1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
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24
25/*
26 * This file is available under and governed by the GNU General Public
27 * License version 2 only, as published by the Free Software Foundation.
28 * However, the following notice accompanied the original version of this
29 * file and, per its terms, should not be removed:
30 *
31 * Copyright (c) 2000 World Wide Web Consortium,
32 * (Massachusetts Institute of Technology, Institut National de
33 * Recherche en Informatique et en Automatique, Keio University). All
34 * Rights Reserved. This program is distributed under the W3C's Software
35 * Intellectual Property License. This program is distributed in the
36 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
37 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
38 * PURPOSE.
39 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
40 */
41
42package org.w3c.dom.traversal;
43
44import org.w3c.dom.Node;
45
46/**
47 * Filters are objects that know how to "filter out" nodes. If a
48 * <code>NodeIterator</code> or <code>TreeWalker</code> is given a
49 * <code>NodeFilter</code>, it applies the filter before it returns the next
50 * node. If the filter says to accept the node, the traversal logic returns
51 * it; otherwise, traversal looks for the next node and pretends that the
52 * node that was rejected was not there.
53 * <p>The DOM does not provide any filters. <code>NodeFilter</code> is just an
54 * interface that users can implement to provide their own filters.
55 * <p><code>NodeFilters</code> do not need to know how to traverse from node
56 * to node, nor do they need to know anything about the data structure that
57 * is being traversed. This makes it very easy to write filters, since the
58 * only thing they have to know how to do is evaluate a single node. One
59 * filter may be used with a number of different kinds of traversals,
60 * encouraging code reuse.
61 * <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>.
62 * @since 9, DOM Level 2
63 */
64public interface NodeFilter {
65    // Constants returned by acceptNode
66    /**
67     * Accept the node. Navigation methods defined for
68     * <code>NodeIterator</code> or <code>TreeWalker</code> will return this
69     * node.
70     */
71    public static final short FILTER_ACCEPT             = 1;
72    /**
73     * Reject the node. Navigation methods defined for
74     * <code>NodeIterator</code> or <code>TreeWalker</code> will not return
75     * this node. For <code>TreeWalker</code>, the children of this node
76     * will also be rejected. <code>NodeIterators</code> treat this as a
77     * synonym for <code>FILTER_SKIP</code>.
78     */
79    public static final short FILTER_REJECT             = 2;
80    /**
81     * Skip this single node. Navigation methods defined for
82     * <code>NodeIterator</code> or <code>TreeWalker</code> will not return
83     * this node. For both <code>NodeIterator</code> and
84     * <code>TreeWalker</code>, the children of this node will still be
85     * considered.
86     */
87    public static final short FILTER_SKIP               = 3;
88
89    // Constants for whatToShow
90    /**
91     * Show all <code>Nodes</code>.
92     */
93    public static final int SHOW_ALL                  = 0xFFFFFFFF;
94    /**
95     * Show <code>Element</code> nodes.
96     */
97    public static final int SHOW_ELEMENT              = 0x00000001;
98    /**
99     * Show <code>Attr</code> nodes. This is meaningful only when creating an
100     * <code>NodeIterator</code> or <code>TreeWalker</code> with an
101     * attribute node as its <code>root</code>; in this case, it means that
102     * the attribute node will appear in the first position of the iteration
103     * or traversal. Since attributes are never children of other nodes,
104     * they do not appear when traversing over the document tree.
105     */
106    public static final int SHOW_ATTRIBUTE            = 0x00000002;
107    /**
108     * Show <code>Text</code> nodes.
109     */
110    public static final int SHOW_TEXT                 = 0x00000004;
111    /**
112     * Show <code>CDATASection</code> nodes.
113     */
114    public static final int SHOW_CDATA_SECTION        = 0x00000008;
115    /**
116     * Show <code>EntityReference</code> nodes.
117     */
118    public static final int SHOW_ENTITY_REFERENCE     = 0x00000010;
119    /**
120     * Show <code>Entity</code> nodes. This is meaningful only when creating
121     * an <code>NodeIterator</code> or <code>TreeWalker</code> with an
122     * <code>Entity</code> node as its <code>root</code>; in this case, it
123     * means that the <code>Entity</code> node will appear in the first
124     * position of the traversal. Since entities are not part of the
125     * document tree, they do not appear when traversing over the document
126     * tree.
127     */
128    public static final int SHOW_ENTITY               = 0x00000020;
129    /**
130     * Show <code>ProcessingInstruction</code> nodes.
131     */
132    public static final int SHOW_PROCESSING_INSTRUCTION = 0x00000040;
133    /**
134     * Show <code>Comment</code> nodes.
135     */
136    public static final int SHOW_COMMENT              = 0x00000080;
137    /**
138     * Show <code>Document</code> nodes.
139     */
140    public static final int SHOW_DOCUMENT             = 0x00000100;
141    /**
142     * Show <code>DocumentType</code> nodes.
143     */
144    public static final int SHOW_DOCUMENT_TYPE        = 0x00000200;
145    /**
146     * Show <code>DocumentFragment</code> nodes.
147     */
148    public static final int SHOW_DOCUMENT_FRAGMENT    = 0x00000400;
149    /**
150     * Show <code>Notation</code> nodes. This is meaningful only when creating
151     * an <code>NodeIterator</code> or <code>TreeWalker</code> with a
152     * <code>Notation</code> node as its <code>root</code>; in this case, it
153     * means that the <code>Notation</code> node will appear in the first
154     * position of the traversal. Since notations are not part of the
155     * document tree, they do not appear when traversing over the document
156     * tree.
157     */
158    public static final int SHOW_NOTATION             = 0x00000800;
159
160    /**
161     * Test whether a specified node is visible in the logical view of a
162     * <code>TreeWalker</code> or <code>NodeIterator</code>. This function
163     * will be called by the implementation of <code>TreeWalker</code> and
164     * <code>NodeIterator</code>; it is not normally called directly from
165     * user code. (Though you could do so if you wanted to use the same
166     * filter to guide your own application logic.)
167     * @param n The node to check to see if it passes the filter or not.
168     * @return A constant to determine whether the node is accepted,
169     *   rejected, or skipped, as defined above.
170     */
171    public short acceptNode(Node n);
172
173}
174