exercise24_5.java

java程序设计 机械工业出版社 书籍代码

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

public class Exercise24_5 extends JApplet {
  // Create images
  private Image imageUS = ImageViewer.createImage(
    "/image/us.gif", this);
  private Image imageFrance = ImageViewer.createImage(
    "/image/fr.gif", this);
  private Image imageUK = ImageViewer.createImage(
    "/image/uk.gif", this);
  private Image imageGermany = ImageViewer.createImage(
    "/image/germany.gif", this);
  private Image imageIndia = ImageViewer.createImage(
    "/image/india.gif", this);
  private Image imageNorway = ImageViewer.createImage(
    "/image/norway.gif", this);
  private Image imageChina = ImageViewer.createImage(
    "/image/china.gif", this);
  private Image imageCanada = ImageViewer.createImage(
    "/image/ca.gif", this);
  private Image imageDenmark = ImageViewer.createImage(
    "/image/denmark.gif", this);

  // Create a combo box model
  DefaultComboBoxModel model = new DefaultComboBoxModel();

  // Create a combo box with the specified model
  JComboBox jcboCountries = new JComboBox(model);

  // Create a list cell renderer
  MyListCellRenderer renderer = new MyListCellRenderer();

  // Create an image viewer
  ImageViewer imageViewer1 = new ImageViewer(imageUS);

  /** Construct the applet */
  public Exercise24_5() {
    model.addElement(new Object[]{imageUS, "United States"});
    model.addElement(new Object[]{imageFrance, "France"});
    model.addElement(new Object[]{imageUK, "United Kingdom"});
    model.addElement(new Object[]{imageGermany, "Germany"});
    model.addElement(new Object[]{imageIndia, "India"});
    model.addElement(new Object[]{imageNorway, "Norway"});
    model.addElement(new Object[]{imageChina, "China"});
    model.addElement(new Object[]{imageCanada, "Canada"});
    model.addElement(new Object[]{imageDenmark, "Denmark"});

    // Set list cell renderer for the combo box
    jcboCountries.setRenderer(renderer);

    getContentPane().add(jcboCountries, java.awt.BorderLayout.NORTH);
    getContentPane().add(imageViewer1, java.awt.BorderLayout.CENTER);

    // Register listener
    jcboCountries.addActionListener(new ActionListener() {
      public void actionPerformed(java.awt.event.ActionEvent evt) {
        Object[] pair = (Object[])(jcboCountries.getSelectedItem());
        imageViewer1.setImage((Image)pair[0]);
      }
    });

    // Listener for keyboard event
    jcboCountries.addKeyListener(new java.awt.event.KeyAdapter() {
      public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_DELETE)
          model.removeElementAt(jcboCountries.getSelectedIndex());
         // jcboCountries.remove(jcboCountries.getSelectedIndex());
      }
    });
  }

  public static void main(String[] args) {
    Exercise24_5 applet = new Exercise24_5();
    JFrame frame = new JFrame();
    //EXIT_ON_CLOSE == 3
    frame.setDefaultCloseOperation(3);
    frame.setTitle("Exercise24_5");
    frame.getContentPane().add(applet, BorderLayout.CENTER);
    applet.init();
    applet.start();
    frame.setSize(400,320);
    Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
    frame.setLocation((d.width - frame.getSize().width) / 2,
                      (d.height - frame.getSize().height) / 2);
    frame.setVisible(true);
  }
}