Author: Real Gagnon
Author's WebSite: http://tactika.com/realhome/realhome.html

 import com.sun.java.swing.*;
 //import javax.swing.*;
 import java.awt.event.*;

 public class ActionJList extends JList {
  /*
  ** sends ACTION_PERFORMED event for double-click
  ** and ENTER key
  */
  ActionListener al;

  public ActionJList(String[] it){
   super(it);

  addMouseListener(new MouseAdapter() {
   public void mouseClicked(MouseEvent me) {
    if (al == null) return;
    Object ob[] = getSelectedValues();
    if (ob.length > 1) return;
    if (me.getClickCount() == 2) {
      System.out.println("Sending ACTION_PERFORMED to ActionListener");
      al.actionPerformed(new ActionEvent(this,
         ActionEvent.ACTION_PERFORMED,
         ob[0].toString()));
      me.consume();
      }
    }
   });

   addKeyListener(new KeyAdapter() {
    public void keyReleased(KeyEvent ke) {
     if (al == null) return;
     Object ob[] = getSelectedValues();
     if (ob.length > 1) return;
       if (ke.getKeyCode() == KeyEvent.VK_ENTER) {
         System.out.println("Sending ACTION_PERFORMED to ActionListener");
         al.actionPerformed(new ActionEvent(this,
         ActionEvent.ACTION_PERFORMED,
         ob[0].toString()));
         ke.consume();
         } 
     }
    });
    this.setSelectedIndex(0); 
   }

   public void addActionListener(ActionListener al){
    this.al = al;
    }
 }

To try it:

 import com.sun.java.swing.*;
 //import javax.swing.*;
 import java.awt.*;
 import java.awt.event.*;

 public class TestActionJList {
  public static void main(String args[]) {
   JFrame jf = new JFrame();
   jf.getContentPane().add(new PanelWithActionJList());
   jf.pack();
   jf.setVisible(true);
   }

 }

 class PanelWithActionJList extends JPanel {
  public PanelWithActionJList() {
   setLayout(new GridLayout(1,1));

   String[] items = 
     { "item 0", "item 1", "item 2", "item 3" , "item 4",
       "item 5", "item 6", "item 7", "item 8" , "item 9" };
   
   final ActionJList ajl = new ActionJList(items);

   ajl.setVisibleRowCount(5);
   ajl.addActionListener(
     new ActionListener() {
        public void actionPerformed(ActionEvent ae) {
         System.out.println("action in Panel " + ajl.getSelectedValue()); 
         }
     });

   JScrollPane jsp = new JScrollPane();
   jsp.getViewport().add(ajl);
   add(jsp);
   }
 }

Posted On: 5-Jul-1999

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