Lucene.Net  3.0.3
Lucene.Net is a port of the Lucene search engine library, written in C# and targeted at .NET runtime users.
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PointPrefixTreeFieldCacheProvider.cs
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2  * Licensed to the Apache Software Foundation (ASF) under one or more
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9  * http://www.apache.org/licenses/LICENSE-2.0
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17 
18 using System;
19 using Lucene.Net.Index;
20 using Lucene.Net.Spatial.Prefix.Tree;
21 using Lucene.Net.Spatial.Util;
22 using Spatial4n.Core.Shapes;
23 
24 namespace Lucene.Net.Spatial.Prefix
25 {
26  /// <summary>
27  /// Implementation of {@link ShapeFieldCacheProvider} designed for {@link PrefixTreeStrategy}s.
28  ///
29  /// Note, due to the fragmented representation of Shapes in these Strategies, this implementation
30  /// can only retrieve the central {@link Point} of the original Shapes.
31  /// </summary>
32  public class PointPrefixTreeFieldCacheProvider : ShapeFieldCacheProvider<Point>
33  {
34  readonly SpatialPrefixTree grid; //
35 
36  public PointPrefixTreeFieldCacheProvider(SpatialPrefixTree grid, String shapeField, int defaultSize)
37  : base(shapeField, defaultSize)
38  {
39  this.grid = grid;
40  }
41 
42  //A kluge that this is a field
43  private Node scanCell = null;
44 
45  protected override Point ReadShape(Term term)
46  {
47  scanCell = grid.GetNode(term.Text, scanCell);
48  return scanCell.IsLeaf() ? scanCell.GetShape().GetCenter() : null;
49  }
50  }
51 }