/*
* $Header: /home/cvspublic/jakarta-commons/jxpath/src/java/org/apache/commons/jxpath/ri/axes/PrecedingOrFollowingContext.java,v 1.8 2002/05/29 00:41:32 dmitri Exp $
* $Revision: 1.8 $
* $Date: 2002/05/29 00:41:32 $
*
* ====================================================================
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999-2001 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 acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", 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 names without prior written
* permission of the Apache Group.
*
* 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) 2001, Plotnix, Inc,
* <http://www.plotnix.com/>.
* For more information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.commons.jxpath.ri.axes;
import java.util.Stack;
import org.apache.commons.jxpath.ri.EvalContext;
import org.apache.commons.jxpath.ri.compiler.NodeTest;
import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.apache.commons.jxpath.ri.model.beans.PropertyIterator;
/**
* EvalContext that walks the "preceding::" and "following::" axes.
*
* @author Dmitri Plotnikov
* @version $Revision: 1.8 $ $Date: 2002/05/29 00:41:32 $
*/
public class PrecedingOrFollowingContext extends EvalContext {
private NodeTest nodeTest;
private boolean setStarted = false;
private boolean started = false;
private Stack stack;
private Stack nameStack;
private NodePointer currentNodePointer;
private NodePointer currentRootLocation;
private boolean includeSelf;
private boolean reverse;
public PrecedingOrFollowingContext(EvalContext parentContext, NodeTest nodeTest, boolean reverse){
super(parentContext);
this.includeSelf = includeSelf;
this.nodeTest = nodeTest;
this.reverse = reverse;
}
public NodePointer getCurrentNodePointer(){
return currentNodePointer;
}
public int getDocumentOrder(){
return reverse ? -1 : 1;
}
public void reset(){
super.reset();
stack = new Stack();
setStarted = false;
}
public boolean setPosition(int position){
if (position < this.position){
reset();
}
while (this.position < position){
if (!nextNode()){
return false;
}
}
return true;
}
public boolean nextNode(){
if (!setStarted){
setStarted = true;
currentRootLocation = parentContext.getCurrentNodePointer();
NodePointer parent = getMaterialPointer(currentRootLocation.getParent());
if (parent != null){
// TBD: check type
stack.push(parent.childIterator(null, reverse, currentRootLocation));
}
}
while (true){
if (stack.isEmpty()){
currentRootLocation = getMaterialPointer(currentRootLocation.getParent());
if (currentRootLocation == null || currentRootLocation.isRoot()){
break;
}
NodePointer parent = getMaterialPointer(currentRootLocation.getParent());
if (parent != null){
stack.push(parent.childIterator(null, reverse, currentRootLocation));
}
}
while (!stack.isEmpty()){
if (!reverse){
NodeIterator it = (NodeIterator)stack.peek();
if (it.setPosition(it.getPosition() + 1)){
currentNodePointer = it.getNodePointer();
if (!currentNodePointer.isLeaf()){
stack.push(currentNodePointer.childIterator(null, reverse, null));
}
if (currentNodePointer.testNode(nodeTest)){
super.setPosition(getCurrentPosition() + 1);
return true;
}
}
else {
// We get here only if the name test failed and the iterator ended
stack.pop();
}
}
else {
NodeIterator it = (NodeIterator)stack.peek();
if (it.setPosition(it.getPosition() + 1)){
currentNodePointer = it.getNodePointer();
if (!currentNodePointer.isLeaf()){
stack.push(currentNodePointer.childIterator(null, reverse, null));
}
else if (currentNodePointer.testNode(nodeTest)){
super.setPosition(getCurrentPosition() + 1);
return true;
}
}
else {
stack.pop();
if (!stack.isEmpty()){
it = (PropertyIterator)stack.peek();
currentNodePointer = it.getNodePointer();
if (currentNodePointer.testNode(nodeTest)){
super.setPosition(getCurrentPosition() + 1);
return true;
}
}
}
}
}
}
return false;
}
/**
* If the pointer is auxiliary, return the parent; otherwise - the pointer itself
*/
private NodePointer getMaterialPointer(NodePointer pointer){
while (pointer != null && !pointer.isNode()){
pointer = pointer.getParent();
}
return pointer;
}
}