Java/Swing JFC/TextField
Содержание
- 1 Add key listener event handler to JTextField
- 2 A hack to make a JTextField really 2 columns wide
- 3 Aligning the Text in a JTextField Component
- 4 A simple label for field form panel
- 5 Associate JLabel component with a JTextField
- 6 Auto complete TextField
- 7 Based on JTextField content, enable or disable a JButton
- 8 Bounded TextField
- 9 Create the textfield
- 10 Cut, paste, and copy in a JTextField under program control.
- 11 EditabilityExample
- 12 extends JTextField to create integer JTextField
- 13 FieldEdit - an Applet to validate data as it"s being entered
- 14 Firing Item Events
- 15 JTextField Alignment Sample
- 16 JTextField Max Length
- 17 JTextField Sample 2
- 18 JTextField Verifier Sample
- 19 Limit JTextField input to a maximum length
- 20 Make a Text Field two columns wide
- 21 Make sure that my JTextField has the focus when a JFrame is created
- 22 Make sure that my Text field has the focus when a JFrame is created
- 23 Make the ENTER key act like the TAB key
- 24 Modify horizontal alignment of text field at runtime
- 25 Non Wrapping(Wrap) TextPane
- 26 Numeric TextField
- 27 Overwritable TextField
- 28 Passive TextField 1
- 29 Passive TextField 2
- 30 Passive TextField 3
- 31 Right justified JTextfield content
- 32 Right justified JTextField contents
- 33 Set the focus on a particular JTextField
- 34 Setting up a textfield and modifying its horizontal alignment at runtime
- 35 Text Accelerator Example
- 36 TextField Elements
- 37 TextField Look Ahead Example
- 38 Textfield only accepts numbers
- 39 Text fields and Java events
- 40 TextFieldViews 2
- 41 TextField with Constaints
- 42 Validate a value on the lostFocus event
- 43 Water mark text field
Add key listener event handler to JTextField
<source lang="java">
import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.HeadlessException; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; public class Main extends JFrame {
public Main() throws HeadlessException {
setSize(200, 200);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new FlowLayout(FlowLayout.LEFT));
JLabel usernameLabel = new JLabel("Username: ");
JTextField usernameTextField = new JTextField();
usernameTextField.setPreferredSize(new Dimension(100, 20));
add(usernameLabel);
add(usernameTextField);
usernameTextField.addKeyListener(new KeyAdapter() {
public void keyReleased(KeyEvent e) {
JTextField textField = (JTextField) e.getSource();
String text = textField.getText();
textField.setText(text.toUpperCase());
}
public void keyTyped(KeyEvent e) {
}
public void keyPressed(KeyEvent e) {
}
});
}
public static void main(String[] args) {
new Main().setVisible(true);
}
}
</source>
A hack to make a JTextField really 2 columns wide
<source lang="java">
import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; public class WidthHack {
public static void main(String[] args) {
JTextField tf = new JTextField("mm");
tf.setPreferredSize(tf.getPreferredSize());
tf.setText("");
JPanel pHacked = new JPanel();
pHacked.setBorder(new javax.swing.border.TitledBorder("hacked 2 columns"));
pHacked.add(tf);
JPanel pStock = new JPanel();
pStock.setBorder(new javax.swing.border.TitledBorder("stock 2 columns"));
pStock.add(new JTextField(2));
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new java.awt.GridLayout(0, 1));
frame.getContentPane().add(pHacked);
frame.getContentPane().add(pStock);
frame.setSize(150, 150);
frame.setVisible(true);
tf.requestFocus();
}
}
</source>
Aligning the Text in a JTextField Component
<source lang="java">
import javax.swing.JTextField; public class Main {
public static void main(String[] argv) {
JTextField textfield = new JTextField("Initial Text");
// Left-justify the text
textfield.setHorizontalAlignment(JTextField.LEFT);
// Center the text
textfield.setHorizontalAlignment(JTextField.CENTER);
// Right-justify the text
textfield.setHorizontalAlignment(JTextField.RIGHT);
}
}
</source>
A simple label for field form panel
<source lang="java">
import java.awt.BorderLayout; import java.awt.FlowLayout; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; public class TextForm extends JPanel {
private JTextField[] fields;
// Create a form with the specified labels, tooltips, and sizes.
public TextForm(String[] labels, char[] mnemonics, int[] widths, String[] tips) {
super(new BorderLayout());
JPanel labelPanel = new JPanel(new GridLayout(labels.length, 1));
JPanel fieldPanel = new JPanel(new GridLayout(labels.length, 1));
add(labelPanel, BorderLayout.WEST);
add(fieldPanel, BorderLayout.CENTER);
fields = new JTextField[labels.length];
for (int i = 0; i < labels.length; i += 1) {
fields[i] = new JTextField();
if (i < tips.length)
fields[i].setToolTipText(tips[i]);
if (i < widths.length)
fields[i].setColumns(widths[i]);
JLabel lab = new JLabel(labels[i], JLabel.RIGHT);
lab.setLabelFor(fields[i]);
if (i < mnemonics.length)
lab.setDisplayedMnemonic(mnemonics[i]);
labelPanel.add(lab);
JPanel p = new JPanel(new FlowLayout(FlowLayout.LEFT));
p.add(fields[i]);
fieldPanel.add(p);
}
}
public String getText(int i) {
return (fields[i].getText());
}
public static void main(String[] args) {
String[] labels = { "First Name", "Middle Initial", "Last Name", "Age" };
char[] mnemonics = { "F", "M", "L", "A" };
int[] widths = { 15, 1, 15, 3 };
String[] descs = { "First Name", "Middle Initial", "Last Name", "Age" };
final TextForm form = new TextForm(labels, mnemonics, widths, descs);
JButton submit = new JButton("Submit Form");
submit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println(form.getText(0) + " " + form.getText(1) + ". " + form.getText(2)
+ ", age " + form.getText(3));
}
});
JFrame f = new JFrame("Text Form Example");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(form, BorderLayout.NORTH);
JPanel p = new JPanel();
p.add(submit);
f.getContentPane().add(p, BorderLayout.SOUTH);
f.pack();
f.setVisible(true);
}
}
</source>
Associate JLabel component with a JTextField
<source lang="java">
import java.awt.FlowLayout; import java.awt.HeadlessException; import java.awt.event.KeyEvent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPasswordField; import javax.swing.JTextField; public class Main extends JFrame {
public Main() throws HeadlessException {
setSize(400, 200);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new FlowLayout(FlowLayout.LEFT));
JLabel usernameLabel = new JLabel("Username: ");
JLabel passwordLabel = new JLabel("Password: ");
JTextField usernameField = new JTextField(20);
JPasswordField passwordField = new JPasswordField(20);
usernameLabel.setDisplayedMnemonic(KeyEvent.VK_U);
usernameLabel.setLabelFor(usernameField);
passwordLabel.setDisplayedMnemonic(KeyEvent.VK_P);
passwordLabel.setLabelFor(passwordField);
getContentPane().add(usernameLabel);
getContentPane().add(usernameField);
getContentPane().add(passwordLabel);
getContentPane().add(passwordField);
}
public static void main(String[] args) {
new Main().setVisible(true);
}
}
</source>
Auto complete TextField
<source lang="java">
/* From http://java.sun.ru/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.
