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
10 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
13 package org.w3c.dom.traversal;
15 import org.w3c.dom.Node;
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>.
35 public interface NodeFilter {
36 // Constants returned by acceptNode
38 * Accept the node. Navigation methods defined for
39 * <code>NodeIterator</code> or <code>TreeWalker</code> will return this
42 public static final short FILTER_ACCEPT = 1;
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>.
50 public static final short FILTER_REJECT = 2;
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
58 public static final short FILTER_SKIP = 3;
60 // Constants for whatToShow
62 * Show all <code>Nodes</code>.
64 public static final int SHOW_ALL = 0xFFFFFFFF;
66 * Show <code>Element</code> nodes.
68 public static final int SHOW_ELEMENT = 0x00000001;
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.
77 public static final int SHOW_ATTRIBUTE = 0x00000002;
79 * Show <code>Text</code> nodes.
81 public static final int SHOW_TEXT = 0x00000004;
83 * Show <code>CDATASection</code> nodes.
85 public static final int SHOW_CDATA_SECTION = 0x00000008;
87 * Show <code>EntityReference</code> nodes.
89 public static final int SHOW_ENTITY_REFERENCE = 0x00000010;
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
99 public static final int SHOW_ENTITY = 0x00000020;
101 * Show <code>ProcessingInstruction</code> nodes.
103 public static final int SHOW_PROCESSING_INSTRUCTION = 0x00000040;
105 * Show <code>Comment</code> nodes.
107 public static final int SHOW_COMMENT = 0x00000080;
109 * Show <code>Document</code> nodes.
111 public static final int SHOW_DOCUMENT = 0x00000100;
113 * Show <code>DocumentType</code> nodes.
115 public static final int SHOW_DOCUMENT_TYPE = 0x00000200;
117 * Show <code>DocumentFragment</code> nodes.
119 public static final int SHOW_DOCUMENT_FRAGMENT = 0x00000400;
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
129 public static final int SHOW_NOTATION = 0x00000800;
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.
142 public short acceptNode(Node n);