from django.contrib.gis.gdal.error import OGRException
#### OGRGeomType ####
class OGRGeomType(object):
"Encapulates OGR Geometry Types."
wkb25bit = -2147483648
# Dictionary of acceptable OGRwkbGeometryType s and their string names.
_types = {0 : 'Unknown',
1 : 'Point',
2 : 'LineString',
3 : 'Polygon',
4 : 'MultiPoint',
5 : 'MultiLineString',
6 : 'MultiPolygon',
7 : 'GeometryCollection',
100 : 'None',
101 : 'LinearRing',
1 + wkb25bit: 'Point25D',
2 + wkb25bit: 'LineString25D',
3 + wkb25bit: 'Polygon25D',
4 + wkb25bit: 'MultiPoint25D',
5 + wkb25bit : 'MultiLineString25D',
6 + wkb25bit : 'MultiPolygon25D',
7 + wkb25bit : 'GeometryCollection25D',
}
# Reverse type dictionary, keyed by lower-case of the name.
_str_types = dict([(v.lower(), k) for k, v in _types.items()])
def __init__(self, type_input):
"Figures out the correct OGR Type based upon the input."
if isinstance(type_input, OGRGeomType):
num = type_input.num
elif isinstance(type_input, basestring):
type_input = type_input.lower()
if type_input == 'geometry': type_input='unknown'
num = self._str_types.get(type_input, None)
if num is None:
raise OGRException('Invalid OGR String Type "%s"' % type_input)
elif isinstance(type_input, int):
if not type_input in self._types:
raise OGRException('Invalid OGR Integer Type: %d' % type_input)
num = type_input
else:
raise TypeError('Invalid OGR input type given.')
# Setting the OGR geometry type number.
self.num = num
def __str__(self):
"Returns the value of the name property."
return self.name
def __eq__(self, other):
"""
Does an equivalence test on the OGR type with the given
other OGRGeomType, the short-hand string, or the integer.
"""
if isinstance(other, OGRGeomType):
return self.num == other.num
elif isinstance(other, basestring):
return self.name.lower() == other.lower()
elif isinstance(other, int):
return self.num == other
else:
return False
def __ne__(self, other):
return not (self == other)
@property
def name(self):
"Returns a short-hand string form of the OGR Geometry type."
return self._types[self.num]
@property
def django(self):
"Returns the Django GeometryField for this OGR Type."
s = self.name.replace('25D', '')
if s in ('LinearRing', 'None'):
return None
elif s == 'Unknown':
s = 'Geometry'
return s + 'Field'
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