*/
import java.util.List; import javax.swing.JTextField; import javax.swing.text.*; public class jexpAutoTextField extends JTextField {
class AutoDocument extends PlainDocument {
public void replace(int i, int j, String s, AttributeSet attributeset)
throws BadLocationException {
super.remove(i, j);
insertString(i, s, attributeset);
}
public void insertString(int i, String s, AttributeSet attributeset)
throws BadLocationException {
if (s == null || "".equals(s))
return;
String s1 = getText(0, i);
String s2 = getMatch(s1 + s);
int j = (i + s.length()) - 1;
if (isStrict && s2 == null) {
s2 = getMatch(s1);
j--;
} else if (!isStrict && s2 == null) {
super.insertString(i, s, attributeset);
return;
}
if (autoComboBox != null && s2 != null)
autoComboBox.setSelectedValue(s2);
super.remove(0, getLength());
super.insertString(0, s2, attributeset);
setSelectionStart(j + 1);
setSelectionEnd(getLength());
}
public void remove(int i, int j) throws BadLocationException {
int k = getSelectionStart();
if (k > 0)
k--;
String s = getMatch(getText(0, k));
if (!isStrict && s == null) {
super.remove(i, j);
} else {
super.remove(0, getLength());
super.insertString(0, s, null);
}
if (autoComboBox != null && s != null)
autoComboBox.setSelectedValue(s);
try {
setSelectionStart(k);
setSelectionEnd(getLength());
} catch (Exception exception) {
}
}
}
public jexpAutoTextField(List list) {
isCaseSensitive = false;
isStrict = true;
autoComboBox = null;
if (list == null) {
throw new IllegalArgumentException("values can not be null");
} else {
dataList = list;
init();
return;
}
}
jexpAutoTextField(List list, jexpAutoComboBox b) {
isCaseSensitive = false;
isStrict = true;
autoComboBox = null;
if (list == null) {
throw new IllegalArgumentException("values can not be null");
} else {
dataList = list;
autoComboBox = b;
init();
return;
}
}
private void init() {
setDocument(new AutoDocument());
if (isStrict && dataList.size() > 0)
setText(dataList.get(0).toString());
}
private String getMatch(String s) {
for (int i = 0; i < dataList.size(); i++) {
String s1 = dataList.get(i).toString();
if (s1 != null) {
if (!isCaseSensitive
&& s1.toLowerCase().startsWith(s.toLowerCase()))
return s1;
if (isCaseSensitive && s1.startsWith(s))
return s1;
}
}
return null;
}
public void replaceSelection(String s) {
AutoDocument _lb = (AutoDocument) getDocument();
if (_lb != null)
try {
int i = Math.min(getCaret().getDot(), getCaret().getMark());
int j = Math.max(getCaret().getDot(), getCaret().getMark());
_lb.replace(i, j - i, s, null);
} catch (Exception exception) {
}
}
public boolean isCaseSensitive() {
return isCaseSensitive;
}
public void setCaseSensitive(boolean flag) {
isCaseSensitive = flag;
}
public boolean isStrict() {
return isStrict;
}
public void setStrict(boolean flag) {
isStrict = flag;
}
public List getDataList() {
return dataList;
}
public void setDataList(List list) {
if (list == null) {
throw new IllegalArgumentException("values can not be null");
} else {
dataList = list;
return;
}
}
private List dataList;
private boolean isCaseSensitive;
private boolean isStrict;
private jexpAutoComboBox autoComboBox;
} import java.awt.event.ItemEvent; import javax.swing.DefaultComboBoxModel; import javax.swing.JComboBox; import javax.swing.plaf.basic.BasicComboBoxEditor; public class jexpAutoComboBox extends JComboBox {
private class AutoTextFieldEditor extends BasicComboBoxEditor {
private jexpAutoTextField getAutoTextFieldEditor() {
return (jexpAutoTextField) editor;
}
AutoTextFieldEditor(java.util.List list) {
editor = new jexpAutoTextField(list, jexpAutoComboBox.this);
}
}
public jexpAutoComboBox(java.util.List list) {
isFired = false;
autoTextFieldEditor = new AutoTextFieldEditor(list);
setEditable(true);
setModel(new DefaultComboBoxModel(list.toArray()) {
protected void fireContentsChanged(Object obj, int i, int j) {
if (!isFired)
super.fireContentsChanged(obj, i, j);
}
});
setEditor(autoTextFieldEditor);
}
public boolean isCaseSensitive() {
return autoTextFieldEditor.getAutoTextFieldEditor().isCaseSensitive();
}
public void setCaseSensitive(boolean flag) {
autoTextFieldEditor.getAutoTextFieldEditor().setCaseSensitive(flag);
}
public boolean isStrict() {
return autoTextFieldEditor.getAutoTextFieldEditor().isStrict();
}
public void setStrict(boolean flag) {
autoTextFieldEditor.getAutoTextFieldEditor().setStrict(flag);
}
public java.util.List getDataList() {
return autoTextFieldEditor.getAutoTextFieldEditor().getDataList();
}
public void setDataList(java.util.List list) {
autoTextFieldEditor.getAutoTextFieldEditor().setDataList(list);
setModel(new DefaultComboBoxModel(list.toArray()));
}
void setSelectedValue(Object obj) {
if (isFired) {
return;
} else {
isFired = true;
setSelectedItem(obj);
fireItemStateChanged(new ItemEvent(this, 701, selectedItemReminder,
1));
isFired = false;
return;
}
}
protected void fireActionEvent() {
if (!isFired)
super.fireActionEvent();
}
private AutoTextFieldEditor autoTextFieldEditor;
private boolean isFired;
}
</source>
Based on JTextField content, enable or disable a JButton
<source lang="java">
import javax.swing.JButton; import javax.swing.JTextField; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; import javax.swing.text.Document; public class Main {
JButton button = new JButton("foo");
JTextField textfield = new JTextField(10);
Document document;
public Main() {
document = textfield.getDocument();
document.addDocumentListener(new JButtonStateController());
}
class JButtonStateController implements DocumentListener {
JButtonStateController() {
}
public void changedUpdate(DocumentEvent e) {
disableIfEmpty(e);
}
public void insertUpdate(DocumentEvent e) {
disableIfEmpty(e);
}
public void removeUpdate(DocumentEvent e) {
disableIfEmpty(e);
}
public void disableIfEmpty(DocumentEvent e) {
button.setEnabled(e.getDocument().getLength() > 0);
}
}
}
</source>
Bounded TextField
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.Toolkit; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.UIManager; import javax.swing.text.AbstractDocument; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.PlainDocument; public class BoundedTextField extends JTextField implements
BoundedPlainDocument.InsertErrorListener {
public BoundedTextField() {
this(null, 0, 0);
}
public BoundedTextField(String text, int columns, int maxLength) {
super(null, text, columns);
if (text != null && maxLength == 0) {
maxLength = text.length();
}
BoundedPlainDocument plainDoc = (BoundedPlainDocument) getDocument();
plainDoc.setMaxLength(maxLength);
plainDoc.addInsertErrorListener(this);
}
public BoundedTextField(int columns, int maxLength) {
this(null, columns, maxLength);
}
public BoundedTextField(String text, int maxLength) {
this(text, 0, maxLength);
}
public void setMaxLength(int maxLength) {
((BoundedPlainDocument) getDocument()).setMaxLength(maxLength);
}
public int getMaxLength() {
return ((BoundedPlainDocument) getDocument()).getMaxLength();
}
// Override to handle insertion error
public void insertFailed(BoundedPlainDocument doc, int offset, String str,
AttributeSet a) {
// By default, just beep
Toolkit.getDefaultToolkit().beep();
}
// Method to create default model
protected Document createDefaultModel() {
return new BoundedPlainDocument();
}
// Test code
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Bounded Text Field Example");
BoundedTextField tf = new BoundedTextField(10, 32);
JLabel l = new JLabel("Type up to 32 characters: ");
f.getContentPane().add(tf, "East");
f.getContentPane().add(l, "West");
f.pack();
f.setVisible(true);
}
} class BoundedPlainDocument extends PlainDocument {
public BoundedPlainDocument() {
// Default constructor - must use setMaxLength later
this.maxLength = 0;
}
public BoundedPlainDocument(int maxLength) {
this.maxLength = maxLength;
}
public BoundedPlainDocument(AbstractDocument.Content content, int maxLength) {
super(content);
if (content.length() > maxLength) {
throw new IllegalArgumentException(
"Initial content larger than maximum size");
}
this.maxLength = maxLength;
}
public void setMaxLength(int maxLength) {
if (getLength() > maxLength) {
throw new IllegalArgumentException(
"Current content larger than new maximum size");
}
this.maxLength = maxLength;
}
public int getMaxLength() {
return maxLength;
}
public void insertString(int offset, String str, AttributeSet a)
throws BadLocationException {
if (str == null) {
return;
}
// Note: be careful here - the content always has a
// trailing newline, which should not be counted!
int capacity = maxLength + 1 - getContent().length();
if (capacity >= str.length()) {
// It all fits
super.insertString(offset, str, a);
} else {
// It doesn"t all fit. Add as much as we can.
if (capacity > 0) {
super.insertString(offset, str.substring(0, capacity), a);
}
// Finally, signal an error.
if (errorListener != null) {
errorListener.insertFailed(this, offset, str, a);
}
}
}
public void addInsertErrorListener(InsertErrorListener l) {
if (errorListener == null) {
errorListener = l;
return;
}
throw new IllegalArgumentException(
"InsertErrorListener already registered");
}
public void removeInsertErrorListener(InsertErrorListener l) {
if (errorListener == l) {
errorListener = null;
}
}
public interface InsertErrorListener {
public abstract void insertFailed(BoundedPlainDocument doc, int offset,
String str, AttributeSet a);
}
protected InsertErrorListener errorListener; // Unicast listener
protected int maxLength;
}
</source>
Create the textfield
<source lang="java">
import javax.swing.*; import java.awt.*; public class JTextFieldTest extends JFrame {
public JTextFieldTest() {
super("JTextField Test");
getContentPane().setLayout(new FlowLayout());
JTextField textField1 = new JTextField("1", 1);
JTextField textField2 = new JTextField("22", 2);
JTextField textField3 = new JTextField("333", 3);
getContentPane().add(textField1);
getContentPane().add(textField2);
getContentPane().add(textField3);
setSize(300, 170);
setVisible(true);
}
public static void main(String argv[]) {
new JTextFieldTest();
}
}
</source>
Cut, paste, and copy in a JTextField under program control.
