/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/data.py
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trunk/thuban/Thuban/Model/data.py revision 1593 by bh, Fri Aug 15 14:10:27 2003 UTC branches/WIP-pyshapelib-bramz/Thuban/Model/data.py revision 2734 by bramz, Thu Mar 1 12:42:59 2007 UTC
# Line 1  Line 1 
1  # Copyright (C) 2003 by Intevation GmbH  # Copyright (C) 2003, 2005 by Intevation GmbH
2  # Authors:  # Authors:
3  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
4  #  #
# Line 45  RAW_PYTHON = "RAW_PYTHON" Line 45  RAW_PYTHON = "RAW_PYTHON"
45  # raw data.  # raw data.
46  RAW_SHAPEFILE = "RAW_SHAPEFILE"  RAW_SHAPEFILE = "RAW_SHAPEFILE"
47    
48    # Raw data in well-known text format
49    RAW_WKT = "RAW_WKT"
50    
51    
52  class ShapefileShape:  class ShapefileShape:
53    
# Line 109  class ShapeTable(transientdb.AutoTransie Line 112  class ShapeTable(transientdb.AutoTransie
112          """Return a tuple containing the shapestore"""          """Return a tuple containing the shapestore"""
113          return (self.store(),)          return (self.store(),)
114    
115    # XXX: (this statement should be kept in mind when re-engeneering)
116    #
117    # From a desing POV it was wrong to distinguish between table and
118    # shapestore.  In hindsight the only reason for doing so was that the
119    # shapelib has different objects for the shapefile(s) and the dbf file,
120    # which of course matches the way the data is organized into different
121    # files.  So the distinction between shapestore and table is an artifact
122    # of the shapefile format.  When we added the postgis support we should
123    # have adopted the table interface for the entire shape store, making the
124    # geometry data an additional column for those shape stores that don't
125    # store the geometries in columns in the first place.
126    
127    class FileShapeStore:
128    
129        """The base class to derive any file-based ShapeStore from.
130    
131        This class contains all information that is needed by a
132        loader routine to actually load the shapestore.
133        This essentially means that the class contains all required information
134        to save the shapestore specification (i.e. in a .thuban file).
135        """
136    
137        def __init__(self, filename, sublayer_name = None):
138            """Initialize the base class with main parameters.
139    
140            filename  -- the source filename.
141                         This filename will be converted to an absolute filename.
142                         The filename will be interpreted relative to the .thuban file anyway,
143                         but when saving a session we need to compare absolute paths
144                         and it's usually safer to always work with absolute paths.
145            sublayer_name -- a string representing a layer within the file shape store.
146                         Some file formats support to contain several layers, or
147                         at least the ogr library says so.
148                         For those filetypes who don't, the sublayer_name can be ignored
149                         and by default it is None.
150            """
151            self._filename = os.path.abspath(filename)
152            self._sublayer_name = sublayer_name
153    
154        def FileName(self):
155            """Return the filename used to open the shapestore.
156    
157            The filename can only be set via __init__ method.
158            """
159            return self._filename
160    
161        def FileType(self):
162            """Return the filetype.
163    
164            The filetype has to be set in all derived classes.
165            It must be string.
166            Known and used types are: "shapefile"
167            """
168            raise NotImplementedError
169    
170        def SublayerName(self):
171            """Return the sublayer_name.
172    
173            This could be None if the shapestore type only supports a single
174            layer.
175            """
176            return self._sublayer_name
177    
178        # Design/Implementation note:
179        # It is not a good idea to have a implementation for a
180        # "setBoundingBox" or BoundingBox in this base class.
181        # In future this data might change during
182        # a Thuban session and thus can not be kept statically here.
183        # It is expected that for many derived classes the bbox must
184        # be retrieved each time anew.
185    
186        def BoundingBox(self):
187            """Return the bounding box of the shapes in the shape store.
188    
189            The coordinate system used is whatever was used in the shape store.
190            If the shape store is empty, return None.
191            """
192            raise NotImplementedError
193    
194  class ShapefileStore:  class ShapefileStore(FileShapeStore):
195    
196      """Combine a shapefile and the corresponding DBF file into one object"""      """Combine a shapefile and the corresponding DBF file into one object"""
197    
198      def __init__(self, session, filename):      def __init__(self, session, filename):
199          # Make the filename absolute. The filename will be          FileShapeStore.__init__(self, filename)
