FULL PRODUCT VERSION :

java version "1.5.0_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_05-b05)
Java HotSpot(TM) Client VM (build 1.5.0_05-b05, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows XP Version 5.1 (Build 2600.xpsp_sp2_gdr.050301-1519: Service Pack 2)

A DESCRIPTION OF THE PROBLEM :
when a tabbed pane is displayed and you delete tabs programatically ( say via a button ) , deleting outer tabs generate state changed but deleting inner tabs do not.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Please find a Abbot base test fixture source code in this bug report.
You will need the Abbot jars in your class path.

http://abbot.sourceforge.net/doc/download.shtml



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
  state changed must be fired when inner tabs are deleted
ACTUAL -
  state changed is fired when outter tabs are deleted

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package com.tabbedpane.test;
//
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.InvocationTargetException;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import junit.extensions.abbot.ComponentTestFixture;
import abbot.tester.ComponentTester;
import abbot.tester.JTabbedPaneLocation;
import abbot.tester.JTabbedPaneTester;
@SuppressWarnings("all")
public class JTabbedPaneCompTestCase extends ComponentTestFixture
{
  private JTabbedPaneTester tester;
  private JFrame f;
  private JTabbedPane tab;
  private JPanel firstPnl, secondPnl, thirdPnl, fourthPnl, controlPnl;
  private JButton removeSecondBtn, removeFourthBtn;
  private boolean fired;
  //
  protected void setUp()
  {
    try
    {
      EventQueue.invokeAndWait(new Runnable()
      {
        public void run()
        {
          firstPnl = new JPanel();
          secondPnl = new JPanel();
          thirdPnl = new JPanel();
          fourthPnl = new JPanel();
          controlPnl = new JPanel();
          //
          removeSecondBtn = new JButton("removeSecond");
          removeSecondBtn.addActionListener(new ActionListener()
          {
            public void actionPerformed(ActionEvent pE)
            {
              tab.remove(secondPnl);
            }
          });
          removeFourthBtn = new JButton("removeFourth");
          removeFourthBtn.addActionListener(new ActionListener()
          {
            public void actionPerformed(ActionEvent pE)
            {
              tab.remove(fourthPnl);
            }
          });
          controlPnl.add(removeSecondBtn);
          controlPnl.add(removeFourthBtn);
          //
          tab = new JTabbedPane();
          tab.add(firstPnl, "firstPnl");
          tab.add(secondPnl, "secondPnl");
          tab.add(thirdPnl, "thirdPnl");
          tab.add(fourthPnl, "fourthPnl");
          tab.addChangeListener(new ChangeListener()
          {
            public void stateChanged(ChangeEvent pE)
            {
              fired = true;
            }
          });
          //
          f = new JFrame("JTabbedPaneTestCase");
          f.add(tab, BorderLayout.CENTER);
          f.add(controlPnl, BorderLayout.SOUTH);
          f.setSize(new Dimension(300, 400));
          f.setVisible(true);
          centerOnScreen(f);
          //
          fired = false;
        }
      });
    }
    catch (InvocationTargetException ex)
    {
      ex.printStackTrace();
    }
    catch (InterruptedException ex)
    {
      ex.printStackTrace();
    }
    tester = (JTabbedPaneTester) ComponentTester.getTester(JTabbedPane.class);
  }
  //
  public final void testRemoveFourthPnl()
  {
    tester.actionDelay(2000);
    tester.actionSelectTab(tab, new JTabbedPaneLocation(3));
    assertTrue("State Changed On Selection:", fired);
    fired = false;
    tester.actionDelay(2000);
    tester.actionClick(removeFourthBtn);
    tester.actionDelay(2000);
    assertTrue("State Changed On Removal:", fired);
  }
  //
  public final void testRemoveSecondPnl()
  {
    tester.actionDelay(2000);
    tester.actionSelectTab(tab, new JTabbedPaneLocation(1));
    assertTrue("State Changed On Selection:", fired);
    fired = false;
    tester.actionDelay(2000);
    tester.actionClick(removeSecondBtn);
    tester.actionDelay(2000);
    assertTrue("State Changed On Removal:", fired);
  }
  //
  @Override
  protected void tearDown() throws Exception
  {
    f.setVisible(false);
    f = null;
  }
  //
  public JTabbedPaneCompTestCase(String name)
  {
    super(name);
  }
  //
  public static void main(String[] args)
  {
    junit.extensions.abbot.TestHelper.runTests(args, JTabbedPaneCompTestCase.class);
  }
  //
  private static final void centerOnScreen(Component pComponent)
  {
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension componentSize = pComponent.getSize();
    if (componentSize.height > screenSize.height)
    {
      componentSize.height = screenSize.height;
    }
    if (componentSize.width > screenSize.width)
    {
      componentSize.width = screenSize.width;
    }
    pComponent.setLocation((screenSize.width - componentSize.width) / 2,
        (screenSize.height - componentSize.height) / 2);
  }
}
---------- END SOURCE ----------
Contribution by java.net member leouser:

