package org.greenstone.gatherer.gui;

import javax.swing.*;
import javax.swing.text.*;


public class NumberField 
    extends JTextField {
 
    public NumberField(String text) {
	super(text);
    }
 
    protected Document createDefaultModel() {
	return new NumberDocument();
    }
 
    static class NumberDocument 
	extends PlainDocument {
		  
	public void insertString(int offs, String str, AttributeSet a) 
	    throws BadLocationException {
				
	    if (str == null) {
		return;
	    }
	    char[] raw = str.toCharArray();
	    StringBuffer result = new StringBuffer("");
	    for (int i = 0; i < raw.length; i++) {
		if(Character.isDigit(raw[i])) {
		    result.append(raw[i]);
		}
	    }
	    super.insertString(offs, result.toString(), a);
	}
    }
}