Thuban/Model/proj.py

# Copyright (c) 2001 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

from Thuban import _

from types import StringTypes

import Projection
BaseProjection = Projection.Projection
del Projection

PROJ_UNITS_METERS  = 1
PROJ_UNITS_DEGREES = 2

class Projection(BaseProjection):

    """A proj4 projection object that remembers the parameters"""

    def __init__(self, params, name = None):
        """Initialize the Projection with a list of 
        'parameter=value' strings and an optional name. If 'name' is
        None, the name will be set to 'Unknown' in the local language.
        """

        BaseProjection.__init__(self, params)

        if name is None:
            self.name = _("Unknown")
        elif isinstance(name, StringTypes):
            self.name = name

        self.params = params

    def ForwardBBox(self, bbox):
        """Return the bounding box of the corners of the bounding box bbox
        """
        # This is not really the correct way to determine the bbox of a
        # projected shape, but for now it works well enough
        llx, lly, urx, ury = bbox
        xs = []; ys = []
        x, y = self.Forward(llx, lly)
        xs.append(x); ys.append(y)
        x, y = self.Forward(llx, ury)
        xs.append(x); ys.append(y)
        x, y = self.Forward(urx, ury)
        xs.append(x); ys.append(y)
        x, y = self.Forward(urx, lly)
        xs.append(x); ys.append(y)
        
        return min(xs), min(ys), max(xs), max(ys)

    def GetName(self):
        """Return the name of the projection."""
        return self.name

    def GetParameter(self, param):
        """Return the projection value for the given parameter.

        If 'param' exists as a valid parameter then the returned
        value is a string with that value. If the parameter doesn't
        exist an empty string is returned.
        """

        for pair in self.params:
            p, v = pair.split("=")
            if p == param:
                return v

        return ""

    def GetAllParameters(self):
        """Return list of 'parameter=value' strings"""
        return self.params

    def GetProjectedUnits(self):
        if self.GetParameter("proj") == "latlong":
            return PROJ_UNITS_DEGREES
        else:
            return PROJ_UNITS_METERS

    def __repr__(self):
        return self.name + ": " + repr(self.params)

class ProjFile:

    def __init__(self, filename):
        """Intialize the ProjFile.

        filename -- name of the file that this ProjFile represents.
        """

        self.__projs = []

        self.SetFilename(filename)
    
    def Add(self, proj):
        """Add the given projection to the end of the file. If 'proj'
        already exists, it is replaced in the same location as the
        original projection.
        """

        try:
            #
            # see if the projection already exists.
            # this only works if Projection doesn't override __eq__
            #
            self.__projs[self.__projs.index(proj)] = proj
        except ValueError:
            self.__projs.append(proj)

    def Remove(self, proj):
        """Remove the object proj from the projection file.

        Raises a ValueError is proj is not found.
        """

        self.__projs.remove(proj)

    def Replace(self, oldproj, newproj):
        """Replace the object 'oldproj' with 'newproj'.
        
        Raises ValueError if oldproj is not in the file.
        """

        #
        # see if the projection already exists.
        # this only works if Projection doesn't override __eq__
        #
        self.__projs[self.__projs.index(oldproj)] = newproj

    def GetFilename(self):
        """Return the filename where the ProjFile was read or will be
        written to.
        """

        return self.__filename

    def SetFilename(self, filename):
        """Set the filename where the ProjFile will be written to."""
        self.__filename = filename

    def GetProjections(self):
        """Return a list of the projections in the order they were read
        from the file or will be written.

        This is not a deep copy list, so any modifications made to the
        Projection objects will be written to the file.
        """

