listapplet.java

Java the UML Way 书中所有源码

/*
 * ListApplet.java  E.L. 2001-08-20
 *
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class ListApplet extends JApplet {
  static final String [] cities =
    {"Tokyo", "New York City", "Mexico City", "Mumbai", "Sao Paulo", "Los Angeles",
     "Shanghai", "Lagos", "Calcutta", "Buenos Aires"};
  private JTextArea text = new JTextArea("You haven't chosen cities yet.", 4, 20);
  private JList cityList = new JList(cities);

  public void init() {
    Container guiContainer = getContentPane();
    JLabel label = new JLabel("Choose among the largest cities in the world:");
    guiContainer.add(label, BorderLayout.NORTH);
    JScrollPane scrollPaneWithList = new JScrollPane(cityList);

    guiContainer.add(scrollPaneWithList, BorderLayout.CENTER);
    ListListener listener = new ListListener();
    cityList.addListSelectionListener(listener);

    text.setLineWrap(true);
    text.setWrapStyleWord(true);
    guiContainer.add(text, BorderLayout.SOUTH);
  }

  class ListListener implements ListSelectionListener {
    public void valueChanged(ListSelectionEvent event) {
      java.lang.Object[] values = cityList.getSelectedValues();
      String newText = "You have now chosen: ";
      for (int i = 0; i < values.length; i++) {
        newText += (String) values[i] + " ";
      }
      text.setText(newText);
    }
  }
}