<source lang="java">
import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.event.CaretEvent; import javax.swing.event.CaretListener; public class Main {
JTextField jtf = new JTextField(15);
JButton jbtnCut = new JButton("Cut");
JButton jbtnPaste = new JButton("Paste");
JButton jbtnCopy = new JButton("Copy");
public Main() {
JFrame jfrm = new JFrame("Cut, Copy, and Paste");
jfrm.setLayout(new FlowLayout());
jfrm.setSize(230, 150);
jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jbtnCut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent le) {
jtf.cut();
update();
}
});
jbtnPaste.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent le) {
jtf.paste();
update();
}
});
jbtnCopy.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent le) {
jtf.copy();
update();
}
});
jtf.addCaretListener(new CaretListener() {
public void caretUpdate(CaretEvent ce) {
update();
}
});
jfrm.add(jtf);
jfrm.add(jbtnCut);
jfrm.add(jbtnPaste);
jfrm.add(jbtnCopy);
jfrm.setVisible(true);
}
private void update() {
System.out.println("All text: " + jtf.getText());
if (jtf.getSelectedText() != null)
System.out.println("Selected text: " + jtf.getSelectedText());
else
System.out.println("Selected text: ");
}
public static void main(String args[]) {
new Main();
}
}
</source>
EditabilityExample
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.BorderFactory; import javax.swing.BoxLayout; import javax.swing.JFrame; import javax.swing.JTextArea; import javax.swing.JTextField; import javax.swing.Timer; import javax.swing.UIManager; public class EditabilityExample {
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Editability Example");
f.getContentPane().setLayout(
new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
f.getContentPane().add(firstField);
JTextField tf = new JTextField("A read-only text field", 20);
tf.setEditable(false);
f.getContentPane().add(tf);
JTextArea ta = new JTextArea("An editable\ntext area", 2, 20);
ta.setBorder(BorderFactory.createLoweredBevelBorder());
f.getContentPane().add(ta);
ta = new JTextArea("A read-only\ntext area", 2, 20);
ta.setBorder(BorderFactory.createLoweredBevelBorder());
ta.setEditable(false);
f.getContentPane().add(ta);
f.pack();
f.show();
if (args.length == 1 && args[0].equals("disable")) {
// Toggle the enabled state of the first
// text field every 10 seconds
Timer t = new Timer(10000, new ActionListener() {
public void actionPerformed(ActionEvent evt) {
firstField.setEnabled(!firstField.isEnabled());
firstField.setText(firstFieldText
+ (firstField.isEnabled() ? "" : " (disabled)"));
}
});
t.start();
}
}
final static String firstFieldText = "An editable text field";
final static JTextField firstField = new JTextField(firstFieldText, 20);
}
</source>
extends JTextField to create integer JTextField
<source lang="java">
/*
* Copyright (C) 2001-2003 Colin Bell * colbell@users.sourceforge.net * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
import java.awt.Toolkit; import javax.swing.JTextField; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.PlainDocument; /**
* This class is a TextField that only allows integer
* values to be entered into it.
*
* @author
*/
public class IntegerField extends JTextField {
/**
* Default ctor.
*/
public IntegerField()
{
super();
}
/**
* Ctor specifying the field width.
*
* @param cols Number of columns.
*/
public IntegerField(int cols)
{
super(cols);
}
/**
* Retrieve the contents of this field as an int.
*
* @return the contents of this field as an int.
*/
public int getInt()
{
final String text = getText();
if (text == null || text.length() == 0)
{
return 0;
}
return Integer.parseInt(text);
}
/**
* Set the contents of this field to the passed int.
*
* @param value The new value for this field.
*/
public void setInt(int value)
{
setText(String.valueOf(value));
}
/**
* Create a new document model for this control that only accepts
* integral values.
*
* @return The new document model.
*/
protected Document createDefaultModel()
{
return new IntegerDocument();
}
/**
* This document only allows integral values to be added to it.
*/
static class IntegerDocument extends PlainDocument
{
public void insertString(int offs, String str, AttributeSet a)
throws BadLocationException
{
if (str != null)
{
try
{
Integer.decode(str);
super.insertString(offs, str, a);
}
catch (NumberFormatException ex)
{
Toolkit.getDefaultToolkit().beep();
}
}
}
}
}
</source>
FieldEdit - an Applet to validate data as it"s being entered
<source lang="java">
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002. * All rights reserved. Software written by Ian F. Darwin and others. * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. * * Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee * cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s, * pioneering role in inventing and promulgating (and standardizing) the Java * language and environment is gratefully acknowledged. * * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for * inventing predecessor languages C and C++ is also gratefully acknowledged. */
import java.applet.Applet; import java.awt.Label; import java.awt.TextField; import java.awt.Toolkit; import java.awt.event.TextEvent; import java.awt.event.TextListener; /**
* FieldEdit - an Applet to validate data as it"s being entered. * * Not very general: a 52 minute hack to show the mechanics of editing. * * Does try to leave the cursor in exactly the right position. * * @author Ian Darwin, http://www.darwinsys.ru/ * @author Bjorn Gudehus, gothic@celestica.ru */
public class FieldEdit extends Applet {
/** The label to display the type of thing we"re editing */
private Label myLabel;
/** The textfield to enter */
private TextField textField;
/** Init() is an Applet method used to set up the GUI and listeners */
public void init() {
add(myLabel = new Label("Hex:"));
add(textField = new TextField(10));
textField.addTextListener(new TextListener() {
public void textValueChanged(TextEvent ev) {
int caret = -1;
TextField tf = FieldEdit.this.textField;
String s = tf.getText();
StringBuffer sb = new StringBuffer();
System.out.println("Text->" + s);
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (Character.digit(c, 16) >= 0)
sb.append(c);
else
caret = tf.getCaretPosition() - 1;
}
if (caret >= 0) {
tf.setText(sb.toString());
tf.setCaretPosition(caret);
Toolkit.getDefaultToolkit().beep();
}
}
});
}
}
</source>
Firing Item Events
<source lang="java">
import java.awt.ItemSelectable; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.event.EventListenerList; public class Main {
public static void main(String[] argv) throws Exception {
MyComponent component = new MyComponent();
JFrame f = new JFrame();
f.add(component);
f.setSize(300, 300);
f.setVisible(true);
}
} class MyComponent extends JTextField implements ItemSelectable {
protected EventListenerList listenerList = new EventListenerList();
public Object[] getSelectedObjects() {
return new String[] { "a", "b", "c" };
}
public void addItemListener(ItemListener l) {
listenerList.add(ItemListener.class, l);
}
public void removeItemListener(ItemListener l) {
listenerList.remove(ItemListener.class, l);
}
void fireItemEvent(Object item, boolean sel) {
ItemEvent evt = new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED, item,
sel ? ItemEvent.SELECTED : ItemEvent.DESELECTED);
Object[] listeners = listenerList.getListenerList();
for (int i = 0; i < listeners.length - 2; i += 2) {
if (listeners[i] == ItemListener.class) {
((ItemListener) listeners[i + 1]).itemStateChanged(evt);
}
}
}
}
</source>
JTextField Alignment Sample
<source lang="java">
import java.awt.Container; import java.awt.GridLayout; import javax.swing.JFrame; import javax.swing.JTextField; public class AlignmentSample {
public static void main(String args[]) {
JFrame frame = new JFrame("Alignment Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container content = frame.getContentPane();
content.setLayout(new GridLayout(0, 1));
JTextField textField = new JTextField("Left");
textField.setHorizontalAlignment(JTextField.LEFT);
content.add(textField);
textField = new JTextField("Center");
textField.setHorizontalAlignment(JTextField.CENTER);
content.add(textField);
textField = new JTextField("Right");
textField.setHorizontalAlignment(JTextField.RIGHT);
content.add(textField);
textField = new JTextField("Leading");
textField.setHorizontalAlignment(JTextField.LEADING);
content.add(textField);
textField = new JTextField("Trailing");
textField.setHorizontalAlignment(JTextField.TRAILING);
content.add(textField);
frame.pack();
frame.setSize(250, (int) frame.getSize().getHeight());
frame.setVisible(true);
}
}
</source>
JTextField Max Length
<source lang="java">
import javax.swing.JTextField; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.PlainDocument; public class JTextFieldMaxLength extends JTextField{
public JTextFieldMaxLength(int length){
this(null,length);
}
public JTextFieldMaxLength(String text, int length){
super(new PlainDocumentMaxLength(length),text,length);
}
} class PlainDocumentMaxLength extends PlainDocument{
private int maxLength;
public PlainDocumentMaxLength(int maxLength) {
this.maxLength = maxLength;
}
public void insertString (int offset, String str, AttributeSet a)
throws BadLocationException { if (getLength() + str.length() > maxLength) {
// Toolkit.getDefaultToolkit().beep();
}else{
super.insertString(offset,str,a);
}
}
}
</source>
JTextField Sample 2
<source lang="java">
/* Definitive Guide to Swing for Java 2, Second Edition By John Zukowski ISBN: 1-893115-78-X Publisher: APress
- /
import java.awt.BorderLayout; import java.awt.Container; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import javax.swing.InputVerifier; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.SwingUtilities; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.JTextComponent; public class JTextFieldSample {
public static void main(String args[]) {
String title = (args.length == 0 ? "TextField Listener Example"
: args[0]);
JFrame frame = new JFrame(title);
Container content = frame.getContentPane();
JPanel namePanel = new JPanel(new BorderLayout());
JLabel nameLabel = new JLabel("Name: ");
nameLabel.setDisplayedMnemonic(KeyEvent.VK_N);
JTextField nameTextField = new JTextField();
nameLabel.setLabelFor(nameTextField);
namePanel.add(nameLabel, BorderLayout.WEST);
namePanel.add(nameTextField, BorderLayout.CENTER);
content.add(namePanel, BorderLayout.NORTH);
JPanel cityPanel = new JPanel(new BorderLayout());
JLabel cityLabel = new JLabel("City: ");
cityLabel.setDisplayedMnemonic(KeyEvent.VK_C);
JTextField cityTextField = new JTextField();
