/*
* 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.*;
import org.w3c.dom.Node;
import org.w3c.dom.DOMException;
import org.w3c.dom.traversal.*;
/**
* <code>DTMNodeIterator</code> gives us an implementation of the
* DTMNodeIterator which returns DOM nodes.
*
* Please note that this is not necessarily equivlaent to a DOM
* NodeIterator operating over the same document. In particular:
* <ul>
*
* <li>If there are several Text nodes in logical succession (ie,
* across CDATASection and EntityReference boundaries), we will return
* only the first; the caller is responsible for stepping through
* them.
* (%REVIEW% Provide a convenience routine here to assist, pending
* proposed DOM Level 3 getAdjacentText() operation?) </li>
*
* <li>Since the whole XPath/XSLT architecture assumes that the source
* document is not altered while we're working with it, we do not
* promise to implement the DOM NodeIterator's "maintain current
* position" response to document mutation. </li>
*
* <li>Since our design for XPath NodeIterators builds a stateful
* filter directly into the traversal object, getNodeFilter() is not
* supported.</li>
*
* </ul>
*
* <p>State: In progress!!</p>
* */
public class DTMNodeIterator implements org.w3c.dom.traversal.NodeIterator
{
private DTMIterator dtm_iter;
private boolean valid=true;
//================================================================
// Methods unique to this class
/** Public constructor: Wrap a DTMNodeIterator around an existing
* and preconfigured DTMIterator
* */
public DTMNodeIterator(DTMIterator dtmIterator)
{
try
{
dtm_iter=(DTMIterator)dtmIterator.clone();
}
catch(CloneNotSupportedException cnse)
{
throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
}
}
/** 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 dtm_iter;
}
//================================================================
// org.w3c.dom.traversal.NodeFilter API follows
/** Detaches the NodeIterator from the set which it iterated over,
* releasing any computational resources and placing the iterator in
* the INVALID state.
* */
public void detach()
{
// Theoretically, we could release dtm_iter at this point. But
// some of the operations may still want to consult it even though
// navigation is now invalid.
valid=false;
}
/** The value of this flag determines whether the children
* of entity reference nodes are visible to the iterator.
*
* @return false, always (the DTM model flattens entity references)
* */
public boolean getExpandEntityReferences()
{
return false;
}
/** Return a handle to the filter used to screen nodes.
*
* This is ill-defined in Xalan's usage of Nodeiterator, where we have
* built stateful XPath-based filtering directly into the traversal
* object. We could return something which supports the NodeFilter interface
* and allows querying whether a given node would be permitted if it appeared
* as our next node, but in the current implementation that would be very
* complex -- and just isn't all that useful.
*
* @throws DOMException -- NOT_SUPPORTED_ERROR because I can't think
* of anything more useful to do in this case
* */
public NodeFilter getFilter()
{
throw new DTMDOMException(DOMException.NOT_SUPPORTED_ERR);
}
/** @return The root node of the NodeIterator, as specified
* when it was created.
* */
public Node getRoot()
{
int handle=dtm_iter.getRoot();
return dtm_iter.getDTM(handle).getNode(handle);
}
/** Return a mask describing which node types are presented via the
* iterator.
**/
public int getWhatToShow()
{
return dtm_iter.getWhatToShow();
}
/** @return the next node in the set and advance the position of the
* iterator in the set.
*
* @throw DOMException - INVALID_STATE_ERR Raised if this method is
* called after the detach method was invoked.
* */
public Node nextNode() throws DOMException
{
if(!valid)
throw new DTMDOMException(DOMException.INVALID_STATE_ERR);
int handle=dtm_iter.nextNode();
if (handle==-1)
return null;
return dtm_iter.getDTM(handle).getNode(handle);
}
/** @return the next previous in the set and advance the position of the
* iterator in the set.
*
* @throw DOMException - INVALID_STATE_ERR Raised if this method is
* called after the detach method was invoked.
* */
public Node previousNode()
{
if(!valid)
throw new DTMDOMException(DOMException.INVALID_STATE_ERR);
int handle=dtm_iter.previousNode();
return dtm_iter.getDTM(handle).getNode(handle);
}
}