1, 40);
          g2.setColor(Color.RED);
          g2.fillRect(true1+10, 100, false1, 40);
          g2.setColor(Color.BLACK);
          //true1 + false 1 is assumed to equal 300.
          g2.drawRect(10, 100, true1 + false1, 40);
          //Drawing the legend of the incorrect percentage to the right of the graph
          g2.setColor(Color.red);
         g2.fillRect(315,104,40,12);
         g2.drawString("Incorrect % = " + fail1,360,116);
         //Drawing the legend of the correct percentage to the right of the graph
         g2.setColor(Color.green);
         g2.fillRect(315,124,40,12);
         g2.drawString("Correct % = " + pass1,360,136);
         //Title of the first graph
         g2.setColor(Color.WHITE);
         g2.drawString(" TEST ONE ", 155, 120);
}do I have to add my graph in some other manner or is it impossible? I'm not quite sure what else I could do to implement my graph and let it still be within my gui.

Answer 1

jbjohnson86 wrote:
Exception in thread "main" java.lang.IllegalArgumentException: adding a window to a containerYou can't add window(JFrame) into a container(JPanel) but a JPanel can have nested panel extend your bar into a JPanel and add that panel to a JFrame. It should be container to a window not window to a container.
In the future Swing related question should be posted in the Swing forum.
http://forum.java.sun.com/forum.jspa?forumID=57