001 /*
002 * Copyright (c) 2000 World Wide Web Consortium,
003 * (Massachusetts Institute of Technology, Institut National de
004 * Recherche en Informatique et en Automatique, Keio University). All
005 * Rights Reserved. This program is distributed under the W3C's Software
006 * Intellectual Property License. This program is distributed in the
007 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even
008 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
009 * PURPOSE.
010 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
011 */
012
013 package org.w3c.dom.traversal;
014
015 import org.w3c.dom.Node;
016 import org.w3c.dom.DOMException;
017
018 /**
019 * <code>NodeIterators</code> are used to step through a set of nodes, e.g.
020 * the set of nodes in a <code>NodeList</code>, the document subtree
021 * governed by a particular <code>Node</code>, the results of a query, or
022 * any other set of nodes. The set of nodes to be iterated is determined by
023 * the implementation of the <code>NodeIterator</code>. DOM Level 2
024 * specifies a single <code>NodeIterator</code> implementation for
025 * document-order traversal of a document subtree. Instances of these
026 * <code>NodeIterators</code> are created by calling
027 * <code>DocumentTraversal</code><code>.createNodeIterator()</code>.
028 * <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>.
029 * @since DOM Level 2
030 */
031 public interface NodeIterator {
032 /**
033 * The root node of the <code>NodeIterator</code>, as specified when it
034 * was created.
035 */
036 public Node getRoot();
037
038 /**
039 * This attribute determines which node types are presented via the
040 * <code>NodeIterator</code>. The available set of constants is defined
041 * in the <code>NodeFilter</code> interface. Nodes not accepted by
042 * <code>whatToShow</code> will be skipped, but their children may still
043 * be considered. Note that this skip takes precedence over the filter,
044 * if any.
045 */
046 public int getWhatToShow();
047
048 /**
049 * The <code>NodeFilter</code> used to screen nodes.
050 */
051 public NodeFilter getFilter();
052
053 /**
054 * The value of this flag determines whether the children of entity
055 * reference nodes are visible to the <code>NodeIterator</code>. If
056 * false, these children and their descendants will be rejected. Note
057 * that this rejection takes precedence over <code>whatToShow</code> and
058 * the filter. Also note that this is currently the only situation where
059 * <code>NodeIterators</code> may reject a complete subtree rather than
060 * skipping individual nodes.
061 * <br>
062 * <br> To produce a view of the document that has entity references
063 * expanded and does not expose the entity reference node itself, use
064 * the <code>whatToShow</code> flags to hide the entity reference node
065 * and set <code>expandEntityReferences</code> to true when creating the
066 * <code>NodeIterator</code>. To produce a view of the document that has
067 * entity reference nodes but no entity expansion, use the
068 * <code>whatToShow</code> flags to show the entity reference node and
069 * set <code>expandEntityReferences</code> to false.
070 */
071 public boolean getExpandEntityReferences();
072
073 /**
074 * Returns the next node in the set and advances the position of the
075 * <code>NodeIterator</code> in the set. After a
076 * <code>NodeIterator</code> is created, the first call to
077 * <code>nextNode()</code> returns the first node in the set.
078 * @return The next <code>Node</code> in the set being iterated over, or
079 * <code>null</code> if there are no more members in that set.
080 * @exception DOMException
081 * INVALID_STATE_ERR: Raised if this method is called after the
082 * <code>detach</code> method was invoked.
083 */
084 public Node nextNode()
085 throws DOMException;
086
087 /**
088 * Returns the previous node in the set and moves the position of the
089 * <code>NodeIterator</code> backwards in the set.
090 * @return The previous <code>Node</code> in the set being iterated over,
091 * or <code>null</code> if there are no more members in that set.
092 * @exception DOMException
093 * INVALID_STATE_ERR: Raised if this method is called after the
094 * <code>detach</code> method was invoked.
095 */
096 public Node previousNode()
097 throws DOMException;
098
099 /**
100 * Detaches the <code>NodeIterator</code> from the set which it iterated
101 * over, releasing any computational resources and placing the
102 * <code>NodeIterator</code> in the INVALID state. After
103 * <code>detach</code> has been invoked, calls to <code>nextNode</code>
104 * or <code>previousNode</code> will raise the exception
105 * INVALID_STATE_ERR.
106 */
107 public void detach();
108
109 }