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 */
017
018package org.apache.commons.jxpath.ri.axes;
019
020import org.apache.commons.jxpath.ri.EvalContext;
021import org.apache.commons.jxpath.ri.compiler.NodeTest;
022import org.apache.commons.jxpath.ri.model.NodePointer;
023
024/**
025 * EvalContext that walks the "parent::" axis.
026 */
027public class ParentContext extends EvalContext {
028
029    private final NodeTest nodeTest;
030    private boolean setStarted;
031    private NodePointer currentNodePointer;
032
033    /**
034     * Constructs a new ParentContext.
035     *
036     * @param parentContext parent context
037     * @param nodeTest      test
038     */
039    public ParentContext(final EvalContext parentContext, final NodeTest nodeTest) {
040        super(parentContext);
041        this.nodeTest = nodeTest;
042    }
043
044    @Override
045    public NodePointer getCurrentNodePointer() {
046        return currentNodePointer;
047    }
048
049    @Override
050    public int getCurrentPosition() {
051        return 1;
052    }
053
054    @Override
055    public int getDocumentOrder() {
056        return -1;
057    }
058
059    @Override
060    public boolean nextNode() {
061        // Each set contains exactly one node: the parent
062        if (setStarted) {
063            return false;
064        }
065        setStarted = true;
066        final NodePointer thisLocation = parentContext.getCurrentNodePointer();
067        currentNodePointer = thisLocation.getImmediateParentPointer();
068        while (currentNodePointer != null && currentNodePointer.isContainer()) {
069            currentNodePointer = currentNodePointer.getImmediateParentPointer();
070        }
071        if (currentNodePointer != null && currentNodePointer.testNode(nodeTest)) {
072            position++;
073            return true;
074        }
075        return false;
076    }
077
078    @Override
079    public void reset() {
080        super.reset();
081        setStarted = false;
082    }
083
084    @Override
085    public boolean setPosition(final int position) {
086        super.setPosition(position);
087        return position == 1;
088    }
089}