286N/A * reserved comment block 286N/A * DO NOT REMOVE OR ALTER! 286N/A * Copyright 1999-2004 The Apache Software Foundation. 286N/A * Licensed under the Apache License, Version 2.0 (the "License"); 286N/A * you may not use this file except in compliance with the License. 286N/A * You may obtain a copy of the License at 286N/A * Unless required by applicable law or agreed to in writing, software 286N/A * distributed under the License is distributed on an "AS IS" BASIS, 286N/A * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 286N/A * See the License for the specific language governing permissions and 286N/A * limitations under the License. 286N/A * <code>DTMIterators</code> are used to step through a (possibly 286N/A * filtered) set of nodes. Their API is modeled largely after the DOM 286N/A * <p>A DTMIterator is a somewhat unusual type of iterator, in that it 286N/A * can serve both single node iteration and random access.</p> 286N/A * <p>The DTMIterator's traversal semantics, i.e. how it walks the tree, 286N/A * are specified when it is created, possibly and probably by an XPath 286N/A * <p>A DTMIterator is meant to be created once as a master static object, and 286N/A * then cloned many times for runtime use. Or the master object itself may 286N/A * be used for simpler use cases.</p> 286N/A * <p>At this time, we do not expect DTMIterator to emulate 286N/A * NodeIterator's "maintain relative position" semantics under 286N/A * document mutation. It's likely to respond more like the 286N/A * TreeWalker's "current node" semantics. However, since the base DTM 286N/A * is immutable, this issue currently makes no practical 286N/A * <p>State: In progress!!</p> */ 286N/A // Constants returned by acceptNode, borrowed from the DOM Traversal chapter 286N/A // %REVIEW% Should we explicitly initialize them from, eg, 286N/A // org.w3c.dom.traversal.NodeFilter.FILTER_ACCEPT? 286N/A * Reject the node. Same behavior as FILTER_SKIP. (In the DOM these 286N/A * differ when applied to a TreeWalker but have the same result when 286N/A * applied to a NodeIterator). 286N/A * Skip this single node. 286N/A * Get an instance of a DTM that "owns" a node handle. Since a node 286N/A * iterator may be passed without a DTMManager, this allows the 286N/A * caller to easily get the DTM using just the iterator. 286N/A * @param nodeHandle the nodeHandle. 286N/A * @return a non-null DTM reference. 286N/A * Get an instance of the DTMManager. Since a node 286N/A * iterator may be passed without a DTMManager, this allows the 286N/A * caller to easily get the DTMManager using just the iterator. 286N/A * @return a non-null DTMManager reference. 286N/A * The root node of the <code>DTMIterator</code>, as specified when it 286N/A * was created. Note the root node is not the root node of the 286N/A * document tree, but the context node from where the iteration 286N/A * @return nodeHandle int Handle of the context node. 286N/A * Reset the root node of the <code>DTMIterator</code>, overriding 286N/A * the value specified when it was created. Note the root node is 286N/A * not the root node of the document tree, but the context node from 286N/A * where the iteration begins. 286N/A * @param nodeHandle int Handle of the context node. 286N/A * @param environment The environment object. 286N/A * The environment in which this iterator operates, which should provide: 286N/A * <li>a node (the context node... same value as "root" defined below) </li> 286N/A * <li>a pair of non-zero positive integers (the context position and the context size) </li> 286N/A * <li>a set of variable bindings </li> 286N/A * <li>a function library </li> 286N/A * <li>the set of namespace declarations in scope for the expression.</li> 286N/A * <p>At this time the exact implementation of this environment is application 286N/A * dependent. Probably a proper interface will be created fairly soon.</p> 286N/A * Reset the iterator to the start. After resetting, the next node returned 286N/A * will be the root node -- or, if that's filtered out, the first node 286N/A * within the root's subtree which is _not_ skipped by the filters. 286N/A * This attribute determines which node types are presented via the 286N/A * iterator. The available set of constants is defined above. 286N/A * Nodes not accepted by 286N/A * <code>whatToShow</code> will be skipped, but their children may still 286N/A * @return one of the SHOW_XXX constants, or several ORed together. 286N/A * <p>The value of this flag determines whether the children of entity 286N/A * reference nodes are visible to the iterator. If false, they and 286N/A * their descendants will be rejected. Note that this rejection takes 286N/A * precedence over <code>whatToShow</code> and the filter. </p> 286N/A * <p> To produce a view of the document that has entity references 286N/A * expanded and does not expose the entity reference node itself, use 286N/A * the <code>whatToShow</code> flags to hide the entity reference node 286N/A * and set <code>expandEntityReferences</code> to true when creating the 286N/A * iterator. To produce a view of the document that has entity reference 286N/A * nodes but no entity expansion, use the <code>whatToShow</code> flags 286N/A * to show the entity reference node and set 286N/A * <code>expandEntityReferences</code> to false.