Source for org.w3c.dom.traversal.NodeIterator

   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>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: 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:      * <code>NodeIterator</code>. The available set of constants is defined 
  41:      * in the <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 <code>NodeIterator</code>. If 
  56:      * false, these children  and their descendants will be rejected. Note 
  57:      * that this rejection takes precedence over <code>whatToShow</code> and 
  58:      * the filter. Also note 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:      * <code>NodeIterator</code>. To produce a view of the document that has 
  67:      * entity reference nodes but no entity expansion, use the 
  68:      * <code>whatToShow</code> flags to show the entity reference node and 
  69:      * set <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:      * <code>NodeIterator</code> in the set. After a 
  76:      * <code>NodeIterator</code> is created, the first call to 
  77:      * <code>nextNode()</code> returns the first node in 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 
 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: }