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# Copyright (c) 2001, 2003 by Intevation GmbH |
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# Authors: |
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# Bernhard Herzog <[email protected]> |
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# |
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# This program is free software under the GPL (>=v2) |
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# Read the file COPYING coming with Thuban for details. |
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|
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__version__ = "$Revision$" |
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|
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from types import StringTypes |
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|
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from Thuban import _ |
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from Thuban.Lib.connector import Publisher |
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|
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import Projection |
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BaseProjection = Projection.Projection |
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del Projection |
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|
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from messages import PROJECTION_ADDED, PROJECTION_REPLACED, PROJECTION_REMOVED |
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|
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PROJ_UNITS_METERS = 1 |
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PROJ_UNITS_DEGREES = 2 |
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|
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class Projection(BaseProjection): |
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|
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"""A proj4 projection object that remembers the parameters""" |
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|
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def __init__(self, params, name = None, epsg = None): |
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"""Initialize the Projection |
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|
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Parameters: |
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|
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params -- a list of 'parameter=value' strings |
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|
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name -- (optional) The name of the projectin. If None or omitted |
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it defaults to 'Unknown' in the local language. |
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|
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epsg -- (optional) The EPSG code as a string. |
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""" |
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BaseProjection.__init__(self, params) |
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|
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if name is None: |
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self.name = _("Unknown") |
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elif isinstance(name, StringTypes): |
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self.name = name |
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|
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self.epsg = epsg |
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self.params = params |
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|
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def ForwardBBox(self, bbox): |
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"""Return the bounding box of the corners of the bounding box bbox |
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""" |
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# This is not really the correct way to determine the bbox of a |
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# projected shape, but for now it works well enough |
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llx, lly, urx, ury = bbox |
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xs = []; ys = [] |
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x, y = self.Forward(llx, lly) |
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xs.append(x); ys.append(y) |
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x, y = self.Forward(llx, ury) |
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xs.append(x); ys.append(y) |
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x, y = self.Forward(urx, ury) |
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xs.append(x); ys.append(y) |
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x, y = self.Forward(urx, lly) |
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xs.append(x); ys.append(y) |
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|
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return min(xs), min(ys), max(xs), max(ys) |
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|
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def GetName(self): |
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"""Return the name of the projection.""" |
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return self.name |
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|
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def Label(self): |
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if self.epsg: |
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return "EPSG % 5s %s" % (self.epsg, self.name) |
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return self.name |
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|
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def EPSGCode(self): |
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"""Return the EPSG code as a string or None if there is none""" |
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return self.epsg |
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|
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def GetParameter(self, param): |
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"""Return the projection value for the given parameter. |
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|
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If 'param' exists as a valid parameter return the associated |
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value as a string. If the parameter does not have a value (like |
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e.g. the 'south' parameter for utm) then the value is the |
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parameter name itself. |
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If the parameter doesn't exist return an empty string. |
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""" |
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|
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for pair in self.params: |
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if "=" in pair: |
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p, v = pair.split("=") |
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else: |
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p = v = pair |
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if p == param: |
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return v |
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|
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return "" |
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|
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def GetAllParameters(self): |
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"""Return list of 'parameter=value' strings""" |
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return self.params |
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|
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def GetProjectedUnits(self): |
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if self.GetParameter("proj") in [ 'latlong', 'longlat' ]: |
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return PROJ_UNITS_DEGREES |
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else: |
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return PROJ_UNITS_METERS |
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|
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def __repr__(self): |
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return self.name + ": " + repr(self.params) |
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|
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|
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class ProjFile(Publisher): |
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def __init__(self, filename): |
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"""Intialize the ProjFile. |
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filename -- name of the file that this ProjFile represents. |
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""" |
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self.__projs = [] |
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self.SetFilename(filename) |
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|
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def Add(self, proj): |
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"""Add the projection to the end of the file.""" |
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self.__projs.append(proj) |
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self.issue(PROJECTION_ADDED, proj) |
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|
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def Remove(self, proj): |
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"""Remove the object proj from the projection file. |
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Raises a ValueError is proj is not found. |
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""" |
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self.__projs.remove(proj) |
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self.issue(PROJECTION_REMOVED, proj) |
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|
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def Replace(self, oldproj, newproj): |
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"""Replace the object 'oldproj' with 'newproj'. |
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|
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Raises ValueError if oldproj is not in the file. |
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""" |
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self.__projs[self.__projs.index(oldproj)] = newproj |
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self.issue(PROJECTION_REPLACED, oldproj, newproj) |
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|
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def GetFilename(self): |
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"""Return the filename where the ProjFile was read or will be |
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written to. |
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""" |
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return self.__filename |
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|
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def SetFilename(self, filename): |
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"""Set the filename where the ProjFile will be written to.""" |
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self.__filename = filename |
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|
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def GetProjections(self): |
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"""Return a list of the projections in the order they were read |
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from the file or will be written. |
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This is not a deep copy list, so any modifications made to the |
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Projection objects will be written to the file. |
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""" |
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return self.__projs |
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