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:
            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 __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			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	jonathan	758	if name is None:
31			self.name = _("Unknown")
32			elif isinstance(name, StringTypes):
33			self.name = name
34	jonathan	745
35	jonathan	758	self.params = params
36
37	bh	6	def ForwardBBox(self, bbox):
38			"""Return the bounding box of the corners of the bounding box bbox
39			"""
40			# This is not really the correct way to determine the bbox of a
41			# projected shape, but for now it works well enough
42			llx, lly, urx, ury = bbox
43			xs = []; ys = []
44			x, y = self.Forward(llx, lly)
45			xs.append(x); ys.append(y)
46			x, y = self.Forward(llx, ury)
47			xs.append(x); ys.append(y)
48			x, y = self.Forward(urx, ury)
49			xs.append(x); ys.append(y)
50			x, y = self.Forward(urx, lly)
51			xs.append(x); ys.append(y)
52	jonathan	758
53	bh	6	return min(xs), min(ys), max(xs), max(ys)
54	jonathan	695
55			def GetName(self):
56	jonathan	738	"""Return the name of the projection."""
57	jonathan	695	return self.name
58
59	jonathan	708	def GetParameter(self, param):
60	jonathan	738	"""Return the projection value for the given parameter.
61	jonathan	708
62	jonathan	738	If 'param' exists as a valid parameter then the returned
63			value is a string with that value. If the parameter doesn't
64			exist an empty string is returned.
65			"""
66
67	jonathan	708	for pair in self.params:
68			p, v = pair.split("=")
69			if p == param:
70			return v
71
72			return ""
73
74			def GetAllParameters(self):
75	jonathan	738	"""Return list of 'parameter=value' strings"""
76	jonathan	695	return self.params
77
78			def __repr__(self):
79	jonathan	726	return self.name + ": " + repr(self.params)
80	jonathan	695
81			class ProjFile:
82
83			def __init__(self, filename):
84	jonathan	738	"""Intialize the ProjFile.
85	jonathan	695
86	jonathan	738	filename -- name of the file that this ProjFile represents.
87			"""
88
89			self.__projs = []
90
91			self.SetFilename(filename)
92	jonathan	695
93			def Add(self, proj):
94	jonathan	738	"""Add the given projection to the end of the file. If 'proj'
95			already exists, it is replaced in the same location as the
96			original projection.
97			"""
98	jonathan	695
99	jonathan	738	try:
100			#
101			# see if the projection already exists.
102			# this only works if Projection doesn't override __eq__
103			#
104			self.__projs[self.__projs.index(proj)] = proj
105			except ValueError:
106			self.__projs.append(proj)
107
108	jonathan	726	def Remove(self, proj):
109	jonathan	758	"""Remove the object proj from the projection file.
110	jonathan	726
111	jonathan	738	Raises a ValueError is proj is not found.
112			"""
113	jonathan	695
114	jonathan	738	self.__projs.remove(proj)
115	jonathan	695
116	jonathan	758	def Replace(self, oldproj, newproj):
117			"""Replace the object 'oldproj' with 'newproj'.
118
119			Raises ValueError if oldproj is not in the file.
120			"""
121
122			#
123			# see if the projection already exists.
124			# this only works if Projection doesn't override __eq__
125			#
126			self.__projs[self.__projs.index(oldproj)] = newproj
127
128	jonathan	738	def GetFilename(self):
129			"""Return the filename where the ProjFile was read or will be
130			written to.
131			"""
132
133			return self.__filename
134
135			def SetFilename(self, filename):
136			"""Set the filename where the ProjFile will be written to."""
137			self.__filename = filename
138
139	jonathan	695	def GetProjections(self):
140	jonathan	738	"""Return a list of the projections in the order they were read
141			from the file or will be written.
142
143			This is not a deep copy list, so any modifications made to the
144			Projection objects will be written to the file.
145			"""
146
147			return self.__projs
148
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svn:keywords	Author Date Id Revision