1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * ident "%Z%%M% %I% %E% SMI" 24 * 25 * Copyright (c) 1998-1999 by Sun Microsystems, Inc. 26 * All rights reserved. 27 */ 28 package com.sun.dhcpmgr.ui; 29 30 import java.awt.*; 31 import java.awt.event.*; 32 import javax.swing.*; 33 import javax.swing.text.*; 34 35 /** 36 * A text field which limits input to only those characters which can legally 37 * appear in a hostname as specified in RFC1123, i.e. the letters, digits 38 * and '-'. 39 */ 40 public class HostnameField extends JTextField { 41 42 /** 43 * Constructs an empty field, 20 characters wide. 44 */ 45 public HostnameField() { 46 this(""); 47 } 48 49 /** 50 * Constructs a field initialized to the provided text. Defaults to 20 51 * characters wide. 52 * @param text the text to display initially 53 */ 54 public HostnameField(String text) { 55 this(text, 20); 56 } 57 58 /** 59 * Constructs a field initialized to the provided text with the requested 60 * size. 61 * @param text the text to display initially 62 * @param length the length in characters the field should size itself to 63 */ 64 public HostnameField(String text, int length) { 65 super(text, length); 66 } 67 68 protected Document createDefaultModel() { 69 return new HostnameDocument(); 70 } 71 72 /* 73 * This is the recommended way to validate/filter input, as opposed to 74 * trapping KeyEvents because this will catch paste operations, too. 75 */ 76 static class HostnameDocument extends PlainDocument { 77 public void insertString(int offs, String str, AttributeSet a) 78 throws BadLocationException { 79 if (str != null) { 80 char [] chars = str.toCharArray(); 81 if ((chars.length != 0) && (getLength() == 0)) { 82 // First character in field must be a letter or digit 83 if (!Character.isLetterOrDigit(chars[0])) { 84 throw new BadLocationException("", offs); 85 } 86 } 87 // Now validate that everything we're inserting is legal 88 for (int i = 0; i < chars.length; ++i) { 89 if (!Character.isLetterOrDigit(chars[i]) 90 && chars[i] != '-') { 91 throw new BadLocationException("", offs); 92 } 93 } 94 } 95 super.insertString(offs, str, a); 96 } 97 } 98 }