/*
* 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.
*/
package mf.org.apache.xerces.dom;
import mf.org.w3c.dom.DOMException;
import mf.org.w3c.dom.Document;
import mf.org.w3c.dom.Node;
import mf.org.w3c.dom.traversal.NodeFilter;
import mf.org.w3c.dom.traversal.TreeWalker;
/**
* This class implements the TreeWalker interface.
*
* @xerces.internal
*
* @version $Id: TreeWalkerImpl.java 536630 2007-05-09 19:37:05Z mrglavas $
*/
public class TreeWalkerImpl implements TreeWalker {
//
// Data
//
/** When TRUE, the children of entites references are returned in the iterator. */
private boolean fEntityReferenceExpansion = false;
/** The whatToShow mask. */
int fWhatToShow = NodeFilter.SHOW_ALL;
/** The NodeFilter reference. */
NodeFilter fNodeFilter;
/** The current Node. */
Node fCurrentNode;
/** The root Node. */
Node fRoot;
/** Use Node.isSameNode() to check if one node is the same as another. */
private boolean fUseIsSameNode;
//
// Implementation Note: No state is kept except the data above
// (fWhatToShow, fNodeFilter, fCurrentNode, fRoot) such that
// setters could be created for these data values and the
// implementation will still work.
//
// Constructor
//
/** Public constructor */
public TreeWalkerImpl(Node root,
int whatToShow,
NodeFilter nodeFilter,
boolean entityReferenceExpansion) {
fCurrentNode = root;
fRoot = root;
fUseIsSameNode = useIsSameNode(root);
fWhatToShow = whatToShow;
fNodeFilter = nodeFilter;
fEntityReferenceExpansion = entityReferenceExpansion;
}
public Node getRoot() {
return fRoot;
}
/** Return the whatToShow value */
public int getWhatToShow() {
return fWhatToShow;
}
public void setWhatShow(int whatToShow){
fWhatToShow = whatToShow;
}
/** Return the NodeFilter */
public NodeFilter getFilter() {
return fNodeFilter;
}
/** Return whether children entity references are included in the iterator. */
public boolean getExpandEntityReferences() {
return fEntityReferenceExpansion;
}
/** Return the current Node. */
public Node getCurrentNode() {
return fCurrentNode;
}
/** Return the current Node. */
public void setCurrentNode(Node node) {
if (node == null) {
String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_SUPPORTED_ERR", null);
throw new DOMException(DOMException.NOT_SUPPORTED_ERR, msg);
}
fCurrentNode = node;
}
/** Return the parent Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node parentNode() {
if (fCurrentNode == null) return null;
Node node = getParentNode(fCurrentNode);
if (node !=null) {
fCurrentNode = node;
}
return node;
}
/** Return the first child Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node firstChild() {
if (fCurrentNode == null) return null;
Node node = getFirstChild(fCurrentNode);
if (node !=null) {
fCurrentNode = node;
}
return node;
}
/** Return the last child Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node lastChild() {
if (fCurrentNode == null) return null;
Node node = getLastChild(fCurrentNode);
if (node !=null) {
fCurrentNode = node;
}
return node;
}
/** Return the previous sibling Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node previousSibling() {
if (fCurrentNode == null) return null;
Node node = getPreviousSibling(fCurrentNode);
if (node !=null) {
fCurrentNode = node;
}
return node;
}
/** Return the next sibling Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node nextSibling(){
if (fCurrentNode == null) return null;
Node node = getNextSibling(fCurrentNode);
if (node !=null) {
fCurrentNode = node;
}
return node;
}
/** Return the previous Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node previousNode() {
Node result;
if (fCurrentNode == null) return null;
// get sibling
result = getPreviousSibling(fCurrentNode);
if (result == null) {
result = getParentNode(fCurrentNode);
if (result != null) {
fCurrentNode = result;
return fCurrentNode;
}
return null;
}
// get the lastChild of result.
