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
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
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
42 package org.w3c.dom.traversal;
43
44 import org.w3c.dom.Node;
45 import org.w3c.dom.DOMException;
46
47 /**
48 * <code>TreeWalker</code> objects are used to navigate a document tree or
49 * subtree using the view of the document defined by their
50 * <code>whatToShow</code> flags and filter (if any). Any function which
51 * performs navigation using a <code>TreeWalker</code> will automatically
52 * support any view defined by a <code>TreeWalker</code>.
53 * <p>Omitting nodes from the logical view of a subtree can result in a
54 * structure that is substantially different from the same subtree in the
55 * complete, unfiltered document. Nodes that are siblings in the
56 * <code>TreeWalker</code> view may be children of different, widely
57 * separated nodes in the original view. For instance, consider a
58 * <code>NodeFilter</code> that skips all nodes except for Text nodes and
59 * the root node of a document. In the logical view that results, all text
60 * nodes will be siblings and appear as direct children of the root node, no
61 * matter how deeply nested the structure of the original document.
62 * <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>.
63 * @since 9, DOM Level 2
64 */
65 public interface TreeWalker {
66 /**
67 * The <code>root</code> node of the <code>TreeWalker</code>, as specified
68 * when it was created.
69 */
70 public Node getRoot();
71
72 /**
73 * This attribute determines which node types are presented via the
74 * <code>TreeWalker</code>. The available set of constants is defined in
75 * the <code>NodeFilter</code> interface. Nodes not accepted by
76 * <code>whatToShow</code> will be skipped, but their children may still
77 * be considered. Note that this skip takes precedence over the filter,
78 * if any.
79 */
80 public int getWhatToShow();
81
82 /**
83 * The filter used to screen nodes.
84 */
85 public NodeFilter getFilter();
86
87 /**
88 * The value of this flag determines whether the children of entity
89 * reference nodes are visible to the <code>TreeWalker</code>. If false,
90 * these children and their descendants will be rejected. Note that
91 * this rejection takes precedence over <code>whatToShow</code> and the
92 * filter, if any.
93 * <br> To produce a view of the document that has entity references
94 * expanded and does not expose the entity reference node itself, use
95 * the <code>whatToShow</code> flags to hide the entity reference node
96 * and set <code>expandEntityReferences</code> to true when creating the
97 * <code>TreeWalker</code>. To produce a view of the document that has
98 * entity reference nodes but no entity expansion, use the
99 * <code>whatToShow</code> flags to show the entity reference node and
100 * set <code>expandEntityReferences</code> to false.
101 */
102 public boolean getExpandEntityReferences();
103
104 /**
105 * The node at which the <code>TreeWalker</code> is currently positioned.
106 * <br>Alterations to the DOM tree may cause the current node to no longer
107 * be accepted by the <code>TreeWalker</code>'s associated filter.
108 * <code>currentNode</code> may also be explicitly set to any node,
109 * whether or not it is within the subtree specified by the
110 * <code>root</code> node or would be accepted by the filter and
111 * <code>whatToShow</code> flags. Further traversal occurs relative to
112 * <code>currentNode</code> even if it is not part of the current view,
113 * by applying the filters in the requested direction; if no traversal
114 * is possible, <code>currentNode</code> is not changed.
115 */
116 public Node getCurrentNode();
117 /**
118 * The node at which the <code>TreeWalker</code> is currently positioned.
119 * <br>Alterations to the DOM tree may cause the current node to no longer
120 * be accepted by the <code>TreeWalker</code>'s associated filter.
121 * <code>currentNode</code> may also be explicitly set to any node,
122 * whether or not it is within the subtree specified by the
123 * <code>root</code> node or would be accepted by the filter and
124 * <code>whatToShow</code> flags. Further traversal occurs relative to
125 * <code>currentNode</code> even if it is not part of the current view,
126 * by applying the filters in the requested direction; if no traversal
127 * is possible, <code>currentNode</code> is not changed.
128 * @exception DOMException
129 * NOT_SUPPORTED_ERR: Raised if an attempt is made to set
130 * <code>currentNode</code> to <code>null</code>.
131 */
132 public void setCurrentNode(Node currentNode)
133 throws DOMException;
134
135 /**
136 * Moves to and returns the closest visible ancestor node of the current
137 * node. If the search for <code>parentNode</code> attempts to step
138 * upward from the <code>TreeWalker</code>'s <code>root</code> node, or
139 * if it fails to find a visible ancestor node, this method retains the
140 * current position and returns <code>null</code>.
141 * @return The new parent node, or <code>null</code> if the current node
142 * has no parent in the <code>TreeWalker</code>'s logical view.
143 */
144 public Node parentNode();
145
146 /**
147 * Moves the <code>TreeWalker</code> to the first visible child of the
148 * current node, and returns the new node. If the current node has no
149 * visible children, returns <code>null</code>, and retains the current
150 * node.
151 * @return The new node, or <code>null</code> if the current node has no
152 * visible children in the <code>TreeWalker</code>'s logical view.
153 */
154 public Node firstChild();
155
156 /**
157 * Moves the <code>TreeWalker</code> to the last visible child of the
158 * current node, and returns the new node. If the current node has no
159 * visible children, returns <code>null</code>, and retains the current
160 * node.
161 * @return The new node, or <code>null</code> if the current node has no
162 * children in the <code>TreeWalker</code>'s logical view.
163 */
164 public Node lastChild();
165
166 /**
167 * Moves the <code>TreeWalker</code> to the previous sibling of the
168 * current node, and returns the new node. If the current node has no
169 * visible previous sibling, returns <code>null</code>, and retains the
170 * current node.
171 * @return The new node, or <code>null</code> if the current node has no
172 * previous sibling. in the <code>TreeWalker</code>'s logical view.
173 */
174 public Node previousSibling();
175
176 /**
177 * Moves the <code>TreeWalker</code> to the next sibling of the current
178 * node, and returns the new node. If the current node has no visible
179 * next sibling, returns <code>null</code>, and retains the current node.
180 * @return The new node, or <code>null</code> if the current node has no
181 * next sibling. in the <code>TreeWalker</code>'s logical view.
182 */
183 public Node nextSibling();
184
185 /**
186 * Moves the <code>TreeWalker</code> to the previous visible node in
187 * document order relative to the current node, and returns the new
188 * node. If the current node has no previous node, or if the search for
189 * <code>previousNode</code> attempts to step upward from the
190 * <code>TreeWalker</code>'s <code>root</code> node, returns
191 * <code>null</code>, and retains the current node.
192 * @return The new node, or <code>null</code> if the current node has no
193 * previous node in the <code>TreeWalker</code>'s logical view.
194 */
195 public Node previousNode();
196
197 /**
198 * Moves the <code>TreeWalker</code> to the next visible node in document
199 * order relative to the current node, and returns the new node. If the
200 * current node has no next node, or if the search for nextNode attempts
201 * to step upward from the <code>TreeWalker</code>'s <code>root</code>
202 * node, returns <code>null</code>, and retains the current node.
203 * @return The new node, or <code>null</code> if the current node has no
204 * next node in the <code>TreeWalker</code>'s logical view.
205 */
206 public Node nextNode();
207
208 }