Java tutorial
/* From http://java.sun.com/docs/books/tutorial/index.html */ /* * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * -Redistribution of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * -Redistribution in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of Sun Microsystems, Inc. or the names of contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. * * You acknowledge that this software is not designed, licensed or intended * for use in the design, construction, operation or maintenance of any * nuclear facility. */ /* * DocumentEventDemo.java is a 1.4 example that * requires no other files. */ import java.awt.Dimension; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.JTextField; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; import javax.swing.text.Document; public class DocumentEventDemo extends JPanel implements ActionListener { JTextField textField; JTextArea textArea; JTextArea displayArea; public DocumentEventDemo() { super(new GridBagLayout()); GridBagLayout gridbag = (GridBagLayout) getLayout(); GridBagConstraints c = new GridBagConstraints(); JButton button = new JButton("Clear"); button.addActionListener(this); textField = new JTextField(20); textField.addActionListener(new MyTextActionListener()); textField.getDocument().addDocumentListener(new MyDocumentListener()); textField.getDocument().putProperty("name", "Text Field"); textArea = new JTextArea(); textArea.getDocument().addDocumentListener(new MyDocumentListener()); textArea.getDocument().putProperty("name", "Text Area"); JScrollPane scrollPane = new JScrollPane(textArea); scrollPane.setPreferredSize(new Dimension(200, 75)); displayArea = new JTextArea(); displayArea.setEditable(false); JScrollPane displayScrollPane = new JScrollPane(displayArea); displayScrollPane.setPreferredSize(new Dimension(200, 75)); c.gridx = 0; c.gridy = 0; c.weightx = 1.0; c.fill = GridBagConstraints.HORIZONTAL; gridbag.setConstraints(textField, c); add(textField); c.gridx = 0; c.gridy = 1; c.weightx = 0.0; c.gridheight = 2; c.fill = GridBagConstraints.BOTH; gridbag.setConstraints(scrollPane, c); add(scrollPane); c.gridx = 1; c.gridy = 0; c.weightx = 1.0; c.weighty = 1.0; gridbag.setConstraints(displayScrollPane, c); add(displayScrollPane); c.gridx = 1; c.gridy = 2; c.weightx = 0.0; c.gridheight = 1; c.weighty = 0.0; c.fill = GridBagConstraints.HORIZONTAL; gridbag.setConstraints(button, c); add(button); setPreferredSize(new Dimension(450, 250)); setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20)); } class MyDocumentListener implements DocumentListener { final String newline = "\n"; public void insertUpdate(DocumentEvent e) { updateLog(e, "inserted into"); } public void removeUpdate(DocumentEvent e) { updateLog(e, "removed from"); } public void changedUpdate(DocumentEvent e) { //Plain text components don't fire these events. } public void updateLog(DocumentEvent e, String action) { Document doc = (Document) e.getDocument(); int changeLength = e.getLength(); displayArea.append(changeLength + " character" + ((changeLength == 1) ? " " : "s ") + action + " " + doc.getProperty("name") + "." + newline + " Text length = " + doc.getLength() + newline); displayArea.setCaretPosition(displayArea.getDocument().getLength()); } } class MyTextActionListener implements ActionListener { /** Handle the text field Return. */ public void actionPerformed(ActionEvent e) { int selStart = textArea.getSelectionStart(); int selEnd = textArea.getSelectionEnd(); textArea.replaceRange(textField.getText(), selStart, selEnd); textField.selectAll(); } } /** Handle button click. */ public void actionPerformed(ActionEvent e) { displayArea.setText(""); textField.requestFocus(); } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Make sure we have nice window decorations. JFrame.setDefaultLookAndFeelDecorated(true); //Create and set up the window. JFrame frame = new JFrame("DocumentEventDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. JComponent newContentPane = new DocumentEventDemo(); newContentPane.setOpaque(true); //content panes must be opaque frame.setContentPane(newContentPane); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }