+
−"""
+
− This module houses the GEOSCoordSeq object, which is used internally
+
− by GEOSGeometry to house the actual coordinates of the Point,
+
− LineString, and LinearRing geometries.
+
−"""
+
−from ctypes import c_double, c_uint, byref
+
−from types import ListType, TupleType
+
−from django.contrib.gis.geos.error import GEOSException, GEOSIndexError
+
−from django.contrib.gis.geos.libgeos import CS_PTR, HAS_NUMPY
+
−from django.contrib.gis.geos.prototypes import cs_clone, cs_getdims, cs_getordinate, cs_getsize, cs_setordinate
+
−if HAS_NUMPY: from numpy import ndarray
+
−
+
−class GEOSCoordSeq(object):
+
−    "The internal representation of a list of coordinates inside a Geometry."
+
−
+
−    #### Python 'magic' routines ####
+
−    def __init__(self, ptr, z=False):
+
−        "Initializes from a GEOS pointer."
+
−        if not isinstance(ptr, CS_PTR):
+
−            raise TypeError('Coordinate sequence should initialize with a CS_PTR.')
+
−        self._ptr = ptr
+
−        self._z = z
+
−
+
−    def __iter__(self):
+
−        "Iterates over each point in the coordinate sequence."
+
−        for i in xrange(self.size):
+
−            yield self[i]
+
−
+
−    def __len__(self):
+
−        "Returns the number of points in the coordinate sequence."
+
−        return int(self.size)
+
−
+
−    def __str__(self):
+
−        "Returns the string representation of the coordinate sequence."
+
−        return str(self.tuple)
+
−
+
−    def __getitem__(self, index):
+
−        "Returns the coordinate sequence value at the given index."
+
−        coords = [self.getX(index), self.getY(index)]
+
−        if self.dims == 3 and self._z:
+
−            coords.append(self.getZ(index))
+
−        return tuple(coords)
+
−
+
−    def __setitem__(self, index, value):
+
−        "Sets the coordinate sequence value at the given index."
+
−        # Checking the input value
+
−        if isinstance(value, (ListType, TupleType)):
+
−            pass
+
−        elif HAS_NUMPY and isinstance(value, ndarray):
+
−            pass
+
−        else:
+
−            raise TypeError('Must set coordinate with a sequence (list, tuple, or numpy array).')
+
−        # Checking the dims of the input
+
−        if self.dims == 3 and self._z:
+
−            n_args = 3
+
−            set_3d = True
+
−        else:
+
−            n_args = 2
+
−            set_3d = False
+
−        if len(value) != n_args:
+
−            raise TypeError('Dimension of value does not match.')
+
−        # Setting the X, Y, Z
+
−        self.setX(index, value[0])
+
−        self.setY(index, value[1])
+
−        if set_3d: self.setZ(index, value[2])
+
−
+
−    #### Internal Routines ####
+
−    def _checkindex(self, index):
+
−        "Checks the given index."
+
−        sz = self.size
+
−        if (sz < 1) or (index < 0) or (index >= sz):
+
−            raise GEOSIndexError('invalid GEOS Geometry index: %s' % str(index))
+
−
+
−    def _checkdim(self, dim):
+
−        "Checks the given dimension."
+
−        if dim < 0 or dim > 2:
+
−            raise GEOSException('invalid ordinate dimension "%d"' % dim)
+
−
+
−    @property
+
−    def ptr(self):
+
−        """
+
−        Property for controlling access to coordinate sequence pointer,
+
−        preventing attempted access to a NULL memory location.
+
−        """
+
−        if self._ptr: return self._ptr
+
−        else: raise GEOSException('NULL coordinate sequence pointer encountered.')
+
−
+
−    #### Ordinate getting and setting routines ####
+
−    def getOrdinate(self, dimension, index):
+
−        "Returns the value for the given dimension and index."
+
−        self._checkindex(index)
+
−        self._checkdim(dimension)
+
−        return cs_getordinate(self.ptr, index, dimension, byref(c_double()))
+
−
+
−    def setOrdinate(self, dimension, index, value):
+
−        "Sets the value for the given dimension and index."
+
−        self._checkindex(index)
+
−        self._checkdim(dimension)
+
−        cs_setordinate(self.ptr, index, dimension, value)
+
−
+
−    def getX(self, index):
+
−        "Get the X value at the index."
+
−        return self.getOrdinate(0, index)
+
−
+
−    def setX(self, index, value):
+
−        "Set X with the value at the given index."
+
−        self.setOrdinate(0, index, value)
+
−
+
−    def getY(self, index):
+
−        "Get the Y value at the given index."
+
−        return self.getOrdinate(1, index)
+
−
+
−    def setY(self, index, value):
+
−        "Set Y with the value at the given index."
+
−        self.setOrdinate(1, index, value)
+
−
+
−    def getZ(self, index):
+
−        "Get Z with the value at the given index."
+
−        return self.getOrdinate(2, index)
+
−
+
−    def setZ(self, index, value):
+
−        "Set Z with the value at the given index."
+
−        self.setOrdinate(2, index, value)
+
−
+
−    ### Dimensions ###
+
−    @property
+
−    def size(self):
+
−        "Returns the size of this coordinate sequence."
+
−        return cs_getsize(self.ptr, byref(c_uint()))
+
−
+
−    @property
+
−    def dims(self):
+
−        "Returns the dimensions of this coordinate sequence."
+
−        return cs_getdims(self.ptr, byref(c_uint()))
+
−
+
−    @property
+
−    def hasz(self):
+
−        """
+
−        Returns whether this coordinate sequence is 3D.  This property value is
+
−        inherited from the parent Geometry.
+
−        """
+
−        return self._z
+
−
+
−    ### Other Methods ###
+
−    def clone(self):
+
−        "Clones this coordinate sequence."
+
−        return GEOSCoordSeq(cs_clone(self.ptr), self.hasz)
+
−
+
−    @property
+
−    def kml(self):
+
−        "Returns the KML representation for the coordinates."
+
−        # Getting the substitution string depending on whether the coordinates have
+
−        #  a Z dimension.
+
−        if self.hasz: substr = '%s,%s,%s '
+
−        else: substr = '%s,%s,0 '
+
−        return '<coordinates>%s</coordinates>' % \
+
−            ''.join([substr % self[i] for i in xrange(len(self))]).strip()
+
−
+
−    @property
+
−    def tuple(self):
+
−        "Returns a tuple version of this coordinate sequence."
+
−        n = self.size
+
−        if n == 1: return self[0]
+
−        else: return tuple([self[i] for i in xrange(n)])