- /*
- * The Apache Software License, Version 1.1
- *
- *
- * Copyright (c) 1999 The Apache Software Foundation. All rights
- * reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. The end-user documentation included with the redistribution,
- * if any, must include the following acknowledgment:
- * "This product includes software developed by the
- * Apache Software Foundation (http://www.apache.org/)."
- * Alternately, this acknowledgment may appear in the software itself,
- * if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Xalan" and "Apache Software Foundation" must
- * not be used to endorse or promote products derived from this
- * software without prior written permission. For written
- * permission, please contact apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache",
- * nor may "Apache" appear in their name, without prior written
- * permission of the Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation and was
- * originally based on software copyright (c) 1999, Lotus
- * Development Corporation., http://www.lotus.com. For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
- */
- package org.apache.xml.dtm.ref;
-
- import org.apache.xml.dtm.*;
-
- /**
- * This class serves as a default base for implementations of DTMAxisIterators.
- */
- public abstract class DTMAxisIteratorBase implements DTMAxisIterator
- {
-
- /** The position of the last node within the iteration, as defined by XPath.
- * Note that this is _not_ the node's handle within the DTM. Also, don't
- * confuse it with the current (most recently returned) position.
- */
- private int _last = -1;
-
- /** The position of the current node within the iteration, as defined by XPath.
- * Note that this is _not_ the node's handle within the DTM!
- */
- private int _position = 0;
-
- /** The position of the marked node within the iteration;
- * a saved itaration state that we may want to come back to.
- * Note that only one mark is maintained; there is no stack.
- */
- protected int _markedNode;
-
- /** The handle to the start, or root, of the iteration.
- * Set this to END to construct an empty iterator.
- */
- protected int _startNode = DTMAxisIterator.END;
-
- /** True if the start node should be considered part of the iteration.
- * False will cause it to be skipped.
- */
- protected boolean _includeSelf = false;
-
- /** True if this iteration can be restarted. False otherwise (eg, if
- * we are iterating over a stream that can not be re-scanned, or if
- * the iterator was produced by cloning another iterator.)
- */
- protected boolean _isRestartable = true;
-
- /**
- * Get start to END should 'close' the iterator,
- * i.e. subsequent call to next() should return END.
- *
- * @return The root node of the iteration.
- */
- public int getStartNode()
- {
- return _startNode;
- }
-
- /**
- * @return A DTMAxisIterator which has been reset to the start node,
- * which may or may not be the same as this iterator.
- * */
- public DTMAxisIterator reset()
- {
-
- final boolean temp = _isRestartable;
-
- _isRestartable = true;
-
- setStartNode(_startNode);
-
- _isRestartable = temp;
-
- return this;
- }
-
- /**
- * Set the flag to include the start node in the iteration.
- *
- *
- * @return This default method returns just returns this DTMAxisIterator,
- * after setting the flag.
- * (Returning "this" permits C++-style chaining of
- * method calls into a single expression.)
- */
- public DTMAxisIterator includeSelf()
- {
-
- _includeSelf = true;
-
- return this;
- }
-
- /** Returns the position of the last node within the iteration, as
- * defined by XPath. In a forward iterator, I believe this equals the number of nodes which this
- * iterator will yield. In a reverse iterator, I believe it should return
- * 1 (since the "last" is the first produced.)
- *
- * This may be an expensive operation when called the first time, since
- * it may have to iterate through a large part of the document to produce
- * its answer.
- *
- * @return The number of nodes in this iterator (forward) or 1 (reverse).
- */
- public int getLast()
- {
-
- if (_last == -1) // Not previously established
- {
- // Note that we're doing both setMark() -- which saves _currentChild
- // -- and explicitly saving our position counter (number of nodes
- // yielded so far).
- //
- // %REVIEW% Should position also be saved by setMark()?
- // (It wasn't in the XSLTC version, but I don't understand why not.)
-
- final int temp = _position; // Save state
- setMark();
-
- reset(); // Count the nodes found by this iterator
- do
- {
- _last++;
- }
- while (next() != END);
-
- gotoMark(); // Restore saved state
- _position = temp;
- }
-
- return _last;
- }
-
- /**
- * @return The position of the current node within the set, as defined by
- * XPath. Note that this is one-based, not zero-based.
- */
- public int getPosition()
- {
- return _position == 0 ? 1 : _position;
- }
-
- /**
- * @return true if this iterator has a reversed axis, else false
- */
- public boolean isReverse()
- {
- return false;
- }
-
- /**
- * Returns a deep copy of this iterator. Cloned iterators may not be
- * restartable. The iterator being cloned may or may not become
- * non-restartable as a side effect of this operation.
- *
- * @return a deep copy of this iterator.
- */
- public DTMAxisIterator cloneIterator()
- {
-
- try
- {
- final DTMAxisIteratorBase clone = (DTMAxisIteratorBase) super.clone();
-
- // clone._isRestartable = false;
-
- // return clone.reset();
- return clone;
- }
- catch (CloneNotSupportedException e)
- {
- throw new org.apache.xml.utils.WrappedRuntimeException(e);
- }
- }
-
- /**
- * Do any final cleanup that is required before returning the node that was
- * passed in, and then return it. The intended use is
- * <br />
- * <code>return returnNode(node);</code>
- *
- * %REVIEW% If we're calling it purely for side effects, should we really
- * be bothering with a return value? Something like
- * <br />
- * <code> accept(node); return node; </code>
- * <br />
- * would probably optimize just about as well and avoid questions
- * about whether what's returned could ever be different from what's
- * passed in.
- *
- * @param node Node handle which iteration is about to yield.
- *
- * @return The node handle passed in. */
- protected final int returnNode(final int node)
- {
- _position++;
-
- return node;
- }
-
- /**
- * Reset the position to zero. NOTE that this does not change the iteration
- * state, only the position number associated with that state.
- *
- * %REVIEW% Document when this would be used?
- *
- * @return This instance.
- */
- protected final DTMAxisIterator resetPosition()
- {
-
- _position = 0;
-
- return this;
- }
-
- /**
- * Returns true if all the nodes in the iteration well be returned in document
- * order.
- *
- * @return true as a default.
- */
- public boolean isDocOrdered()
- {
- return true;
- }
-
- /**
- * Returns the axis being iterated, if it is known.
- *
- * @return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple
- * types.
- */
- public int getAxis()
- {
- return -1;
- }
-
- }