</p> 286N/A * <p>NOTE: In Xalan's use of DTM we will generally have fully expanded 286N/A * entity references when the document tree was built, and thus this 286N/A * flag will have no effect.</p> 286N/A * @return true if entity references will be expanded. */ 286N/A * Returns the next node in the set and advances the position of the 286N/A * iterator in the set. After a <code>DTMIterator</code> has setRoot called, 286N/A * the first call to <code>nextNode()</code> returns that root or (if it 286N/A * is rejected by the filters) the first node within its subtree which is 286N/A * @return The next node handle in the set being iterated over, or 286N/A * <code>DTM.NULL</code> if there are no more members in that set. 286N/A * Returns the previous node in the set and moves the position of the 286N/A * <code>DTMIterator</code> backwards in the set. 286N/A * @return The previous node handle in the set being iterated over, 286N/A * or <code>DTM.NULL</code> if there are no more members in that set. 286N/A * Detaches the <code>DTMIterator</code> from the set which it iterated 286N/A * over, releasing any computational resources and placing the iterator 286N/A * in the INVALID state. After <code>detach</code> has been invoked, 286N/A * calls to <code>nextNode</code> or <code>previousNode</code> will 286N/A * raise a runtime exception. 286N/A * Specify if it's OK for detach to release the iterator for reuse. 286N/A * @param allowRelease true if it is OK for detach to release this iterator 286N/A * Get the current node in the iterator. Note that this differs from 286N/A * the DOM's NodeIterator, where the current position lies between two 286N/A * nodes (as part of the maintain-relative-position semantic). 286N/A * @return The current node handle, or -1. 286N/A * Tells if this NodeSetDTM is "fresh", in other words, if 286N/A * the first nextNode() that is called will return the 286N/A * first node in the set. 286N/A * @return true if the iteration of this list has not yet begun. 286N/A //========= Random Access ========== 286N/A * If setShouldCacheNodes(true) is called, then nodes will 286N/A * be cached, enabling random access, and giving the ability to do 286N/A * sorts and the like. They are not cached by default. 286N/A * %REVIEW% Shouldn't the other random-access methods throw an exception 286N/A * if they're called on a DTMIterator with this flag set false? 286N/A * @param b true if the nodes should be cached. 286N/A * Tells if this iterator can have nodes added to it or set via 286N/A * the <code>setItem(int node, int index)</code> method. 286N/A * @return True if the nodelist can be mutated. 286N/A /** Get the current position within the cached list, which is one 286N/A * less than the next nextNode() call will retrieve. i.e. if you 286N/A * call getCurrentPos() and the return is 0, the next fetch will 286N/A * take place at index 1. 286N/A * @return The position of the iteration. 286N/A * If an index is requested, NodeSetDTM will call this method 286N/A * to run the iterator to the index. By default this sets 286N/A * m_next to the index. If the index argument is -1, this 286N/A * signals that the iterator should be run to the end and 286N/A * completely fill the cache. 286N/A * @param index The index to run to, or -1 if the iterator should be run 286N/A * Set the current position in the node set. 286N/A * @param i Must be a valid index. 286N/A * Returns the <code>node handle</code> of an item in the collection. If 286N/A * <code>index</code> is greater than or equal to the number of nodes in 286N/A * the list, this returns <code>null</code>. 286N/A * @param index of the item. 286N/A * @return The node handle at the <code>index</code>th position in the 286N/A * <code>DTMIterator</code>, or <code>-1</code> if that is not a valid 286N/A * Sets the node at the specified index of this vector to be the 286N/A * specified node. The previous component at that position is discarded. 286N/A * <p>The index must be a value greater than or equal to 0 and less 286N/A * than the current size of the vector. 286N/A * The iterator must be in cached mode.</p> 286N/A * <p>Meant to be used for sorted iterators.</p> 286N/A * @param node Node to set 286N/A * @param index Index of where to set the node 286N/A * The number of nodes in the list. The range of valid child node indices 286N/A * is 0 to <code>length-1</code> inclusive. Note that this requires running 286N/A * the iterator to completion, and presumably filling the cache. 286N/A * @return The number of nodes in the list. 286N/A //=========== Cloning operations. ============ 286N/A * Get a cloned Iterator that is reset to the start of the iteration. 286N/A * @return A clone of this iteration that has been reset. 286N/A * @throws CloneNotSupportedException 286N/A * Get a clone of this iterator, but don't reset the iteration in the 286N/A * process, so that it may be used from the current position. 286N/A * @return A clone of this object. 286N/A * @throws CloneNotSupportedException 286N/A * Returns true if all the nodes in the iteration well be returned in document 286N/A * @return true if all the nodes in the iteration well be returned in document 286N/A * Returns the axis being iterated, if it is known. 286N/A * @return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple