    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.Pointer;
    021import org.apache.commons.jxpath.ri.EvalContext;
    022import org.apache.commons.jxpath.ri.model.NodePointer;
    023
    024/**
    025 * A single-set EvalContext that provides access to the current node of the parent context and nothing else. It does not pass the iteration on to the parent
    026 * context.
    027 */
    028public class InitialContext extends EvalContext {
    029
    030    private boolean started;
    031    private boolean collection;
    032    private final NodePointer nodePointer;
    033
    034    /**
    035     * Constructs a new InitialContext.
    036     *
    037     * @param parentContext parent context
    038     */
    039    public InitialContext(final EvalContext parentContext) {
    040        super(parentContext);
    041        nodePointer = (NodePointer) parentContext.getCurrentNodePointer().clone();
    042        if (nodePointer != null) {
    043            collection = nodePointer.getIndex() == NodePointer.WHOLE_COLLECTION;
    044        }
    045    }
    046
    047    @Override
    048    public NodePointer getCurrentNodePointer() {
    049        return nodePointer;
    050    }
    051
    052    @Override
    053    public Pointer getSingleNodePointer() {
    054        return nodePointer;
    055    }
    056
    057    @Override
    058    public Object getValue() {
    059        return nodePointer.getValue();
    060    }
    061
    062    @Override
    063    public boolean nextNode() {
    064        return setPosition(position + 1);
    065    }
    066
    067    @Override
    068    public boolean nextSet() {
    069        if (started) {
    070            return false;
    071        }
    072        started = true;
    073        return true;
    074    }
    075
    076    @Override
    077    public boolean setPosition(final int position) {
    078        this.position = position;
    079        if (collection) {
    080            if (position >= 1 && position <= nodePointer.getLength()) {
    081                nodePointer.setIndex(position - 1);
    082                return true;
    083            }
    084            return false;
    085        }
    086        return position == 1;
    087    }
    088}