Coverage Report - org.jaxen.util.PrecedingAxisIterator

Classes in this File Line Coverage Branch Coverage Complexity
PrecedingAxisIterator
89% 
100% 
4.6

 1  
 package org.jaxen.util;
 2  
 
 3  
 /*
 4  
  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/util/PrecedingAxisIterator.java,v 1.8 2005/07/24 11:51:14 elharo Exp $
 5  
  * $Revision: 1.8 $
 6  
  * $Date: 2005/07/24 11:51:14 $
 7  
  *
 8  
  * ====================================================================
 9  
  *
 10  
  * Copyright (C) 2000-2005 bob mcwhirter & James Strachan.
 11  
  * All rights reserved.
 12  
  *
 13  
  * Redistribution and use in source and binary forms, with or without
 14  
  * modification, are permitted provided that the following conditions
 15  
  * are met:
 16  
  *
 17  
  * 1. Redistributions of source code must retain the above copyright
 18  
  *    notice, this list of conditions, and the following disclaimer.
 19  
  *
 20  
  * 2. Redistributions in binary form must reproduce the above copyright
 21  
  *    notice, this list of conditions, and the disclaimer that follows
 22  
  *    these conditions in the documentation and/or other materials
 23  
  *    provided with the distribution.
 24  
  *
 25  
  * 3. The name "Jaxen" must not be used to endorse or promote products
 26  
  *    derived from this software without prior written permission.  For
 27  
  *    written permission, please contact license@jaxen.org.
 28  
  *
 29  
  * 4. Products derived from this software may not be called "Jaxen", nor
 30  
  *    may "Jaxen" appear in their name, without prior written permission
 31  
  *    from the Jaxen Project Management (pm@jaxen.org).
 32  
  *
 33  
  * In addition, we request (but do not require) that you include in the
 34  
  * end-user documentation provided with the redistribution and/or in the
 35  
  * software itself an acknowledgement equivalent to the following:
 36  
  *     "This product includes software developed by the
 37  
  *      Jaxen Project <http://www.jaxen.org/>."
 38  
  * Alternatively, the acknowledgment may be graphical using the logos
 39  
  * available at http://www.jaxen.org/
 40  
  *
 41  
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 42  
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 43  
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 44  
  * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
 45  
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 46  
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 47  
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 48  
  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 49  
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 50  
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 51  
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 52  
  * SUCH DAMAGE.
 53  
  *
 54  
  * ====================================================================
 55  
  * This software consists of voluntary contributions made by many
 56  
  * individuals on behalf of the Jaxen Project and was originally
 57  
  * created by bob mcwhirter <bob@werken.com> and
 58  
  * James Strachan <jstrachan@apache.org>.  For more information on the
 59  
  * Jaxen Project, please see <http://www.jaxen.org/>.
 60  
  *
 61  
  * $Id: PrecedingAxisIterator.java,v 1.8 2005/07/24 11:51:14 elharo Exp $
 62  
 */
 63  
 
 64  
 import org.jaxen.JaxenConstants;
 65  
 import org.jaxen.JaxenRuntimeException;
 66  
 import org.jaxen.Navigator;
 67  
 import org.jaxen.UnsupportedAxisException;
 68  
 
 69  
 import java.util.ArrayList;
 70  
 import java.util.Iterator;
 71  
 import java.util.ListIterator;
 72  
 import java.util.NoSuchElementException;
 73  
 
 74  
 /**
 75  
  * This implementation of 'preceding' works like so:
 76  
  * the preceding axis includes preceding-siblings of this node and their
 77  
  * descendants. Also, for each ancestor node of this node, it includes
 78  
  * all preceding-siblings of that ancestor, and their descendants. Finally, it
 79  
  * includes the ancestor nodes themselves.
 80  
  * <p/>
 81  
  * The reversed descendant-or-self axes that are required are calculated using a
 82  
  * stack of reversed 'child-or-self' axes. When asked for a node, it is always taken
 83  
  * from a child-or-self axis. If it was the last node on that axis, the node is returned.
 84  
  * Otherwise, this axis is pushed on the stack, and the process is repeated with the child-or-self
 85  
  * of the node. Eventually this recurses down to the last descendant of any node, then works
 86  
  * back up to the root.
 87  
  * <p/>
 88  
  * I reckon most object models could provide a faster implementation of the reversed
 89  
  * 'children-or-self' used here.
 90  
  */
 91  
 public class PrecedingAxisIterator implements Iterator
 92  
 {
 93  
     private Iterator ancestorOrSelf;
 94  
     private Iterator precedingSibling;
 95  
     private ListIterator childrenOrSelf;
 96  
     private ArrayList stack;
 97  
 
