/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.geotools.factory.Hints;
import org.geotools.util.Converter;
import org.geotools.util.ConverterFactory;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.LinearRing;
import com.vividsolutions.jts.geom.MultiLineString;
import com.vividsolutions.jts.geom.MultiPoint;
import com.vividsolutions.jts.geom.MultiPolygon;
import com.vividsolutions.jts.geom.Point;
import com.vividsolutions.jts.geom.Polygon;
/**
* Converter factory performing conversions among JTS geometries
* of different types.
*
* - single type geometries (Point, LineString, Polygon) are converted to multi types
* (MultiPoint, LineString, MultiPolygon) containing 1 geometry element.
* - GeometryCollection(s) are converted to multi types, converting each element to the
* permitted type (Point, LineString or Polygon).
*
* @author m.bartolomeoli
*
*
*
* @source $URL$
*/
public class GeometryTypeConverterFactory implements ConverterFactory {
private static final Logger LOGGER = org.geotools.util.logging.Logging.getLogger(GeometryTypeConverterFactory.class);
static GeometryFactory gFac=new GeometryFactory();
public Converter createConverter(Class<?> source, Class<?> target,
Hints hints) {
// we can convert geometric types
if(Geometry.class.isAssignableFrom(source) && Geometry.class.isAssignableFrom(target)) {
return new Converter() {
/**
* Converts all the geometries of the given GeometryCollection to a specified
* simple type.
* @param <T>
* @param gc
* @param target
* @return
* @throws Exception
*/
public <T> List<T> convertAll(GeometryCollection gc,Class<T> target) throws Exception {
List<T> result=new ArrayList<T>();
for(int count=0;count<gc.getNumGeometries();count++) {
T geo=(T)convert(gc.getGeometryN(count),target);
if(geo!=null)
result.add(geo);
}
return result;
}
public Object convert(Object source, Class target)
throws Exception {
// hierarchy compatible geometries -> nothing to do
if(target.isAssignableFrom(source.getClass()))
return source;
if(source instanceof Geometry) {
Geometry sourceGeometry=(Geometry)source;
Geometry destGeometry = null;
// multi<geometry> types: for each one we
// try the followings:
// - if source is <geometry> we create a multi<geometry> with just 1 element
// - if source is a GeometryCollection, we try to convert each element to <geometry>
// - else we firtsly convert the geometry to a <geometry> and then we create a multi<geometry> with the obtained element
if(MultiPoint.class.isAssignableFrom(target)) {
Point[] points;
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
points = new Point[0];
else if(source instanceof Point)
points=new Point[] {(Point)source};
else if(source instanceof GeometryCollection)
points=this.convertAll((GeometryCollection)source,Point.class).toArray(new Point[] {});
else
points=new Point[] {(Point)this.convert(source,Point.class)};
destGeometry = gFac.createMultiPoint(points);
}
else if(MultiLineString.class.isAssignableFrom(target)) {
LineString[] lineStrings;
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
lineStrings = new LineString[0];
else if(source instanceof LineString)
lineStrings=new LineString[] {(LineString)source};
else if(source instanceof GeometryCollection)
lineStrings=this.convertAll((GeometryCollection)source,LineString.class).toArray(new LineString[] {});
else
lineStrings=new LineString[] {(LineString)this.convert(source,LineString.class)};
destGeometry = gFac.createMultiLineString(lineStrings);
}
else if(MultiPolygon.class.isAssignableFrom(target)) {
Polygon[] polygons;
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
polygons = new Polygon[0];
else if(source instanceof Polygon)
polygons=new Polygon[] {(Polygon)source};
else if(source instanceof GeometryCollection)
polygons=this.convertAll((GeometryCollection)source,Polygon.class).toArray(new Polygon[] {});
else
polygons=new Polygon[] {(Polygon)this.convert(source,Polygon.class)};
destGeometry = gFac.createMultiPolygon(polygons);
}
// target is a geometrycollection: we add the source to
// a new geometrycollection
else if(GeometryCollection.class.isAssignableFrom(target)) {
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
destGeometry = gFac
.createGeometryCollection(new Geometry[0]);
else
destGeometry = gFac.createGeometryCollection(new Geometry[] {(Geometry)source});
}
// target is a point: we return the centroid of any complex geometry
else if(Point.class.isAssignableFrom(target)) {
