Mega Code Archive
Extends JTextField to create integer JTextField
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/*
* 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 <CODE>TextField</CODE> that only allows integer
* values to be entered into it.
*
* @author <A HREF="mailto:colbell@users.sourceforge.net">Colin Bell</A>
*/
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 <TT>int</TT>.
*
* @return the contents of this field as an <TT>int</TT>.
*/
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 <TT>int</TT>.
*
* @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();
}
}
}
}
}
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