def __init__(self, *args):
"""
The initialization function may take an OGREnvelope structure, 4-element
tuple or list, or 4 individual arguments.
"""
if len(args) == 1:
if isinstance(args[0], OGREnvelope):
# OGREnvelope (a ctypes Structure) was passed in.
self._envelope = args[0]
elif isinstance(args[0], (tuple, list)):
# A tuple was passed in.
if len(args[0]) != 4:
raise OGRException(
'Incorrect number of tuple elements (%d).' %
len(args[0]))
else:
self._from_sequence(args[0])
else:
raise TypeError('Incorrect type of argument: %s' %
str(type(args[0])))
elif len(args) == 4:
# Individual parameters passed in.
# Thanks to ww for the help
self._from_sequence(map(float, args))
else:
raise OGRException('Incorrect number (%d) of arguments.' %
len(args))
# Checking the x,y coordinates
if self.min_x > self.max_x:
raise OGRException('Envelope minimum X > maximum X.')
if self.min_y > self.max_y:
raise OGRException('Envelope minimum Y > maximum Y.')
def __init__(self, dr_input):
"Initializes an OGR driver on either a string or integer input."
if isinstance(dr_input, basestring):
# If a string name of the driver was passed in
self._register()
# Checking the alias dictionary (case-insensitive) to see if an alias
# exists for the given driver.
if dr_input.lower() in self._alias:
name = self._alias[dr_input.lower()]
else:
name = dr_input
# Attempting to get the OGR driver by the string name.
dr = capi.get_driver_by_name(name)
elif isinstance(dr_input, int):
self._register()
dr = capi.get_driver(dr_input)
elif isinstance(dr_input, c_void_p):
dr = dr_input
else:
raise OGRException('Unrecognized input type for OGR Driver: %s' % str(type(dr_input)))
# Making sure we get a valid pointer to the OGR Driver
if not dr:
raise OGRException('Could not initialize OGR Driver on input: %s' % str(dr_input))
self.ptr = dr
def __init__(self, ds_input, ds_driver=False, write=False):
# The write flag.
if write:
self._write = 1
else:
self._write = 0
# Registering all the drivers, this needs to be done
# _before_ we try to open up a data source.
if not capi.get_driver_count():
capi.register_all()
if isinstance(ds_input, basestring):
# The data source driver is a void pointer.
ds_driver = Driver.ptr_type()
try:
# OGROpen will auto-detect the data source type.
ds = capi.open_ds(ds_input, self._write, byref(ds_driver))
except OGRException:
# Making the error message more clear rather than something
# like "Invalid pointer returned from OGROpen".
raise OGRException('Could not open the datasource at "%s"' % ds_input)
elif isinstance(ds_input, self.ptr_type) and isinstance(ds_driver, Driver.ptr_type):
ds = ds_input
else:
raise OGRException('Invalid data source input type: %s' % type(ds_input))
if bool(ds):
self.ptr = ds
self.driver = Driver(ds_driver)
else:
# Raise an exception if the returned pointer is NULL
raise OGRException('Invalid data source file "%s"' % ds_input)
def __init__(self, feat, fdefn):
"Initializes on the pointers for the feature and the layer definition."
if not feat or not fdefn:
raise OGRException(
'Cannot create OGR Feature, invalid pointer given.')
self.ptr = feat
self._fdefn = fdefn
def expand_to_include(self, *args):
"""
Modifies the envelope to expand to include the boundaries of
the passed-in 2-tuple (a point), 4-tuple (an extent) or
envelope.
"""
# We provide a number of different signatures for this method,
# and the logic here is all about converting them into a
# 4-tuple single parameter which does the actual work of
# expanding the envelope.
if len(args) == 1:
if isinstance(args[0], Envelope):
return self.expand_to_include(args[0].tuple)
elif hasattr(args[0], 'x') and hasattr(args[0], 'y'):
return self.expand_to_include(args[0].x, args[0].y, args[0].x,
args[0].y)
elif isinstance(args[0], (tuple, list)):
