001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.jxpath.ri.axes;
018
019import org.apache.commons.jxpath.ri.EvalContext;
020import org.apache.commons.jxpath.ri.compiler.NodeTest;
021import org.apache.commons.jxpath.ri.model.NodePointer;
022
023/**
024 * EvalContext that walks the "parent::" axis.
025 *
026 * @author Dmitri Plotnikov
027 * @version $Revision: 652845 $ $Date: 2008-05-02 19:46:46 +0200 (Fr, 02 Mai 2008) $
028 */
029public class ParentContext extends EvalContext {
030    private NodeTest nodeTest;
031    private boolean setStarted = false;
032    private NodePointer currentNodePointer;
033
034    /**
035     * Create a new ParentContext.
036     * @param parentContext parent context
037     * @param nodeTest test
038     */
039    public ParentContext(EvalContext parentContext, NodeTest nodeTest) {
040        super(parentContext);
041        this.nodeTest = nodeTest;
042    }
043
044    public NodePointer getCurrentNodePointer() {
045        return currentNodePointer;
046    }
047
048    public int getCurrentPosition() {
049        return 1;
050    }
051
052    public int getDocumentOrder() {
053        return -1;
054    }
055
056    public void reset() {
057        super.reset();
058        setStarted = false;
059    }
060
061    public boolean setPosition(int position) {
062        super.setPosition(position);
063        return position == 1;
064    }
065
066    public boolean nextNode() {
067        // Each set contains exactly one node: the parent
068        if (setStarted) {
069            return false;
070        }
071        setStarted = true;
072        NodePointer thisLocation = parentContext.getCurrentNodePointer();
073        currentNodePointer = thisLocation.getImmediateParentPointer();
074        while (currentNodePointer != null
075            && currentNodePointer.isContainer()) {
076            currentNodePointer = currentNodePointer.getImmediateParentPointer();
077        }
078        if (currentNodePointer != null
079            && currentNodePointer.testNode(nodeTest)) {
080            position++;
081            return true;
082        }
083        return false;
084    }
085}