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() throws DOMException;
085:
086: /**
087: * Returns the previous node in the set and moves the position of the
088: * <code>NodeIterator</code> backwards in the set.
089: * @return The previous <code>Node</code> in the set being iterated over,
090: * or <code>null</code> if there are no more members in that set.
091: * @exception DOMException
092: * INVALID_STATE_ERR: Raised if this method is called after the
093: * <code>detach</code> method was invoked.
094: */
095: public Node previousNode() throws DOMException;
096:
097: /**
098: * Detaches the <code>NodeIterator</code> from the set which it iterated
099: * over, releasing any computational resources and placing the
100: * <code>NodeIterator</code> in the INVALID state. After
101: * <code>detach</code> has been invoked, calls to <code>nextNode</code>
102: * or <code>previousNode</code> will raise the exception
103: * INVALID_STATE_ERR.
104: */
105: public void detach();
106:
107: }
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