         # interpreted relative to that anyway, but when saving a  
         # session we need to compare absolute paths and it's usually  
         # safer to always work with absolute paths.  
         self.filename = os.path.abspath(filename)  
200    
         self.shapefile = shapelib.ShapeFile(self.filename)  
201          self.dbftable = table.DBFTable(filename)          self.dbftable = table.DBFTable(filename)
202          self.table = ShapeTable(self, session.TransientDB(), self.dbftable)          self._table = ShapeTable(self, session.TransientDB(), self.dbftable)
203            self._bbox = None
204            self._open_shapefile()
205    
206        def _open_shapefile(self):
207            self.shapefile = shapelib.ShapeFile(self.FileName())
208          self.numshapes, shapetype, mins, maxs = self.shapefile.info()          self.numshapes, shapetype, mins, maxs = self.shapefile.info()
209          if self.numshapes:          if self.numshapes:
210              self.bbox = mins[:2] + maxs[:2]              self._bbox = mins[:2] + maxs[:2]
211          else:          else:
212              self.bbox = None              self._bbox = None
213          self.shapetype = shapelib_shapetypes[shapetype]          self.shapetype = shapelib_shapetypes[shapetype]
214    
215          # estimate a good depth for the quad tree. Each depth multiplies          # estimate a good depth for the quad tree. Each depth multiplies
# Line 144  class ShapefileStore: Line 224  class ShapefileStore:
224                                           maxdepth)                                           maxdepth)
225    
226      def Table(self):      def Table(self):
227          """Return the table containing the attribute data"""          """Return the table containing the attribute data."""
228          return self.table          return self._table
229    
230      def Shapefile(self):      def Shapefile(self):
231          """Return the shapefile object"""          """Return the shapefile object"""
232          return self.shapefile          return self.shapefile
233    
     def FileName(self):  
         """Return the filename used to open the shapefile"""  
         return self.filename  
   
234      def FileType(self):      def FileType(self):
235          """Return the filetype. This is always the string 'shapefile'"""          """Return the filetype. This is always the string 'shapefile'"""
236          return "shapefile"          return "shapefile"
# Line 171  class ShapefileStore: Line 247  class ShapefileStore:
247          return RAW_SHAPEFILE          return RAW_SHAPEFILE
248    
249      def NumShapes(self):      def NumShapes(self):
250          """Return the number of shapes in the shape store"""          """Return the number of shapes in the shapefile"""
251          return self.numshapes          return self.numshapes
252    
253      def Dependencies(self):      def Dependencies(self):
# Line 189  class ShapefileStore: Line 265  class ShapefileStore:
265          return None          return None
266    
267      def BoundingBox(self):      def BoundingBox(self):
268          """Return the bounding box of the shapes in the shapestore.          """Return the bounding box of the shapes in the shapefile.
269    
270          The coordinate system used is whatever was used in the shapefile.          The coordinate system used is whatever was used in the shapefile.
271          If the shapefile is empty, return None.          If the shapefileis empty, return None.
272          """          """
273          return self.bbox          return self._bbox
274    
275      def ShapesInRegion(self, bbox):      def ShapesInRegion(self, bbox):
276          """Return an iterable over the shapes that overlap the bounding box.          """Return an iterable over the shapes that overlap the bounding box.
277    
278          The bbox parameter should be the bounding box as a tuple in the          The bbox parameter should be the bounding box as a tuple in the
279          form (minx, miny, maxx, maxy) in the coordinate system of the          form (minx, miny, maxx, maxy) in the coordinate system of the
280          shape store.          shapefile.
281          """          """
282            # Bind a few globals to locals to make it a bit faster
283            cls = ShapefileShape
284            shapefile = self.shapefile
285    
286          left, bottom, right, top = bbox          left, bottom, right, top = bbox
287          for i in self.shapetree.find_shapes((left, bottom), (right, top)):          for i in self.shapetree.find_shapes((left, bottom), (right, top)):
288              yield ShapefileShape(self.shapefile, i)              yield cls(shapefile, i)
289    
290      def AllShapes(self):      def AllShapes(self):
291          """Return an iterable over the shapes in the shape store."""          """Return an iterable over the shapes in the shapefile."""
292          for i in xrange(self.NumShapes()):          for i in xrange(self.NumShapes()):
293              yield ShapefileShape(self.shapefile, i)              yield ShapefileShape(self.shapefile, i)
294    
# Line 217  class ShapefileStore: Line 297  class ShapefileStore:
297          return ShapefileShape(self.shapefile, index)          return ShapefileShape(self.shapefile, index)
298    
299    
   
300  class DerivedShapeStore:  class DerivedShapeStore:
301    
302      """A ShapeStore derived from other shapestores or tables"""      """A ShapeStore derived from other shapestores or tables"""
# Line 270  class DerivedShapeStore: Line 349  class DerivedShapeStore:
349          return self.shapestore.ShapesInRegion(bbox)          return self.shapestore.ShapesInRegion(bbox)
350    
351      def AllShapes(self):      def AllShapes(self):
352          """Return an iterable over the shapes in the shape store.          """Return an iterable over the shapes in the shapefile.
353    
354          This method is simply delegated to the shapestore the          This method is simply delegated to the shapestore the
355          DerivedShapeStore was instantiated with.          DerivedShapeStore was instantiated with.
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