1 /* 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 9 * PURPOSE. 10 * See W3C License http://www.w3.org/Consortium/Legal/ for more details. 11 */ 12 13 package org.w3c.dom.traversal; 14 15 import org.w3c.dom.DOMException; 16 import org.w3c.dom.Node; 17 18 /** 19 * <code>NodeIterators</code> are used to step through a set of nodes, e.g. 20 * the set of nodes in a <code>NodeList</code>, the document subtree 21 * governed by a particular <code>Node</code>, the results of a query, or 22 * any other set of nodes. The set of nodes to be iterated is determined by 23 * the implementation of the <code>NodeIterator</code>. DOM Level 2 24 * specifies a single <code>NodeIterator</code> implementation for 25 * document-order traversal of a document subtree. Instances of these 26 * <code>NodeIterators</code> are created by calling 27 * <code>DocumentTraversal</code><code>.createNodeIterator()</code>. 28 * <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>. 29 * @since DOM Level 2 30 * 31 * @hide 32 */ 33 public interface NodeIterator { 34 /** 35 * The root node of the <code>NodeIterator</code>, as specified when it 36 * was created. 37 */ 38 public Node getRoot(); 39 40 /** 41 * This attribute determines which node types are presented via the 42 * <code>NodeIterator</code>. The available set of constants is defined 43 * in the <code>NodeFilter</code> interface. Nodes not accepted by 44 * <code>whatToShow</code> will be skipped, but their children may still 45 * be considered. Note that this skip takes precedence over the filter, 46 * if any. 47 */ 48 public int getWhatToShow(); 49 50 /** 51 * The <code>NodeFilter</code> used to screen nodes. 52 */ 53 public NodeFilter getFilter(); 54 55 /** 56 * The value of this flag determines whether the children of entity 57 * reference nodes are visible to the <code>NodeIterator</code>. If 58 * false, these children and their descendants will be rejected. Note 59 * that this rejection takes precedence over <code>whatToShow</code> and 60 * the filter. Also note that this is currently the only situation where 61 * <code>NodeIterators</code> may reject a complete subtree rather than 62 * skipping individual nodes. 63 * <br> 64 * <br> To produce a view of the document that has entity references 65 * expanded and does not expose the entity reference node itself, use 66 * the <code>whatToShow</code> flags to hide the entity reference node 67 * and set <code>expandEntityReferences</code> to true when creating the 68 * <code>NodeIterator</code>. To produce a view of the document that has 69 * entity reference nodes but no entity expansion, use the 70 * <code>whatToShow</code> flags to show the entity reference node and 71 * set <code>expandEntityReferences</code> to false. 72 */ 73 public boolean getExpandEntityReferences(); 74 75 /** 76 * Returns the next node in the set and advances the position of the 77 * <code>NodeIterator</code> in the set. After a 78 * <code>NodeIterator</code> is created, the first call to 79 * <code>nextNode()</code> returns the first node in the set. 80 * @return The next <code>Node</code> in the set being iterated over, or 81 * <code>null</code> if there are no more members in that set. 82 * @exception DOMException 83 * INVALID_STATE_ERR: Raised if this method is called after the 84 * <code>detach</code> method was invoked. 85 */ 86 public Node nextNode() 87 throws DOMException; 88 89 /** 90 * Returns the previous node in the set and moves the position of the 91 * <code>NodeIterator</code> backwards in the set. 92 * @return The previous <code>Node</code> in the set being iterated over, 93 * or <code>null</code> if there are no more members in that set. 94 * @exception DOMException 95 * INVALID_STATE_ERR: Raised if this method is called after the 96 * <code>detach</code> method was invoked. 97 */ 98 public Node previousNode() 99 throws DOMException; 100 101 /** 102 * Detaches the <code>NodeIterator</code> from the set which it iterated 103 * over, releasing any computational resources and placing the 104 * <code>NodeIterator</code> in the INVALID state. After 105 * <code>detach</code> has been invoked, calls to <code>nextNode</code> 106 * or <code>previousNode</code> will raise the exception 107 * INVALID_STATE_ERR. 108 */ 109 public void detach(); 110 111 } 112