Node lastChild = getLastChild(result);
Node prev = lastChild ;
while (lastChild != null) {
prev = lastChild ;
lastChild = getLastChild(prev) ;
}
lastChild = prev ;
// if there is a lastChild which passes filters return it.
if (lastChild != null) {
fCurrentNode = lastChild;
return fCurrentNode;
}
// otherwise return the previous sibling.
if (result != null) {
fCurrentNode = result;
return fCurrentNode;
}
// otherwise return null.
return null;
}
/** Return the next Node from the current node,
* after applying filter, whatToshow.
* If result is not null, set the current Node.
*/
public Node nextNode() {
if (fCurrentNode == null) return null;
Node result = getFirstChild(fCurrentNode);
if (result != null) {
fCurrentNode = result;
return result;
}
result = getNextSibling(fCurrentNode);
if (result != null) {
fCurrentNode = result;
return result;
}
// return parent's 1st sibling.
Node parent = getParentNode(fCurrentNode);
while (parent != null) {
result = getNextSibling(parent);
if (result != null) {
fCurrentNode = result;
return result;
} else {
parent = getParentNode(parent);
}
}
// end , return null
return null;
}
/** Internal function.
* Return the parent Node, from the input node
* after applying filter, whatToshow.
* The current node is not consulted or set.
*/
Node getParentNode(Node node) {
if (node == null || isSameNode(node, fRoot)) return null;
Node newNode = node.getParentNode();
if (newNode == null) return null;
int accept = acceptNode(newNode);
if (accept == NodeFilter.FILTER_ACCEPT)
return newNode;
else
//if (accept == NodeFilter.SKIP_NODE) // and REJECT too.
{
return getParentNode(newNode);
}
}
/** Internal function.
* Return the nextSibling Node, from the input node
* after applying filter, whatToshow.
* The current node is not consulted or set.
*/
Node getNextSibling(Node node) {
return getNextSibling(node, fRoot);
}
/** Internal function.
* Return the nextSibling Node, from the input node
* after applying filter, whatToshow.
* NEVER TRAVERSES ABOVE THE SPECIFIED ROOT NODE.
* The current node is not consulted or set.
*/
Node getNextSibling(Node node, Node root) {
if (node == null || isSameNode(node, root)) return null;
Node newNode = node.getNextSibling();
if (newNode == null) {
newNode = node.getParentNode();
if (newNode == null || isSameNode(newNode, root)) return null;
int parentAccept = acceptNode(newNode);
if (parentAccept==NodeFilter.FILTER_SKIP) {
return getNextSibling(newNode, root);
}
return null;
}
int accept = acceptNode(newNode);
if (accept == NodeFilter.FILTER_ACCEPT)
return newNode;
else
if (accept == NodeFilter.FILTER_SKIP) {
Node fChild = getFirstChild(newNode);
if (fChild == null) {
return getNextSibling(newNode, root);
}
return fChild;
}
else
//if (accept == NodeFilter.REJECT_NODE)
{
return getNextSibling(newNode, root);
}
} // getNextSibling(Node node) {
/** Internal function.
* Return the previous sibling Node, from the input node
* after applying filter, whatToshow.
* The current node is not consulted or set.
*/
Node getPreviousSibling(Node node) {
return getPreviousSibling(node, fRoot);
}
/** Internal function.
* Return the previousSibling Node, from the input node
* after applying filter, whatToshow.
* NEVER TRAVERSES ABOVE THE SPECIFIED ROOT NODE.
* The current node is not consulted or set.
