• 1.9
  • dev
  • Documentation version: 1.10

Source code for django.contrib.gis.geos.collections

"""
 This module houses the Geometry Collection objects:
 GeometryCollection, MultiPoint, MultiLineString, and MultiPolygon
"""
import json
import warnings
from ctypes import byref, c_int, c_uint

from django.contrib.gis.geos import prototypes as capi
from django.contrib.gis.geos.error import GEOSException
from django.contrib.gis.geos.geometry import GEOSGeometry, LinearGeometryMixin
from django.contrib.gis.geos.libgeos import geos_version_info, get_pointer_arr
from django.contrib.gis.geos.linestring import LinearRing, LineString
from django.contrib.gis.geos.point import Point
from django.contrib.gis.geos.polygon import Polygon
from django.utils.deprecation import RemovedInDjango20Warning
from django.utils.six.moves import range


[docs]class GeometryCollection(GEOSGeometry): _typeid = 7 def __init__(self, *args, **kwargs): "Initializes a Geometry Collection from a sequence of Geometry objects." # Checking the arguments 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 range(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 json(self): if self.__class__.__name__ == 'GeometryCollection': return json.dumps({ 'type': self.__class__.__name__, 'geometries': [ {'type': geom.__class__.__name__, 'coordinates': geom.coords} for geom in self ], }) return super(GeometryCollection, self).json geojson = json @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.
[docs]class MultiPoint(GeometryCollection): _allowed = Point _typeid = 4
[docs]class MultiLineString(LinearGeometryMixin, GeometryCollection): _allowed = (LineString, LinearRing) _typeid = 5 @property def closed(self): if geos_version_info()['version'] < '3.5': raise GEOSException("MultiLineString.closed requires GEOS >= 3.5.0.") return super(MultiLineString, self).closed
[docs]class MultiPolygon(GeometryCollection): _allowed = Polygon _typeid = 6 @property def cascaded_union(self): "Returns a cascaded union of this MultiPolygon." warnings.warn( "`cascaded_union` is deprecated, use the `unary_union` property instead.", RemovedInDjango20Warning, 2 ) return GEOSGeometry(capi.geos_cascaded_union(self.ptr), self.srid)
# Setting the allowed types here since GeometryCollection is defined before # its subclasses. GeometryCollection._allowed = (Point, LineString, LinearRing, Polygon, MultiPoint, MultiLineString, MultiPolygon)
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