        return self.__projs

1	bh	6	# Copyright (c) 2001 by Intevation GmbH
2			# Authors:
3			# Bernhard Herzog <[email protected]>
4			#
5			# This program is free software under the GPL (>=v2)
6			# Read the file COPYING coming with Thuban for details.
7
8			__version__ = "$Revision$"
9
10	jonathan	745	from Thuban import _
11
12	jonathan	726	from types import StringTypes
13
14	bh	6	import Projection
15			BaseProjection = Projection.Projection
16			del Projection
17
18	jonathan	1250	PROJ_UNITS_METERS = 1
19			PROJ_UNITS_DEGREES = 2
20
21	bh	6	class Projection(BaseProjection):
22
23			"""A proj4 projection object that remembers the parameters"""
24
25	jonathan	745	def __init__(self, params, name = None):
26			"""Initialize the Projection with a list of
27			'parameter=value' strings and an optional name. If 'name' is
28			None, the name will be set to 'Unknown' in the local language.
29			"""
30
31	bh	6	BaseProjection.__init__(self, params)
32	jonathan	745
33	jonathan	758	if name is None:
34			self.name = _("Unknown")
35			elif isinstance(name, StringTypes):
36			self.name = name
37	jonathan	745
38	jonathan	758	self.params = params
39
40	bh	6	def ForwardBBox(self, bbox):
41			"""Return the bounding box of the corners of the bounding box bbox
42			"""
43			# This is not really the correct way to determine the bbox of a
44			# projected shape, but for now it works well enough
45			llx, lly, urx, ury = bbox
46			xs = []; ys = []
47			x, y = self.Forward(llx, lly)
48			xs.append(x); ys.append(y)
49			x, y = self.Forward(llx, ury)
50			xs.append(x); ys.append(y)
51			x, y = self.Forward(urx, ury)
52			xs.append(x); ys.append(y)
53			x, y = self.Forward(urx, lly)
54			xs.append(x); ys.append(y)
55	jonathan	758
56	bh	6	return min(xs), min(ys), max(xs), max(ys)
57	jonathan	695
58			def GetName(self):
59	jonathan	738	"""Return the name of the projection."""
60	jonathan	695	return self.name
61
62	jonathan	708	def GetParameter(self, param):
63	jonathan	738	"""Return the projection value for the given parameter.
64	jonathan	708
65	jonathan	738	If 'param' exists as a valid parameter then the returned
66			value is a string with that value. If the parameter doesn't
67			exist an empty string is returned.
68			"""
69
70	jonathan	708	for pair in self.params:
71			p, v = pair.split("=")
72			if p == param:
73			return v
74
75			return ""
76
77			def GetAllParameters(self):
78	jonathan	738	"""Return list of 'parameter=value' strings"""
79	jonathan	695	return self.params
80
81	jonathan	1250	def GetProjectedUnits(self):
82			if self.GetParameter("proj") == "latlong":
83			return PROJ_UNITS_DEGREES
84			else:
85			return PROJ_UNITS_METERS
86
87	jonathan	695	def __repr__(self):
88	jonathan	726	return self.name + ": " + repr(self.params)
89	jonathan	695
90			class ProjFile:
91
92			def __init__(self, filename):
93	jonathan	738	"""Intialize the ProjFile.
94	jonathan	695
95	jonathan	738	filename -- name of the file that this ProjFile represents.
96			"""
97
98			self.__projs = []
99
100			self.SetFilename(filename)
101	jonathan	695
102			def Add(self, proj):
103	jonathan	738	"""Add the given projection to the end of the file. If 'proj'
104			already exists, it is replaced in the same location as the
105			original projection.
106			"""
107	jonathan	695
108	jonathan	738	try:
109			#
110			# see if the projection already exists.
111			# this only works if Projection doesn't override __eq__
112			#
113			self.__projs[self.__projs.index(proj)] = proj
114			except ValueError:
115			self.__projs.append(proj)
116
117	jonathan	726	def Remove(self, proj):
118	jonathan	758	"""Remove the object proj from the projection file.
119	jonathan	726
120	jonathan	738	Raises a ValueError is proj is not found.
121			"""
122	jonathan	695
123	jonathan	738	self.__projs.remove(proj)
124	jonathan	695
125	jonathan	758	def Replace(self, oldproj, newproj):
126			"""Replace the object 'oldproj' with 'newproj'.
127
128			Raises ValueError if oldproj is not in the file.
129			"""
130
131			#
132			# see if the projection already exists.
133			# this only works if Projection doesn't override __eq__
134			#
135			self.__projs[self.__projs.index(oldproj)] = newproj
136
137	jonathan	738	def GetFilename(self):
138			"""Return the filename where the ProjFile was read or will be
139			written to.
140			"""
141
142			return self.__filename
143
144			def SetFilename(self, filename):
145			"""Set the filename where the ProjFile will be written to."""
146			self.__filename = filename
147
148	jonathan	695	def GetProjections(self):
149	jonathan	738	"""Return a list of the projections in the order they were read
150			from the file or will be written.
151
152			This is not a deep copy list, so any modifications made to the
153			Projection objects will be written to the file.
154			"""
155
156			return self.__projs
157
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision