Mega Code Archive
DocumentListener and DocumentEvent
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/*
* Copyright (c) 1995 - 2008 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:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions 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 nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* DocumentEventDemo.java 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() {
// 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();
}
});
}
}
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