A DESCRIPTION OF THE FIX :
BUGID: 6368047 jtabbedpane does not fire state changed when inner tabs are removed
FILES AFFECTED: javax.swing.JTabbedPane.
JDK VERSION
jdk-6-rc-bin-b64-linux-i586-15_dec_2005.bin

Discusion(embeded in test case):
/**
 * BUGID: 6368047 jtabbedpane does not fire state changed when inner tabs are removed.
 * Ive ran into this bug in real life and I don't like it! The problem is 2 fold
 * 1rst in removeTabAt it only selects if were at the end index.
 * 2nd in the DefaultSingleSelectionModel, we only fire a ChangeEvent if
 * there is a change numerically. It doesn't matter if its different tab
 * or not. To remedy this I have:
 * made sure in removeTabAt always selects somethings. It also
 * doesn't matter what remove is called, they all appear to route
 * to removeTabAt which is where the selection happens.
 * Subclassed DefaultSingleSelectionModel to fire in most cases a ChangeEvent
 * if there was a selection, regardless of selected index. I chose subclassing
 * over writing a new version because it saves alot of code duplication and
 * there aren't too many gymnastics involved with making it fire, just a flag.
 *
 * Being able to know if a different Tab has been selected after removal is
 * essential to the user. Ive had to play games with the JTabbedPane because
 * of this behavior. This 'correct' behavior would eliminate alot of the
 * shenanigans Ive had to write.
 *
 * TESTING STRATEGY:
 * Hit the remove button and it will remove the current tab. Watch for output
 * on the console. A different hashcode should come up as well as the correct
 * tab name for the newly selected tab. To show the change execute this against
 * an unmodified JTabbedPane and see the results.
 *
 * FILES AFFECTED: javax.swing.JTabbedPane.
 * JDK VERSION
 * jdk-6-rc-bin-b64-linux-i586-15_dec_2005.bin
 *
 * test ran succesfully on a SUSE 7.3 Linux distribution
 *
 * Brian Harry
 * ###@###.###
 * Jan 20, 2006
 */

UNIFIED DIFF:
--- /home/nstuff/java6/jdk1.6.0/javax/swing/JTabbedPane.java Thu Dec 15 02:17:37 2005
+++ /home/javarefs/javax/swing/JTabbedPane.java Fri Jan 20 17:05:13 2006
@@ -176,7 +176,7 @@
         setTabPlacement(tabPlacement);
         setTabLayoutPolicy(tabLayoutPolicy);
         pages = new Vector(1);
- setModel(new DefaultSingleSelectionModel());
+ setModel(new AlwaysFiringSingleSelectionModel());
         updateUI();
     }
 
