/// <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)
{
var p = new Point();
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(p);
}
p.X = GetNextNumber(tokenizer);
p.Y = GetNextNumber(tokenizer);
GetNextCloser(tokenizer);
return(p);
}
/// <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)
{
var mp = new MultiPoint();
var 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="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)
{
var geometries = new GeometryCollection();
var 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 <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)
{
var lines = new MultiLineString();
var 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 Geometry ReadGeometryTaggedText(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
var type = tokenizer.GetStringValue().ToUpper();
Geometry geometry;
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(string.Format(CultureInfo.InvariantCulture,
"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)
{
var pol = new Polygon();
var 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)
{
var polygons = new MultiPolygon();
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(polygons);
}
var 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>
/// 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());
}
/// <summary>
/// Converts a Well-known Text representation to a <see cref="Mapsui.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="Mapsui.Geometries.Geometry" /> read from StreamReader.
/// An exception will be thrown if there is a parsing problem.
/// </returns>
public static Geometry Parse(TextReader reader)
{
var tokenizer = new WktStreamTokenizer(reader);
return(ReadGeometryTaggedText(tokenizer));
}
/// <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)
{
var pol = new Polygon();
var 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>
/// 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();
}
/// <summary>
/// Returns the next ")" in the stream.
/// </summary>
/// <param name="tokenizer">
/// Tokenizer over a stream of text in Well-known Text
/// format. The next token must be ")".
/// </param>
/// <returns>Returns the next ")" in the stream.</returns>
/// <remarks>
/// ParseException is thrown if the next token is not ")".
/// </remarks>
private static void GetNextCloser(WktStreamTokenizer tokenizer)
{
var nextWord = GetNextWord(tokenizer);
if (nextWord == ")")
return;
throw new Exception("Expected ')' but encountered '" + nextWord + "'");
}
/// <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>
/// 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)
{
var lines = new MultiLineString();
var 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 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>
/// 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 Geometry ReadGeometryTaggedText(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
var type = tokenizer.GetStringValue().ToUpper();
Geometry geometry;
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(string.Format(CultureInfo.InvariantCulture,
"Geometrytype '{0}' is not supported.",
type));
}
return geometry;
}
/// <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)
{
var geometries = new GeometryCollection();
var 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>
/// Returns the next word in the stream as uppercase text.
/// </summary>
/// <param name="tokenizer">
/// Tokenizer over a stream of text in Well-known Text
/// format. The next token must be a word.
/// </param>
/// <returns>Returns the next word in the stream as uppercase text.</returns>
/// <remarks>
/// Exception is thrown if the next token is not a word.
/// </remarks>
private static string GetNextWord(WktStreamTokenizer tokenizer)
{
var type = tokenizer.NextToken();
var token = tokenizer.GetStringValue();
if (type == TokenType.Number)
throw new Exception("Expected a number but got " + token);
if (type == TokenType.Word)
return token.ToUpper();
if (token == "(")
return "(";
if (token == ")")
return ")";
if (token == ",")
return ",";
throw new Exception("Not a valid symbol in WKT format.");
}
/// <summary>
/// Returns the next array of Coordinates in the stream.
/// </summary>
/// <param name="tokenizer">
/// Tokenizer over a stream of text in Well-known Text format. The
/// next element returned by the stream should be "(" (the beginning of "(x1 y1, x2 y2, ..., xn yn)" or
/// "EMPTY".
/// </param>
/// <returns>
/// The next array of Coordinates in the stream, or an empty array of "EMPTY" is the
/// next element returned by the stream.
/// </returns>
private static Collection<Point> GetCoordinates(WktStreamTokenizer tokenizer)
{
var coordinates = new Collection<Point>();
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY") return coordinates;
var externalCoordinate = new Point {X = GetNextNumber(tokenizer), Y = GetNextNumber(tokenizer)};
coordinates.Add(externalCoordinate);
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
var internalCoordinate = new Point {X = GetNextNumber(tokenizer), Y = GetNextNumber(tokenizer)};
coordinates.Add(internalCoordinate);
nextToken = GetNextCloserOrComma(tokenizer);
}
return coordinates;
}
/// <summary>
/// Returns the next ")" or "," in the stream.
/// </summary>
/// <param name="tokenizer">
/// tokenizer over a stream of text in Well-known Text
/// format. The next token must be ")" or ",".
/// </param>
/// <returns>Returns the next ")" or "," in the stream.</returns>
/// <remarks>
/// ParseException is thrown if the next token is not ")" or ",".
/// </remarks>
private static string GetNextCloserOrComma(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
var nextWord = tokenizer.GetStringValue();
if ((nextWord == ",") || (nextWord == ")"))
return nextWord;
throw new Exception("Expected ')' or ',' but encountered '" + nextWord + "'");
}
/// <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)
{
var p = new Point();
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
return p;
p.X = GetNextNumber(tokenizer);
p.Y = GetNextNumber(tokenizer);
GetNextCloser(tokenizer);
return p;
}
/// <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)
{
var mp = new MultiPoint();
var 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>
/// Returns the next "EMPTY" or "(" in the stream as uppercase text.
/// </summary>
/// <param name="tokenizer">
/// Tokenizer over a stream of text in Well-known Text
/// format. The next token must be "EMPTY" or "(".
/// </param>
/// <returns>
/// the next "EMPTY" or "(" in the stream as uppercase
/// text.
/// </returns>
/// <remarks>
/// ParseException is thrown if the next token is not "EMPTY" or "(".
/// </remarks>
private static string GetNextEmptyOrOpener(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
var nextWord = tokenizer.GetStringValue();
if ((nextWord == "EMPTY") || (nextWord == "("))
return nextWord;
throw new Exception("Expected 'EMPTY' or '(' but encountered '" + nextWord + "'");
}
/// <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)
{
var polygons = new MultiPolygon();
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
return polygons;
var 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="Mapsui.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="Mapsui.Geometries.Geometry" /> read from StreamReader.
/// An exception will be thrown if there is a parsing problem.
/// </returns>
public static Geometry Parse(TextReader reader)
{
var tokenizer = new WktStreamTokenizer(reader);
return ReadGeometryTaggedText(tokenizer);
}