/*
 * 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 org.apache.lucene.spatial.prefix;

import java.util.Iterator;

import org.apache.lucene.spatial.prefix.tree.Cell;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.BytesRefIterator;

A reset'able BytesRefIterator wrapper around an Iterator of Cells. 
See Also:
PrefixTreeStrategy.newCellToBytesRefIterator()
@lucene.internal
/**
 * A reset'able {@link org.apache.lucene.util.BytesRefIterator} wrapper around
 * an {@link java.util.Iterator} of {@link org.apache.lucene.spatial.prefix.tree.Cell}s.
 *
 * @see PrefixTreeStrategy#newCellToBytesRefIterator()
 *
 * @lucene.internal
 */
public class CellToBytesRefIterator implements BytesRefIterator {

  protected Iterator<Cell> cellIter;
  protected BytesRef bytesRef = new BytesRef();

  public void reset(Iterator<Cell> cellIter) {
    this.cellIter = cellIter;
  }

  @Override
  public BytesRef next() {
    if (!cellIter.hasNext()) {
      return null;
    }
    return cellIter.next().getTokenBytesWithLeaf(bytesRef);
  }
}