/// <summary>
/// Creates a Point using the next token in the stream.
/// </summary>
/// <param name="tokenizer">Tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a <Point Text>.</param>
/// <returns>Returns a Point specified by the next token in
/// the stream.</returns>
/// <remarks>
/// ParseException is thrown if an unexpected token is encountered.
/// </remarks>
private static Point ReadPointText(WktStreamTokenizer tokenizer)
{
Point p = new Point();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(p);
}
p.X = GetNextNumber(tokenizer);
p.Y = GetNextNumber(tokenizer);
GetNextCloser(tokenizer);
return(p);
}
/// <summary>
/// Creates a <see cref="GeometryCollection"/> using the next token in the stream.
/// </summary>
/// <param name="tokenizer"> Tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a GeometryCollection Text.</param>
/// <returns>
/// A <see cref="GeometryCollection"/> specified by the next token in the stream.</returns>
private static GeometryCollection ReadGeometryCollectionText(WktStreamTokenizer tokenizer)
{
GeometryCollection geometries = new GeometryCollection();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken.Equals("EMPTY"))
{
return(geometries);
}
geometries.Collection.Add(ReadGeometryTaggedText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken.Equals(","))
{
geometries.Collection.Add(ReadGeometryTaggedText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(geometries);
}
/// <summary>
/// Creates a Point using the next token in the stream.
/// </summary>
/// <param name="tokenizer">Tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a <Point Text>.</param>
/// <returns>Returns a Point specified by the next token in
/// the stream.</returns>
/// <remarks>
/// ParseException is thrown if an unexpected token is encountered.
/// </remarks>
private static MultiPoint ReadMultiPointText(WktStreamTokenizer tokenizer)
{
MultiPoint mp = new MultiPoint();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(mp);
}
mp.Points.Add(new Point(GetNextNumber(tokenizer), GetNextNumber(tokenizer)));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
mp.Points.Add(new Point(GetNextNumber(tokenizer), GetNextNumber(tokenizer)));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(mp);
}
/// <summary>
/// Creates a <see cref="MultiLineString"/> using the next token in the stream.
/// </summary>
/// <param name="tokenizer">tokenizer over a stream of text in Well-known Text format. The next tokens must form a MultiLineString Text</param>
/// <returns>a <see cref="MultiLineString"/> specified by the next token in the stream</returns>
private static MultiLineString ReadMultiLineStringText(WktStreamTokenizer tokenizer)
{
MultiLineString lines = new MultiLineString();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(lines);
}
lines.LineStrings.Add(ReadLineStringText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
lines.LineStrings.Add(ReadLineStringText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(lines);
}
/// <summary>
/// Creates a Geometry using the next token in the stream.
/// </summary>
/// <param name="tokenizer">Tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a <Geometry Tagged Text>.</param>
/// <returns>Returns a Geometry specified by the next token in the stream.</returns>
/// <remarks>
/// Exception is thrown if the coordinates used to create a Polygon
/// shell and holes do not form closed linestrings, or if an unexpected
/// token is encountered.
/// </remarks>
private static RGeos.Geometries.Geometry ReadGeometryTaggedText(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
string type = tokenizer.GetStringValue().ToUpper();
RGeos.Geometries.Geometry geometry = null;
switch (type)
{
case "POINT":
geometry = ReadPointText(tokenizer);
break;
case "LINESTRING":
geometry = ReadLineStringText(tokenizer);
break;
case "MULTIPOINT":
geometry = ReadMultiPointText(tokenizer);
break;
case "MULTILINESTRING":
geometry = ReadMultiLineStringText(tokenizer);
break;
case "POLYGON":
geometry = ReadPolygonText(tokenizer);
break;
case "MULTIPOLYGON":
geometry = ReadMultiPolygonText(tokenizer);
break;
case "GEOMETRYCOLLECTION":
geometry = ReadGeometryCollectionText(tokenizer);
break;
default:
throw new Exception();
//throw new Exception(String.Format(Map.NumberFormatEnUs, "Geometrytype '{0}' is not supported.",
// type));
}
return(geometry);
}
/// <summary>
/// Creates a Polygon using the next token in the stream.
/// </summary>
/// <param name="tokenizer">Tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a <Polygon Text>.</param>
/// <returns>Returns a Polygon specified by the next token
/// in the stream</returns>
/// <remarks>
/// ParseException is thown if the coordinates used to create the Polygon
/// shell and holes do not form closed linestrings, or if an unexpected
/// token is encountered.
/// </remarks>
private static Polygon ReadPolygonText(WktStreamTokenizer tokenizer)
{
Polygon pol = new Polygon();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(pol);
}
pol.ExteriorRing = new LinearRing(GetCoordinates(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
//Add holes
pol.InteriorRings.Add(new LinearRing(GetCoordinates(tokenizer)));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(pol);
}
/// <summary>
/// Creates a <see cref="MultiPolygon"/> using the next token in the stream.
/// </summary>
/// <param name="tokenizer">tokenizer over a stream of text in Well-known Text
/// format. The next tokens must form a MultiPolygon.</param>
/// <returns>a <code>MultiPolygon</code> specified by the next token in the
/// stream, or if if the coordinates used to create the <see cref="Polygon"/>
/// shells and holes do not form closed linestrings.</returns>
private static MultiPolygon ReadMultiPolygonText(WktStreamTokenizer tokenizer)
{
MultiPolygon polygons = new MultiPolygon();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(polygons);
}
Polygon polygon = ReadPolygonText(tokenizer);
polygons.Polygons.Add(polygon);
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
polygon = ReadPolygonText(tokenizer);
polygons.Polygons.Add(polygon);
nextToken = GetNextCloserOrComma(tokenizer);
}
return(polygons);
}
/// <summary>
/// Converts a Well-known Text representation to a <see cref="RGeos.Geometries.Geometry"/>.
/// </summary>
/// <param name="reader">A Reader which will return a Geometry Tagged Text
/// string (see the OpenGIS Simple Features Specification)</param>
/// <returns>Returns a <see cref="RGeos.Geometries.Geometry"/> read from StreamReader.
/// An exception will be thrown if there is a parsing problem.</returns>
public static RGeos.Geometries.Geometry Parse(TextReader reader)
{
WktStreamTokenizer tokenizer = new WktStreamTokenizer(reader);
return(ReadGeometryTaggedText(tokenizer));
}
/// <summary>
/// Creates a LineString using the next token in the stream.
/// </summary>
/// <param name="tokenizer">Tokenizer over a stream of text in Well-known Text format. The next
/// tokens must form a LineString Text.</param>
/// <returns>Returns a LineString specified by the next token in the stream.</returns>
/// <remarks>
/// ParseException is thrown if an unexpected token is encountered.
/// </remarks>
private static LineString ReadLineStringText(WktStreamTokenizer tokenizer)
{
return(new LineString(GetCoordinates(tokenizer)));
}
/// <summary>
/// Returns the next number in the stream.
/// </summary>
/// <param name="tokenizer">Tokenizer over a stream of text in Well-known text format. The next token
/// must be a number.</param>
/// <returns>Returns the next number in the stream.</returns>
/// <remarks>
/// ParseException is thrown if the next token is not a number.
/// </remarks>
private static double GetNextNumber(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
return(tokenizer.GetNumericValue());
}
