testlists.java

java2 primer plus一书源程序

/*
 * TestLists.java
 *
 * Created on July 30, 2002, 2:36 PM
 */

package com.samspublishing.jpp.ch13;
import java.awt.*;
import java.awt.event.*;

/**
 *
 * @author  Stephen Potts
 * @version
 */
public class TestLists extends Frame implements ItemListener
{
   List lstBread;
   
   TextField tField;
   
   /** Creates new TestLists*/
   public TestLists()
   {
      lstBread = new List(3, true);
      lstBread.add("White Bread");
      
      lstBread.add("Wheat Bread");
      
      lstBread.add("Rye Bread");
      lstBread.addItemListener(this);
      
      tField = new TextField(" ",30);
      
      setLayout(new FlowLayout());
      add(lstBread);
      add(tField);
      
      addWindowListener(new WinCloser());
      setTitle("Using Lists");
      setBounds( 100, 100, 300, 300);
      setVisible(true);
   }
   
   public void itemStateChanged(ItemEvent ie)
   {
      List selBread = (List)ie.getItemSelectable();
      if (selBread.getSelectedItem()!= null)
         tField.setText("You selected " + selBread.getSelectedItem());
      else
      {
         tField.setText("");
         for (int i=0; i< selBread.getItemCount() ; i++)
         {
            if (selBread.isIndexSelected(i))
            {
               String oldString = tField.getText();
               tField.setText( oldString + " " +
                                 selBread.getItem(i));
            }
         }
      }
      
   }
   
   public static void main(String[] args)
   {
      TestLists tc = new TestLists();
   }
   
}

class WinCloser extends WindowAdapter
{
   public void windowClosing(WindowEvent e)
   {
      System.exit(0);
   }
}