1 #

     2 # Copyright (c) 2008-2017 Thierry Florac <tflorac AT ulthar.net>

     3 # All Rights Reserved.

     4 #

     5 # This software is subject to the provisions of the Zope Public License,

     6 # Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.

     7 # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED

     8 # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

     9 # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS

    10 # FOR A PARTICULAR PURPOSE.

    11 #

    12 

    13 __docformat__ = 'restructuredtext'

    14 

    15 

    16 # import standard library

    17 try:

    18     from osgeo.osr import SpatialReference, CoordinateTransformation

    19     have_gdal = True

    20 except ImportError:

    21     have_gdal = False

    22 from persistent import Persistent

    23 

    24 # import interfaces

    25 from pyams_gis.interfaces import WGS84, IGeoArea

    26 

    27 # import packages

    28 from zope.interface import implementer

    29 from zope.schema.fieldproperty import FieldProperty

    30 

    31 

    32 @implementer(IGeoArea)

    33 class GeoArea(Persistent):

    34     """GeoArea attribute object"""

    35 

    36     x1 = FieldProperty(IGeoArea['x1'])

    37     y1 = FieldProperty(IGeoArea['y1'])

    38     x2 = FieldProperty(IGeoArea['x2'])

    39     y2 = FieldProperty(IGeoArea['y2'])

    40     projection = FieldProperty(IGeoArea['projection'])

    41 

    42     def __bool__(self):

    43         return bool(self.x1 and self.y1 and self.x2 and self.y2)

    44 

    45     def get_coordinates(self, projection=WGS84):

    46         if projection == self.projection:

    47             return (self.x1, self.y1), (self.x2, self.y2)

    48         if (not have_gdal) or not self:

    49             return None, None

    50         source = SpatialReference()

    51         source.ImportFromEPSG(self.projection)

    52         destination = SpatialReference()

    53         destination.ImportFromEPSG(projection)

    54         transformation = CoordinateTransformation(source, destination)

    55         return transformation.TransformPoint(float(self.x1), float(self.y1))[0:2], \

    56                transformation.TransformPoint(float(self.x2), float(self.y2))[0:2]

    57 

    58     @property

    59     def wgs_coordinates(self):

    60         return self.get_coordinates(WGS84)