Thuban/Model/proj.py

# Copyright (c) 2001, 2003 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, epsg = None):
        """Initialize the Projection

        Parameters:

        params -- a list of 'parameter=value' strings

        name -- (optional) The name of the projectin. If None or omitted
                it defaults to 'Unknown' in the local language.

        epsg -- (optional) The EPSG code as a string.
        """
        BaseProjection.__init__(self, params)

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

        self.epsg = epsg
        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 Label(self):
        if self.epsg:
            return "EPSG % 5s %s" % (self.epsg, self.name)
        return self.name

    def EPSGCode(self):
        """Return the EPSG code as a string or None if there is none"""
        return self.epsg

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

        If 'param' exists as a valid parameter return the associated
        value as a string. If the parameter does not have a value (like
        e.g. the 'south' parameter for utm) then the value is the
        parameter name itself.

        If the parameter doesn't exist return an empty string.
        """

        for pair in self.params:
            if "=" in pair:
                p, v = pair.split("=")
            else:
                p = v = pair
            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 projection to the end of the file."""
        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	# Copyright (c) 2001, 2003 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	from Thuban import _
11
12	from types import StringTypes
13
14	import Projection
15	BaseProjection = Projection.Projection
16	del Projection
17
18	PROJ_UNITS_METERS = 1
19	PROJ_UNITS_DEGREES = 2
20
21	class Projection(BaseProjection):
22
23	"""A proj4 projection object that remembers the parameters"""
24
25	def __init__(self, params, name = None, epsg = None):
26	"""Initialize the Projection
27
28	Parameters:
29
30	params -- a list of 'parameter=value' strings
31
32	name -- (optional) The name of the projectin. If None or omitted
33	it defaults to 'Unknown' in the local language.
34
35	epsg -- (optional) The EPSG code as a string.
36	"""
37	BaseProjection.__init__(self, params)
38
39	if name is None:
40	self.name = _("Unknown")
41	elif isinstance(name, StringTypes):
42	self.name = name
43
44	self.epsg = epsg
45	self.params = params
46
47	def ForwardBBox(self, bbox):
48	"""Return the bounding box of the corners of the bounding box bbox
49	"""
50	# This is not really the correct way to determine the bbox of a
51	# projected shape, but for now it works well enough
52	llx, lly, urx, ury = bbox
53	xs = []; ys = []
54	x, y = self.Forward(llx, lly)
55	xs.append(x); ys.append(y)
56	x, y = self.Forward(llx, ury)
57	xs.append(x); ys.append(y)
58	x, y = self.Forward(urx, ury)
59	xs.append(x); ys.append(y)
60	x, y = self.Forward(urx, lly)
61	xs.append(x); ys.append(y)
62
63	return min(xs), min(ys), max(xs), max(ys)
64
65	def GetName(self):
66	"""Return the name of the projection."""
67	return self.name
68
69	def Label(self):
70	if self.epsg:
71	return "EPSG % 5s %s" % (self.epsg, self.name)
72	return self.name
73
74	def EPSGCode(self):
75	"""Return the EPSG code as a string or None if there is none"""
76	return self.epsg
77
78	def GetParameter(self, param):
79	"""Return the projection value for the given parameter.
80
81	If 'param' exists as a valid parameter return the associated
82	value as a string. If the parameter does not have a value (like
83	e.g. the 'south' parameter for utm) then the value is the
84	parameter name itself.
85
86	If the parameter doesn't exist return an empty string.
87	"""
88
89	for pair in self.params:
90	if "=" in pair:
91	p, v = pair.split("=")
92	else:
93	p = v = pair
94	if p == param:
95	return v
96
97	return ""
98
99	def GetAllParameters(self):
100	"""Return list of 'parameter=value' strings"""
101	return self.params
102
103	def GetProjectedUnits(self):
104	if self.GetParameter("proj") == "latlong":
105	return PROJ_UNITS_DEGREES
106	else:
107	return PROJ_UNITS_METERS
108
109	def __repr__(self):
110	return self.name + ": " + repr(self.params)
111
112
113	class ProjFile:
114
115	def __init__(self, filename):
116	"""Intialize the ProjFile.
117
118	filename -- name of the file that this ProjFile represents.
119	"""
120
121	self.__projs = []
122
123	self.SetFilename(filename)
124
125	def Add(self, proj):
126	"""Add the projection to the end of the file."""
127	self.__projs.append(proj)
128
129	def Remove(self, proj):
130	"""Remove the object proj from the projection file.
131
132	Raises a ValueError is proj is not found.
133	"""
134
135	self.__projs.remove(proj)
136
137	def Replace(self, oldproj, newproj):
138	"""Replace the object 'oldproj' with 'newproj'.
139
140	Raises ValueError if oldproj is not in the file.
141	"""
142
143	#
144	# see if the projection already exists.
145	# this only works if Projection doesn't override __eq__
146	#
147	self.__projs[self.__projs.index(oldproj)] = newproj
148
149	def GetFilename(self):
150	"""Return the filename where the ProjFile was read or will be
151	written to.
152	"""
153
154	return self.__filename
155
156	def SetFilename(self, filename):
157	"""Set the filename where the ProjFile will be written to."""
158	self.__filename = filename
159
160	def GetProjections(self):
161	"""Return a list of the projections in the order they were read
162	from the file or will be written.
163
164	This is not a deep copy list, so any modifications made to the
165	Projection objects will be written to the file.
166	"""
167
168	return self.__projs
169
Name	Value
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svn:keywords	Author Date Id Revision