🚀 go-pugleaf

 To All,

 This problem occurs when using the TAB key to traverse focus
 between Swing components. If one of the components is a JTable
 contained within a JScrollPane, then it takes two(2) TAB's to
 get focus on the JTable.

 I did discover that if the JTable is placed into a JPanel first,
 and then placed into the JScrollPane, it works with a single TAB.

 The following test class demonstrates this problem.

 Test 1: using JTable in a JScrollPane FAILS(or demonstrates problem)
 Test 2: with JTable in a JPanel and then a JScrollPane works fine

 // Begin TabTestPanel Class
 import java.awt.*;
 import java.awt.event.*;
 import javax.swing.*;
 import javax.swing.event.*;
 import javax.swing.table.*;
 import java.util.*;

 public class TabTestPanel extends JPanel
 {
     JScrollPane scrollPane = null;
     JTextField field = new JTextField( 10 );
     JTable table = null;
     JPanel innerPanel = null;

     // Listeners for use by all components
     KeyListener   keyListener   = new KeyEventHandler();
     FocusListener focusListener = new FocusEventHandler();

   /**  * Creates a new instance.  */  public TabTestPanel()  {  // Setup a
 JTable  TableModel dataModel = new AbstractTableModel() {  public int
 getColumnCount() { return 5; }  public int getRowCount() { return 4;}  public
 Object getValueAt(int row, int col) { return new String( row + ", " + col );
 }  };  table = new JTable( dataModel );

   /*  * Add JComponent to JScrollPane  *  * NOTE: First select JComponent to
 test by uncommenting it's line below.  *  * Test 1: This test consists of
 JComponents placed directly  * into a JScrollPane.  *  * Test 2: This test
 consists of JComponents contained in a JPanel  * and then added to a
 JScrollPane.  *  * NOTE: For the following tests, comment out comment marks
 * for the test to perform. Then uncomment the comment marks for  * the test
 to disable.  */

         String test = new String( "Test" );

         /*
         * Jcomponents to test.
         *
         * Uncomment the particular component to test. One and only one
         * Jcomponent should be uncommented at a time.
         *
         */
 // Focus,Highlight
 //YES, YES        JTextField jComponent = new JTextField( test, 10 );
 //YES, NO         JTree jComponent = new JTree();
 // NO, NO
          JTable jComponent = table;
 //YES, NO         JList jComponent = new JList();
 //YES, YES        JComboBox jComponent = new JComboBox();
 //YES, YES        JTextArea jComponent = new JTextArea( test, 4, 20 );
 //YES, YES        JCheckBox jComponent = new JCheckBox( test );
 //YES, YES        JButton jComponent = new JButton( test );

         // Test 1: ScrollPane->JComponent
 ///*
         scrollPane = new JScrollPane( jComponent );
 //*/

         // Test 2: ScrollPane->JPanel->JComponent
         // WORKS!!!
 /*
         innerPanel = new JPanel();
         innerPanel.add( jComponent );
         innerPanel.addFocusListener( focusListener );
         scrollPane = new JScrollPane( innerPanel );
 */

  // Assign FocusListener and KeyListener to Jcomponent and it's parents 
jComponent.addFocusListener( focusListener );  jComponent.addKeyListener(
keyListener );

   System.out.println( "\nParents of " + jComponent.getClass().getName() );

         Enumeration parents = getParentsOfJComponent( jComponent );
         while( parents.hasMoreElements() )
         {
             JComponent parent = (JComponent)parents.nextElement();
             System.out.println( "\t" + parent.getClass().getName() );

             parent.addFocusListener( focusListener );
             parent.addKeyListener( keyListener );
         }
         System.out.println( "\n" );

         // Assign FocusListener and KeyListener to other components
         field.addFocusListener( focusListener );
         field.addKeyListener( keyListener );

         scrollPane.addFocusListener( focusListener );
         scrollPane.addKeyListener( keyListener );

         scrollPane.getViewport().addFocusListener( focusListener );
         scrollPane.getViewport().addKeyListener( keyListener );

         // Assign FocusListener and KeyListener to this JPanel
         addFocusListener( focusListener );
         addKeyListener( keyListener );

         // Add JTextField and JScrollPane to JPanel
         add( field );
         add( scrollPane );
      }

     private Enumeration getParentsOfJComponent( JComponent jComponent )
     {
         if( jComponent == null )
             return null;

         Vector parents = new Vector();

   for( Component parent = jComponent.getParent(); parent != null; parent =
 parent.getParent() )  parents.add( parent );

         return parents.elements();
     }

 // // Begin - Inner classes //  /**  * Class to handle key events.  */
 private class KeyEventHandler extends KeyAdapter  {  /**  * Invoked when a
 key has been pressed.  */  public void keyPressed(KeyEvent e)  {  if(
 e.getKeyCode() == KeyEvent.VK_TAB )  {  if( e.isControlDown() )
 System.out.println( "TabTestPanel:KeyEventHandler.keyPressed CTRL-TAB pressed
 in " +

 ((JComponent)e.getComponent()).getClass().getName() );  else
 System.out.println( "TabTestPanel:KeyEventHandler.keyPressed TAB pressed in "
 +

 ((JComponent)e.getComponent()).getClass().getName() );  }  else
 System.out.println( "TabTestPanel:KeyEventHandler.keyPressed " +
 e.getKeyText( e.getKeyCode() ) +  " pressed in " +
 ((JComponent)e.getComponent()).getClass().getName() );  }

     }

   /**  * Class to handle focus events.  */  private class FocusEventHandler
 extends FocusAdapter  {  /**  * Invoked when a component gains the keyboard
 focus.  */  public void focusGained(FocusEvent e)  {  System.out.println(
 "TabTestPanel:FocusEventHandler.focusGained for " +

 ((JComponent)e.getComponent()).getClass().getName() );
         }

   /**  * Invoked when a component loses the keyboard focus.  */  public void
 focusLost(FocusEvent e)  {  System.out.println(
 "TabTestPanel:FocusEventHandler.focusLost for " +

 ((JComponent)e.getComponent()).getClass().getName() );
         }
     }

 //
 // End - Inner classes
 //

     /**
      * Test code.
      *
      * @param args String array of command line arguments.
      */
     public static void main( String[] args )
     {
 //        String lafClassName =
 "com.sun.java.swing.plaf.motif.MotifLookAndFeel";
         String lafClassName =
 "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
 //        String lafClassName = "javax.swing.plaf.metal.MetalLookAndFeel";
 //        String lafClassName = "com.sun.java.swing.plaf.mac.MacLookAndFeel";

         try
         {
             UIManager.setLookAndFeel( lafClassName );
         }
         catch( Exception ex )
         {
             ex.printStackTrace();
         }

         JFrame frame = new JFrame( "Test - " + lafClassName );

         frame.getContentPane().add( new TabTestPanel() );
         frame.pack();
         frame.setVisible( true );
     }

 }
 // End of TabTestPanel Class

 Thanks.....

 Scott Lavender
 ICC/GR Software
 100 Deerfield Point
 12725 Morris Road, Suite 300
 Alpharetta, GA 30004
 ----------------------------------
 Voice: 770-610-4166
 Fax: 770-475-5126
 Email: lavenders@genrad.com
 ----------------------------------



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