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

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:
            name = _("Unknown")

        self.params = params
        self.name = name

    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 SetName(self, name):
        """Set the name of the projection."""
        if isinstance(name, StringTypes):
            self.name = 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 __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 objection proj from the projection file.

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

        self.__projs.remove(proj)

    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			class Projection(BaseProjection):
19
20			"""A proj4 projection object that remembers the parameters"""
21
22	jonathan	745	def __init__(self, params, name = None):
23			"""Initialize the Projection with a list of
24			'parameter=value' strings and an optional name. If 'name' is
25			None, the name will be set to 'Unknown' in the local language.
26			"""
27
28	bh	6	BaseProjection.__init__(self, params)
29	jonathan	745
30			if name is None:
31			name = _("Unknown")
32
33	bh	6	self.params = params
34	jonathan	695	self.name = name
35	bh	6
36			def ForwardBBox(self, bbox):
37			"""Return the bounding box of the corners of the bounding box bbox
38			"""
39			# This is not really the correct way to determine the bbox of a
40			# projected shape, but for now it works well enough
41			llx, lly, urx, ury = bbox
42			xs = []; ys = []
43			x, y = self.Forward(llx, lly)
44			xs.append(x); ys.append(y)
45			x, y = self.Forward(llx, ury)
46			xs.append(x); ys.append(y)
47			x, y = self.Forward(urx, ury)
48			xs.append(x); ys.append(y)
49			x, y = self.Forward(urx, lly)
50			xs.append(x); ys.append(y)
51			return min(xs), min(ys), max(xs), max(ys)
52	jonathan	695
53			def GetName(self):
54	jonathan	738	"""Return the name of the projection."""
55	jonathan	695	return self.name
56
57	jonathan	726	def SetName(self, name):
58	jonathan	738	"""Set the name of the projection."""
59	jonathan	726	if isinstance(name, StringTypes):
60			self.name = 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			def __repr__(self):
82	jonathan	726	return self.name + ": " + repr(self.params)
83	jonathan	695
84			class ProjFile:
85
86			def __init__(self, filename):
87	jonathan	738	"""Intialize the ProjFile.
88	jonathan	695
89	jonathan	738	filename -- name of the file that this ProjFile represents.
90			"""
91
92			self.__projs = []
93
94			self.SetFilename(filename)
95	jonathan	695
96			def Add(self, proj):
97	jonathan	738	"""Add the given projection to the end of the file. If 'proj'
98			already exists, it is replaced in the same location as the
99			original projection.
100			"""
101	jonathan	695
102	jonathan	738	try:
103			#
104			# see if the projection already exists.
105			# this only works if Projection doesn't override __eq__
106			#
107			self.__projs[self.__projs.index(proj)] = proj
108			except ValueError:
109			self.__projs.append(proj)
110
111	jonathan	726	def Remove(self, proj):
112	jonathan	738	"""Remove the objection proj from the projection file.
113	jonathan	726
114	jonathan	738	Raises a ValueError is proj is not found.
115			"""
116	jonathan	695
117	jonathan	738	self.__projs.remove(proj)
118	jonathan	695
119	jonathan	738	def GetFilename(self):
120			"""Return the filename where the ProjFile was read or will be
121			written to.
122			"""
123
124			return self.__filename
125
126			def SetFilename(self, filename):
127			"""Set the filename where the ProjFile will be written to."""
128			self.__filename = filename
129
130	jonathan	695	def GetProjections(self):
131	jonathan	738	"""Return a list of the projections in the order they were read
132			from the file or will be written.
133
134			This is not a deep copy list, so any modifications made to the
135			Projection objects will be written to the file.
136			"""
137
138			return self.__projs
139
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svn:keywords	Author Date Id Revision