/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/proj.py
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revision 726 by jonathan, Thu Apr 24 16:05:56 2003 UTC revision 1982 by bh, Thu Nov 27 15:25:34 2003 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001 by Intevation GmbH  # Copyright (c) 2001, 2003 by Intevation GmbH
2  # Authors:  # Authors:
3  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
4  #  #
# Line 9  __version__ = "$Revision$" Line 9  __version__ = "$Revision$"
9    
10  from types import StringTypes  from types import StringTypes
11    
12    from Thuban import _
13    from Thuban.Lib.connector import Publisher
14    
15  import Projection  import Projection
16  BaseProjection = Projection.Projection  BaseProjection = Projection.Projection
17  del Projection  del Projection
18    
19    from messages import PROJECTION_ADDED, PROJECTION_REPLACED, PROJECTION_REMOVED
20    
21    PROJ_UNITS_METERS  = 1
22    PROJ_UNITS_DEGREES = 2
23    
24  class Projection(BaseProjection):  class Projection(BaseProjection):
25    
26      """A proj4 projection object that remembers the parameters"""      """A proj4 projection object that remembers the parameters"""
27    
28      def __init__(self, params, name = "Unknown"):      def __init__(self, params, name = None, epsg = None):
29            """Initialize the Projection
30    
31            Parameters:
32    
33            params -- a list of 'parameter=value' strings
34    
35            name -- (optional) The name of the projectin. If None or omitted
36                    it defaults to 'Unknown' in the local language.
37    
38            epsg -- (optional) The EPSG code as a string.
39            """
40          BaseProjection.__init__(self, params)          BaseProjection.__init__(self, params)
41    
42            if name is None:
43                self.name = _("Unknown")
44            elif isinstance(name, StringTypes):
45                self.name = name
46    
47            self.epsg = epsg
48          self.params = params          self.params = params
         self.name = name  
49    
50      def ForwardBBox(self, bbox):      def _transform_bbox(self, trafo, bbox):
         """Return the bounding box of the corners of the bounding box bbox  
         """  
51          # This is not really the correct way to determine the bbox of a          # This is not really the correct way to determine the bbox of a
52          # projected shape, but for now it works well enough          # projected bbox, but for now it works well enough
53          llx, lly, urx, ury = bbox          llx, lly, urx, ury = bbox
54          xs = []; ys = []          xs = []; ys = []
55          x, y = self.Forward(llx, lly)          for x, y in ((llx, lly), (llx, ury), (urx, lly), (urx, ury)):
56          xs.append(x); ys.append(y)              x, y = trafo(x, y)
57          x, y = self.Forward(llx, ury)              xs.append(x); ys.append(y)
         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)  
58          return min(xs), min(ys), max(xs), max(ys)          return min(xs), min(ys), max(xs), max(ys)
59    
60        def ForwardBBox(self, bbox):
61            """Return the bounding box of the corners of the bounding box bbox
62            """
63            return self._transform_bbox(self.Forward, bbox)
64    
65        def InverseBBox(self, bbox):
66            return self._transform_bbox(self.Inverse, bbox)
67    
68      def GetName(self):      def GetName(self):
69            """Return the name of the projection."""
70          return self.name          return self.name
71    
72      def SetName(self, name):      def Label(self):
73          if isinstance(name, StringTypes):          if self.epsg:
74              self.name = name              return "EPSG % 5s %s" % (self.epsg, self.name)
75            return self.name
76    
77        def EPSGCode(self):
78            """Return the EPSG code as a string or None if there is none"""
79            return self.epsg
80    
81      def GetParameter(self, param):      def GetParameter(self, param):
82            """Return the projection value for the given parameter.
83    
84            If 'param' exists as a valid parameter return the associated
85            value as a string. If the parameter does not have a value (like
86            e.g. the 'south' parameter for utm) then the value is the
87            parameter name itself.
88    
89            If the parameter doesn't exist return an empty string.
90            """
91    
92          for pair in self.params:          for pair in self.params:
93              p, v = pair.split("=")              if "=" in pair:
94                    p, v = pair.split("=")
95                else:
96                    p = v = pair
97              if p == param:              if p == param:
98                  return v                  return v
99    
100          return ""          return ""
101    
102      def GetAllParameters(self):      def GetAllParameters(self):
103            """Return list of 'parameter=value' strings"""
104          return self.params          return self.params
105    
106        def GetProjectedUnits(self):
107            if self.GetParameter("proj") in [ 'latlong', 'longlat' ]:
108                return PROJ_UNITS_DEGREES
109            else:
110                return PROJ_UNITS_METERS
111    
112      def __repr__(self):      def __repr__(self):
113          return self.name + ": " + repr(self.params)          return self.name + ": " + repr(self.params)
114    
115  class ProjFile:  
116    class ProjFile(Publisher):
117    
118      def __init__(self, filename):      def __init__(self, filename):
119          self.projs = {}          """Intialize the ProjFile.
120    
121            filename -- name of the file that this ProjFile represents.
122            """
123    
124            self.__projs = []
125    
126            self.SetFilename(filename)
127    
         self.SetFileName(filename)  
       
128      def Add(self, proj):      def Add(self, proj):
129          self.projs[proj] = 0          """Add the projection to the end of the file."""
130            self.__projs.append(proj)
131            self.issue(PROJECTION_ADDED, proj)
132    
133      def Remove(self, proj):      def Remove(self, proj):
134          if self.projs.has_key(proj):          """Remove the object proj from the projection file.
             del self.projs[proj]  
135    
136      def GetFileName(self):          Raises a ValueError is proj is not found.
137          return self.filename          """
138            self.__projs.remove(proj)
139            self.issue(PROJECTION_REMOVED, proj)
140    
141      def SetFileName(self, filename):      def Replace(self, oldproj, newproj):
142          self.filename = filename          """Replace the object 'oldproj' with 'newproj'.
143    
144            Raises ValueError if oldproj is not in the file.
145            """
146            self.__projs[self.__projs.index(oldproj)] = newproj
147            self.issue(PROJECTION_REPLACED, 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):      def GetProjections(self):
161          return self.projs.keys()          """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    
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