testtextarea.java

java2 primer plus一书源程序

/*
 * TestTextArea.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 TestTextArea extends Frame implements ActionListener
{
   Button btnExit;
   Button btnAppend;
   Button btnInsert;
   Button btnReplace;
   TextArea taLetter;
   
   /** Creates new TestDialog */
   public TestTextArea()
   {
      btnAppend = new Button("Append");
      btnAppend.addActionListener(this);
      btnInsert = new Button("Insert");
      btnInsert.addActionListener(this);
      btnReplace = new Button("Replace");
      btnReplace.addActionListener(this);
      btnExit = new Button("Exit");
      btnExit.addActionListener(this);
      taLetter = 
               new TextArea("",10,30, TextArea.SCROLLBARS_VERTICAL_ONLY);
      taLetter.append("I am writing this letter to inform you that you");
      taLetter.append(" have been drafted into the United States Army.");
      taLetter.append(" You will report to Fort Bragg, North Carolina ");
      taLetter.append("on July 20, 1966.  You will be assigned to ");
      taLetter.append("Vietnam.");
      
      
      add(btnAppend);
      add(btnInsert);
      add(btnReplace);
      add(btnExit);
      add(taLetter);

      this.setLayout(new FlowLayout());
     
      addWindowListener(new WinCloser());
      setTitle("Using a TextArea Object");
      setBounds( 100, 100, 400, 400);
      setVisible(true);
   }
   
   public void actionPerformed(ActionEvent ae)
   {
      if (ae.getActionCommand().equals("Append"))
         taLetter.append("\n\nSincerely, \n     The Draft Board");
      if (ae.getActionCommand().equals("Insert"))
         taLetter.insert("Dear Steve,\n     ", 0);
      if (ae.getActionCommand().equals("Replace"))
         taLetter.replaceRange("Dear Jerry,\n     ", 0, 12);
      if (ae.getActionCommand().equals("Exit"))
         System.exit(0);
   }
   
   public static void main(String[] args)
   {
      TestTextArea tta = new TestTextArea();
   }
   
}

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