/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/data.py
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revision 984 by bh, Thu May 22 16:37:48 2003 UTC revision 1593 by bh, Fri Aug 15 14:10:27 2003 UTC
# Line 7  Line 7 
7    
8  """Data source abstractions"""  """Data source abstractions"""
9    
10    from __future__ import generators
11    
12  __version__ = "$Revision$"  __version__ = "$Revision$"
13  # $Source$  # $Source$
14  # $Id$  # $Id$
15    
16  import os  import os
 import warnings  
17  import weakref  import weakref
18    from math import ceil, log
19    
20  import shapelib  import shapelib
21    import shptree
22  import table  import table
23  import transientdb  import transientdb
24    
25    from Thuban import _
26    
27    # Shape type constants
28    SHAPETYPE_POLYGON = "polygon"
29    SHAPETYPE_ARC = "arc"
30    SHAPETYPE_POINT = "point"
31    
32    # mapping from shapelib shapetype constants to our constants
33    shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
34                           shapelib.SHPT_ARC: SHAPETYPE_ARC,
35                           shapelib.SHPT_POINT: SHAPETYPE_POINT}
36    
37    #
38    # Raw shape data formats
39    #
40    
41    # Raw data is the same as that returned by the points method.
42    RAW_PYTHON = "RAW_PYTHON"
43    
44    # Raw data is a shapefile. The Shape object will use the shapeid as the
45    # raw data.
46    RAW_SHAPEFILE = "RAW_SHAPEFILE"
47    
48    
49    class ShapefileShape:
50    
51        """Represent one shape of a shapefile"""
52    
53        def __init__(self, shapefile, shapeid):
54            self.shapefile = shapefile
55            self.shapeid = shapeid
56    
57        def compute_bbox(self):
58            """
59            Return the bounding box of the shape as a tuple (minx,miny,maxx,maxy)
60            """
61            xs = []
62            ys = []
63            for part in self.Points():
64                for x, y in part:
65                    xs.append(x)
66                    ys.append(y)
67            return (min(xs), min(ys), max(xs), max(ys))
68    
69        def ShapeID(self):
70            return self.shapeid
71    
72        def Points(self):
73            """Return the coordinates of the shape as a list of lists of pairs"""
74            shape = self.shapefile.read_object(self.shapeid)
75            points = shape.vertices()
76            if self.shapefile.info()[1] == shapelib.SHPT_POINT:
77                points = [points]
78            return points
79    
80        def RawData(self):
81            """Return the shape id to use with the shapefile"""
82            return self.shapeid
83    
84        def Shapefile(self):
85            """Return the shapefile object"""
86            return self.shapefile
87    
88    
89  class ShapeTable(transientdb.AutoTransientTable):  class ShapeTable(transientdb.AutoTransientTable):
90    
# Line 59  class ShapefileStore: Line 125  class ShapefileStore:
125          self.dbftable = table.DBFTable(filename)          self.dbftable = table.DBFTable(filename)
126          self.table = ShapeTable(self, session.TransientDB(), self.dbftable)          self.table = ShapeTable(self, session.TransientDB(), self.dbftable)
127    
128            self.numshapes, shapetype, mins, maxs = self.shapefile.info()
129            if self.numshapes:
130                self.bbox = mins[:2] + maxs[:2]
131            else:
132                self.bbox = None
133            self.shapetype = shapelib_shapetypes[shapetype]
134    
135            # estimate a good depth for the quad tree. Each depth multiplies
136            # the number of nodes by four, therefore we basically take the
137            # base 4 logarithm of the number of shapes.
138            if self.numshapes < 4:
139                maxdepth = 1
140            else:
141                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
142    
143            self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
144                                             maxdepth)
145    
146      def Table(self):      def Table(self):
147          """Return the table containing the attribute data"""          """Return the table containing the attribute data"""
148          return self.table          return self.table
# Line 75  class ShapefileStore: Line 159  class ShapefileStore:
159          """Return the filetype. This is always the string 'shapefile'"""          """Return the filetype. This is always the string 'shapefile'"""
160          return "shapefile"          return "shapefile"
161    
162        def ShapeType(self):
163            """Return the type of the shapes in the shapestore.
164    
165            This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
166            """
167            return self.shapetype
168    
169        def RawShapeFormat(self):
170            """Return the raw data format of the shape data, i.e. RAW_SHAPEFILE"""
171            return RAW_SHAPEFILE
172    
173        def NumShapes(self):
174            """Return the number of shapes in the shape store"""
175            return self.numshapes
176    
177      def Dependencies(self):      def Dependencies(self):
178          """Return the empty tuple.          """Return the empty tuple.
