AsEncodedPolyline Class Reference

Encodes a LineString as into the Polyline String dataformat. More...

Inheritance diagram for AsEncodedPolyline:

Collaboration diagram for AsEncodedPolyline:

Public Member Functions
String	operation (Geometry geom)
String	getURI ()
Value	evaluate (ValueFactory valueFactory, Value... args) throws ValueExprEvaluationException

Static Public Member Functions
static String	encodePolyline (final LineString linestring)

Static Private Member Functions
static void	encode (long v, StringBuffer result)

Detailed Description

Encodes a LineString as into the Polyline String dataformat.

Member Function Documentation

encode()

static void encode ( long  v, StringBuffer  result  )

staticprivate

                                                            {
        v = v < 0 ? ~(v << 1) : v << 1;
        while (v >= 0x20) {
            result.append(Character.toChars((int) ((0x20 | (v & 0x1f)) + 63)));
            v >>= 5;
        }
        result.append(Character.toChars((int) (v + 63)));
    }

Referenced by AsEncodedPolyline.encodePolyline().

encodePolyline()

static String encodePolyline ( final LineString  linestring )

static

                                                                         {
        long lastLat = 0;
        long lastLng = 0;
 
        final StringBuffer result = new StringBuffer();
 
        for (final Coordinate point : linestring.getCoordinates()) {
            long lat = Math.round(point.x * 1e5);
            long lng = Math.round(point.y * 1e5);
 
            long dLat = lat - lastLat;
            long dLng = lng - lastLng;
 
            encode(dLat, result);
            encode(dLng, result);
 
            lastLat = lat;
            lastLng = lng;
        }
        return result.toString();
    }

References AsEncodedPolyline.encode().

Referenced by AsEncodedPolyline.operation().

evaluate()

Value evaluate ( ValueFactory  valueFactory, Value...  args  ) throws ValueExprEvaluationException

inherited

                                                                                                            {
                if (args.length != 1) {
                        throw new ValueExprEvaluationException(getURI() + " requires exactly 1 arguments, got " + args.length);
                }
 
                LiteralType l=LiteralRegistry.getLiteral(((Literal)args[0]).getDatatype().toString());
                if(l instanceof VectorLiteral) {
                        Geometry geom=((VectorLiteral)l).read(args[0].stringValue());
                        String result = operation(geom);
                        return valueFactory.createLiteral(result);
                }
                throw new ValueExprEvaluationException("Argument given is not a geometry literal");
                
        }

References LiteralRegistry.getLiteral(), and GeometricStringExportFunction.operation().

Referenced by AsBinaryTest.testAsBinary(), AsEncodedPolylineTest.testAsEncodedPolyline(), AsGARSTest.testAsGARS(), AsGeoJSONTest.testAsGeoJSON(), AsGeoRSSTest.testAsGeoRSS(), AsGeoURITest.testAsGeoURI(), AsLatLonTextTest.testAsLatLonText(), AsOSMLinkTest.testAsOSMLink(), AsPolyshapeTest.testAsPolyShape(), AsTextTest.testAsText(), AsTextRawTest.testAsTextRaw(), AsTextTest.testAsTextZ(), DumpTest.testDump(), GeomCRSToWKTTest.testGeomCRSToWKT(), GeometryTypeTest.testLineString(), SridGetAxis1OrientationTest.testSridAxis1Orientation(), SridGetAxis2OrientationTest.testSridAxis2Orientation(), SridGetAxis1NameTest.testSridGetAxis1Name(), SridGetAxis2NameTest.testSridGetAxis2Name(), and SridGetDatumTest.testSridGetDatum().

getURI()

String getURI

(

)

                               {
                return POSTGIS.ST_ASENCODEDPOLYLINE.stringValue();
        }

References POSTGIS.ST_ASENCODEDPOLYLINE.

operation()

String operation

(

Geometry

geom

)

Reimplemented from GeometricStringExportFunction.

                                               {
                if (geom instanceof LineString) {
                String result=encodePolyline((LineString)geom);
                return result;
        }
                return null;
        }

References AsEncodedPolyline.encodePolyline().