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.Node; 16 17 /** 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>. 33 * @since DOM Level 2 34 * 35 * @hide 36 */ 37 public interface NodeFilter { 38 // Constants returned by acceptNode 39 /** 40 * Accept the node. Navigation methods defined for 41 * <code>NodeIterator</code> or <code>TreeWalker</code> will return this 42 * node. 43 */ 44 public static final short FILTER_ACCEPT = 1; 45 /** 46 * Reject the node. Navigation methods defined for 47 * <code>NodeIterator</code> or <code>TreeWalker</code> will not return 48 * this node. For <code>TreeWalker</code>, the children of this node 49 * will also be rejected. <code>NodeIterators</code> treat this as a 50 * synonym for <code>FILTER_SKIP</code>. 51 */ 52 public static final short FILTER_REJECT = 2; 53 /** 54 * Skip this single node. Navigation methods defined for 55 * <code>NodeIterator</code> or <code>TreeWalker</code> will not return 56 * this node. For both <code>NodeIterator</code> and 57 * <code>TreeWalker</code>, the children of this node will still be 58 * considered. 59 */ 60 public static final short FILTER_SKIP = 3; 61 62 // Constants for whatToShow 63 /** 64 * Show all <code>Nodes</code>. 65 */ 66 public static final int SHOW_ALL = 0xFFFFFFFF; 67 /** 68 * Show <code>Element</code> nodes. 69 */ 70 public static final int SHOW_ELEMENT = 0x00000001; 71 /** 72 * Show <code>Attr</code> nodes. This is meaningful only when creating an 73 * <code>NodeIterator</code> or <code>TreeWalker</code> with an 74 * attribute node as its <code>root</code>; in this case, it means that 75 * the attribute node will appear in the first position of the iteration 76 * or traversal. Since attributes are never children of other nodes, 77 * they do not appear when traversing over the document tree. 78 */ 79 public static final int SHOW_ATTRIBUTE = 0x00000002; 80 /** 81 * Show <code>Text</code> nodes. 82 */ 83 public static final int SHOW_TEXT = 0x00000004; 84 /** 85 * Show <code>CDATASection</code> nodes. 86 */ 87 public static final int SHOW_CDATA_SECTION = 0x00000008; 88 /** 89 * Show <code>EntityReference</code> nodes. 90 */ 91 public static final int SHOW_ENTITY_REFERENCE = 0x00000010; 92 /** 93 * Show <code>Entity</code> nodes. This is meaningful only when creating 94 * an <code>NodeIterator</code> or <code>TreeWalker</code> with an 95 * <code>Entity</code> node as its <code>root</code>; in this case, it 96 * means that the <code>Entity</code> node will appear in the first 97 * position of the traversal. Since entities are not part of the 98 * document tree, they do not appear when traversing over the document 99 * tree. 100 */ 101 public static final int SHOW_ENTITY = 0x00000020; 102 /** 103 * Show <code>ProcessingInstruction</code> nodes. 104 */ 105 public static final int SHOW_PROCESSING_INSTRUCTION = 0x00000040; 106 /** 107 * Show <code>Comment</code> nodes. 108 */ 109 public static final int SHOW_COMMENT = 0x00000080; 110 /** 111 * Show <code>Document</code> nodes. 112 */ 113 public static final int SHOW_DOCUMENT = 0x00000100; 114 /** 115 * Show <code>DocumentType</code> nodes. 116 */ 117 public static final int SHOW_DOCUMENT_TYPE = 0x00000200; 118 /** 119 * Show <code>DocumentFragment</code> nodes. 120 */ 121 public static final int SHOW_DOCUMENT_FRAGMENT = 0x00000400; 122 /** 123 * Show <code>Notation</code> nodes. This is meaningful only when creating 124 * an <code>NodeIterator</code> or <code>TreeWalker</code> with a 125 * <code>Notation</code> node as its <code>root</code>; in this case, it 126 * means that the <code>Notation</code> node will appear in the first 127 * position of the traversal. Since notations are not part of the 128 * document tree, they do not appear when traversing over the document 129 * tree. 130 */ 131 public static final int SHOW_NOTATION = 0x00000800; 132 133 /** 134 * Test whether a specified node is visible in the logical view of a 135 * <code>TreeWalker</code> or <code>NodeIterator</code>. This function 136 * will be called by the implementation of <code>TreeWalker</code> and 137 * <code>NodeIterator</code>; it is not normally called directly from 138 * user code. (Though you could do so if you wanted to use the same 139 * filter to guide your own application logic.) 140 * @param n The node to check to see if it passes the filter or not. 141 * @return A constant to determine whether the node is accepted, 142 * rejected, or skipped, as defined above. 143 */ acceptNode(Node n)144 public short acceptNode(Node n); 145 146 } 147