org.h2gis.drivers.shp.internal
Class PolygonHandler

java.lang.Object
  org.h2gis.drivers.shp.internal.PolygonHandler

All Implemented Interfaces:

ShapeHandler

public class PolygonHandler
extends Object
implements ShapeHandler

Wrapper for a Shapefile polygon.

Version:

$Id: PolygonHandler.java 22264 2006-10-19 10:10:35Z acuster $

Author:

aaime, Ian Schneider

See Also:

"http://svn.geotools.org/geotools/tags/2.3.1/plugin/shapefile/src/org/geotools/data/shapefile/shp/PolygonHandler.java"

Constructor Summary

PolygonHandler()

PolygonHandler(ShapeType type)

Method Summary

static int	computeOrientation(com.vividsolutions.jts.geom.CoordinateSequence cs, int p1, int p2, int q)
int	getLength(Object geometry) Get the length of the given geometry Object in bytes not 16-bit words.
ShapeType	getShapeType() Get the ShapeType of this handler.
static boolean	isCCW(com.vividsolutions.jts.geom.CoordinateSequence ring) Computes whether a ring defined by an array of Coordinates is oriented counter-clockwise.
com.vividsolutions.jts.geom.Geometry	read(ReadBufferManager buffer, ShapeType type) Read a geometry from the ByteBuffer.
void	write(WriteBufferManager buffer, Object geometry) Write the geometry into the ByteBuffer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PolygonHandler

public PolygonHandler()

PolygonHandler

public PolygonHandler(ShapeType type)
               throws ShapefileException

Throws:

ShapefileException

Method Detail

getShapeType

public ShapeType getShapeType()

Description copied from interface: ShapeHandler

Get the ShapeType of this handler.

Specified by:

getShapeType in interface ShapeHandler

Returns:

The ShapeType.

getLength

public int getLength(Object geometry)

Description copied from interface: ShapeHandler

Get the length of the given geometry Object in bytes not 16-bit words. This is easier to keep track of, since the ByteBuffer deals with bytes. Do not include the 8 bytes of record.

Specified by:

getLength in interface ShapeHandler

Parameters:

geometry - The geometry to analyze.

Returns:

The number of bytes the shape will take up.

read

public com.vividsolutions.jts.geom.Geometry read(ReadBufferManager buffer,
                                                 ShapeType type)
                                          throws IOException

Description copied from interface: ShapeHandler

Read a geometry from the ByteBuffer. The buffer's position, byteOrder, and limit are set to that which is needed. The record has been read as well as the shape type integer. The handler need not worry about reading unused information as the ShapefileReader will correctly adjust the buffer position after this call.

Specified by:

read in interface ShapeHandler

Parameters:

buffer - The ByteBuffer to read from.

Returns:

A geometry object.

Throws:

IOException

isCCW

public static boolean isCCW(com.vividsolutions.jts.geom.CoordinateSequence ring)

Computes whether a ring defined by an array of Coordinates is oriented counter-clockwise.

• The list of points is assumed to have the first and last points equal.
• This will handle coordinate lists which contain repeated points.

This algorithm is only guaranteed to work with valid rings. If the ring is invalid (e.g. self-crosses or touches), the computed result may not be correct.

Parameters:

ring - an array of Coordinates forming a ring

Returns:

true if the ring is oriented counter-clockwise.

computeOrientation

public static int computeOrientation(com.vividsolutions.jts.geom.CoordinateSequence cs,
                                     int p1,
                                     int p2,
                                     int q)

write

public void write(WriteBufferManager buffer,
                  Object geometry)
           throws IOException

Description copied from interface: ShapeHandler

Write the geometry into the ByteBuffer. The position, byteOrder, and limit are all set. The handler is not responsible for writing the record or shape type integer.

Specified by:

write in interface ShapeHandler

Parameters:

buffer - The ByteBuffer to write to.

geometry - The geometry to write.

Throws:

IOException