    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.Compiler;
    021import org.apache.commons.jxpath.ri.EvalContext;
    022import org.apache.commons.jxpath.ri.QName;
    023import org.apache.commons.jxpath.ri.compiler.NodeNameTest;
    024import org.apache.commons.jxpath.ri.compiler.NodeTest;
    025import org.apache.commons.jxpath.ri.compiler.NodeTypeTest;
    026import org.apache.commons.jxpath.ri.model.NodeIterator;
    027import org.apache.commons.jxpath.ri.model.NodePointer;
    028
    029/**
    030 * EvalContext that walks the "attribute::" axis.
    031 */
    032public class AttributeContext extends EvalContext {
    033
    034    private static final QName WILDCARD = new QName(null, "*");
    035    private final NodeTest nodeTest;
    036    private boolean setStarted;
    037    private NodeIterator iterator;
    038    private NodePointer currentNodePointer;
    039
    040    /**
    041     * Constructs a new AttributeContext.
    042     *
    043     * @param parentContext represents the previous step on the path
    044     * @param nodeTest      is the name of the attribute we are looking for
    045     */
    046    public AttributeContext(final EvalContext parentContext, final NodeTest nodeTest) {
    047        super(parentContext);
    048        this.nodeTest = nodeTest;
    049    }
    050
    051    @Override
    052    public NodePointer getCurrentNodePointer() {
    053        return currentNodePointer;
    054    }
    055
    056    @Override
    057    public boolean nextNode() {
    058        super.setPosition(getCurrentPosition() + 1);
    059        if (!setStarted) {
    060            setStarted = true;
    061            QName qName;
    062            if (nodeTest instanceof NodeNameTest) {
    063                qName = ((NodeNameTest) nodeTest).getNodeName();
    064            } else if (nodeTest instanceof NodeTypeTest && ((NodeTypeTest) nodeTest).getNodeType() == Compiler.NODE_TYPE_NODE) {
    065                qName = WILDCARD;
    066            } else {
    067                iterator = null;
    068                return false;
    069            }
    070            iterator = parentContext.getCurrentNodePointer().attributeIterator(qName);
    071        }
    072        if (iterator == null) {
    073            return false;
    074        }
    075        if (!iterator.setPosition(iterator.getPosition() + 1)) {
    076            return false;
    077        }
    078        currentNodePointer = iterator.getNodePointer();
    079        return true;
    080    }
    081
    082    @Override
    083    public void reset() {
    084        setStarted = false;
    085        iterator = null;
    086        super.reset();
    087    }
    088
    089    @Override
    090    public boolean setPosition(final int position) {
    091        if (position < getCurrentPosition()) {
    092            reset();
    093        }
    094        while (getCurrentPosition() < position) {
    095            if (!nextNode()) {
    096                return false;
    097            }
    098        }
    099        return true;
    100    }
    101}