diff options
Diffstat (limited to 'lib/python2.7/site-packages/django/contrib/gis/gdal/layer.py')
| -rw-r--r-- | lib/python2.7/site-packages/django/contrib/gis/gdal/layer.py | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/lib/python2.7/site-packages/django/contrib/gis/gdal/layer.py b/lib/python2.7/site-packages/django/contrib/gis/gdal/layer.py deleted file mode 100644 index 7f935cd..0000000 --- a/lib/python2.7/site-packages/django/contrib/gis/gdal/layer.py +++ /dev/null @@ -1,218 +0,0 @@ -# Needed ctypes routines -from ctypes import c_double, byref - -# Other GDAL imports. -from django.contrib.gis.gdal.base import GDALBase -from django.contrib.gis.gdal.envelope import Envelope, OGREnvelope -from django.contrib.gis.gdal.error import OGRException, OGRIndexError, SRSException -from django.contrib.gis.gdal.feature import Feature -from django.contrib.gis.gdal.field import OGRFieldTypes -from django.contrib.gis.gdal.geomtype import OGRGeomType -from django.contrib.gis.gdal.geometries import OGRGeometry -from django.contrib.gis.gdal.srs import SpatialReference - -# GDAL ctypes function prototypes. -from django.contrib.gis.gdal.prototypes import ds as capi, geom as geom_api, srs as srs_api - -from django.utils.encoding import force_bytes, force_text -from django.utils import six -from django.utils.six.moves import xrange - -# For more information, see the OGR C API source code: -# http://www.gdal.org/ogr/ogr__api_8h.html -# -# The OGR_L_* routines are relevant here. -class Layer(GDALBase): - "A class that wraps an OGR Layer, needs to be instantiated from a DataSource object." - - #### Python 'magic' routines #### - 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(b'RandomRead') - - def __getitem__(self, index): - "Gets the Feature at the specified index." - if isinstance(index, six.integer_types): - # An integer index was given -- we cannot do a check based on the - # number of features because the beginning and ending feature IDs - # are not guaranteed to be 0 and len(layer)-1, respectively. - if index < 0: raise OGRIndexError('Negative indices are not allowed on OGR Layers.') - return self._make_feature(index) - elif isinstance(index, slice): - # A slice was given - start, stop, stride = index.indices(self.num_feat) - return [self._make_feature(fid) for fid in xrange(start, stop, stride)] - else: - raise TypeError('Integers and slices may only be used when indexing OGR Layers.') - - def __iter__(self): - "Iterates over each Feature in the Layer." - # ResetReading() must be called before iteration is to begin. - capi.reset_reading(self._ptr) - for i in xrange(self.num_feat): - yield Feature(capi.get_next_feature(self._ptr), self) - - def __len__(self): - "The length is the number of features." - return self.num_feat - - def __str__(self): - "The string name of the layer." - return self.name - - def _make_feature(self, feat_id): - """ - Helper routine for __getitem__ that constructs a Feature from the given - Feature ID. If the OGR Layer does not support random-access reading, - then each feature of the layer will be incremented through until the - a Feature is found matching the given feature ID. - """ - if self._random_read: - # If the Layer supports random reading, return. - try: - return Feature(capi.get_feature(self.ptr, feat_id), self) - except OGRException: - pass - else: - # Random access isn't supported, have to increment through - # each feature until the given feature ID is encountered. - for feat in self: - if feat.fid == feat_id: return feat - # Should have returned a Feature, raise an OGRIndexError. - raise OGRIndexError('Invalid feature id: %s.' % feat_id) - - #### Layer properties #### - @property - def extent(self): - "Returns the extent (an Envelope) of this layer." - env = OGREnvelope() - capi.get_extent(self.ptr, byref(env), 1) - return Envelope(env) - - @property - def name(self): - "Returns the name of this layer in the Data Source." - name = capi.get_fd_name(self._ldefn) - return force_text(name, self._ds.encoding, strings_only=True) - - @property - def num_feat(self, force=1): - "Returns the number of features in the Layer." - return capi.get_feature_count(self.ptr, force) - - @property - def num_fields(self): - "Returns the number of fields in the Layer." - return capi.get_field_count(self._ldefn) - - @property - def geom_type(self): - "Returns the geometry type (OGRGeomType) of the Layer." - return OGRGeomType(capi.get_fd_geom_type(self._ldefn)) - - @property - def srs(self): - "Returns the Spatial Reference used in this Layer." - try: - ptr = capi.get_layer_srs(self.ptr) - return SpatialReference(srs_api.clone_srs(ptr)) - except SRSException: - return None - - @property - def fields(self): - """ - Returns a list of string names corresponding to each of the Fields - available in this Layer. - """ - return [force_text(capi.get_field_name(capi.get_field_defn(self._ldefn, i)), - self._ds.encoding, strings_only=True) - for i in xrange(self.num_fields)] - - @property - def field_types(self): - """ - Returns a list of the types of fields in this Layer. For example, - the list [OFTInteger, OFTReal, OFTString] would be returned for - an OGR layer that had an integer, a floating-point, and string - fields. - """ - return [OGRFieldTypes[capi.get_field_type(capi.get_field_defn(self._ldefn, i))] - for i in xrange(self.num_fields)] - - @property - def field_widths(self): - "Returns a list of the maximum field widths for the features." - return [capi.get_field_width(capi.get_field_defn(self._ldefn, i)) - for i in xrange(self.num_fields)] - - @property - def field_precisions(self): - "Returns the field precisions for the features." - return [capi.get_field_precision(capi.get_field_defn(self._ldefn, i)) - for i in xrange(self.num_fields)] - - def _get_spatial_filter(self): - try: - return OGRGeometry(geom_api.clone_geom(capi.get_spatial_filter(self.ptr))) - except OGRException: - return None - - def _set_spatial_filter(self, filter): - if isinstance(filter, OGRGeometry): - capi.set_spatial_filter(self.ptr, filter.ptr) - elif isinstance(filter, (tuple, list)): - if not len(filter) == 4: - raise ValueError('Spatial filter list/tuple must have 4 elements.') - # Map c_double onto params -- if a bad type is passed in it - # will be caught here. - xmin, ymin, xmax, ymax = map(c_double, filter) - capi.set_spatial_filter_rect(self.ptr, xmin, ymin, xmax, ymax) - elif filter is None: - capi.set_spatial_filter(self.ptr, None) - else: - raise TypeError('Spatial filter must be either an OGRGeometry instance, a 4-tuple, or None.') - - spatial_filter = property(_get_spatial_filter, _set_spatial_filter) - - #### Layer Methods #### - 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 get_geoms(self, geos=False): - """ - Returns a list containing the OGRGeometry for every Feature in - the Layer. - """ - if geos: - from django.contrib.gis.geos import GEOSGeometry - return [GEOSGeometry(feat.geom.wkb) for feat in self] - else: - return [feat.geom for feat in self] - - def test_capability(self, capability): - """ - Returns a bool indicating whether the this Layer supports the given - capability (a string). Valid capability strings include: - 'RandomRead', 'SequentialWrite', 'RandomWrite', 'FastSpatialFilter', - 'FastFeatureCount', 'FastGetExtent', 'CreateField', 'Transactions', - 'DeleteFeature', and 'FastSetNextByIndex'. - """ - return bool(capi.test_capability(self.ptr, force_bytes(capability))) |