--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/gis/geos/collections.py	Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,123 @@
+"""
+ This module houses the Geometry Collection objects:
+ GeometryCollection, MultiPoint, MultiLineString, and MultiPolygon
+"""
+from ctypes import c_int, c_uint, byref
+from django.contrib.gis.geos.error import GEOSException, GEOSIndexError
+from django.contrib.gis.geos.geometry import GEOSGeometry
+from django.contrib.gis.geos.libgeos import get_pointer_arr, GEOM_PTR, GEOS_PREPARE
+from django.contrib.gis.geos.linestring import LineString, LinearRing
+from django.contrib.gis.geos.point import Point
+from django.contrib.gis.geos.polygon import Polygon
+from django.contrib.gis.geos import prototypes as capi
+
+class GeometryCollection(GEOSGeometry):
+    _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], (tuple, list)):
+                init_geoms = args[0]
+            else:
+                init_geoms = args
+        else:
+            init_geoms = args
+
+        # Ensuring that only the permitted geometries are allowed in this collection
+        # this is moved to list mixin super class
+        self._check_allowed(init_geoms)
+
+        # Creating the geometry pointer array.
+        collection = self._create_collection(len(init_geoms), iter(init_geoms))
+        super(GeometryCollection, self).__init__(collection, **kwargs)
+
+    def __iter__(self):
+        "Iterates over each Geometry in the Collection."
+        for i in xrange(len(self)):
+            yield self[i]
+
+    def __len__(self):
+        "Returns the number of geometries in this Collection."
+        return self.num_geom
+
+    ### Methods for compatibility with ListMixin ###
+    def _create_collection(self, length, items):
+        # Creating the geometry pointer array.
+        geoms = get_pointer_arr(length)
+        for i, g in enumerate(items):
+            # this is a little sloppy, but makes life easier
+            # allow GEOSGeometry types (python wrappers) or pointer types
+            geoms[i] = capi.geom_clone(getattr(g, 'ptr', g))
+
+        return capi.create_collection(c_int(self._typeid), byref(geoms), c_uint(length))
+
+    def _get_single_internal(self, index):
+        return capi.get_geomn(self.ptr, index)
+
+    def _get_single_external(self, index):
+        "Returns the Geometry from this Collection at the given index (0-based)."
+        # Checking the index and returning the corresponding GEOS geometry.
+        return GEOSGeometry(capi.geom_clone(self._get_single_internal(index)), srid=self.srid)
+
+    def _set_list(self, length, items):
+        "Create a new collection, and destroy the contents of the previous pointer."
+        prev_ptr = self.ptr
+        srid = self.srid
+        self.ptr = self._create_collection(length, items)
+        if srid: self.srid = srid
+        capi.destroy_geom(prev_ptr)
+
+    _set_single = GEOSGeometry._set_single_rebuild
+    _assign_extended_slice = GEOSGeometry._assign_extended_slice_rebuild
+
+    @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
+
+    @property
+    def merged(self):
+        """ 
+        Returns a LineString representing the line merge of this 
+        MultiLineString.
+        """ 
+        return self._topology(capi.geos_linemerge(self.ptr))         
+
+class MultiPolygon(GeometryCollection):
+    _allowed = Polygon
+    _typeid = 6
+
+    @property
+    def cascaded_union(self):
+        "Returns a cascaded union of this MultiPolygon."
+        if GEOS_PREPARE:
+            return GEOSGeometry(capi.geos_cascaded_union(self.ptr), self.srid)
+        else:
+            raise GEOSException('The cascaded union operation requires GEOS 3.1+.')
+
+# Setting the allowed types here since GeometryCollection is defined before
+# its subclasses.
+GeometryCollection._allowed = (Point, LineString, LinearRing, Polygon, MultiPoint, MultiLineString, MultiPolygon)