--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/gis/geos/collections.py	Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,105 @@
+"""
+ This module houses the Geometry Collection objects:
+ GeometryCollection, MultiPoint, MultiLineString, and MultiPolygon
+"""
+from ctypes import c_int, c_uint, byref
+from types import TupleType, ListType
+from django.contrib.gis.geos.base import GEOSGeometry
+from django.contrib.gis.geos.error import GEOSException, GEOSIndexError
+from django.contrib.gis.geos.geometries import Point, LineString, LinearRing, Polygon
+from django.contrib.gis.geos.libgeos import get_pointer_arr, GEOM_PTR
+from django.contrib.gis.geos.prototypes import create_collection, destroy_geom, geom_clone, geos_typeid, get_cs, get_geomn
+
+class GeometryCollection(GEOSGeometry):
+    _allowed = (Point, LineString, LinearRing, Polygon)
+    _typeid = 7
+
+    def __init__(self, *args, **kwargs):
+        "Initializes a Geometry Collection from a sequence of Geometry objects."
+
+        # Checking the arguments
+        if not args:
+            raise TypeError, 'Must provide at least one Geometry to initialize %s.' % self.__class__.__name__
+
+        if len(args) == 1: 
+            # If only one geometry provided or a list of geometries is provided
+            #  in the first argument.
+            if isinstance(args[0], (TupleType, ListType)):
+                init_geoms = args[0]
+            else:
+                init_geoms = args
+        else:
+            init_geoms = args
+
+        # Ensuring that only the permitted geometries are allowed in this collection
+        if False in [isinstance(geom, self._allowed) for geom in init_geoms]:
+            raise TypeError('Invalid Geometry type encountered in the arguments.')
+
+        # Creating the geometry pointer array.
+        ngeoms = len(init_geoms)
+        geoms = get_pointer_arr(ngeoms)
+        for i in xrange(ngeoms): geoms[i] = geom_clone(init_geoms[i].ptr)
+        super(GeometryCollection, self).__init__(create_collection(c_int(self._typeid), byref(geoms), c_uint(ngeoms)), **kwargs)
+
+    def __getitem__(self, index):
+        "Returns the Geometry from this Collection at the given index (0-based)."
+        # Checking the index and returning the corresponding GEOS geometry.
+        self._checkindex(index)
+        return GEOSGeometry(geom_clone(get_geomn(self.ptr, index)), srid=self.srid)
+
+    def __setitem__(self, index, geom):
+        "Sets the Geometry at the specified index."
+        self._checkindex(index)
+        if not isinstance(geom, self._allowed):
+            raise TypeError('Incompatible Geometry for collection.')
+        
+        ngeoms = len(self)
+        geoms = get_pointer_arr(ngeoms)
+        for i in xrange(ngeoms):
+            if i == index:
+                geoms[i] = geom_clone(geom.ptr)
+            else:
+                geoms[i] = geom_clone(get_geomn(self.ptr, i))
+        
+        # Creating a new collection, and destroying the contents of the previous poiner.
+        prev_ptr = self.ptr
+        srid = self.srid
+        self._ptr = create_collection(c_int(self._typeid), byref(geoms), c_uint(ngeoms))
+        if srid: self.srid = srid
+        destroy_geom(prev_ptr)
+
+    def __iter__(self):
+        "Iterates over each Geometry in the Collection."
+        for i in xrange(len(self)):
+            yield self.__getitem__(i)
+
+    def __len__(self):
+        "Returns the number of geometries in this Collection."
+        return self.num_geom
+
+    def _checkindex(self, index):
+        "Checks the given geometry index."
+        if index < 0 or index >= self.num_geom:
+            raise GEOSIndexError('invalid GEOS Geometry index: %s' % str(index))
+
+    @property
+    def kml(self):
+        "Returns the KML for this Geometry Collection."
+        return '<MultiGeometry>%s</MultiGeometry>' % ''.join([g.kml for g in self])
+
+    @property
+    def tuple(self):
+        "Returns a tuple of all the coordinates in this Geometry Collection"
+        return tuple([g.tuple for g in self])
+    coords = tuple
+
+# MultiPoint, MultiLineString, and MultiPolygon class definitions.
+class MultiPoint(GeometryCollection): 
+    _allowed = Point
+    _typeid = 4
+class MultiLineString(GeometryCollection): 
+    _allowed = (LineString, LinearRing)
+    _typeid = 5
+class MultiPolygon(GeometryCollection): 
+    _allowed = Polygon
+    _typeid = 6