cityLabel.setLabelFor(cityTextField);
cityPanel.add(cityLabel, BorderLayout.WEST);
cityPanel.add(cityTextField, BorderLayout.CENTER);
content.add(cityPanel, BorderLayout.SOUTH);
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
System.out
.println("Command: " + actionEvent.getActionCommand());
}
};
nameTextField.setActionCommand("Yo");
nameTextField.addActionListener(actionListener);
cityTextField.addActionListener(actionListener);
KeyListener keyListener = new KeyListener() {
public void keyPressed(KeyEvent keyEvent) {
printIt("Pressed", keyEvent);
}
public void keyReleased(KeyEvent keyEvent) {
printIt("Released", keyEvent);
}
public void keyTyped(KeyEvent keyEvent) {
printIt("Typed", keyEvent);
}
private void printIt(String title, KeyEvent keyEvent) {
int keyCode = keyEvent.getKeyCode();
String keyText = KeyEvent.getKeyText(keyCode);
System.out.println(title + " : " + keyText + " / "
+ keyEvent.getKeyChar());
}
};
nameTextField.addKeyListener(keyListener);
cityTextField.addKeyListener(keyListener);
InputVerifier verifier = new InputVerifier() {
public boolean verify(JComponent input) {
final JTextComponent source = (JTextComponent) input;
String text = source.getText();
if ((text.length() != 0) && !(text.equals("Exit"))) {
Runnable runnable = new Runnable() {
public void run() {
JOptionPane.showMessageDialog(source,
"Can"t leave.", "Error Dialog",
JOptionPane.ERROR_MESSAGE);
}
};
SwingUtilities.invokeLater(runnable);
return false;
} else {
return true;
}
}
};
nameTextField.setInputVerifier(verifier);
cityTextField.setInputVerifier(verifier);
DocumentListener documentListener = new DocumentListener() {
public void changedUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
public void insertUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
public void removeUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
private void printIt(DocumentEvent documentEvent) {
DocumentEvent.EventType type = documentEvent.getType();
String typeString = null;
if (type.equals(DocumentEvent.EventType.CHANGE)) {
typeString = "Change";
} else if (type.equals(DocumentEvent.EventType.INSERT)) {
typeString = "Insert";
} else if (type.equals(DocumentEvent.EventType.REMOVE)) {
typeString = "Remove";
}
System.out.print("Type : " + typeString + " / ");
Document source = documentEvent.getDocument();
int length = source.getLength();
try {
System.out
.println("Contents: " + source.getText(0, length));
} catch (BadLocationException badLocationException) {
System.out.println("Contents: Unknown");
}
}
};
nameTextField.getDocument().addDocumentListener(documentListener);
cityTextField.getDocument().addDocumentListener(documentListener);
frame.setSize(250, 150);
frame.setVisible(true);
}
}
</source>
JTextField Verifier Sample
<source lang="java">
import java.awt.BorderLayout; import java.awt.Container; import javax.swing.InputVerifier; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JTextField; public class VerifierSample {
public static void main(String args[]) {
JFrame frame = new JFrame("Verifier Sample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField textField1 = new JTextField();
JTextField textField2 = new JTextField();
JTextField textField3 = new JTextField();
InputVerifier verifier = new InputVerifier() {
public boolean verify(JComponent comp) {
boolean returnValue;
JTextField textField = (JTextField) comp;
try {
Integer.parseInt(textField.getText());
returnValue = true;
} catch (NumberFormatException e) {
returnValue = false;
}
return returnValue;
}
};
textField1.setInputVerifier(verifier);
textField3.setInputVerifier(verifier);
Container contentPane = frame.getContentPane();
contentPane.add(textField1, BorderLayout.NORTH);
contentPane.add(textField2, BorderLayout.CENTER);
contentPane.add(textField3, BorderLayout.SOUTH);
frame.setSize(300, 100);
frame.setVisible(true);
}
}
</source>
Limit JTextField input to a maximum length
<source lang="java">
import java.awt.FlowLayout; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.PlainDocument; class JTextFieldLimit extends PlainDocument {
private int limit;
JTextFieldLimit(int limit) {
super();
this.limit = limit;
}
JTextFieldLimit(int limit, boolean upper) {
super();
this.limit = limit;
}
public void insertString(int offset, String str, AttributeSet attr) throws BadLocationException {
if (str == null)
return;
if ((getLength() + str.length()) <= limit) {
super.insertString(offset, str, attr);
}
}
} public class Main extends JFrame {
JTextField textfield1;
JLabel label1;
public void init() {
setLayout(new FlowLayout());
label1 = new JLabel("max 10 chars");
textfield1 = new JTextField(15);
add(label1);
add(textfield1);
textfield1.setDocument(new JTextFieldLimit(10));
setSize(300,300);
setVisible(true);
}
}
</source>
Make a Text Field two columns wide
<source lang="java">
import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; public class Main {
public static void main(String[] args) {
JTextField tf = new JTextField("mm");
tf.setPreferredSize(tf.getPreferredSize());
tf.setText("");
JPanel pHacked = new JPanel();
pHacked.add(tf);
JPanel pStock = new JPanel();
pStock.add(new JTextField(2));
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new java.awt.GridLayout(0, 1));
frame.add(pHacked);
frame.add(pStock);
frame.setSize(150, 150);
frame.setVisible(true);
tf.requestFocus();
}
}
</source>
Make sure that my JTextField has the focus when a JFrame is created
<source lang="java">
import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; class Main extends JFrame {
JTextField field1 = new JTextField(10);;
JTextField field2 = new JTextField(10);;
JPanel panel = new JPanel();
public Main() {
panel.add(new JLabel("Field 1:"));
panel.add(field1);
panel.add(new JLabel("Field 2:"));
panel.add(field2);
getContentPane().add("Center", panel);
addWindowListener(new WindowAdapter() {
public void windowOpened(WindowEvent e) {
field1.requestFocus();
}
});
pack();
setVisible(true);
}
public static void main(String[] argv) {
new Main();
}
}
</source>
Make sure that my Text field has the focus when a JFrame is created
<source lang="java">
import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame; import javax.swing.JTextField; class MyFrame extends JFrame {
JTextField field1;
public MyFrame() {
field1 = new JTextField(10);
getContentPane().add("Center", field1);
addWindowListener(new WindowAdapter() {
public void windowOpened(WindowEvent e) {
field1.requestFocus();
}
});
pack();
setVisible(true);
}
} public class Main {
public static void main(String[] argv) {
MyFrame myFrame = new MyFrame();
}
}
</source>
Make the ENTER key act like the TAB key
<source lang="java">
import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import javax.swing.JTextField; class MyTextField extends JTextField {
MyTextField(int len) {
super(len);
addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent evt) {
int key = evt.getKeyCode();
if (key == KeyEvent.VK_ENTER)
transferFocus();
}
});
}
}
</source>
Modify horizontal alignment of text field at runtime
<source lang="java">
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {
public static void main(String[] args) {
final JTextField tf = new JTextField("press <enter>", 20);
tf.setHorizontalAlignment(JTextField.RIGHT);
tf.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int old = tf.getHorizontalAlignment();
if (old == JTextField.LEFT)
tf.setHorizontalAlignment(JTextField.RIGHT);
if (old == JTextField.RIGHT)
tf.setHorizontalAlignment(JTextField.CENTER);
if (old == JTextField.CENTER)
tf.setHorizontalAlignment(JTextField.LEFT);
}
});
JFrame frame = new JFrame("JTextFieldExample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new java.awt.FlowLayout());
frame.getContentPane().add(tf);
frame.setSize(275, 75);
frame.setVisible(true);
tf.requestFocus();
}
}
</source>
Non Wrapping(Wrap) TextPane
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.ruponent; import java.awt.GridLayout; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTextPane; import javax.swing.UIManager; import javax.swing.plaf.ruponentUI; import javax.swing.text.StyledDocument; public class NonWrappingTextPane extends JTextPane {
public NonWrappingTextPane() {
super();
}
public NonWrappingTextPane(StyledDocument doc) {
super(doc);
}
// Override getScrollableTracksViewportWidth
// to preserve the full width of the text
public boolean getScrollableTracksViewportWidth() {
Component parent = getParent();
ComponentUI ui = getUI();
return parent != null ? (ui.getPreferredSize(this).width <= parent
.getSize().width) : true;
}
// Test method
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
String content = "The plaque on the Apollo 11 Lunar Module\n"
+ "\"Eagle\" reads:\n\n"
+ "\"Here men from the planet Earth first\n"
+ "set foot upon the Moon, July, 1969 AD\n"
+ "We came in peace for all mankind.\"\n\n"
+ "It is signed by the astronauts and the\n"
+ "President of the United States.";
JFrame f = new JFrame("Non-wrapping Text Pane Example");
JTextPane tp = new JTextPane();
tp.setText(content);
NonWrappingTextPane nwtp = new NonWrappingTextPane();
nwtp.setText(content);
f.getContentPane().setLayout(new GridLayout(2, 1));
f.getContentPane().add(new JScrollPane(tp));
f.getContentPane().add(new JScrollPane(nwtp));
f.setSize(300, 200);
f.setVisible(true);
}
}
</source>
Numeric TextField
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.text.DecimalFormat; import java.text.ParseException; import java.text.ParsePosition; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.UIManager; import javax.swing.text.AbstractDocument; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.PlainDocument; import javax.swing.text.AbstractDocument.Content; public class NumericTextField extends JTextField implements
NumericPlainDocument.InsertErrorListener {
public NumericTextField() {
this(null, 0, null);
}
public NumericTextField(String text, int columns, DecimalFormat format) {
super(null, text, columns);
NumericPlainDocument numericDoc = (NumericPlainDocument) getDocument();
if (format != null) {
numericDoc.setFormat(format);
}
numericDoc.addInsertErrorListener(this);
}
public NumericTextField(int columns, DecimalFormat format) {
this(null, columns, format);
}
public NumericTextField(String text) {
this(text, 0, null);
}
public NumericTextField(String text, int columns) {
this(text, columns, null);
}
public void setFormat(DecimalFormat format) {
((NumericPlainDocument) getDocument()).setFormat(format);
}
public DecimalFormat getFormat() {
return ((NumericPlainDocument) getDocument()).getFormat();
}
public void formatChanged() {
// Notify change of format attributes.
