jtextareatest.java

Java程序设计技巧与开发实例附书源代码。

import javax.swing.*;
import javax.swing.event.*;

public class JTextAreaTest
    extends JFrame
    implements DocumentListener {
  private JTextArea label = new JTextArea(3, 10);

  public JTextAreaTest() {
    super("MultiLineLabel Test");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    label.setLineWrap(true);
    label.setWrapStyleWord(true);
    label.setText("This text area contains some editable text.");

    getContentPane().add("Center", new JScrollPane(label));
    label.getDocument().addDocumentListener(this);
    validate();
    pack();
    setVisible(true);
  }

  public void changedUpdate(DocumentEvent e) {
    System.out.println("Change Event: \n" + eventInfo(e));
  }

  public void insertUpdate(DocumentEvent e) {
    System.out.println("Insert Event: \n" + eventInfo(e));
  }

  public void removeUpdate(DocumentEvent e) {
    System.out.println("Remove Event: \n" + eventInfo(e));
  }

  private String eventInfo(DocumentEvent e) {
    return "Length: " + e.getLength() + ", Offset: " + e.getOffset();
  }

  public static void main(String args[]) {
    JTextAreaTest tat = new JTextAreaTest();
  }
}