- /*
- * 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.axes;
-
- import java.util.Stack;
-
- import org.apache.commons.jxpath.ri.EvalContext;
- 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.apache.commons.jxpath.ri.model.beans.PropertyIterator;
-
- /**
- * EvalContext that walks the "preceding::" and "following::" axes.
- *
- * @author Dmitri Plotnikov
- * @version $Revision: 1.15 $ $Date: 2004/03/25 03:49:50 $
- */
- public class PrecedingOrFollowingContext extends EvalContext {
- private NodeTest nodeTest;
- private boolean setStarted = false;
- private boolean started = false;
- private Stack stack;
- private Stack nameStack;
- private NodePointer currentNodePointer;
- private NodePointer currentRootLocation;
- private boolean reverse;
-
- public PrecedingOrFollowingContext(
- EvalContext parentContext,
- NodeTest nodeTest,
- boolean reverse)
- {
- super(parentContext);
- this.nodeTest = nodeTest;
- this.reverse = reverse;
- }
-
- public NodePointer getCurrentNodePointer() {
- return currentNodePointer;
- }
-
- public int getDocumentOrder() {
- return reverse ? -1 : 1;
- }
-
- public void reset() {
- super.reset();
- stack = new Stack();
- setStarted = false;
- }
-
- public boolean setPosition(int position) {
- if (position < this.position) {
- reset();
- }
-
- while (this.position < position) {
- if (!nextNode()) {
- return false;
- }
- }
- return true;
- }
-
- public boolean nextNode() {
- if (!setStarted) {
- setStarted = true;
- currentRootLocation = parentContext.getCurrentNodePointer();
- NodePointer parent = currentRootLocation.getParent();
- if (parent != null) {
- // TBD: check type
- stack.push(
- parent.childIterator(null, reverse, currentRootLocation));
- }
- }
-
- while (true) {
- if (stack.isEmpty()) {
- currentRootLocation = currentRootLocation.getParent();
-
- if (currentRootLocation == null
- || currentRootLocation.isRoot()) {
- break;
- }
-
- NodePointer parent = currentRootLocation.getParent();
- if (parent != null) {
- stack.push(
- parent.childIterator(
- null,
- reverse,
- currentRootLocation));
- }
- }
-
- while (!stack.isEmpty()) {
- if (!reverse) {
- NodeIterator it = (NodeIterator) stack.peek();
- if (it.setPosition(it.getPosition() + 1)) {
- currentNodePointer = it.getNodePointer();
- if (!currentNodePointer.isLeaf()) {
- stack.push(
- currentNodePointer.childIterator(
- null,
- reverse,
- null));
- }
- if (currentNodePointer.testNode(nodeTest)) {
- super.setPosition(getCurrentPosition() + 1);
- return true;
- }
- }
- else {
- // We get here only if the name test failed
- // and the iterator ended
- stack.pop();
- }
- }
- else {
- NodeIterator it = (NodeIterator) stack.peek();
- if (it.setPosition(it.getPosition() + 1)) {
- currentNodePointer = it.getNodePointer();
- if (!currentNodePointer.isLeaf()) {
- stack.push(
- currentNodePointer.childIterator(
- null,
- reverse,
- null));
- }
- else if (currentNodePointer.testNode(nodeTest)) {
- super.setPosition(getCurrentPosition() + 1);
- return true;
- }
- }
- else {
- stack.pop();
- if (!stack.isEmpty()) {
- it = (PropertyIterator) stack.peek();
- currentNodePointer = it.getNodePointer();
- if (currentNodePointer.testNode(nodeTest)) {
- super.setPosition(getCurrentPosition() + 1);
- return true;
- }
- }
- }
- }
- }
- }
- return false;
- }
- }