Re: Drawing on Tabs

From:

Knute Johnson <nospam@rabbitbrush.frazmtn.com>

Newsgroups:

comp.lang.java.help

Date:

Sat, 02 Dec 2006 16:05:09 -0800

Message-ID:

<Vwoch.75275$Vu4.30040@newsfe10.phx>

SkippyBoy wrote:

Hi all - I have an application where my main frame has a tabbed interface,
and each tab has a JPanel.

I would like to draw a line graph on the second tab (the first tab is where
data is entered) and a bar graph on the second tab.

The problem I have is how to draw on the second or 3rd tabs.

I googled and one solution was to subclass the JPanel and then override the
paintComponent() method. I tried but it doesn't seem to work. I am probably
just doing it wrong.

How would I go about defining/extending the JPanel class? or is there some
other container that would serve this purpose better?

Any help is appreciated.

(remove the +NOSPAM from my email address...)

This is how I would do it. You will need to make it look better but the
big pieces are all here.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class test {
     public static void main(String[] args) {
         Runnable r = new Runnable() {
             public void run() {
                 class ChartPanel extends JPanel {
                     private int value = 0;

                     public ChartPanel() {
                         setPreferredSize(new Dimension(200,150));
                     }

                     public void setValue(int v) {
                         value = v;
                     }

                     public void paintComponent(Graphics g) {
                         int w = getWidth();
                         int h = getHeight();
                         g.setColor(Color.WHITE);
                         g.fillRect(0,0,w,h);
                         g.setColor(Color.BLUE);
                         g.drawString("100%",0,10);
                         g.drawString("0%",0,h);
                         g.fillRect(w/3,h - (h * value / 100),
                          w/3,h * value / 100);
                     }
                 }
                 JFrame f = new JFrame();
                 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                 final ChartPanel cp = new ChartPanel();
                 SpinnerNumberModel nm =
                  new SpinnerNumberModel(0,0,100,1);
                 JSpinner sp = new JSpinner(nm);
                 sp.addChangeListener(new ChangeListener() {
                     public void stateChanged(ChangeEvent ce) {
                         JSpinner sp = (JSpinner)ce.getSource();
                          cp.setValue(
                           ((Integer)sp.getValue()).intValue());
                     }
                 });
                 JTabbedPane tp = new JTabbedPane();
                 tp.add(sp,"Changer");
                 tp.add(cp,"Chart");

                 f.add(tp);
                 f.pack();
                 f.setVisible(true);
             }
         };
         EventQueue.invokeLater(r);
     }
}

--

Knute Johnson
email s/nospam/knute/