/*
 * 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./**
 * 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();
    }
}