- /*
- * 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.
- */
- package org.apache.commons.jxpath.ri.model.jdom;
-
- import java.util.Collections;
- import java.util.List;
-
- 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.jdom.Document;
- import org.jdom.Element;
-
- /**
- * An iterator of children of a JDOM Node.
- *
- * @author Dmitri Plotnikov
- * @version $Revision: 1.6 $ $Date: 2004/02/29 14:17:40 $
- */
- public class JDOMNodeIterator implements NodeIterator {
- private NodePointer parent;
- private NodeTest nodeTest;
-
- private boolean reverse;
- private int position = 0;
- private int index = 0;
- private List children;
- private Object child;
-
- public JDOMNodeIterator(
- NodePointer parent, NodeTest nodeTest,
- boolean reverse, NodePointer startWith)
- {
- this.parent = parent;
- if (startWith != null) {
- this.child = startWith.getNode();
- }
- // TBD: optimize me for different node tests
- Object node = parent.getNode();
- if (node instanceof Document) {
- this.children = ((Document) node).getContent();
- }
- else if (node instanceof Element) {
- this.children = ((Element) node).getContent();
- }
- else {
- this.children = Collections.EMPTY_LIST;
- }
- this.nodeTest = nodeTest;
- this.reverse = reverse;
- }
-
- public NodePointer getNodePointer() {
- if (child == null) {
- if (!setPosition(1)) {
- return null;
- }
- position = 0;
- }
-
- return new JDOMNodePointer(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;
- }
-
- /**
- * This is actually never invoked during the normal evaluation
- * of xpaths - an iterator is always going forward, never backwards.
- * So, this is implemented only for completeness and perhaps for
- * those who use these iterators outside of XPath evaluation.
- */
- private boolean previous() {
- position--;
- if (!reverse) {
- while (--index >= 0) {
- child = children.get(index);
- if (testChild()) {
- return true;
- }
- }
- }
- else {
- for (; index < children.size(); index++) {
- child = children.get(index);
- if (testChild()) {
- return true;
- }
- }
- }
- return false;
- }
-
- private boolean next() {
- position++;
- if (!reverse) {
- if (position == 1) {
- index = 0;
- if (child != null) {
- index = children.indexOf(child) + 1;
- }
- }
- else {
- index++;
- }
- for (; index < children.size(); index++) {
- child = children.get(index);
- if (testChild()) {
- return true;
- }
- }
- return false;
- }
- else {
- if (position == 1) {
- index = children.size() - 1;
- if (child != null) {
- index = children.indexOf(child) - 1;
- }
- }
- else {
- index--;
- }
- for (; index >= 0; index--) {
- child = children.get(index);
- if (testChild()) {
- return true;
- }
- }
- return false;
- }
- }
-
- private boolean testChild() {
- return JDOMNodePointer.testNode(parent, child, nodeTest);
- }
- }