*/
Node getPreviousSibling(Node node, Node root) {
if (node == null || isSameNode(node, root)) return null;
Node newNode = node.getPreviousSibling();
if (newNode == null) {
newNode = node.getParentNode();
if (newNode == null || isSameNode(newNode, root)) return null;
int parentAccept = acceptNode(newNode);
if (parentAccept==NodeFilter.FILTER_SKIP) {
return getPreviousSibling(newNode, root);
}
return null;
}
int accept = acceptNode(newNode);
if (accept == NodeFilter.FILTER_ACCEPT)
return newNode;
else
if (accept == NodeFilter.FILTER_SKIP) {
Node fChild = getLastChild(newNode);
if (fChild == null) {
return getPreviousSibling(newNode, root);
}
return fChild;
}
else
//if (accept == NodeFilter.REJECT_NODE)
{
return getPreviousSibling(newNode, root);
}
} // getPreviousSibling(Node node) {
/** Internal function.
* Return the first child Node, from the input node
* after applying filter, whatToshow.
* The current node is not consulted or set.
*/
Node getFirstChild(Node node) {
if (node == null) return null;
if ( !fEntityReferenceExpansion
&& node.getNodeType() == Node.ENTITY_REFERENCE_NODE)
return null;
Node newNode = node.getFirstChild();
if (newNode == null) return null;
int accept = acceptNode(newNode);
if (accept == NodeFilter.FILTER_ACCEPT)
return newNode;
else
if (accept == NodeFilter.FILTER_SKIP
&& newNode.hasChildNodes())
{
Node fChild = getFirstChild(newNode);
if (fChild == null) {
return getNextSibling(newNode, node);
}
return fChild;
}
else
//if (accept == NodeFilter.REJECT_NODE)
{
return getNextSibling(newNode, node);
}
}
/** Internal function.
* Return the last child Node, from the input node
* after applying filter, whatToshow.
* The current node is not consulted or set.
*/
Node getLastChild(Node node) {
if (node == null) return null;
if ( !fEntityReferenceExpansion
&& node.getNodeType() == Node.ENTITY_REFERENCE_NODE)
return null;
Node newNode = node.getLastChild();
if (newNode == null) return null;
int accept = acceptNode(newNode);
if (accept == NodeFilter.FILTER_ACCEPT)
return newNode;
else
if (accept == NodeFilter.FILTER_SKIP
&& newNode.hasChildNodes())
{
Node lChild = getLastChild(newNode);
if (lChild == null) {
return getPreviousSibling(newNode, node);
}
return lChild;
}
else
//if (accept == NodeFilter.REJECT_NODE)
{
return getPreviousSibling(newNode, node);
}
}
/** Internal function.
* The node whatToShow and the filter are combined into one result. */
short acceptNode(Node node) {
/***
7.1.2.4. Filters and whatToShow flags
Iterator and TreeWalker apply whatToShow flags before applying Filters. If a node is rejected by the
active whatToShow flags, a Filter will not be called to evaluate that node. When a node is rejected by
the active whatToShow flags, children of that node will still be considered, and Filters may be called to
evaluate them.
***/
if (fNodeFilter == null) {
if ( ( fWhatToShow & (1 << node.getNodeType()-1)) != 0) {
return NodeFilter.FILTER_ACCEPT;
} else {
return NodeFilter.FILTER_SKIP;
}
} else {
if ((fWhatToShow & (1 << node.getNodeType()-1)) != 0 ) {
return fNodeFilter.acceptNode(node);
} else {
// What to show has failed. See above excerpt from spec.
// Equivalent to FILTER_SKIP.
return NodeFilter.FILTER_SKIP;
}
}
}
/**
* Use isSameNode() for testing node identity if the DOM implementation
* supports DOM Level 3 core and it isn't the Xerces implementation.
*/
private boolean useIsSameNode(Node node) {
if (node instanceof NodeImpl) {
return false;
}
Document doc = node.getNodeType() == Node.DOCUMENT_NODE
? (Document) node : node.getOwnerDocument();
return (doc != null && doc.getImplementation().hasFeature("Core", "3.0"));
}
/**
* Returns true if <code>m</code> is the same node <code>n</code>.
*/
private boolean isSameNode(Node m, Node n) {
return (fUseIsSameNode) ? m.isSameNode(n) : m == n;
}
}