@@ -859,6 +859,9 @@
             }
         }
 
+ if (selected < (tabCount - 1)) {
+ setSelectedIndexImpl(getSelectedIndex());
+ }
         revalidate();
         repaint();
     }
@@ -2213,4 +2216,25 @@
         }
         return -1;
     }
+
+ @SuppressWarnings("serial")
+ private static class AlwaysFiringSingleSelectionModel extends DefaultSingleSelectionModel{
+
+ boolean fired;
+ @Override
+ public void setSelectedIndex(int index){
+ fired = false;
+ super.setSelectedIndex(index);
+ if(!fired && index != -1)
+ fireStateChanged();
+ }
+
+ @Override
+ public void fireStateChanged(){
+ fired = true;
+ super.fireStateChanged();
+ }
+
+ }
+
 }


JUnit TESTCASE :
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import static java.lang.System.out;

/**
 * BUGID: 6368047 jtabbedpane does not fire state changed when inner tabs are removed.
 * Ive ran into this bug in real life and I don't like it! The problem is 2 fold
 * 1rst in removeTabAt it only selects if were at the end index.
 * 2nd in the DefaultSingleSelectionModel, we only fire a ChangeEvent if
 * there is a change numerically. It doesn't matter if its different tab
 * or not. To remedy this I have:
 * made sure in removeTabAt always selects somethings. It also
 * doesn't matter what remove is called, they all appear to route
 * to removeTabAt which is where the selection happens.
 * Subclassed DefaultSingleSelectionModel to fire in most cases a ChangeEvent
 * if there was a selection, regardless of selected index. I chose subclassing
 * over writing a new version because it saves alot of code duplication and
 * there aren't too many gymnastics involved with making it fire, just a flag.
 *
 * Being able to know if a different Tab has been selected after removal is
 * essential to the user. Ive had to play games with the JTabbedPane because
 * of this behavior. This 'correct' behavior would eliminate alot of the
 * shenanigans Ive had to write.
 *
 * TESTING STRATEGY:
 * Hit the remove button and it will remove the current tab. Watch for output
 * on the console. A different hashcode should come up as well as the correct
 * tab name for the newly selected tab. To show the change execute this against
 * an unmodified JTabbedPane and see the results.
 *
 * FILES AFFECTED: javax.swing.JTabbedPane.
 * JDK VERSION
 * jdk-6-rc-bin-b64-linux-i586-15_dec_2005.bin
 *
 * test ran succesfully on a SUSE 7.3 Linux distribution
 *
 * Brian Harry
 * ###@###.###
 * Jan 20, 2006
 */
public class TestTab implements ChangeListener{

    JTabbedPane jtp;
    public void stateChanged(ChangeEvent ce){
out.println(ce);
Component c = jtp.getSelectedComponent();
int i = jtp.getSelectedIndex();
        if(c != null){
out.println(c.hashCode());
out.println("Selected Name should be: " + jtp.getTitleAt(i));
}
    }

    public void testTabbedPane(){

JFrame jf = new JFrame();
final JTabbedPane jtp = this.jtp = new JTabbedPane();
jf.add(jtp);
for(int i = 0; i < 10; i++)
jtp.addTab(String.valueOf(i), new JLabel(String.valueOf(i)));
jtp.addChangeListener(this);
Action remove = new AbstractAction("Remove Tab"){
public void actionPerformed(ActionEvent ae){
out.println("WATCH FOR A CHANGE EVENT!:");
//Component c = jtp.getSelectedComponent();
//jtp.remove(c);
int index = jtp.getSelectedIndex();
if(index >= 0)
jtp.remove(index);
//jtp.removeAll();
out.println("WAS THERE A CHANGE EVENT?");
}

};

JButton jb = new JButton(remove);
jf.add(jb, BorderLayout.SOUTH);
jf.pack();
jf.setVisible(true);


    }

    public static void main(String ... args){

Runnable run = new Runnable(){
public void run(){
new TestTab().testTabbedPane();
}

};
SwingUtilities.invokeLater(run);

    }


}


FIX FOR BUG NUMBER:
6368047