1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.jxpath.ri.axes;
18
19 import org.apache.commons.jxpath.ri.EvalContext;
20 import org.apache.commons.jxpath.ri.compiler.NodeTest;
21 import org.apache.commons.jxpath.ri.model.NodePointer;
22
23 /**
24 * EvalContext that walks the "ancestor::" and "ancestor-or-self::" axes.
25 *
26 * @author Dmitri Plotnikov
27 * @version $Revision: 652845 $ $Date: 2008-05-02 19:46:46 +0200 (Fr, 02 Mai 2008) $
28 */
29 public class AncestorContext extends EvalContext {
30 private NodeTest nodeTest;
31 private boolean setStarted = false;
32 private NodePointer currentNodePointer;
33 private boolean includeSelf;
34
35 /**
36 * Create a new AncestorContext.
37 * @param parentContext represents the previous step on the path
38 * @param includeSelf differentiates between "ancestor::" and
39 * "ancestor-or-self::" axes
40 * @param nodeTest is the name of the element(s) we are looking for
41 */
42 public AncestorContext(
43 EvalContext parentContext,
44 boolean includeSelf,
45 NodeTest nodeTest) {
46 super(parentContext);
47 this.includeSelf = includeSelf;
48 this.nodeTest = nodeTest;
49 }
50
51 public NodePointer getCurrentNodePointer() {
52 return currentNodePointer;
53 }
54
55 public int getDocumentOrder() {
56 return -1;
57 }
58
59 public void reset() {
60 super.reset();
61 setStarted = false;
62 }
63
64 public boolean setPosition(int position) {
65 if (position < getCurrentPosition()) {
66 reset();
67 }
68
69 while (getCurrentPosition() < position) {
70 if (!nextNode()) {
71 return false;
72 }
73 }
74 return true;
75 }
76
77 public boolean nextNode() {
78 if (!setStarted) {
79 setStarted = true;
80 currentNodePointer = parentContext.getCurrentNodePointer();
81 if (includeSelf && currentNodePointer.testNode(nodeTest)) {
82 position++;
83 return true;
84 }
85 }
86
87 while (true) {
88 currentNodePointer = currentNodePointer.getImmediateParentPointer();
89
90 if (currentNodePointer == null) {
91 return false;
92 }
93
94 if (currentNodePointer.testNode(nodeTest)) {
95 position++;
96 return true;
97 }
98 }
99 }
100 }