KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > jxpath > ri > axes > ParentContext


1 /*
2  * Copyright 1999-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.jxpath.ri.axes;
17
18 import org.apache.commons.jxpath.ri.EvalContext;
19 import org.apache.commons.jxpath.ri.compiler.NodeTest;
20 import org.apache.commons.jxpath.ri.model.NodePointer;
21
22 /**
23  * EvalContext that walks the "parent::" axis.
24  *
25  * @author Dmitri Plotnikov
26  * @version $Revision: 1.15 $ $Date: 2004/03/25 03:49:50 $
27  */
28 public class ParentContext extends EvalContext {
29     private NodeTest nodeTest;
30     private boolean setStarted = false;
31     private NodePointer currentNodePointer;
32
33     public ParentContext(EvalContext parentContext, NodeTest nodeTest) {
34         super(parentContext);
35         this.nodeTest = nodeTest;
36     }
37
38     public NodePointer getCurrentNodePointer() {
39         return currentNodePointer;
40     }
41
42     public int getCurrentPosition() {
43         return 1;
44     }
45
46     public int getDocumentOrder() {
47         return -1;
48     }
49
50     public void reset() {
51         super.reset();
52         setStarted = false;
53     }
54
55     public boolean setPosition(int position) {
56         super.setPosition(position);
57         return position == 1;
58     }
59
60     public boolean nextNode() {
61         // Each set contains exactly one node: the parent
62 if (setStarted) {
63             return false;
64         }
65         setStarted = true;
66         NodePointer thisLocation = parentContext.getCurrentNodePointer();
67         currentNodePointer = thisLocation.getImmediateParentPointer();
68         while (currentNodePointer != null
69             && currentNodePointer.isContainer()) {
70             currentNodePointer = currentNodePointer.getImmediateParentPointer();
71         }
72         if (currentNodePointer != null
73             && currentNodePointer.testNode(nodeTest)) {
74             position++;
75             return true;
76         }
77         return false;
78     }
79 }
Popular Tags