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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/NormalizeSpaceFunction.java,v 1.6 2004/09/16 21:38:19 bewins Exp $
3    * $Revision: 1.6 $
4    * $Date: 2004/09/16 21:38:19 $
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: NormalizeSpaceFunction.java,v 1.6 2004/09/16 21:38:19 bewins Exp $
60   */
61  
62  
63  package org.jaxen.function;
64  
65  import java.util.List;
66  
67  import org.jaxen.Context;
68  import org.jaxen.Function;
69  import org.jaxen.FunctionCallException;
70  import org.jaxen.Navigator;
71  
72  /***
73   * <p><b>4.2</b> <code><i>string</i> normalize-space(<i>string</i>)</code> 
74   * 
75   * @author James Strachan (james@metastuff.com)
76   */
77  public class NormalizeSpaceFunction implements Function
78  {
79  
80      public Object call(Context context,
81                         List args) throws FunctionCallException
82      {
83          if (args.size() >= 1)
84          {
85              return evaluate( args.get(0),
86                               context.getNavigator() );
87          }
88      
89          throw new FunctionCallException( "normalize-space() requires one argument" );
90      }
91  
92      public static String evaluate(Object strArg,
93                                    Navigator nav) 
94      {
95          String str = StringFunction.evaluate( strArg,
96                                                nav );
97  
98          char[] buffer = str.toCharArray();
99          int write = 0;
100         int lastWrite = 0;
101         boolean wroteOne = false;
102         int read = 0;
103         while (read < buffer.length)
104         {
105             if (Character.isWhitespace(buffer[read]))
106             {
107                 if (wroteOne)
108                 {
109                     buffer[write++] = ' ';
110                 }
111                 do
112                 {
113                     read++;
114                 }
115                 while(read < buffer.length && Character.isWhitespace(buffer[read]));
116             }
117             else
118             {
119                 buffer[write++] = buffer[read++];
120                 wroteOne = true;
121                 lastWrite = write;
122             }
123         }
124 
125         return new String(buffer, 0, lastWrite);
126     }
127 }