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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ext/MatrixConcatFunction.java,v 1.4 2003/06/29 18:04:41 ssanders Exp $
3    * $Revision: 1.4 $
4    * $Date: 2003/06/29 18:04:41 $
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: MatrixConcatFunction.java,v 1.4 2003/06/29 18:04:41 ssanders Exp $
60   */
61  
62  package org.jaxen.function.ext;
63  
64  import java.util.ArrayList;
65  import java.util.Enumeration;
66  import java.util.Iterator;
67  import java.util.List;
68  
69  import org.jaxen.Context;
70  import org.jaxen.Function;
71  import org.jaxen.Navigator;
72  import org.jaxen.function.StringFunction;
73  
74  /*** <p><b>Extension Function</b> <code><i>boolean</i> matrix-concat(<i>nodeSet</i>,<i>nodeSet</i>,<i>nodeSet*</i>)</code> 
75    * 
76    * @author James Pereira (JPereira@CT.BBD.CO.ZA)
77    */
78  
79  public class MatrixConcatFunction implements Function {
80      
81      public Object call(Context context, List args) {
82          if ( args.size() >= 2 ) {
83              return evaluate(args, context.getNavigator());
84          }
85          return null;
86      }
87      
88      public static Object evaluate(List list, Navigator nav) {        
89          ArrayList matrix = new ArrayList();       
90          
91          Iterator argIter = list.iterator();
92  
93          while (argIter.hasNext()) {
94              ArrayList v = new ArrayList();
95              Object obj = argIter.next();
96              if (obj instanceof List) {
97                  List args = (List) obj;
98                  for ( int i = 0, size = args.size(); i < size; i++ ) {
99                      v.add( StringFunction.evaluate( args.get(i), nav ) );
100                 }
101             }
102             else {
103                 v.add( StringFunction.evaluate( obj, nav ) );
104             }
105             matrix.add(v);
106         }
107         
108         ArrayList result = new ArrayList();
109         Enumeration elemList = new MatrixEnum( matrix );
110         while (elemList.hasMoreElements()) {
111             Object obj = elemList.nextElement();
112             if (obj instanceof List) {
113                 StringBuffer text = new StringBuffer(127);
114                 List args = (List) obj;
115                 for (Iterator it = args.iterator(); it.hasNext(); ) {
116                     text.append(it.next());
117                 }
118                 result.add( text.toString() );
119             }
120             else {
121                 result.add( obj );
122             }
123         }
124         return result;
125     }
126     
127     public static class MatrixEnum implements Enumeration {
128         private ArrayList m_source;
129         private int m_maxSize = 0;
130         private int m_currIdx = -1;
131         
132         public MatrixEnum (ArrayList _source) {
133             m_source = _source;
134             
135             for ( Iterator iter = m_source.iterator(); iter.hasNext(); ) {
136                 ArrayList element = (ArrayList) iter.next();
137                 int size = element.size();
138                 if (size > m_maxSize) {
139                     m_maxSize = size;
140                 }
141             }
142         }
143         
144         public MatrixEnum (ArrayList _source, int _maxSize) {
145             m_source = _source;
146             m_maxSize = _maxSize;
147         }
148         
149         public boolean hasMoreElements() {
150             if ((m_maxSize != 0) && (++m_currIdx < m_maxSize)) {
151                 return true;
152             }
153             else {
154                 return false;
155             }
156         }
157         
158         public Object nextElement() {
159             ArrayList result = new ArrayList();
160             for ( Iterator iter = m_source.iterator(); iter.hasNext(); ) {
161                 ArrayList element = (ArrayList) iter.next();
162                 int size = element.size();
163                 if ( m_currIdx < size ) {
164                     result.add( element.get( m_currIdx ) );
165                 }
166                 else {
167                     if ( size > 0 ) {
168                         result.add( element.get( size - 1 ) );
169                     }
170                     else {
171                         // XXXX: what to do now?
172                         result.add( "" );
173                     }
174                 }
175             }
176             return result;
177         }
178     }
179 }