# A tuple was passed in.
if len(args[0]) == 2:
return self.expand_to_include(
(args[0][0], args[0][1], args[0][0], args[0][1]))
elif len(args[0]) == 4:
(minx, miny, maxx, maxy) = args[0]
if minx < self._envelope.MinX:
self._envelope.MinX = minx
if miny < self._envelope.MinY:
self._envelope.MinY = miny
if maxx > self._envelope.MaxX:
self._envelope.MaxX = maxx
if maxy > self._envelope.MaxY:
self._envelope.MaxY = maxy
else:
raise OGRException(
'Incorrect number of tuple elements (%d).' %
len(args[0]))
else:
raise TypeError('Incorrect type of argument: %s' %
str(type(args[0])))
elif len(args) == 2:
# An x and an y parameter were passed in
return self.expand_to_include((args[0], args[1], args[0], args[1]))
elif len(args) == 4:
# Individual parameters passed in.
return self.expand_to_include(args)
else:
raise OGRException('Incorrect number (%d) of arguments.' %
len(args[0]))
def check_pointer(result, func, cargs):
"Makes sure the result pointer is valid."
if isinstance(result, (int, long)):
result = c_void_p(result)
if bool(result):
return result
else:
raise OGRException('Invalid pointer returned from "%s"' % func.__name__)
def get_fields(self, field_name):
"""
Returns a list containing the given field name for every Feature
in the Layer.
"""
if not field_name in self.fields:
raise OGRException('invalid field name: %s' % field_name)
return [feat.get(field_name) for feat in self]
def check_geom(result, func, cargs):
"Checks a function that returns a geometry."
# OGR_G_Clone may return an integer, even though the
# restype is set to c_void_p
if isinstance(result, (int, long)):
result = c_void_p(result)
if not result:
raise OGRException('Invalid geometry pointer returned from "%s".' % func.__name__)
return result
def as_datetime(self):
"Retrieves the Field's value as a tuple of date & time components."
yy, mm, dd, hh, mn, ss, tz = [c_int() for i in range(7)]
status = capi.get_field_as_datetime(self._feat, self._index, byref(yy), byref(mm), byref(dd),
byref(hh), byref(mn), byref(ss), byref(tz))
if status:
return (yy, mm, dd, hh, mn, ss, tz)
else:
raise OGRException('Unable to retrieve date & time information from the field.')
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 add(self, geom):
"Add the geometry to this Geometry Collection."
if isinstance(geom, OGRGeometry):
if isinstance(geom, self.__class__):
for g in geom: capi.add_geom(self.ptr, g.ptr)
else:
capi.add_geom(self.ptr, geom.ptr)
elif isinstance(geom, basestring):
tmp = OGRGeometry(geom)
capi.add_geom(self.ptr, tmp.ptr)
else:
raise OGRException('Must add an OGRGeometry.')
def __eq__(self, other):
"""
Returns True if the envelopes are equivalent; can compare against
other Envelopes and 4-tuples.
"""
if isinstance(other, Envelope):
return (self.min_x == other.min_x) and (self.min_y == other.min_y) and \
(self.max_x == other.max_x) and (self.max_y == other.max_y)
elif isinstance(other, tuple) and len(other) == 4:
return (self.min_x == other[0]) and (self.min_y == other[1]) and \
(self.max_x == other[2]) and (self.max_y == other[3])
else:
raise OGRException(
'Equivalence testing only works with other Envelopes.')
def __init__(self, layer_ptr, ds):
"""
Initializes on an OGR C pointer to the Layer and the `DataSource` object
that owns this layer. The `DataSource` object is required so that a
reference to it is kept with this Layer. This prevents garbage
collection of the `DataSource` while this Layer is still active.
"""
if not layer_ptr:
raise OGRException('Cannot create Layer, invalid pointer given')
self.ptr = layer_ptr
self._ds = ds
self._ldefn = capi.get_layer_defn(self._ptr)
# Does the Layer support random reading?
self._random_read = self.test_capability('RandomRead')
def __init__(self, feat, index):
"""
Initializes on the feature pointer and the integer index of
the field within the feature.