179    
# Line 82  class ShapefileStore: Line 181  class ShapefileStore:
181          """          """
182          return ()          return ()
183    
184        def OrigShapeStore(self):
185            """Return None.
186    
187            The ShapefileStore was not derived from another shapestore.
188            """
189            return None
190    
191        def BoundingBox(self):
192            """Return the bounding box of the shapes in the shapestore.
193    
194            The coordinate system used is whatever was used in the shapefile.
195            If the shapefile is empty, return None.
196            """
197            return self.bbox
198    
199        def ShapesInRegion(self, bbox):
200            """Return an iterable over the shapes that overlap the bounding box.
201    
202            The bbox parameter should be the bounding box as a tuple in the
203            form (minx, miny, maxx, maxy) in the coordinate system of the
204            shape store.
205            """
206            left, bottom, right, top = bbox
207            for i in self.shapetree.find_shapes((left, bottom), (right, top)):
208                yield ShapefileShape(self.shapefile, i)
209    
210        def AllShapes(self):
211            """Return an iterable over the shapes in the shape store."""
212            for i in xrange(self.NumShapes()):
213                yield ShapefileShape(self.shapefile, i)
214    
215        def Shape(self, index):
216            """Return the shape with index index"""
217            return ShapefileShape(self.shapefile, index)
218    
219    
220    
221  class DerivedShapeStore:  class DerivedShapeStore:
222    
# Line 92  class DerivedShapeStore: Line 227  class DerivedShapeStore:
227    
228          The arguments are a shapestore for the shapedata and a table for          The arguments are a shapestore for the shapedata and a table for
229          the tabular data.          the tabular data.
230    
231            Raises ValueError if the number of shapes in the shapestore
232            is different from the number of rows in the table.
233          """          """
234    
235            numShapes = shapestore.Shapefile().info()[0]
236            if numShapes != table.NumRows():
237                raise ValueError(_("Table not compatible with shapestore."))
238    
239          self.shapestore = shapestore          self.shapestore = shapestore
240          self.table = table          self.table = table
241    
# Line 101  class DerivedShapeStore: Line 244  class DerivedShapeStore:
244          return self.table          return self.table
245    
246      def Shapefile(self):      def Shapefile(self):
247          """Return the shapefile of he underlying shapestore"""          """Return the shapefile of the underlying shapestore"""
248          return self.shapestore.Shapefile()          return self.shapestore.Shapefile()
249    
250      def Dependencies(self):      def Dependencies(self):
251          """Return a tuple containing the shapestore and the table"""          """Return a tuple containing the shapestore and the table"""
252          return (self.shapestore, self.table)          return (self.shapestore, self.table)
253    
254        def OrigShapeStore(self):
255            """
256            Return the original shapestore the derived store was instantiated with
257            """
258            return self.shapestore
259    
260  class SimpleStore:      def Shape(self, index):
261            """Return the shape with index index"""
262            return self.shapestore.Shape(index)
263    
264      """Combine a shapefile and a table object"""      def ShapesInRegion(self, bbox):
265            """Return the ids of the shapes that overlap the box.
266    
267      def __init__(self, shapefile, table):          This method is simply delegated to the shapestore the
268          warnings.warn("The SimpleStore is deprecated."          DerivedShapeStore was instantiated with.
269                        " Use DerivedShapeStore instead",          """
270                        DeprecationWarning, stacklevel = 2)          return self.shapestore.ShapesInRegion(bbox)
         self.shapefile = shapefile  
         self.table = table  
         self.filename = None  
271    
272      def Table(self):      def AllShapes(self):
273          return self.table          """Return an iterable over the shapes in the shape store.
274    
275      def Shapefile(self):          This method is simply delegated to the shapestore the
276          return self.shapefile          DerivedShapeStore was instantiated with.
277            """
278            return self.shapestore.AllShapes()
279    
280        def ShapeType(self):
281            """Return the type of the shapes in the layer.
282    
283            This method is simply delegated to the shapestore the
284            DerivedShapeStore was instantiated with.
285            """
286            return self.shapestore.ShapeType()
287    
288        def RawShapeFormat(self):
289            """Return the raw data format of the shapes.
290    
291            This method is simply delegated to the shapestore the
292            DerivedShapeStore was instantiated with.
293            """
294            return self.shapestore.RawShapeFormat()
295    
296        def NumShapes(self):
297            """Return the number of shapes in the shapestore."""
298            return self.shapestore.NumShapes()
299    
300        def BoundingBox(self):
301            """Return the bounding box of the shapes in the shapestore.
302    
303            This method is simply delegated to the shapestore the
304            DerivedShapeStore was instantiated with.
305            """
306            return self.shapestore.BoundingBox()
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