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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/DefaultNavigator.java,v 1.15 2005/01/13 23:51:18 elharo Exp $
3    * $Revision: 1.15 $
4    * $Date: 2005/01/13 23:51:18 $
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: DefaultNavigator.java,v 1.15 2005/01/13 23:51:18 elharo Exp $
60   */
61  
62  
63  
64  package org.jaxen;
65  
66  import java.util.Iterator;
67  
68  import org.jaxen.pattern.Pattern;
69  import org.jaxen.util.AncestorAxisIterator;
70  import org.jaxen.util.AncestorOrSelfAxisIterator;
71  import org.jaxen.util.DescendantAxisIterator;
72  import org.jaxen.util.DescendantOrSelfAxisIterator;
73  import org.jaxen.util.FollowingAxisIterator;
74  import org.jaxen.util.FollowingSiblingAxisIterator;
75  import org.jaxen.util.PrecedingAxisIterator;
76  import org.jaxen.util.PrecedingSiblingAxisIterator;
77  import org.jaxen.util.SelfAxisIterator;
78  
79  /*** Default implementation of {@link Navigator}.
80   *
81   *  <p>
82   *  This implementation is an abstract class, since
83   *  some required operations cannot be implemented without
84   *  additional knowledge of the object model.
85   *  </p>
86   *
87   *  <p>
88   *  When possible, default method implementations build
89   *  upon each other, to reduce the number of methods required
90   *  to be implemented for each object model.  All methods,
91   *  of course, may be overridden, to provide more-efficient
92   *  implementations.
93   *  </p>
94   *
95   *  @author bob mcwhirter (bob@werken.com)
96   *  @author Erwin Bolwidt (ejb@klomp.org)
97   */
98  public abstract class DefaultNavigator implements Navigator
99  {
100     /*** Throws <code>UnsupportedAxisException</code>
101      */
102     public Iterator getChildAxisIterator(Object contextNode) throws UnsupportedAxisException
103     {
104         throw new UnsupportedAxisException("child");
105     }
106 
107     public Iterator getDescendantAxisIterator(Object contextNode) throws UnsupportedAxisException
108     {
109         return new DescendantAxisIterator( contextNode,
110                                            this );
111     }
112 
113     /*** Throws <code>UnsupportedAxisException</code>
114      */
115     public Iterator getParentAxisIterator(Object contextNode) throws UnsupportedAxisException
116     {
117         throw new UnsupportedAxisException("parent");
118     }
119 
120     public Iterator getAncestorAxisIterator(Object contextNode) throws UnsupportedAxisException
121     {
122         return new AncestorAxisIterator( contextNode,
123                                          this );
124     }
125 
126     /*** Throws <code>UnsupportedAxisException</code>
127      */
128     public Iterator getFollowingSiblingAxisIterator(Object contextNode) throws UnsupportedAxisException
129     {
130         return new FollowingSiblingAxisIterator( contextNode,
131                                                  this );
132     }
133 
134     /*** Throws <code>UnsupportedAxisException</code>
135      */
136     public Iterator getPrecedingSiblingAxisIterator(Object contextNode) throws UnsupportedAxisException
137     {
138         return new PrecedingSiblingAxisIterator( contextNode,
139                                                  this );
140     }
141 
142     /*** Throws <code>UnsupportedAxisException</code>
143      */
144     public Iterator getFollowingAxisIterator(Object contextNode) throws UnsupportedAxisException
145     {
146         return new FollowingAxisIterator( contextNode,
147                                           this );
148 
149         // throw new UnsupportedAxisException("following");
150     }
151 
152     /*** Throws <code>UnsupportedAxisException</code>
153      */
154     public Iterator getPrecedingAxisIterator(Object contextNode) throws UnsupportedAxisException
155     {
156         return new PrecedingAxisIterator( contextNode,
157                                          this );
158 
159         // throw new UnsupportedAxisException("preceding");
160     }
161 
162     /*** Throws <code>UnsupportedAxisException</code>
163      */
164     public Iterator getAttributeAxisIterator(Object contextNode) throws UnsupportedAxisException
165     {
166         throw new UnsupportedAxisException("attribute");
167     }
168 
169     /*** Throws <code>UnsupportedAxisException</code>
170      */
171     public Iterator getNamespaceAxisIterator(Object contextNode) throws UnsupportedAxisException
172     {
173         throw new UnsupportedAxisException("namespace");
174     }
175 
176     public Iterator getSelfAxisIterator(Object contextNode) throws UnsupportedAxisException
177     {
178         return new SelfAxisIterator( contextNode );
179     }
180 
181     public Iterator getDescendantOrSelfAxisIterator(Object contextNode) throws UnsupportedAxisException
182     {
183         return new DescendantOrSelfAxisIterator( contextNode,
184                                                  this );
185     }
186 
187     public Iterator getAncestorOrSelfAxisIterator(Object contextNode) throws UnsupportedAxisException
188     {
189         return new AncestorOrSelfAxisIterator( contextNode,
190                                                this );
191     }
192 
193     public Object getDocumentNode(Object contextNode)
194     {
195         return null;
196     }
197     
198     public String translateNamespacePrefixToUri(String prefix, Object element)
199     {
200         return null;
201     }
202 
203     public String getProcessingInstructionTarget(Object obj)
204     {
205         return null;
206     }
207 
208     public String getProcessingInstructionData(Object obj)
209     {
210         return null;
211     }
212 
213     public short getNodeType(Object node)
214     {
215         if ( isElement(node) ) 
216         {
217             return Pattern.ELEMENT_NODE;
218         }
219         else if ( isAttribute(node) ) 
220         {
221             return Pattern.ATTRIBUTE_NODE;
222         }
223         else if ( isText(node) ) 
224         {
225             return Pattern.TEXT_NODE;
226         }
227         else if ( isComment(node) ) 
228         {
229             return Pattern.COMMENT_NODE;
230         }
231         else if ( isDocument(node) ) 
232         {
233             return Pattern.DOCUMENT_NODE;
234         }
235         else if ( isProcessingInstruction(node) ) 
236         {
237             return Pattern.PROCESSING_INSTRUCTION_NODE;
238         }
239         else {
240             return Pattern.UNKNOWN_NODE;
241         }
242     }
243     
244     public Object getParentNode(Object contextNode) throws UnsupportedAxisException
245     {
246         Iterator iter = getParentAxisIterator( contextNode );
247         if ( iter != null && iter.hasNext() )
248         {
249             return iter.next();
250         }
251         return null;
252     }
253 
254     public Object getDocument(String url) throws FunctionCallException
255     {
256         return null;
257     }
258 
259     /***
260      *  Default implementation that cannot find elements. Override in subclass
261      *  if subclass does know about attribute types.
262      *
263      *  @param contextNode   a node from the document in which to look for the
264      *                       id
265      *  @param elementId   id to look for
266      *
267      *  @return   null
268      */
269     public Object getElementById(Object contextNode, String elementId)
270     {
271         return null;
272     }
273 }