"""
# Setting the feature pointer and index.
self._feat = feat
self._index = index
# Getting the pointer for this field.
fld_ptr = capi.get_feat_field_defn(feat, index)
if not fld_ptr:
raise OGRException('Cannot create OGR Field, invalid pointer given.')
self.ptr = fld_ptr
# Setting the class depending upon the OGR Field Type (OFT)
self.__class__ = OGRFieldTypes[self.type]
# OFTReal with no precision should be an OFTInteger.
if isinstance(self, OFTReal) and self.precision == 0:
self.__class__ = OFTInteger
self._double = True
def gdal_version_info():
ver = gdal_version()
m = version_regex.match(ver)
if not m: raise OGRException('Could not parse GDAL version string "%s"' % ver)
return dict([(key, m.group(key)) for key in ('major', 'minor', 'subminor')])
try:
from my_django.conf import settings
lib_path = settings.GDAL_LIBRARY_PATH
except (AttributeError, EnvironmentError, ImportError):
lib_path = None
if lib_path:
lib_names = None
elif os.name == 'nt':
# Windows NT shared libraries
lib_names = ['gdal18', 'gdal17', 'gdal16', 'gdal15']
elif os.name == 'posix':
# *NIX library names.
lib_names = ['gdal', 'GDAL', 'gdal1.8.0', 'gdal1.7.0', 'gdal1.6.0', 'gdal1.5.0', 'gdal1.4.0']
else:
raise OGRException('Unsupported OS "%s"' % os.name)
# Using the ctypes `find_library` utility to find the
# path to the GDAL library from the list of library names.
if lib_names:
for lib_name in lib_names:
lib_path = find_library(lib_name)
if not lib_path is None: break
if lib_path is None:
raise OGRException('Could not find the GDAL library (tried "%s"). '
'Try setting GDAL_LIBRARY_PATH in your settings.' %
'", "'.join(lib_names))
# This loads the GDAL/OGR C library
lgdal = CDLL(lib_path)
def __init__(self, geom_input, srs=None):
"Initializes Geometry on either WKT or an OGR pointer as input."
str_instance = isinstance(geom_input, basestring)
# If HEX, unpack input to to a binary buffer.
if str_instance and hex_regex.match(geom_input):
geom_input = buffer(a2b_hex(geom_input.upper()))
str_instance = False
# Constructing the geometry,
if str_instance:
# Checking if unicode
if isinstance(geom_input, unicode):
# Encoding to ASCII, WKT or HEX doesn't need any more.
geom_input = geom_input.encode('ascii')
wkt_m = wkt_regex.match(geom_input)
json_m = json_regex.match(geom_input)
if wkt_m:
if wkt_m.group('srid'):
# If there's EWKT, set the SRS w/value of the SRID.
srs = int(wkt_m.group('srid'))
if wkt_m.group('type').upper() == 'LINEARRING':
# OGR_G_CreateFromWkt doesn't work with LINEARRING WKT.
# See http://trac.osgeo.org/gdal/ticket/1992.
g = capi.create_geom(OGRGeomType(wkt_m.group('type')).num)
capi.import_wkt(g, byref(c_char_p(wkt_m.group('wkt'))))
else:
g = capi.from_wkt(byref(c_char_p(wkt_m.group('wkt'))), None, byref(c_void_p()))
elif json_m:
if GEOJSON:
g = capi.from_json(geom_input)
else:
raise NotImplementedError('GeoJSON input only supported on GDAL 1.5+.')
else:
# Seeing if the input is a valid short-hand string
# (e.g., 'Point', 'POLYGON').
ogr_t = OGRGeomType(geom_input)
g = capi.create_geom(OGRGeomType(geom_input).num)
elif isinstance(geom_input, buffer):
# WKB was passed in
g = capi.from_wkb(str(geom_input), None, byref(c_void_p()), len(geom_input))
elif isinstance(geom_input, OGRGeomType):
# OGRGeomType was passed in, an empty geometry will be created.
g = capi.create_geom(geom_input.num)
elif isinstance(geom_input, self.ptr_type):
# OGR pointer (c_void_p) was the input.
g = geom_input
else:
raise OGRException('Invalid input type for OGR Geometry construction: %s' % type(geom_input))
# Now checking the Geometry pointer before finishing initialization
# by setting the pointer for the object.
if not g:
raise OGRException('Cannot create OGR Geometry from input: %s' % str(geom_input))
self.ptr = g
# Assigning the SpatialReference object to the geometry, if valid.
if bool(srs): self.srs = srs
# Setting the class depending upon the OGR Geometry Type
self.__class__ = GEO_CLASSES[self.geom_type.num]
def __setstate__(self, state):
wkb, srs = state
ptr = capi.from_wkb(wkb, None, byref(c_void_p()), len(wkb))
if not ptr: raise OGRException('Invalid OGRGeometry loaded from pickled state.')
self.ptr = ptr
self.srs = srs