setFormat(getFormat());
}
// Methods to get the field value
public Long getLongValue() throws ParseException {
return ((NumericPlainDocument) getDocument()).getLongValue();
}
public Double getDoubleValue() throws ParseException {
return ((NumericPlainDocument) getDocument()).getDoubleValue();
}
public Number getNumberValue() throws ParseException {
return ((NumericPlainDocument) getDocument()).getNumberValue();
}
// Methods to install numeric values
public void setValue(Number number) {
setText(getFormat().format(number));
}
public void setValue(long l) {
setText(getFormat().format(l));
;
}
public void setValue(double d) {
setText(getFormat().format(d));
}
public void normalize() throws ParseException {
// format the value according to the format string
setText(getFormat().format(getNumberValue()));
}
// Override to handle insertion error
public void insertFailed(NumericPlainDocument doc, int offset, String str,
AttributeSet a) {
// By default, just beep
Toolkit.getDefaultToolkit().beep();
}
// Method to create default model
protected Document createDefaultModel() {
return new NumericPlainDocument();
}
// Test code
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
DecimalFormat format = new DecimalFormat("#,###.###");
format.setGroupingUsed(true);
format.setGroupingSize(3);
format.setParseIntegerOnly(false);
JFrame f = new JFrame("Numeric Text Field Example");
final NumericTextField tf = new NumericTextField(10, format);
tf.setValue((double) 123456.789);
JLabel lbl = new JLabel("Type a number: ");
f.getContentPane().add(tf, "East");
f.getContentPane().add(lbl, "West");
tf.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
try {
tf.normalize();
Long l = tf.getLongValue();
System.out.println("Value is (Long)" + l);
} catch (ParseException e1) {
try {
Double d = tf.getDoubleValue();
System.out.println("Value is (Double)" + d);
} catch (ParseException e2) {
System.out.println(e2);
}
}
}
});
f.pack();
f.setVisible(true);
}
} class NumericPlainDocument extends PlainDocument {
public NumericPlainDocument() {
setFormat(null);
}
public NumericPlainDocument(DecimalFormat format) {
setFormat(format);
}
public NumericPlainDocument(AbstractDocument.Content content,
DecimalFormat format) {
super(content);
setFormat(format);
try {
format
.parseObject(content.getString(0, content.length()),
parsePos);
} catch (Exception e) {
throw new IllegalArgumentException(
"Initial content not a valid number");
}
if (parsePos.getIndex() != content.length() - 1) {
throw new IllegalArgumentException(
"Initial content not a valid number");
}
}
public void setFormat(DecimalFormat fmt) {
this.format = fmt != null ? fmt : (DecimalFormat) defaultFormat.clone();
decimalSeparator = format.getDecimalFormatSymbols()
.getDecimalSeparator();
groupingSeparator = format.getDecimalFormatSymbols()
.getGroupingSeparator();
positivePrefix = format.getPositivePrefix();
positivePrefixLen = positivePrefix.length();
negativePrefix = format.getNegativePrefix();
negativePrefixLen = negativePrefix.length();
positiveSuffix = format.getPositiveSuffix();
positiveSuffixLen = positiveSuffix.length();
negativeSuffix = format.getNegativeSuffix();
negativeSuffixLen = negativeSuffix.length();
}
public DecimalFormat getFormat() {
return format;
}
public Number getNumberValue() throws ParseException {
try {
String content = getText(0, getLength());
parsePos.setIndex(0);
Number result = format.parse(content, parsePos);
if (parsePos.getIndex() != getLength()) {
throw new ParseException("Not a valid number: " + content, 0);
}
return result;
} catch (BadLocationException e) {
throw new ParseException("Not a valid number", 0);
}
}
public Long getLongValue() throws ParseException {
Number result = getNumberValue();
if ((result instanceof Long) == false) {
throw new ParseException("Not a valid long", 0);
}
return (Long) result;
}
public Double getDoubleValue() throws ParseException {
Number result = getNumberValue();
if ((result instanceof Long) == false
&& (result instanceof Double) == false) {
throw new ParseException("Not a valid double", 0);
}
if (result instanceof Long) {
result = new Double(result.doubleValue());
}
return (Double) result;
}
public void insertString(int offset, String str, AttributeSet a)
throws BadLocationException {
if (str == null || str.length() == 0) {
return;
}
Content content = getContent();
int length = content.length();
int originalLength = length;
parsePos.setIndex(0);
// Create the result of inserting the new data,
// but ignore the trailing newline
String targetString = content.getString(0, offset) + str
+ content.getString(offset, length - offset - 1);
// Parse the input string and check for errors
do {
boolean gotPositive = targetString.startsWith(positivePrefix);
boolean gotNegative = targetString.startsWith(negativePrefix);
length = targetString.length();
// If we have a valid prefix, the parse fails if the
// suffix is not present and the error is reported
// at index 0. So, we need to add the appropriate
// suffix if it is not present at this point.
if (gotPositive == true || gotNegative == true) {
String suffix;
int suffixLength;
int prefixLength;
if (gotPositive == true && gotNegative == true) {
// This happens if one is the leading part of
// the other - e.g. if one is "(" and the other "(("
if (positivePrefixLen > negativePrefixLen) {
gotNegative = false;
} else {
gotPositive = false;
}
}
if (gotPositive == true) {
suffix = positiveSuffix;
suffixLength = positiveSuffixLen;
prefixLength = positivePrefixLen;
} else {
// Must have the negative prefix
suffix = negativeSuffix;
suffixLength = negativeSuffixLen;
prefixLength = negativePrefixLen;
}
// If the string consists of the prefix alone,
// do nothing, or the result won"t parse.
if (length == prefixLength) {
break;
}
// We can"t just add the suffix, because part of it
// may already be there. For example, suppose the
// negative prefix is "(" and the negative suffix is
// "$)". If the user has typed "(345$", then it is not
// correct to add "$)". Instead, only the missing part
// should be added, in this case ")".
if (targetString.endsWith(suffix) == false) {
int i;
for (i = suffixLength - 1; i > 0; i--) {
if (targetString
.regionMatches(length - i, suffix, 0, i)) {
targetString += suffix.substring(i);
break;
}
}
if (i == 0) {
// None of the suffix was present
targetString += suffix;
}
length = targetString.length();
}
}
format.parse(targetString, parsePos);
int endIndex = parsePos.getIndex();
if (endIndex == length) {
break; // Number is acceptable
}
// Parse ended early
// Since incomplete numbers don"t always parse, try
// to work out what went wrong.
// First check for an incomplete positive prefix
if (positivePrefixLen > 0 && endIndex < positivePrefixLen
&& length <= positivePrefixLen
&& targetString.regionMatches(0, positivePrefix, 0, length)) {
break; // Accept for now
}
// Next check for an incomplete negative prefix
if (negativePrefixLen > 0 && endIndex < negativePrefixLen
&& length <= negativePrefixLen
&& targetString.regionMatches(0, negativePrefix, 0, length)) {
break; // Accept for now
}
// Allow a number that ends with the group
// or decimal separator, if these are in use
char lastChar = targetString.charAt(originalLength - 1);
int decimalIndex = targetString.indexOf(decimalSeparator);
if (format.isGroupingUsed() && lastChar == groupingSeparator
&& decimalIndex == -1) {
// Allow a "," but only in integer part
break;
}
if (format.isParseIntegerOnly() == false
&& lastChar == decimalSeparator
&& decimalIndex == originalLength - 1) {
// Allow a ".", but only one
break;
}
// No more corrections to make: must be an error
if (errorListener != null) {
errorListener.insertFailed(this, offset, str, a);
}
return;
} while (true == false);
// Finally, add to the model
super.insertString(offset, str, a);
}
public void addInsertErrorListener(InsertErrorListener l) {
if (errorListener == null) {
errorListener = l;
return;
}
throw new IllegalArgumentException(
"InsertErrorListener already registered");
}
public void removeInsertErrorListener(InsertErrorListener l) {
if (errorListener == l) {
errorListener = null;
}
}
public interface InsertErrorListener {
public abstract void insertFailed(NumericPlainDocument doc, int offset,
String str, AttributeSet a);
}
protected InsertErrorListener errorListener;
protected DecimalFormat format;
protected char decimalSeparator;
protected char groupingSeparator;
protected String positivePrefix;
protected String negativePrefix;
protected int positivePrefixLen;
protected int negativePrefixLen;
protected String positiveSuffix;
protected String negativeSuffix;
protected int positiveSuffixLen;
protected int negativeSuffixLen;
protected ParsePosition parsePos = new ParsePosition(0);
protected static DecimalFormat defaultFormat = new DecimalFormat();
}
</source>
Overwritable TextField
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.Graphics; import java.awt.Rectangle; import java.awt.event.ActionEvent; import java.awt.event.FocusEvent; import java.awt.event.KeyEvent; import javax.swing.Action; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.KeyStroke; import javax.swing.UIManager; import javax.swing.plaf.TextUI; import javax.swing.text.BadLocationException; import javax.swing.text.Caret; import javax.swing.text.DefaultCaret; import javax.swing.text.Document; import javax.swing.text.JTextComponent; import javax.swing.text.Keymap; import javax.swing.text.TextAction; public class OverwritableTextField extends JTextField {
public OverwritableTextField() {
this(null, null, 0);
}
public OverwritableTextField(String text) {
this(null, text, 0);
}
public OverwritableTextField(int columns) {
this(null, null, columns);
}
public OverwritableTextField(String text, int columns) {
this(null, text, columns);
}
public OverwritableTextField(Document doc, String text, int columns) {
super(doc, text, columns);
overwriteCaret = new OverwriteCaret();
super.setCaret(overwriting ? overwriteCaret : insertCaret);
}
public void setKeymap(Keymap map) {
if (map == null) {
super.setKeymap(null);
sharedKeymap = null;
return;
}
if (getKeymap() == null) {
if (sharedKeymap == null) {
// Switch keymaps. Add extra bindings.
