FieldEdit - an Applet to validate data as it's being entered : TextField « Swing JFC « Java
FieldEdit - an Applet to validate data as it's being entered
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 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.com/
* @author Bjorn Gudehus, gothic@celestica.com
*/
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();
}
}
});
}
}
