KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > w3c > dom > traversal > NodeFilter


1 /*
2  * Copyright (c) 2000 World Wide Web Consortium,
3  * (Massachusetts Institute of Technology, Institut National de
4  * Recherche en Informatique et en Automatique, Keio University). All
5  * Rights Reserved. This program is distributed under the W3C's Software
6  * Intellectual Property License. This program is distributed in the
7  * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
8  * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
9  * PURPOSE.
10  * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
11  */
12
13 package org.w3c.dom.traversal;
14
15 import org.w3c.dom.Node JavaDoc;
16
17 /**
18  * Filters are objects that know how to "filter out" nodes. If a
19  * <code>NodeIterator</code> or <code>TreeWalker</code> is given a
20  * <code>NodeFilter</code>, it applies the filter before it returns the next
21  * node. If the filter says to accept the node, the traversal logic returns
22  * it; otherwise, traversal looks for the next node and pretends that the
23  * node that was rejected was not there.
24  * <p>The DOM does not provide any filters. <code>NodeFilter</code> is just an
25  * interface that users can implement to provide their own filters.
26  * <p><code>NodeFilters</code> do not need to know how to traverse from node
27  * to node, nor do they need to know anything about the data structure that
28  * is being traversed. This makes it very easy to write filters, since the
29  * only thing they have to know how to do is evaluate a single node. One
30  * filter may be used with a number of different kinds of traversals,
31  * encouraging code reuse.
32  * <p>See also the <a HREF='http://www.w3.org/TR/2000/REC-DOM-Level-2-Traversal-Range-20001113'>Document Object Model (DOM) Level 2 Traversal and Range Specification</a>.
33  * @since DOM Level 2
34  */
35 public interface NodeFilter {
36     // Constants returned by acceptNode
37 /**
38      * Accept the node. Navigation methods defined for
39      * <code>NodeIterator</code> or <code>TreeWalker</code> will return this
40      * node.
41      */
42     public static final short FILTER_ACCEPT = 1;
43     /**
44      * Reject the node. Navigation methods defined for
45      * <code>NodeIterator</code> or <code>TreeWalker</code> will not return
46      * this node. For <code>TreeWalker</code>, the children of this node
47      * will also be rejected. <code>NodeIterators</code> treat this as a
48      * synonym for <code>FILTER_SKIP</code>.
49      */
50     public static final short FILTER_REJECT = 2;
51     /**
52      * Skip this single node. Navigation methods defined for
53      * <code>NodeIterator</code> or <code>TreeWalker</code> will not return
54      * this node. For both <code>NodeIterator</code> and
55      * <code>TreeWalker</code>, the children of this node will still be
56      * considered.
57      */
58     public static final short FILTER_SKIP = 3;
59
60     // Constants for whatToShow
61 /**
62      * Show all <code>Nodes</code>.
63      */
64     public static final int SHOW_ALL = 0xFFFFFFFF;
65     /**
66      * Show <code>Element</code> nodes.
67      */
68     public static final int SHOW_ELEMENT = 0x00000001;
69     /**
70      * Show <code>Attr</code> nodes. This is meaningful only when creating an
71      * <code>NodeIterator</code> or <code>TreeWalker</code> with an
72      * attribute node as its <code>root</code>; in this case, it means that
73      * the attribute node will appear in the first position of the iteration
74      * or traversal. Since attributes are never children of other nodes,
75      * they do not appear when traversing over the document tree.
76      */
77     public static final int SHOW_ATTRIBUTE = 0x00000002;
78     /**
79      * Show <code>Text</code> nodes.
80      */
81     public static final int SHOW_TEXT = 0x00000004;
82     /**
83      * Show <code>CDATASection</code> nodes.
84      */
85     public static final int SHOW_CDATA_SECTION = 0x00000008;
86     /**
87      * Show <code>EntityReference</code> nodes.
88      */
89     public static final int SHOW_ENTITY_REFERENCE = 0x00000010;
90     /**
91      * Show <code>Entity</code> nodes. This is meaningful only when creating
92      * an <code>NodeIterator</code> or <code>TreeWalker</code> with an
93      * <code>Entity</code> node as its <code>root</code>; in this case, it
94      * means that the <code>Entity</code> node will appear in the first
95      * position of the traversal. Since entities are not part of the
96      * document tree, they do not appear when traversing over the document
97      * tree.
98      */
99     public static final int SHOW_ENTITY = 0x00000020;
100     /**
101      * Show <code>ProcessingInstruction</code> nodes.
102      */
103     public static final int SHOW_PROCESSING_INSTRUCTION = 0x00000040;
104     /**
105      * Show <code>Comment</code> nodes.
106      */
107     public static final int SHOW_COMMENT = 0x00000080;
108     /**
109      * Show <code>Document</code> nodes.
110      */
111     public static final int SHOW_DOCUMENT = 0x00000100;
112     /**
113      * Show <code>DocumentType</code> nodes.
114      */
115     public static final int SHOW_DOCUMENT_TYPE = 0x00000200;
116     /**
117      * Show <code>DocumentFragment</code> nodes.
118      */
119     public static final int SHOW_DOCUMENT_FRAGMENT = 0x00000400;
120     /**
121      * Show <code>Notation</code> nodes. This is meaningful only when creating
122      * an <code>NodeIterator</code> or <code>TreeWalker</code> with a
123      * <code>Notation</code> node as its <code>root</code>; in this case, it
124      * means that the <code>Notation</code> node will appear in the first
125      * position of the traversal. Since notations are not part of the
126      * document tree, they do not appear when traversing over the document
127      * tree.
128      */
129     public static final int SHOW_NOTATION = 0x00000800;
130
131     /**
132      * Test whether a specified node is visible in the logical view of a
133      * <code>TreeWalker</code> or <code>NodeIterator</code>. This function
134      * will be called by the implementation of <code>TreeWalker</code> and
135      * <code>NodeIterator</code>; it is not normally called directly from
136      * user code. (Though you could do so if you wanted to use the same
137      * filter to guide your own application logic.)
138      * @param n The node to check to see if it passes the filter or not.
139      * @return A constant to determine whether the node is accepted,
140      * rejected, or skipped, as defined above.
141      */
142     public short acceptNode(Node JavaDoc n);
143
144 }
145
Popular Tags