| /* |
| * 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.xpath.axes; |
| |
| import java.util.Vector; |
| |
| import org.apache.xpath.axes.LocPathIterator; |
| import org.apache.xpath.XPath; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.compiler.OpCodes; |
| import org.apache.xpath.objects.XObject; |
| |
| import javax.xml.transform.TransformerException; |
| |
| import org.w3c.dom.Node; |
| import org.w3c.dom.traversal.NodeFilter; |
| |
| /** |
| * Walker for a reverse axes. |
| * @see <a href="http://www.w3.org/TR/xpath#predicates">XPath 2.4 Predicates</a> |
| */ |
| public class ReverseAxesWalker extends AxesWalker |
| { |
| |
| /** |
| * Construct an AxesWalker using a LocPathIterator. |
| * |
| * @param locPathIterator The location path iterator that 'owns' this walker. |
| */ |
| public ReverseAxesWalker(LocPathIterator locPathIterator) |
| { |
| super(locPathIterator); |
| } |
| |
| /** |
| * Tells if this is a reverse axes. Overrides AxesWalker#isReverseAxes. |
| * |
| * @return true for this class. |
| */ |
| public boolean isReverseAxes() |
| { |
| return true; |
| } |
| |
| /** |
| * Set the root node of the TreeWalker. |
| * |
| * @param root The context node of this step. |
| */ |
| public void setRoot(Node root) |
| { |
| super.setRoot(root); |
| } |
| |
| /** |
| * Get the current sub-context position. In order to do the |
| * reverse axes count, for the moment this re-searches the axes |
| * up to the predicate. An optimization on this is to cache |
| * the nodes searched, but, for the moment, this case is probably |
| * rare enough that the added complexity isn't worth it. |
| * |
| * @param predicateIndex The predicate index of the proximity position. |
| * |
| * @return The pridicate index, or -1. |
| */ |
| protected int getProximityPosition(int predicateIndex) |
| { |
| // A negative predicate index seems to occur with |
| // (preceding-sibling::*|following-sibling::*)/ancestor::*[position()]/*[position()] |
| // -sb |
| if(predicateIndex < 0) |
| return -1; |
| |
| if (m_proximityPositions[predicateIndex] <= 0) |
| { |
| AxesWalker savedWalker = m_lpi.getLastUsedWalker(); |
| |
| try |
| { |
| ReverseAxesWalker clone = (ReverseAxesWalker) this.clone(); |
| |
| clone.setRoot(this.getRoot()); |
| |
| clone.setPredicateCount(predicateIndex); |
| |
| clone.setPrevWalker(null); |
| clone.setNextWalker(null); |
| m_lpi.setLastUsedWalker(clone); |
| |
| // Count 'em all |
| int count = 1; |
| Node next; |
| |
| while (null != (next = clone.nextNode())) |
| { |
| count++; |
| } |
| |
| m_proximityPositions[predicateIndex] += count; |
| } |
| catch (CloneNotSupportedException cnse) |
| { |
| |
| // can't happen |
| } |
| finally |
| { |
| m_lpi.setLastUsedWalker(savedWalker); |
| } |
| } |
| |
| return m_proximityPositions[predicateIndex]; |
| } |
| |
| /** |
| * Count backwards one proximity position. |
| * |
| * @param i The predicate index. |
| */ |
| protected void countProximityPosition(int i) |
| { |
| if (i < m_proximityPositions.length) |
| m_proximityPositions[i]--; |
| } |
| |
| /** |
| * Get the number of nodes in this node list. The function is probably ill |
| * named? |
| * |
| * |
| * @param xctxt The XPath runtime context. |
| * |
| * @return the number of nodes in this node list. |
| */ |
| public int getLastPos(XPathContext xctxt) |
| { |
| |
| int count = 0; |
| AxesWalker savedWalker = m_lpi.getLastUsedWalker(); |
| |
| try |
| { |
| ReverseAxesWalker clone = (ReverseAxesWalker) this.clone(); |
| |
| clone.setRoot(this.getRoot()); |
| |
| clone.setPredicateCount(this.getPredicateCount() - 1); |
| |
| clone.setPrevWalker(null); |
| clone.setNextWalker(null); |
| m_lpi.setLastUsedWalker(clone); |
| |
| // Count 'em all |
| // count = 1; |
| Node next; |
| |
| while (null != (next = clone.nextNode())) |
| { |
| count++; |
| } |
| } |
| catch (CloneNotSupportedException cnse) |
| { |
| |
| // can't happen |
| } |
| finally |
| { |
| m_lpi.setLastUsedWalker(savedWalker); |
| } |
| |
| // System.out.println("getLastPos - pos: "+count); |
| return count; |
| } |
| } |