removeKeymap(keymapName);
sharedKeymap = addKeymap(keymapName, map);
loadKeymap(sharedKeymap, bindings, defaultActions);
}
map = sharedKeymap;
}
super.setKeymap(map);
}
public void replaceSelection(String content) {
Document doc = getDocument();
if (doc != null) {
// If we are not overwriting, just do the
// usual insert. Also, if there is a selection,
// just overwrite that (and that only).
if (overwriting == true && getSelectionStart() == getSelectionEnd()) {
// Overwrite and no selection. Remove
// the stretch that we will overwrite,
// then use the usual code to insert the
// new text.
int insertPosition = getCaretPosition();
int overwriteLength = doc.getLength() - insertPosition;
int length = content.length();
if (overwriteLength > length) {
overwriteLength = length;
}
// Remove the range being overwritten
try {
doc.remove(insertPosition, overwriteLength);
} catch (BadLocationException e) {
// Won"t happen
}
}
}
super.replaceSelection(content);
}
// Change the global overwriting mode
public static void setOverwriting(boolean overwriting) {
OverwritableTextField.overwriting = overwriting;
}
public static boolean isOverwriting() {
return overwriting;
}
// Configuration of the insert caret
public void setCaret(Caret caret) {
insertCaret = caret;
}
// Allow configuration of a new
// overwrite caret.
public void setOverwriteCaret(Caret caret) {
overwriteCaret = caret;
}
public Caret getOverwriteCaret() {
return overwriteCaret;
}
// Caret switching
public void processFocusEvent(FocusEvent evt) {
if (evt.getID() == FocusEvent.FOCUS_GAINED) {
selectCaret();
}
super.processFocusEvent(evt);
}
protected void selectCaret() {
// Select the appropriate caret for the
// current overwrite mode.
Caret newCaret = overwriting ? overwriteCaret : insertCaret;
if (newCaret != getCaret()) {
Caret caret = getCaret();
int mark = caret.getMark();
int dot = caret.getDot();
caret.setVisible(false);
super.setCaret(newCaret);
newCaret.setDot(mark);
newCaret.moveDot(dot);
newCaret.setVisible(true);
}
}
protected Caret overwriteCaret;
protected Caret insertCaret;
protected static boolean overwriting = true;
public static final String toggleOverwriteAction = "toggle-overwrite";
protected static Keymap sharedKeymap;
protected static final String keymapName = "OverwriteMap";
protected static final Action[] defaultActions = { new ToggleOverwriteAction() };
protected static JTextComponent.KeyBinding[] bindings = { new JTextComponent.KeyBinding(
KeyStroke.getKeyStroke(KeyEvent.VK_INSERT, 0),
toggleOverwriteAction) };
// Insert/overwrite toggling action
public static class ToggleOverwriteAction extends TextAction {
ToggleOverwriteAction() {
super(toggleOverwriteAction);
}
public void actionPerformed(ActionEvent evt) {
OverwritableTextField.setOverwriting(!OverwritableTextField
.isOverwriting());
JTextComponent target = getFocusedComponent();
if (target instanceof OverwritableTextField) {
OverwritableTextField field = (OverwritableTextField) target;
field.selectCaret();
}
}
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Overwrite test");
OverwritableTextField tf = new OverwritableTextField(20);
f.getContentPane().add(tf, "North");
tf = new OverwritableTextField(20);
f.getContentPane().add(tf, "South");
f.pack();
f.setVisible(true);
}
} class OverwriteCaret extends DefaultCaret {
protected synchronized void damage(Rectangle r) {
if (r != null) {
try {
JTextComponent comp = getComponent();
TextUI mapper = comp.getUI();
Rectangle r2 = mapper.modelToView(comp, getDot() + 1);
int width = r2.x - r.x;
if (width == 0) {
width = MIN_WIDTH;
}
comp.repaint(r.x, r.y, width, r.height);
// Swing 1.1 beta 2 compat
this.x = r.x;
this.y = r.y;
this.width = width;
this.height = r.height;
} catch (BadLocationException e) {
}
}
}
public void paint(Graphics g) {
if (isVisible()) {
try {
JTextComponent comp = getComponent();
TextUI mapper = comp.getUI();
Rectangle r1 = mapper.modelToView(comp, getDot());
Rectangle r2 = mapper.modelToView(comp, getDot() + 1);
g = g.create();
g.setColor(comp.getForeground());
g.setXORMode(comp.getBackground());
int width = r2.x - r1.x;
if (width == 0) {
width = MIN_WIDTH;
}
g.fillRect(r1.x, r1.y, width, r1.height);
g.dispose();
} catch (BadLocationException e) {
}
}
}
protected static final int MIN_WIDTH = 8;
}
</source>
Passive TextField 1
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import javax.swing.BoxLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.KeyStroke; import javax.swing.UIManager; import javax.swing.text.Keymap; public class PassiveTextField1 extends JTextField {
public static void main(String[] args) {
JFrame f = new JFrame("Passive Text Field");
f.getContentPane().setLayout(new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
final JTextField ptf = new JTextField(32);
JTextField tf = new JTextField(32);
JPanel p = new JPanel();
JButton b = new JButton("OK");
p.add(b);
f.getContentPane().add(ptf);
f.getContentPane().add(tf);
f.getContentPane().add(p);
Keymap map = ptf.getKeymap(); // Gets the shared map
KeyStroke key = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0);
map.removeKeyStrokeBinding(key);
ActionListener l = new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out.println("Action event from a text field");
}
};
ptf.addActionListener(l);
tf.addActionListener(l);
// Make the button the default button
f.getRootPane().setDefaultButton(b);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out.println("Content of text field: <" + ptf.getText()
+ ">");
}
});
f.pack();
f.setVisible(true);
}
}
</source>
Passive TextField 2
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.Action; import javax.swing.BoxLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.KeyStroke; import javax.swing.SwingUtilities; import javax.swing.UIManager; import javax.swing.text.Document; import javax.swing.text.Keymap; public class PassiveTextField2 extends JTextField {
public PassiveTextField2() {
this(null, null, 0);
}
public PassiveTextField2(String text) {
this(null, text, 0);
}
public PassiveTextField2(int columns) {
this(null, null, columns);
}
public PassiveTextField2(String text, int columns) {
this(null, text, columns);
}
public PassiveTextField2(Document doc, String text, int columns) {
super(doc, text, columns);
}
public void setKeymap(Keymap map) {
if (map == null) {
// Uninstalling keymap.
super.setKeymap(null);
sharedKeymap = null;
return;
}
if (getKeymap() == null) {
if (sharedKeymap == null) {
// Initial keymap, or first
// keymap after L&F switch.
