FilterIterator.java

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed 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.
 */
/*
 * $Id: FilterIterator.java,v 1.2.4.1 2005/09/06 06:21:10 pvedula Exp $
 */

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

/**
 * Similar to a CurrentNodeListIterator except that the filter has a
 * simpler interface (only needs the node, no position, last, etc.)
 * It takes a source iterator and a Filter object and returns nodes
 * from the source after filtering them by calling filter.test(node).
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
public final class FilterIterator extends DTMAxisIteratorBase {

    /**
     * Reference to source iterator.
     */
    private DTMAxisIterator _source;

    /**
     * Reference to a filter object that to be applied to each node.
     */
    private final DTMFilter _filter;

    /**
     * A flag indicating if position is reversed.
     */
    private final boolean _isReverse;

    public FilterIterator(DTMAxisIterator source, DTMFilter filter) {
        _source = source;
// System.out.println("FI souce = " + source + " this = " + this);
        _filter = filter;
        _isReverse = source.isReverse();
    }

    public boolean isReverse() {
        return _isReverse;
    }


    public void setRestartable(boolean isRestartable) {
        _isRestartable = isRestartable;
        _source.setRestartable(isRestartable);
    }

    public DTMAxisIterator cloneIterator() {

        try {
            final FilterIterator clone = (FilterIterator) 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 DTMAxisIterator reset() {
        _source.reset();
        return resetPosition();
    }

    public int next() {
        int node;
        while ((node = _source.next()) != END) {
            if (_filter.acceptNode(node, DTMFilter.SHOW_ALL) == DTMIterator.FILTER_ACCEPT) {
                return returnNode(node);
            }
        }
        return END;
    }

    public DTMAxisIterator setStartNode(int node) {
        if (_isRestartable) {
            _source.setStartNode(_startNode = node);
            return resetPosition();
        }
        return this;
    }

    public void setMark() {
        _source.setMark();
    }

    public void gotoMark() {
        _source.gotoMark();
    }

}