/*
* Copyright (c) 2002-2010 Gargoyle Software Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.gargoylesoftware.htmlunit.html.xpath;
import javax.xml.transform.TransformerException;
import org.apache.xml.dtm.DTM;
import org.apache.xml.utils.IntStack;
import org.apache.xpath.XPathContext;
import org.apache.xpath.functions.FunctionDef1Arg;
import org.apache.xpath.objects.XBoolean;
import org.apache.xpath.objects.XObject;
import org.w3c.dom.Node;
import com.gargoylesoftware.htmlunit.html.HtmlForm;
/**
* An XPath function which returns <tt>true</tt> if the current node is a descendant of the node used as the
* initial XPath context. In addition, if the node used as the initial XPath context was an {@link HtmlForm}
* instance, this function considers {@link HtmlForm#getLostChildren() lost children} to be descendants of the
* form, even if they aren't really descendants from a DOM point of view.
*
* @version $Revision: 5301 $
* @author Daniel Gredler
*/
public class IsDescendantOfContextualFormFunction extends FunctionDef1Arg {
/** Serial version UID. */
private static final long serialVersionUID = -7865865499040147609L;
/**
* {@inheritDoc}
*/
@Override
public XObject execute(final XPathContext ctx) throws TransformerException {
boolean descendant = false;
final int possibleAncestor;
final IntStack nodeStack = ctx.getCurrentNodeStack();
if (nodeStack.size() > 1) {
possibleAncestor = nodeStack.elementAt(1);
}
else {
possibleAncestor = DTM.NULL;
}
if (DTM.NULL != possibleAncestor) {
final int currentNode = ctx.getContextNode();
final DTM dtm = ctx.getDTM(currentNode);
for (int ancestor = dtm.getParent(currentNode); ancestor != DTM.NULL; ancestor = dtm.getParent(ancestor)) {
if (ancestor == possibleAncestor) {
descendant = true;
break;
}
}
if (!descendant) {
final Node n = dtm.getNode(possibleAncestor);
if (n instanceof HtmlForm) {
final HtmlForm f = (HtmlForm) n;
descendant = f.getLostChildren().contains(dtm.getNode(currentNode));
}
}
}
return new XBoolean(descendant);
}
}