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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/pattern/UnionPattern.java,v 1.6 2002/05/20 08:34:10 jstrachan Exp $
3    * $Revision: 1.6 $
4    * $Date: 2002/05/20 08:34:10 $
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: UnionPattern.java,v 1.6 2002/05/20 08:34:10 jstrachan Exp $
60   */
61  
62  package org.jaxen.pattern;
63  
64  import org.jaxen.Context;
65  import org.jaxen.JaxenException;
66  
67  /*** <p><code>UnionPattern</code> represents a union pattern.</p>
68    *
69    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
70    * @version $Revision: 1.6 $
71    */
72  public class UnionPattern extends Pattern {
73  
74      private Pattern lhs;
75      private Pattern rhs;
76      private short nodeType = ANY_NODE;
77      private String matchesNodeName = null;
78      
79      
80      public UnionPattern() 
81      {
82      }
83      
84      public UnionPattern(Pattern lhs, Pattern rhs) 
85      {
86          this.lhs = lhs;
87          this.rhs = rhs;
88          init();
89      }
90      
91      
92      public Pattern getLHS() 
93      {
94          return lhs;
95      }
96      
97      public void setLHS(Pattern lhs) 
98      {
99          this.lhs = lhs;
100         init();
101     }
102     
103     public Pattern getRHS() 
104     {
105         return rhs;
106     }
107     
108     public void setRHS(Pattern rhs) 
109     {
110         this.rhs = rhs;
111         init();
112     }
113     
114     
115     // Pattern interface
116     //-------------------------------------------------------------------------    
117     
118     /*** @return true if the pattern matches the given node
119       */
120     public boolean matches( Object node, Context context ) throws JaxenException
121     {
122         return lhs.matches( node, context ) || rhs.matches( node, context );
123     }
124     
125     public Pattern[] getUnionPatterns() 
126     {
127         return new Pattern[] { lhs, rhs };
128     }
129 
130     
131     public short getMatchType() 
132     {
133         return nodeType;
134     }
135 
136 
137     public String getMatchesNodeName() 
138     {
139         return matchesNodeName;
140     }
141     
142     
143     public Pattern simplify() 
144     {
145         this.lhs = lhs.simplify();
146         this.rhs = rhs.simplify();
147         init();
148         return this;
149     }
150     
151     public String getText() 
152     {
153         return lhs.getText() + " | " + rhs.getText();
154     }
155         
156     public String toString()
157     {
158         return super.toString() + "[ lhs: " + lhs + " rhs: " + rhs + " ]";
159     }
160     
161     // Implementation methods
162     //-------------------------------------------------------------------------    
163     private void init() 
164     {
165         short type1 = lhs.getMatchType();
166         short type2 = rhs.getMatchType();
167         this.nodeType = ( type1 == type2 ) ? type1 : ANY_NODE;
168         
169         String name1 = lhs.getMatchesNodeName();
170         String name2 = rhs.getMatchesNodeName();
171         
172         this.matchesNodeName = null;
173         if ( name1 != null && name2 != null && name1.equals( name2 ) ) 
174         {
175             this.matchesNodeName = name1;
176         }
177     }    
178 }