1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/util/PrecedingSiblingAxisIterator.java,v 1.12 2005/04/11 19:14:10 elharo Exp $ 3 * $Revision: 1.12 $ 4 * $Date: 2005/04/11 19:14:10 $ 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 1.12 2005/04/11 19:14:10 elharo Exp $ 60 */ 61 62 63 64 package org.jaxen.util; 65 66 import java.util.Iterator; 67 import java.util.LinkedList; 68 import java.util.NoSuchElementException; 69 70 import org.jaxen.JaxenConstants; 71 import org.jaxen.Navigator; 72 import org.jaxen.UnsupportedAxisException; 73 74 public class PrecedingSiblingAxisIterator implements Iterator 75 { 76 private Object contextNode; 77 private Navigator navigator; 78 79 private Iterator siblingIter; 80 private Object nextObj; 81 82 public PrecedingSiblingAxisIterator(Object contextNode, 83 Navigator navigator) throws UnsupportedAxisException 84 { 85 this.contextNode = contextNode; 86 this.navigator = navigator; 87 88 init(); 89 if ( siblingIter.hasNext() ) 90 { 91 this.nextObj = siblingIter.next(); 92 } 93 } 94 95 private void init() throws UnsupportedAxisException 96 { 97 98 Object parent = this.navigator.getParentNode( this.contextNode ); 99 100 if ( parent != null ) 101 { 102 Iterator childIter = this.navigator.getChildAxisIterator( parent ); 103 LinkedList siblings = new LinkedList(); 104 105 while ( childIter.hasNext() ) 106 { 107 Object eachChild = childIter.next(); 108 if ( eachChild.equals(this.contextNode) ) 109 { 110 break; 111 } 112 siblings.addFirst( eachChild ); 113 } 114 115 this.siblingIter = siblings.iterator(); 116 117 } 118 else { 119 this.siblingIter = JaxenConstants.EMPTY_ITERATOR; 120 } 121 122 } 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 if ( siblingIter.hasNext() ) 138 { 139 this.nextObj = siblingIter.next(); 140 } 141 else { 142 this.nextObj = null; 143 } 144 return obj; 145 } 146 147 public void remove() throws UnsupportedOperationException 148 { 149 throw new UnsupportedOperationException(); 150 } 151 152 }