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):
        """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 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):
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	BaseProjection.__init__(self, params)
32
33	if name is None:
34	self.name = _("Unknown")
35	elif isinstance(name, StringTypes):
36	self.name = name
37
38	self.params = params
39
40	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
56	return min(xs), min(ys), max(xs), max(ys)
57
58	def GetName(self):
59	"""Return the name of the projection."""
60	return self.name
61
62	def GetParameter(self, param):
63	"""Return the projection value for the given parameter.
64
65	If 'param' exists as a valid parameter return the associated
66	value as a string. If the parameter does not have a value (like
67	e.g. the 'south' parameter for utm) then the value is the
68	parameter name itself.
69
70	If the parameter doesn't exist return an empty string.
71	"""
72
73	for pair in self.params:
74	if "=" in pair:
75	p, v = pair.split("=")
76	else:
77	p = v = pair
78	if p == param:
79	return v
80
81	return ""
82
83	def GetAllParameters(self):
84	"""Return list of 'parameter=value' strings"""
85	return self.params
86
87	def GetProjectedUnits(self):
88	if self.GetParameter("proj") == "latlong":
89	return PROJ_UNITS_DEGREES
90	else:
91	return PROJ_UNITS_METERS
92
93	def __repr__(self):
94	return self.name + ": " + repr(self.params)
95
96	class ProjFile:
97
98	def __init__(self, filename):
99	"""Intialize the ProjFile.
100
101	filename -- name of the file that this ProjFile represents.
102	"""
103
104	self.__projs = []
105
106	self.SetFilename(filename)
107
108	def Add(self, proj):
109	"""Add the projection to the end of the file."""
110	self.__projs.append(proj)
111
112	def Remove(self, proj):
113	"""Remove the object proj from the projection file.
114
115	Raises a ValueError is proj is not found.
116	"""
117
118	self.__projs.remove(proj)
119
120	def Replace(self, oldproj, newproj):
121	"""Replace the object 'oldproj' with 'newproj'.
122
123	Raises ValueError if oldproj is not in the file.
124	"""
125
126	#
127	# see if the projection already exists.
128	# this only works if Projection doesn't override __eq__
129	#
130	self.__projs[self.__projs.index(oldproj)] = newproj
131
132	def GetFilename(self):
133	"""Return the filename where the ProjFile was read or will be
134	written to.
135	"""
136
137	return self.__filename
138
139	def SetFilename(self, filename):
140	"""Set the filename where the ProjFile will be written to."""
141	self.__filename = filename
142
143	def GetProjections(self):
144	"""Return a list of the projections in the order they were read
145	from the file or will be written.
146
147	This is not a deep copy list, so any modifications made to the
148	Projection objects will be written to the file.
149	"""
150
151	return self.__projs
152
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svn:keywords	Author Date Id Revision