// Generate a new keymap
sharedKeymap = addKeymap(null, map.getResolveParent());
KeyStroke[] strokes = map.getBoundKeyStrokes();
for (int i = 0; i < strokes.length; i++) {
Action a = map.getAction(strokes[i]);
if (a.getValue(Action.NAME) == JTextField.notifyAction) {
continue;
}
sharedKeymap.addActionForKeyStroke(strokes[i], a);
}
}
map = sharedKeymap;
}
super.setKeymap(map);
}
protected static Keymap sharedKeymap;
// Test method
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Passive Text Field");
f.getContentPane().setLayout(
new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
final PassiveTextField2 ptf = new PassiveTextField2(32);
JTextField tf = new JTextField(32);
JPanel p = new JPanel();
JButton b = new JButton("OK");
p.add(b);
f.getContentPane().add(ptf);
f.getContentPane().add(tf);
f.getContentPane().add(p);
SwingUtilities.updateComponentTreeUI(f);
ActionListener l = new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out.println("Action event from a text field");
}
};
ptf.addActionListener(l);
tf.addActionListener(l);
// Make the button the default button
f.getRootPane().setDefaultButton(b);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out.println("Content of text field: <" + ptf.getText()
+ ">");
}
});
f.pack();
f.setVisible(true);
}
}
</source>
Passive TextField 3
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import javax.swing.BoxLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.UIManager; import javax.swing.text.Document; public class PassiveTextField extends JTextField {
public PassiveTextField() {
this(null, null, 0);
}
public PassiveTextField(String text) {
this(null, text, 0);
}
public PassiveTextField(int columns) {
this(null, null, columns);
}
public PassiveTextField(String text, int columns) {
this(null, text, columns);
}
public PassiveTextField(Document doc, String text, int columns) {
super(doc, text, columns);
}
public void processComponentKeyEvent(KeyEvent evt) {
switch (evt.getID()) {
case KeyEvent.KEY_PRESSED:
case KeyEvent.KEY_RELEASED:
if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
return;
}
break;
case KeyEvent.KEY_TYPED:
if (evt.getKeyChar() == "\r") {
return;
}
break;
}
super.processComponentKeyEvent(evt);
}
// Test method
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Passive Text Field");
f.getContentPane().setLayout(
new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
final PassiveTextField ptf = new PassiveTextField(32);
JTextField tf = new JTextField(32);
JPanel p = new JPanel();
JButton b = new JButton("OK");
p.add(b);
f.getContentPane().add(ptf);
f.getContentPane().add(tf);
f.getContentPane().add(p);
ActionListener l = new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out.println("Action event from a text field");
}
};
ptf.addActionListener(l);
tf.addActionListener(l);
// Make the button the default button
f.getRootPane().setDefaultButton(b);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
System.out.println("Content of text field: <" + ptf.getText()
+ ">");
}
});
f.pack();
f.setVisible(true);
}
}
</source>
Right justified JTextfield content
<source lang="java">
import javax.swing.JTextField; public class Main{
public static void main(String[] argv) {
JTextField textfield = new JTextField(10);
textfield.setHorizontalAlignment(JTextField.RIGHT);
}
}
</source>
Right justified JTextField contents
<source lang="java">
import java.awt.Container; import java.awt.Dimension; import java.awt.FlowLayout; import javax.swing.JFrame; import javax.swing.JTextField; public class Main extends JFrame {
public Main() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(200, 200);
Container container = getContentPane();
container.setLayout(new FlowLayout(FlowLayout.LEFT));
JTextField textField = new JTextField(15);
textField.setPreferredSize(new Dimension(100, 20));
// Right justify the JTextField contents
textField.setHorizontalAlignment(JTextField.RIGHT);
container.add(textField);
}
public static void main(String[] args) {
new Main().setVisible(true);
}
}
</source>
Set the focus on a particular JTextField
<source lang="java">
import javax.swing.JTextField; import javax.swing.SwingUtilities; public class Main {
public static void main(String[] argv) throws Exception {
final JTextField textfield = new JTextField(10);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
textfield.requestFocus();
}
});
}
}
</source>
Setting up a textfield and modifying its horizontal alignment at runtime
<source lang="java">
/* Java Swing, 2nd Edition By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole ISBN: 0-596-00408-7 Publisher: O"Reilly
- /
// JTextFieldExample.java //An example of setting up a textfield and modifying its horizontal alignment //at runtime. // import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JFrame; import javax.swing.JTextField; public class JTextFieldExample {
public static void main(String[] args) {
final JTextField tf = new JTextField("press <enter>", 20);
tf.setHorizontalAlignment(JTextField.RIGHT);
tf.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int old = tf.getHorizontalAlignment();
if (old == JTextField.LEFT)
tf.setHorizontalAlignment(JTextField.RIGHT);
if (old == JTextField.RIGHT)
tf.setHorizontalAlignment(JTextField.CENTER);
if (old == JTextField.CENTER)
tf.setHorizontalAlignment(JTextField.LEFT);
}
});
JFrame frame = new JFrame("JTextFieldExample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new java.awt.FlowLayout());
frame.getContentPane().add(tf);
frame.setSize(275, 75);
frame.setVisible(true);
tf.requestFocus();
}
}
</source>
Text Accelerator Example
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.Container; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.Insets; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.SwingConstants; import javax.swing.UIManager; public class TextAcceleratorExample {
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JLabel l;
JTextField t;
JButton b;
JFrame f = new JFrame("Text Accelerator Example");
Container cp = f.getContentPane();
cp.setLayout(new GridBagLayout());
cp.setBackground(UIManager.getColor("control"));
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = GridBagConstraints.RELATIVE;
c.gridwidth = 1;
c.gridheight = 1;
c.insets = new Insets(2, 2, 2, 2);
c.anchor = GridBagConstraints.EAST;
cp.add(l = new JLabel("Name:", SwingConstants.RIGHT), c);
l.setDisplayedMnemonic("n");
cp.add(l = new JLabel("House/Street:", SwingConstants.RIGHT), c);
l.setDisplayedMnemonic("h");
cp.add(l = new JLabel("City:", SwingConstants.RIGHT), c);
l.setDisplayedMnemonic("c");
cp.add(l = new JLabel("State/County:", SwingConstants.RIGHT), c);
l.setDisplayedMnemonic("s");
cp.add(l = new JLabel("Zip/Post code:", SwingConstants.RIGHT), c);
l.setDisplayedMnemonic("z");
cp.add(l = new JLabel("Telephone:", SwingConstants.RIGHT), c);
l.setDisplayedMnemonic("t");
cp.add(b = new JButton("Clear"), c);
b.setMnemonic("l");
c.gridx = 1;
c.gridy = 0;
c.weightx = 1.0;
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.CENTER;
cp.add(t = new JTextField(35), c);
t.setFocusAccelerator("n");
c.gridx = 1;
c.gridy = GridBagConstraints.RELATIVE;
cp.add(t = new JTextField(35), c);
t.setFocusAccelerator("h");
cp.add(t = new JTextField(35), c);
t.setFocusAccelerator("c");
cp.add(t = new JTextField(35), c);
t.setFocusAccelerator("s");
cp.add(t = new JTextField(35), c);
t.setFocusAccelerator("z");
cp.add(t = new JTextField(35), c);
t.setFocusAccelerator("t");
c.weightx = 0.0;
c.fill = GridBagConstraints.NONE;
cp.add(b = new JButton("OK"), c);
b.setMnemonic("o");
f.pack();
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent evt) {
System.exit(0);
}
});
f.setVisible(true);
}
}
</source>
TextField Elements
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import javax.swing.*; import javax.swing.text.*; public class TextFieldElements {
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Text Field Elements");
JTextField tf = new JTextField(32);
tf.setText("That"s one small step for man...");
f.getContentPane().add(tf);
f.pack();
f.setVisible(true);
((AbstractDocument)tf.getDocument()).dump(System.out);
}
}
</source>
TextField Look Ahead Example
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.FocusEvent; import java.awt.event.FocusListener; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.UIManager; import javax.swing.text.BadLocationException; import javax.swing.text.Document; public class LookAheadExample {
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Text Lookahead");
StringArrayLookAhead lookAhead = new StringArrayLookAhead(values);
LookAheadTextField tf = new LookAheadTextField(20, lookAhead);
f.getContentPane().add(tf, "Center");
f.pack();
f.setVisible(true);
}
// The possible look-ahead values
public static String[] values = new String[] { "aback", "abacus",
"abandon", "abashed", "abate", "abdomen", "abide", "ability",
"baby", "back", "backache", "backgammon" };
} class LookAheadTextField extends JTextField {
public LookAheadTextField() {
this(0, null);
}
public LookAheadTextField(int columns) {
this(columns, null);
}
public LookAheadTextField(int columns, TextLookAhead lookAhead) {
super(columns);
setLookAhead(lookAhead);
addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
// Remove any existing selection
setCaretPosition(getDocument().getLength());
}
});
addFocusListener(new FocusListener() {
public void focusGained(FocusEvent evt) {
}
public void focusLost(FocusEvent evt) {
if (evt.isTemporary() == false) {
// Remove any existing selection
setCaretPosition(getDocument().getLength());
}
}
});
}
public void setLookAhead(TextLookAhead lookAhead) {
this.lookAhead = lookAhead;
}
public TextLookAhead getLookAhead() {
return lookAhead;
}
public void replaceSelection(String content) {
super.replaceSelection(content);
if (isEditable() == false || isEnabled() == false) {
return;
}
Document doc = getDocument();
if (doc != null && lookAhead != null) {
try {
String oldContent = doc.getText(0, doc.getLength());
String newContent = lookAhead.doLookAhead(oldContent);
if (newContent != null) {
// Substitute the new content
setText(newContent);
// Highlight the added text
setCaretPosition(newContent.length());
moveCaretPosition(oldContent.length());
}
} catch (BadLocationException e) {
// Won"t happen
}
}
}
protected TextLookAhead lookAhead;
// The TextLookAhead interface
public interface TextLookAhead {
public String doLookAhead(String key);
}
} class StringArrayLookAhead implements LookAheadTextField.TextLookAhead {
public StringArrayLookAhead() {
values = new String[0];
}
public StringArrayLookAhead(String[] values) {
this.values = values;
}
public void setValues(String[] values) {
this.values = values;
}
public String[] getValues() {
return values;
}
public String doLookAhead(String key) {
int length = values.length;
// Look for a string that starts with the key