 98  
     private Navigator navigator;
 99  
 
 100  
     public PrecedingAxisIterator(Object contextNode,
 101  
                                  Navigator navigator) throws UnsupportedAxisException
 102  474
     {
 103  474
         this.navigator = navigator;
 104  474
         this.ancestorOrSelf = navigator.getAncestorOrSelfAxisIterator(contextNode);
 105  474
         this.precedingSibling = JaxenConstants.EMPTY_ITERATOR;
 106  474
         this.childrenOrSelf = JaxenConstants.EMPTY_LIST_ITERATOR;
 107  474
         this.stack = new ArrayList();
 108  474
     }
 109  
 
 110  
 
 111  
     public boolean hasNext()
 112  
     {
 113  
         try
 114  
         {
 115  5352
             while (!childrenOrSelf.hasPrevious())
 116  
             {
 117  2022
                 if (stack.isEmpty())
 118  
                 {
 119  2418
                     while (!precedingSibling.hasNext())
 120  
                     {
 121  1866
                         if (!ancestorOrSelf.hasNext())
 122  
                         {
 123  468
                             return false;
 124  
                         }
 125  1398
                         Object contextNode = ancestorOrSelf.next();
 126  1398
                         precedingSibling = new PrecedingSiblingAxisIterator(contextNode, navigator);
 127  
                     }
 128  552
                     Object node = precedingSibling.next();
 129  552
                     childrenOrSelf = childrenOrSelf(node);
 130  
                 }
 131  
                 else
 132  
                 {
 133  1002
                     childrenOrSelf = (ListIterator) stack.remove(stack.size()-1);
 134  
                 }
 135  
             }
 136  3330
             return true;
 137  
         }
 138  0
         catch (UnsupportedAxisException e)
 139  
         {
 140  0
             throw new JaxenRuntimeException(e);
 141  
         }
 142  
     }
 143  
 
 144  
     private ListIterator childrenOrSelf(Object node)
 145  
     {
 146  
         try
 147  
         {
 148  1554
             ArrayList reversed = new ArrayList();
 149  1554
             reversed.add(node);
 150  1554
             Iterator childAxisIterator = navigator.getChildAxisIterator(node);
 151  1554
             if (childAxisIterator != null)
 152  
             {
 153  2556
                 while (childAxisIterator.hasNext())
 154  
                 {
 155  1002
                     reversed.add(childAxisIterator.next());
 156  
                 }
 157  
             }
 158  1554
             return reversed.listIterator(reversed.size());
 159  
         }
 160  0
         catch (UnsupportedAxisException e)
 161  
         {
 162  0
             throw new JaxenRuntimeException(e);
 163  
         }
 164  
     }
 165  
 
 166  
     public Object next() throws NoSuchElementException
 167  
     {
 168  1560
         if (!hasNext())
 169  
         {
 170  6
             throw new NoSuchElementException();
 171  
         }
 172  
         while (true)
 173  
         {
 174  2556
             Object result = childrenOrSelf.previous();
 175  2556
             if (childrenOrSelf.hasPrevious())
 176  
             {
 177  
                 // if this isn't 'self' construct 'descendant-or-self'
 178  1002
                 stack.add(childrenOrSelf);
 179  1002
                 childrenOrSelf = childrenOrSelf(result);
 180  1002
                 continue;
 181  
             }
 182  1554
             return result;
 183  
         }
 184  
     }
 185  
 
 186  
 
 187  
     public void remove() throws UnsupportedOperationException
 188  
     {
 189  6
         throw new UnsupportedOperationException();
 190  
     }
 191  
 }