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

from ctypes import c_uint

from django.contrib.gis import gdal
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

[docs]class Point(GEOSGeometry): _minlength = 2 _maxlength = 3 has_cs = True def __init__(self, x=None, y=None, z=None, srid=None): """ The Point object may be initialized with either a tuple, or individual parameters. For example: >>> p = Point((5, 23)) # 2D point, passed in as a tuple >>> p = Point(5, 23, 8) # 3D point, passed in with individual parameters """ if x is None: coords = [] elif isinstance(x, (tuple, list)): # Here a tuple or list was passed in under the `x` parameter. coords = x elif isinstance(x, (float, int)) and isinstance(y, (float, int)): # Here X, Y, and (optionally) Z were passed in individually, as parameters. if isinstance(z, (float, int)): coords = [x, y, z] else: coords = [x, y] else: raise TypeError('Invalid parameters given for Point initialization.') point = self._create_point(len(coords), coords) # Initializing using the address returned from the GEOS # createPoint factory. super().__init__(point, srid=srid) def _to_pickle_wkb(self): return None if self.empty else super()._to_pickle_wkb() def _from_pickle_wkb(self, wkb): return self._create_empty() if wkb is None else super()._from_pickle_wkb(wkb) def _ogr_ptr(self): return gdal.geometries.Point._create_empty() if self.empty else super()._ogr_ptr() @classmethod def _create_empty(cls): return cls._create_point(None, None) @classmethod def _create_point(cls, ndim, coords): """ Create a coordinate sequence, set X, Y, [Z], and create point """ if not ndim: return capi.create_point(None) if ndim < 2 or ndim > 3: raise TypeError('Invalid point dimension: %s' % ndim) cs = capi.create_cs(c_uint(1), c_uint(ndim)) i = iter(coords) capi.cs_setx(cs, 0, next(i)) capi.cs_sety(cs, 0, next(i)) if ndim == 3: capi.cs_setz(cs, 0, next(i)) return capi.create_point(cs) def _set_list(self, length, items): ptr = self._create_point(length, items) if ptr: srid = self.srid capi.destroy_geom(self.ptr) self._ptr = ptr if srid is not None: self.srid = srid self._post_init() else: # can this happen? raise GEOSException('Geometry resulting from slice deletion was invalid.') def _set_single(self, index, value): self._cs.setOrdinate(index, 0, value) def __iter__(self): "Iterate over coordinates of this Point." for i in range(len(self)): yield self[i] def __len__(self): "Return the number of dimensions for this Point (either 0, 2 or 3)." if self.empty: return 0 if self.hasz: return 3 else: return 2 def _get_single_external(self, index): if index == 0: return self.x elif index == 1: return self.y elif index == 2: return self.z _get_single_internal = _get_single_external @property def x(self): "Return the X component of the Point." return self._cs.getOrdinate(0, 0) @x.setter def x(self, value): "Set the X component of the Point." self._cs.setOrdinate(0, 0, value) @property def y(self): "Return the Y component of the Point." return self._cs.getOrdinate(1, 0) @y.setter def y(self, value): "Set the Y component of the Point." self._cs.setOrdinate(1, 0, value) @property def z(self): "Return the Z component of the Point." return self._cs.getOrdinate(2, 0) if self.hasz else None @z.setter def z(self, value): "Set the Z component of the Point." if not self.hasz: raise GEOSException('Cannot set Z on 2D Point.') self._cs.setOrdinate(2, 0, value) # ### Tuple setting and retrieval routines. ### @property def tuple(self): "Return a tuple of the point." return self._cs.tuple @tuple.setter def tuple(self, tup): "Set the coordinates of the point with the given tuple." self._cs[0] = tup # The tuple and coords properties coords = tuple
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