    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    package org.apache.commons.jxpath.ri.axes;
    018
    019    import org.apache.commons.jxpath.Pointer;
    020    import org.apache.commons.jxpath.ri.EvalContext;
    021    import org.apache.commons.jxpath.ri.model.NodePointer;
    022
    023    /**
    024     * A single-set EvalContext that provides access to the current node of
    025     * the parent context and nothing else.  It does not pass the iteration
    026     * on to the parent context.
    027     *
    028     * @author Dmitri Plotnikov
    029     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
    030     */
    031    public class InitialContext extends EvalContext {
    032        private boolean started = false;
    033        private boolean collection;
    034        private NodePointer nodePointer;
    035
    036        /**
    037         * Create a new InitialContext.
    038         * @param parentContext parent context
    039         */
    040        public InitialContext(EvalContext parentContext) {
    041            super(parentContext);
    042            nodePointer =
    043                (NodePointer) parentContext.getCurrentNodePointer().clone();
    044            if (nodePointer != null) {
    045                collection =
    046                    (nodePointer.getIndex() == NodePointer.WHOLE_COLLECTION);
    047            }
    048        }
    049
    050        public Pointer getSingleNodePointer() {
    051            return nodePointer;
    052        }
    053
    054        public NodePointer getCurrentNodePointer() {
    055            return nodePointer;
    056        }
    057
    058        public Object getValue() {
    059            return nodePointer.getValue();
    060        }
    061
    062        public boolean nextNode() {
    063            return setPosition(position + 1);
    064        }
    065
    066        public boolean setPosition(int position) {
    067            this.position = position;
    068            if (collection) {
    069                if (position >= 1 && position <= nodePointer.getLength()) {
    070                    nodePointer.setIndex(position - 1);
    071                    return true;
    072                }
    073                return false;
    074            }
    075            return position == 1;
    076        }
    077
    078        public boolean nextSet() {
    079            if (started) {
    080                return false;
    081            }
    082            started = true;
    083            return true;
    084        }
    085    }