1 /* Namespaces.java -
2    Copyright (C) 2004 Free Software Foundation, Inc.
3 
4 This file is part of GNU Classpath.
5 
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10 
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING.  If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20 
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library.  Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25 
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module.  An independent module is a module which is not derived from
33 or based on this library.  If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so.  If you do not wish to do so, delete this
36 exception statement from your version. */
37 
38 package gnu.xml.libxmlj.sax;
39 
40 import java.util.ArrayList;
41 import java.util.Collections;
42 import java.util.HashMap;
43 import java.util.Iterator;
44 
45 /**
46  * Helper class for managing namespaces.
47  *
48  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
49  */
50 class Namespaces
51 {
52 
53   ArrayList stack = new ArrayList ();
54 
55   /**
56    * Increments the tree depth.
57    * This allocates a new potential namespace entry.
58    */
push()59   void push ()
60   {
61     stack.add (null);
62   }
63 
64   /**
65    * Decrements the tree depth.
66    * This removes namespaces defined at the extremity.
67    */
pop()68   void pop ()
69   {
70     stack.remove (stack.size() - 1);
71   }
72 
73   /**
74    * Searches for the namespace URI corresponding to the specified prefix.
75    */
getURI(String prefix)76   String getURI (String prefix)
77   {
78     for (int i = stack.size () - 1; i >= 0; i--)
79     {
80       HashMap ns = (HashMap) stack.get (i);
81       if (ns != null && ns.containsKey (prefix))
82       {
83         String ret = (String) ns.get (prefix);
84         return (ret == null) ? "" : ret;
85       }
86     }
87     return "";
88   }
89 
90   /**
91    * Defines the specified prefix-URI mapping at the current depth in the
92    * tree.
93    */
define(String prefix, String uri)94   void define (String prefix, String uri)
95   {
96     int index = stack.size () - 1;
97     HashMap ns = (HashMap) stack.get (index);
98     if (ns == null)
99     {
100       ns = new HashMap ();
101       stack.set (index, ns);
102     }
103     ns.put (prefix, uri);
104   }
105 
106   /**
107    * Returns an iterator over the prefixes defined at the current depth.
108    */
currentPrefixes()109   Iterator currentPrefixes ()
110   {
111     HashMap ns = (HashMap) stack.get (stack.size () - 1);
112     if (ns == null)
113       {
114         return Collections.EMPTY_LIST.iterator ();
115       }
116     else
117       {
118         return ns.keySet ().iterator ();
119       }
120   }
121 
122 }
123