    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.ri.EvalContext;
    020    import org.apache.commons.jxpath.ri.compiler.NodeTest;
    021    import 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 12:46:46 -0500 (Fri, 02 May 2008) $
    028     */
    029    public 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    }