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
destGeometry = gFac.createPoint((Coordinate) null);
else if(source instanceof MultiPoint && sourceGeometry.getNumGeometries()==1)
destGeometry = (Geometry) ((MultiPoint)source).getGeometryN(0).clone();
else {
if(LOGGER.isLoggable(Level.FINE))
LOGGER.fine("Converting Geometry "+source.toString()+" to Point. This could be unsafe");
destGeometry = ((Geometry)source).getCentroid();
}
}
// target is a linestring: we return the linestring connecting all the geometry coordinates
else if(LineString.class.isAssignableFrom(target)) {
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
destGeometry = gFac.createLineString(new Coordinate[0]);
else if(source instanceof MultiLineString && sourceGeometry.getNumGeometries()==1)
destGeometry = (Geometry) ((MultiLineString)source).getGeometryN(0).clone();
else {
if(LOGGER.isLoggable(Level.FINE))
LOGGER.fine("Converting Geometry "+source.toString()+" to LineString. This could be unsafe");
destGeometry = gFac.createLineString(getLineStringCoordinates(((Geometry)source).getCoordinates()));
}
}
// target is a polygon: we return a polygon connecting all the coordinates of the given geometry
else if(Polygon.class.isAssignableFrom(target)) {
// NC - Empty Geometry Support
if (sourceGeometry.isEmpty())
destGeometry = gFac.createLineString(new Coordinate[0]);
else if(source instanceof MultiPolygon && sourceGeometry.getNumGeometries()==1)
destGeometry = (Geometry) ((MultiPolygon)source).getGeometryN(0).clone();
else {
if(LOGGER.isLoggable(Level.FINE))
LOGGER.fine("Converting Geometry "+source.toString()+" to Polygon. This could be unsafe");
Coordinate[] coords=getPolygonCoordinates(((Geometry)source).getCoordinates());
destGeometry = gFac.createPolygon(gFac.createLinearRing(coords), new LinearRing[] {});
}
}
// NC - added cloning above for cases where an existing geometry is used
// for purpose for changing user data - we don't want any side effects
// NC-added, copy userdata
if (destGeometry != null) {
Map<Object, Object> newUserData = new HashMap<Object, Object>();
// copy if anything is already in destination data
if (destGeometry.getUserData() instanceof Map) {
newUserData.putAll((Map) destGeometry.getUserData());
} else if (destGeometry.getUserData() instanceof CoordinateReferenceSystem) {
newUserData.put(CoordinateReferenceSystem.class,
destGeometry.getUserData());
}
// overwrite with source
if (sourceGeometry.getUserData() instanceof Map) {
newUserData.putAll((Map) sourceGeometry.getUserData());
} else if (sourceGeometry.getUserData() instanceof CoordinateReferenceSystem) {
newUserData.put(CoordinateReferenceSystem.class,
sourceGeometry.getUserData());
}
destGeometry.setUserData(newUserData);
}
return destGeometry;
}
return null;
}
@SuppressWarnings("unchecked")
private <T> T[] arrayCopy(T[] original,int length) {
Class<?> arrayType = original.getClass().getComponentType();
T[] copy = (T[])java.lang.reflect.Array.newInstance(arrayType, length);
System.arraycopy(original, 0, copy, 0, original.length<length ? original.length : length);
return copy;
}
/**
* Add dummy coordinates to the given array to reach
* numpoints points.
* If the array is already made of numpoints or
* more coordinates, it will be returned untouched.
* @param input
* @param numpoints
* @return
*/
private Coordinate[] growCoordinatesNum(Coordinate[] input,int numpoints) {
if(input.length<numpoints) {
Coordinate[] newCoordinates=arrayCopy(input,numpoints);
Arrays.fill(newCoordinates, input.length, numpoints,input[0]);
input=newCoordinates;
}
return input;
}
/**
* Gets a set of coordinates valid to create a linestring:
* - at least 2 coordinates
*
* @param coordinates
* @return
*/
private Coordinate[] getLineStringCoordinates(
Coordinate[] coordinates) {
// at least 2 points
coordinates=growCoordinatesNum(coordinates, 2);
return coordinates;
}
/**
* Gets a set of coordinates valid to create a polygon:
* - at least 4 coordinates
* - closed path
* @param coordinates
* @return
*/
private Coordinate[] getPolygonCoordinates(
Coordinate[] coordinates) {
// at least 4 points
coordinates=growCoordinatesNum(coordinates, 4);
if(!coordinates[coordinates.length-1].equals(coordinates[0])) {
Coordinate[] newCoordinates=arrayCopy(coordinates,coordinates.length+1);
newCoordinates[newCoordinates.length-1]=newCoordinates[0];
coordinates=newCoordinates;
}
return coordinates;
}
};
}
return null;
}
}