/**
* Build an appropriate <code>Geometry</code>, <code>MultiGeometry</code>, or <code>
* GeometryCollection</code> to contain the <code>Geometry</code>s in it. For example:<br>
*
* <ul>
* <li>If <code>geomList</code> contains a single <code>Polygon</code>, the <code>Polygon</code>
* is returned.
* <li>If <code>geomList</code> contains several <code>Polygon</code>s, a <code>MultiPolygon
* </code> is returned.
* <li>If <code>geomList</code> contains some <code>Polygon</code>s and some <code>LineString
* </code>s, a <code>GeometryCollection</code> is returned.
* <li>If <code>geomList</code> is empty, an empty <code>GeometryCollection</code> is returned
* </ul>
*
* Note that this method does not "flatten" Geometries in the input, and hence if any
* MultiGeometries are contained in the input a GeometryCollection containing them will be
* returned.
*
* @param geomList the <code>Geometry</code>s to combine
* @return a <code>Geometry</code> of the "smallest", "most type-specific" class that can contain
* the elements of <code>geomList</code> .
*/
public Geometry buildGeometry(Collection geomList) {
/** Determine some facts about the geometries in the list */
Class geomClass = null;
boolean isHeterogeneous = false;
boolean hasGeometryCollection = false;
for (Iterator i = geomList.iterator(); i.hasNext(); ) {
Geometry geom = (Geometry) i.next();
Class partClass = geom.getClass();
if (geomClass == null) {
geomClass = partClass;
}
if (partClass != geomClass) {
isHeterogeneous = true;
}
if (geom instanceof GeometryCollection) hasGeometryCollection = true;
}
/** Now construct an appropriate geometry to return */
// for the empty geometry, return an empty GeometryCollection
if (geomClass == null) {
return createGeometryCollection(null);
}
if (isHeterogeneous || hasGeometryCollection) {
return createGeometryCollection(toGeometryArray(geomList));
}
// at this point we know the collection is hetereogenous.
// Determine the type of the result from the first Geometry in the list
// this should always return a geometry, since otherwise an empty collection would have already
// been returned
Geometry geom0 = (Geometry) geomList.iterator().next();
boolean isCollection = geomList.size() > 1;
if (isCollection) {
if (geom0 instanceof Polygon) {
return createMultiPolygon(toPolygonArray(geomList));
} else if (geom0 instanceof LineString) {
return createMultiLineString(toLineStringArray(geomList));
} else if (geom0 instanceof Point) {
return createMultiPoint(toPointArray(geomList));
}
Assert.shouldNeverReachHere("Unhandled class: " + geom0.getClass().getName());
}
return geom0;
}
public static Point createPointFromInternalCoord(Coordinate coord, Geometry exemplar) {
exemplar.getPrecisionModel().makePrecise(coord);
return exemplar.getFactory().createPoint(coord);
}
