1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/util/PrecedingSiblingAxisIterator.java,v 1.5 2003/06/29 18:01:34 ssanders Exp $ 3 * $Revision: 1.5 $ 4 * $Date: 2003/06/29 18:01:34 $ 5 * 6 * ==================================================================== 7 * 8 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer. 17 * 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions, and the disclaimer that follows 20 * these conditions in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * 3. The name "Jaxen" must not be used to endorse or promote products 24 * derived from this software without prior written permission. For 25 * written permission, please contact license@jaxen.org. 26 * 27 * 4. Products derived from this software may not be called "Jaxen", nor 28 * may "Jaxen" appear in their name, without prior written permission 29 * from the Jaxen Project Management (pm@jaxen.org). 30 * 31 * In addition, we request (but do not require) that you include in the 32 * end-user documentation provided with the redistribution and/or in the 33 * software itself an acknowledgement equivalent to the following: 34 * "This product includes software developed by the 35 * Jaxen Project (http://www.jaxen.org/)." 36 * Alternatively, the acknowledgment may be graphical using the logos 37 * available at http://www.jaxen.org/ 38 * 39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT 43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * ==================================================================== 53 * This software consists of voluntary contributions made by many 54 * individuals on behalf of the Jaxen Project and was originally 55 * created by bob mcwhirter <bob@werken.com> and 56 * James Strachan <jstrachan@apache.org>. For more information on the 57 * Jaxen Project, please see <http://www.jaxen.org/>. 58 * 59 * $Id: PrecedingSiblingAxisIterator.java,v 1.5 2003/06/29 18:01:34 ssanders Exp $ 60 */ 61 62 63 64 package org.jaxen.util; 65 66 import java.util.Collections; 67 import java.util.Iterator; 68 import java.util.LinkedList; 69 import java.util.List; 70 import java.util.NoSuchElementException; 71 72 import org.jaxen.Navigator; 73 import org.jaxen.UnsupportedAxisException; 74 75 public class PrecedingSiblingAxisIterator implements Iterator 76 { 77 private Object contextNode; 78 private Navigator navigator; 79 80 private Iterator siblingIter; 81 82 private Object nextObj; 83 84 public PrecedingSiblingAxisIterator(Object contextNode, 85 Navigator navigator) throws UnsupportedAxisException 86 { 87 this.contextNode = contextNode; 88 this.navigator = navigator; 89 90 init(); 91 92 stepAhead(); 93 } 94 95 private void init() throws UnsupportedAxisException 96 { 97 Object parent = this.navigator.getParentNode( this.contextNode ); 98 99 List siblings = Collections.EMPTY_LIST; 100 101 if ( parent != null ) 102 { 103 Iterator childIter = this.navigator.getChildAxisIterator( parent ); 104 Object eachChild = null; 105 106 siblings = new LinkedList(); 107 108 while ( childIter.hasNext() ) 109 { 110 eachChild = childIter.next(); 111 112 if ( eachChild == this.contextNode ) 113 { 114 break; 115 } 116 117 ((LinkedList)siblings).addFirst( eachChild ); 118 } 119 } 120 121 this.siblingIter = siblings.iterator(); 122 } 123 124 public boolean hasNext() 125 { 126 return ( this.nextObj != null ); 127 } 128 129 public Object next() throws NoSuchElementException 130 { 131 if ( ! hasNext() ) 132 { 133 throw new NoSuchElementException(); 134 } 135 136 Object obj = this.nextObj; 137 138 this.nextObj = null; 139 140 stepAhead(); 141 142 return obj; 143 } 144 145 public void remove() throws UnsupportedOperationException 146 { 147 throw new UnsupportedOperationException(); 148 } 149 150 private void stepAhead() 151 { 152 if ( this.nextObj != null ) 153 { 154 return; 155 } 156 157 Object obj = null; 158 159 while ( siblingIter.hasNext() ) 160 { 161 obj = siblingIter.next(); 162 163 this.nextObj = obj; 164 break; 165 166 /* 167 168 This should iterate through all nodes, not necessarily just elements 169 170 if ( this.navigator.isElement( obj ) ) 171 { 172 this.nextObj = obj; 173 break; 174 } 175 */ 176 } 177 } 178 }