intdocument.java

《j2ee开发全程实录》随书源码

/* ===========================================================
 * JDBMonitor : a flexiable JDBC Monitor for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2006-2006, by yang zhongke
 *
 * Project Info:  http://www.cownew.com
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------
 * IntDocument.java
 * ---------------
 * (C) Copyright 2006-2006, by yang zhongke
 *
 * Original Author:  yang zhongke;
 *
 * Changes
 * -------
 *
 */
package com.cownew.ctk.ui.swing;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;

/**
 * A plain document that maintains integer characters
 * @author yang zhongke
 */
public class IntDocument extends PlainDocument
{

	private static final long serialVersionUID = -2481909795386682332L;

	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");

		} catch (NumberFormatException e)
		{
			return;
		}
		super.insertString(offs, str, a);
	}
}