/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.sun.org.apache.xalan.internal.xsltc.dom;

import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;

import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;

import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;

/**

 * This iterator is a wrapper that always returns the position of

 * a node in document order. It is needed for the case where

 * a call to position() occurs in the context of an XSLT element

 * such as xsl:for-each, xsl:apply-templates, etc.

 *

 * The getPosition() methods in DTMAxisIterators defined

 * in DTMDefaultBaseIterators always return the position

 * in document order, which is backwards for XPath in the

 * case of the ancestor, ancestor-or-self, previous and

 * previous-sibling.

 *

 * XSLTC implements position() with the

 * BasisLibrary.positionF() method, and uses the

 * DTMAxisIterator.isReverse() method to determine

 * whether the result of getPosition() should be

 * interpreted as being equal to position().

 * But when the expression appears in apply-templates of

 * for-each, the position() function operates in document

 * order.

 *

 * The only effect of the ForwardPositionIterator is to force

 * the result of isReverse() to false, so that

 * BasisLibrary.positionF() calculates position() in a way

 * that's consistent with the context in which the

 * iterator is being used."

 *

 * (Apparently the correction of isReverse() occurs

 * implicitly, by inheritance. This class also appears

 * to maintain its own position counter, which seems

 * redundant.)

 *

 * @deprecated This class exists only for backwards compatibility with old

 *             translets.  New code should not reference it.

 */

@Deprecated

public final class ForwardPositionIterator extends DTMAxisIteratorBase {

    private DTMAxisIterator _source;

    public ForwardPositionIterator(DTMAxisIterator source) {

        _source = source;

    }

    public DTMAxisIterator cloneIterator() {

        try {

            final ForwardPositionIterator clone =

                (ForwardPositionIterator) super.clone();

            clone._source = _source.cloneIterator();

            clone._isRestartable = false;

            return clone.reset();

        }

        catch (CloneNotSupportedException e) {

            BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,

                                      e.toString());

            return null;

        }

    }

    public int next() {

        return returnNode(_source.next());

    }

    public DTMAxisIterator setStartNode(int node) {

        _source.setStartNode(node);

        return this;

    }

    public DTMAxisIterator reset() {

        _source.reset();

        return resetPosition();

    }

    public void setMark() {

        _source.setMark();

    }

    public void gotoMark() {

        _source.gotoMark();

    }

}