/*
* 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 org.apache.commons.jxpath.ri.model.dom;
import org.apache.commons.jxpath.ri.compiler.NodeTest;
import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.w3c.dom.Node;
/**
* An iterator of children of a DOM Node.
*
* @author Dmitri Plotnikov
* @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
*/
public class DOMNodeIterator implements NodeIterator {
private NodePointer parent;
private NodeTest nodeTest;
private Node node;
private Node child = null;
private boolean reverse;
private int position = 0;
/**
* Create a new DOMNodeIterator.
* @param parent parent pointer
* @param nodeTest test
* @param reverse whether to iterate in reverse
* @param startWith starting pointer
*/
public DOMNodeIterator(
NodePointer parent,
NodeTest nodeTest,
boolean reverse,
NodePointer startWith) {
this.parent = parent;
this.node = (Node) parent.getNode();
if (startWith != null) {
this.child = (Node) startWith.getNode();
}
this.nodeTest = nodeTest;
this.reverse = reverse;
}
public NodePointer getNodePointer() {
if (position == 0) {
setPosition(1);
}
return child == null ? null : new DOMNodePointer(parent, child);
}
public int getPosition() {
return position;
}
public boolean setPosition(int position) {
while (this.position < position) {
if (!next()) {
return false;
}
}
while (this.position > position) {
if (!previous()) {
return false;
}
}
return true;
}
/**
* Set the previous position.
* @return whether valid
*/
private boolean previous() {
position--;
if (!reverse) {
if (position == 0) {
child = null;
}
else if (child == null) {
child = node.getLastChild();
}
else {
child = child.getPreviousSibling();
}
while (child != null && !testChild()) {
child = child.getPreviousSibling();
}
}
else {
child = child.getNextSibling();
while (child != null && !testChild()) {
child = child.getNextSibling();
}
}
return child != null;
}
/**
* Set the next position.
* @return whether valid
*/
private boolean next() {
position++;
if (!reverse) {
if (position == 1) {
if (child == null) {
child = node.getFirstChild();
}
else {
child = child.getNextSibling();
}
}
else {
child = child.getNextSibling();
}
while (child != null && !testChild()) {
child = child.getNextSibling();
}
}
else {
if (position == 1) {
if (child == null) {
child = node.getLastChild();
}
else {
child = child.getPreviousSibling();
}
}
else {
child = child.getPreviousSibling();
}
while (child != null && !testChild()) {
child = child.getPreviousSibling();
}
}
return child != null;
}
/**
* Test child.
* @return result of the test
*/
private boolean testChild() {
return DOMNodePointer.testNode(child, nodeTest);
}
}
|