/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/*
* $Id: DTMNodeList.java 468653 2006-10-28 07:07:05Z minchau $
*/
package org.apache.xml.dtm.ref;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMIterator;
import org.w3c.dom.Node;
/**
* DTMNodeList
gives us an implementation of the DOM's
* NodeList interface wrapped around a DTM Iterator. The author
* considers this something of an abominations, since NodeList was not
* intended to be a general purpose "list of nodes" API and is
* generally considered by the DOM WG to have be a mistake... but I'm
* told that some of the XPath/XSLT folks say they must have this
* solution.
*
* Please note that this is not necessarily equivlaent to a DOM
* NodeList operating over the same document. In particular:
*
State: In progress!!
* */ public class DTMNodeList extends DTMNodeListBase { private DTMIterator m_iter; //================================================================ // Methods unique to this class private DTMNodeList() { } /** * Public constructor: Wrap a DTMNodeList around an existing * and preconfigured DTMIterator * * WARNING: THIS HAS THE SIDE EFFECT OF ISSUING setShouldCacheNodes(true) * AGAINST THE DTMIterator. * */ public DTMNodeList(DTMIterator dtmIterator) { if (dtmIterator != null) { int pos = dtmIterator.getCurrentPos(); try { m_iter=(DTMIterator)dtmIterator.cloneWithReset(); } catch(CloneNotSupportedException cnse) { m_iter = dtmIterator; } m_iter.setShouldCacheNodes(true); m_iter.runTo(-1); m_iter.setCurrentPos(pos); } } /** * Access the wrapped DTMIterator. I'm not sure whether anyone will * need this or not, but let's write it and think about it. * */ public DTMIterator getDTMIterator() { return m_iter; } //================================================================ // org.w3c.dom.NodeList API follows /** * Returns theindex
th item in the collection. If
* index
is greater than or equal to the number of nodes in
* the list, this returns null
.
* @param index Index into the collection.
* @return The node at the index
th position in the
* NodeList
, or null
if that is not a valid
* index.
*/
public Node item(int index)
{
if (m_iter != null) {
int handle=m_iter.item(index);
if (handle == DTM.NULL) {
return null;
}
return m_iter.getDTM(handle).getNode(handle);
} else {
return null;
}
}
/**
* The number of nodes in the list. The range of valid child node indices
* is 0 to length-1
inclusive.
*/
public int getLength() {
return (m_iter != null) ? m_iter.getLength() : 0;
}
}