for (int i = 0; i < length; i++) {
if (values[i].startsWith(key) == true) {
return values[i];
}
}
// No match found - return null
return null;
}
protected String[] values;
}
</source>
Textfield only accepts numbers
<source lang="java">
import java.awt.Container; import java.awt.Graphics; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.PlainDocument; public class ValidationTestFrame extends JFrame implements DocumentListener {
JLabel label = new JLabel("I only accept numbers");
private IntTextField intFiled;
public ValidationTestFrame() {
setTitle("ValidationTest");
setSize(300, 200);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = getContentPane();
JPanel p = new JPanel();
intFiled = new IntTextField(12, 3);
p.add(intFiled);
intFiled.getDocument().addDocumentListener(this);
contentPane.add(p, "South");
contentPane.add(label, "Center");
}
public void insertUpdate(DocumentEvent e) {
setLabel();
}
public void removeUpdate(DocumentEvent e) {
setLabel();
}
public void changedUpdate(DocumentEvent e) {
}
public void setLabel() {
if (intFiled.isValid() ) {
int value = intFiled.getValue();
label.setText(Integer.toString(value));
}
}
public static void main(String[] args) {
JFrame frame = new ValidationTestFrame();
frame.show();
}
} class IntTextField extends JTextField {
public IntTextField(int defval, int size) {
super("" + defval, size);
}
protected Document createDefaultModel() {
return new IntTextDocument();
}
public boolean isValid() {
try {
Integer.parseInt(getText());
return true;
} catch (NumberFormatException e) {
return false;
}
}
public int getValue() {
try {
return Integer.parseInt(getText());
} catch (NumberFormatException e) {
return 0;
}
}
class IntTextDocument extends PlainDocument {
public void insertString(int offs, String str, AttributeSet a)
throws BadLocationException {
if (str == null)
return;
String oldString = getText(0, getLength());
String newString = oldString.substring(0, offs) + str
+ oldString.substring(offs);
try {
Integer.parseInt(newString + "0");
super.insertString(offs, str, a);
} catch (NumberFormatException e) {
}
}
}
}
</source>
Text fields and Java events
<source lang="java">
// : c14:TextFields.java // Text fields and Java events. // <applet code=TextFields width=375 height=125></applet> // From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002 // www.BruceEckel.ru. See copyright notice in CopyRight.txt. import java.awt.Container; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JApplet; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.PlainDocument; public class TextFields extends JApplet {
private JButton b1 = new JButton("Get Text"), b2 = new JButton("Set Text");
private JTextField t1 = new JTextField(30), t2 = new JTextField(30),
t3 = new JTextField(30);
private String s = new String();
private UpperCaseDocument ucd = new UpperCaseDocument();
public void init() {
t1.setDocument(ucd);
ucd.addDocumentListener(new T1());
b1.addActionListener(new B1());
b2.addActionListener(new B2());
DocumentListener dl = new T1();
t1.addActionListener(new T1A());
Container cp = getContentPane();
cp.setLayout(new FlowLayout());
cp.add(b1);
cp.add(b2);
cp.add(t1);
cp.add(t2);
cp.add(t3);
}
class T1 implements DocumentListener {
public void changedUpdate(DocumentEvent e) {
}
public void insertUpdate(DocumentEvent e) {
t2.setText(t1.getText());
t3.setText("Text: " + t1.getText());
}
public void removeUpdate(DocumentEvent e) {
t2.setText(t1.getText());
}
}
class T1A implements ActionListener {
private int count = 0;
public void actionPerformed(ActionEvent e) {
t3.setText("t1 Action Event " + count++);
}
}
class B1 implements ActionListener {
public void actionPerformed(ActionEvent e) {
if (t1.getSelectedText() == null)
s = t1.getText();
else
s = t1.getSelectedText();
t1.setEditable(true);
}
}
class B2 implements ActionListener {
public void actionPerformed(ActionEvent e) {
ucd.setUpperCase(false);
t1.setText("Inserted by Button 2: " + s);
ucd.setUpperCase(true);
t1.setEditable(false);
}
}
public static void main(String[] args) {
run(new TextFields(), 375, 125);
}
public static void run(JApplet applet, int width, int height) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(applet);
frame.setSize(width, height);
applet.init();
applet.start();
frame.setVisible(true);
}
} class UpperCaseDocument extends PlainDocument {
private boolean upperCase = true;
public void setUpperCase(boolean flag) {
upperCase = flag;
}
public void insertString(int offset, String str, AttributeSet attSet)
throws BadLocationException {
if (upperCase)
str = str.toUpperCase();
super.insertString(offset, str, attSet);
}
} ///:~
</source>
TextFieldViews 2
<source lang="java">
/* Core SWING Advanced Programming By Kim Topley ISBN: 0 13 083292 8 Publisher: Prentice Hall
- /
import java.io.PrintStream; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.UIManager; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.JTextComponent; import javax.swing.text.View; public class TextFieldViews {
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
JFrame f = new JFrame("Text Field View");
JTextField tf = new JTextField(32);
tf.setText("That"s one small step for man...");
f.getContentPane().add(tf);
f.pack();
f.setVisible(true);
ViewDisplayer.displayViews(tf, System.out);
}
} class ViewDisplayer {
public static void displayViews(JTextComponent comp, PrintStream out) {
View rootView = comp.getUI().getRootView(comp);
displayView(rootView, 0, comp.getDocument(), out);
}
public static void displayView(View view, int indent, Document doc,
PrintStream out) {
String name = view.getClass().getName();
for (int i = 0; i < indent; i++) {
out.print("\t");
}
int start = view.getStartOffset();
int end = view.getEndOffset();
out.println(name + "; offsets [" + start + ", " + end + "]");
int viewCount = view.getViewCount();
if (viewCount == 0) {
int length = Math.min(32, end - start);
try {
String txt = doc.getText(start, length);
for (int i = 0; i < indent + 1; i++) {
out.print("\t");
}
out.println("[" + txt + "]");
} catch (BadLocationException e) {
}
} else {
for (int i = 0; i < viewCount; i++) {
displayView(view.getView(i), indent + 1, doc, out);
}
}
}
}
</source>
TextField with Constaints
<source lang="java">
/* Definitive Guide to Swing for Java 2, Second Edition By John Zukowski ISBN: 1-893115-78-X Publisher: APress
- /
import java.awt.Container; import java.awt.GridLayout; import java.awt.Toolkit; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.Document; import javax.swing.text.PlainDocument; public class RangeSample {
public static void main(String args[]) {
JFrame frame = new JFrame("Range Example");
Container content = frame.getContentPane();
content.setLayout(new GridLayout(3, 2));
content.add(new JLabel("Range: 0-255"));
Document rangeOne = new IntegerRangeDocument(0, 255);
JTextField textFieldOne = new JTextField();
textFieldOne.setDocument(rangeOne);
content.add(textFieldOne);
content.add(new JLabel("Range: -100-100"));
Document rangeTwo = new IntegerRangeDocument(-100, 100);
JTextField textFieldTwo = new JTextField();
textFieldTwo.setDocument(rangeTwo);
content.add(textFieldTwo);
content.add(new JLabel("Range: 1000-2000"));
Document rangeThree = new IntegerRangeDocument(1000, 2000);
JTextField textFieldThree = new JTextField();
textFieldThree.setDocument(rangeThree);
content.add(textFieldThree);
frame.setSize(250, 150);
frame.setVisible(true);
}
} class IntegerRangeDocument extends PlainDocument {
int minimum, maximum;
int currentValue = 0;
public IntegerRangeDocument(int minimum, int maximum) {
this.minimum = minimum;
this.maximum = maximum;
}
public int getValue() {
return currentValue;
}
public void insertString(int offset, String string, AttributeSet attributes)
throws BadLocationException {
if (string == null) {
return;
} else {
String newValue;
int length = getLength();
if (length == 0) {
newValue = string;
} else {
String currentContent = getText(0, length);
StringBuffer currentBuffer = new StringBuffer(currentContent);
currentBuffer.insert(offset, string);
newValue = currentBuffer.toString();
}
try {
currentValue = checkInput(newValue);
super.insertString(offset, string, attributes);
} catch (Exception exception) {
Toolkit.getDefaultToolkit().beep();
}
}
}
public void remove(int offset, int length) throws BadLocationException {
int currentLength = getLength();
String currentContent = getText(0, currentLength);
String before = currentContent.substring(0, offset);
String after = currentContent.substring(length + offset, currentLength);
String newValue = before + after;
try {
currentValue = checkInput(newValue);
super.remove(offset, length);
} catch (Exception exception) {
Toolkit.getDefaultToolkit().beep();
}
}
public int checkInput(String proposedValue) throws NumberFormatException {
int newValue = 0;
if (proposedValue.length() > 0) {
newValue = Integer.parseInt(proposedValue);
}
if ((minimum <= newValue) && (newValue <= maximum)) {
return newValue;
} else {
throw new NumberFormatException();
}
}
}
</source>
Validate a value on the lostFocus event
<source lang="java">
import java.awt.event.FocusEvent; import java.awt.event.FocusListener; import javax.swing.JComponent; import javax.swing.JTextField; import javax.swing.SwingUtilities; public class Main {
JTextField tf1;
public void init() {
tf1 = new JTextField(5);
tf1.addFocusListener(new FocusListener() {
public void focusGained(FocusEvent e) {
};
public void focusLost(FocusEvent e) {
if (!e.isTemporary()) {
String content = tf1.getText();
if (!content.equals("a") ) {
System.out.println("illegal value! " + content);
SwingUtilities.invokeLater(new FocusGrabber(tf1));
}
}
}
});
}
} class FocusGrabber implements Runnable {
private JComponent component;
public FocusGrabber(JComponent component) {
this.ruponent = component;
}
public void run() {
component.grabFocus();
}
}
</source>
Water mark text field
<source lang="java">
import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import java.awt.TexturePaint; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; import javax.swing.JFrame; import javax.swing.JTextField; public class WatermarkTextField extends JTextField {
BufferedImage img;
TexturePaint texture;
public WatermarkTextField(File file) {
super();
try {
img = ImageIO.read(file);
} catch (IOException e) {
e.printStackTrace();
}
Rectangle rect = new Rectangle(0, 0, img.getWidth(null), img.getHeight(null));
texture = new TexturePaint(img, rect);
setOpaque(false);
}
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(texture);
g.fillRect(0, 0, getWidth(), getHeight());
super.paintComponent(g);
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField textfield = new WatermarkTextField(new File("waterMarkImage.png"));
textfield.setText("www.jexp.ru");
frame.getContentPane().add(textfield);
frame.pack();
frame.setVisible(true);
}
}
</source>
