j_combobox.java.bak

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// ////////////////////////////////////////////////////////
// 
// J_ComboBox.java
// 
// Created by Jun-Hai Yong,    on XX xx, xxxx (Date)
// ////////////////////////////////////////////////////////
//      Example of JComboBox and JList.
// ////////////////////////////////////////////////////////
// Using this example, please explicitly refer to the book:
//     Jun-Hai Yong. Programming in Java. 
//     Beijing: Tsinghua University Press, 2004.
// 使用本例子，请注明引用:
//     雍俊海. Java 程序设计. 北京: 清华大学出版社, 2004.
// Please note that the author and publisher make no 
// warranty of any kind on the examples provided.
// ////////////////////////////////////////////////////////

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

public class J_ComboBox extends JApplet
{
    private String    m_items[] ={ "snow.gif", "flag.gif" };
    private JComboBox m_comboBox=new JComboBox( m_items );
    private JList     m_list    =new JList( m_items );
    private JLabel    m_label   =new JLabel( );
    private Icon      m_icons[] =new ImageIcon[2];

    public void init( )
    { 
    	Image theImage[] = {getImage(getCodeBase( ), m_items[0]), 
    	                    getImage(getCodeBase( ), m_items[1]) };
    	m_icons[0]= new ImageIcon(theImage[0]);
    	m_icons[1]= new ImageIcon(theImage[1]);
        Container container = getContentPane( );
        container.setLayout(new FlowLayout( ));


        container.add( m_comboBox );
        m_comboBox.addItemListener(new ItemListener( ) // Register event handler
            {// anonymous inner class to handle JComboBox events
                public void itemStateChanged( ItemEvent event )
                {
                    if ( event.getStateChange( ) == ItemEvent.SELECTED )
                    {
                        m_list.setSelectedIndex( m_comboBox.getSelectedIndex( ) );
                        m_label.setIcon( m_icons[ m_comboBox.getSelectedIndex( ) ] );
                    }
                } // End of method: itemStateChanged
            } // End of anonymous inner class (ItemListener)
        ); // End of invoking addItemListener

        container.add( m_list );
        m_list.setSelectedIndex(0);
        m_list.addListSelectionListener(new ListSelectionListener( ) // Register event handler
            {// anonymous inner class to handle events
                public void valueChanged(ListSelectionEvent e )
                {
                    int i= m_list.getAnchorSelectionIndex( );
                    if ( 0<= i && i<=1 )
                        m_comboBox.setSelectedIndex( i );
                } // End of method: valueChanged
            } // End of anonymous inner class (ListSelectionListener)
        ); // End of invoking addListSelectionListener

        container.add( m_label );
        m_label.setIcon( m_icons[ 0 ] );
    } // End of method: init

}  // End of class J_ComboBox