http://lucene.apache.org/lucene-parent/lucene-spatial-extras: Advanced Spatial Shape Strategies for Apache Lucene (The Apache Software Foundation) 
/*
 * 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;

import java.io.IOException;

import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.SegmentCacheable;


Produces ShapeValues per-segment 
/**
 * Produces {@link ShapeValues} per-segment
 */
public abstract class ShapeValuesSource implements SegmentCacheable {

  
Get a ShapeValues instance for the given leaf reader context 
/**
   * Get a {@link ShapeValues} instance for the given leaf reader context
   */
  public abstract ShapeValues getValues(LeafReaderContext ctx) throws IOException;

}