- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * 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.
- */
- /*
- * $Id: DTMNodeIterator.java,v 1.9 2004/02/16 23:06:11 minchau Exp $
- */
- package com.sun.org.apache.xml.internal.dtm.ref;
-
- import com.sun.org.apache.xml.internal.dtm.DTM;
- import com.sun.org.apache.xml.internal.dtm.DTMDOMException;
- import com.sun.org.apache.xml.internal.dtm.DTMIterator;
-
- import org.w3c.dom.DOMException;
- import org.w3c.dom.Node;
- import org.w3c.dom.traversal.NodeFilter;
-
- /**
- * <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 com.sun.org.apache.xml.internal.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.
- *
- * @throws 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==DTM.NULL)
- 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.
- *
- * @throws 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();
- if (handle==DTM.NULL)
- return null;
- return dtm_iter.getDTM(handle).getNode(handle);
- }
- }