libjava/org/w3c/dom/traversal/NodeIterator.java

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