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 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 = "Unknown"):
        BaseProjection.__init__(self, params)
        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	# 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	from types import StringTypes
11
12	import Projection
13	BaseProjection = Projection.Projection
14	del Projection
15
16	class Projection(BaseProjection):
17
18	"""A proj4 projection object that remembers the parameters"""
19
20	def __init__(self, params, name = "Unknown"):
21	BaseProjection.__init__(self, params)
22	self.params = params
23	self.name = name
24
25	def ForwardBBox(self, bbox):
26	"""Return the bounding box of the corners of the bounding box bbox
27	"""
28	# This is not really the correct way to determine the bbox of a
29	# projected shape, but for now it works well enough
30	llx, lly, urx, ury = bbox
31	xs = []; ys = []
32	x, y = self.Forward(llx, lly)
33	xs.append(x); ys.append(y)
34	x, y = self.Forward(llx, ury)
35	xs.append(x); ys.append(y)
36	x, y = self.Forward(urx, ury)
37	xs.append(x); ys.append(y)
38	x, y = self.Forward(urx, lly)
39	xs.append(x); ys.append(y)
40	return min(xs), min(ys), max(xs), max(ys)
41
42	def GetName(self):
43	"""Return the name of the projection."""
44	return self.name
45
46	def SetName(self, name):
47	"""Set the name of the projection."""
48	if isinstance(name, StringTypes):
49	self.name = name
50
51	def GetParameter(self, param):
52	"""Return the projection value for the given parameter.
53
54	If 'param' exists as a valid parameter then the returned
55	value is a string with that value. If the parameter doesn't
56	exist an empty string is returned.
57	"""
58
59	for pair in self.params:
60	p, v = pair.split("=")
61	if p == param:
62	return v
63
64	return ""
65
66	def GetAllParameters(self):
67	"""Return list of 'parameter=value' strings"""
68	return self.params
69
70	def __repr__(self):
71	return self.name + ": " + repr(self.params)
72
73	class ProjFile:
74
75	def __init__(self, filename):
76	"""Intialize the ProjFile.
77
78	filename -- name of the file that this ProjFile represents.
79	"""
80
81	self.__projs = []
82
83	self.SetFilename(filename)
84
85	def Add(self, proj):
86	"""Add the given projection to the end of the file. If 'proj'
87	already exists, it is replaced in the same location as the
88	original projection.
89	"""
90
91	try:
92	#
93	# see if the projection already exists.
94	# this only works if Projection doesn't override __eq__
95	#
96	self.__projs[self.__projs.index(proj)] = proj
97	except ValueError:
98	self.__projs.append(proj)
99
100	def Remove(self, proj):
101	"""Remove the objection proj from the projection file.
102
103	Raises a ValueError is proj is not found.
104	"""
105
106	self.__projs.remove(proj)
107
108	def GetFilename(self):
109	"""Return the filename where the ProjFile was read or will be
110	written to.
111	"""
112
113	return self.__filename
114
115	def SetFilename(self, filename):
116	"""Set the filename where the ProjFile will be written to."""
117	self.__filename = filename
118
119	def GetProjections(self):
120	"""Return a list of the projections in the order they were read
121	from the file or will be written.
122
123	This is not a deep copy list, so any modifications made to the
124	Projection objects will be written to the file.
125	"""
126
127	return self.__projs
128
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