/[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 1551 by bh, Wed Aug 6 17:21:07 2003 UTC
# Line 12  __version__ = "$Revision$" Line 12  __version__ = "$Revision$"
12  # $Id$  # $Id$
13    
14  import os  import os
 import warnings  
15  import weakref  import weakref
16    from math import ceil, log
17    
18  import shapelib  import shapelib
19    import shptree
20  import table  import table
21  import transientdb  import transientdb
22    
23    from Thuban import _
24    
25    # Shape type constants
26    SHAPETYPE_POLYGON = "polygon"
27    SHAPETYPE_ARC = "arc"
28    SHAPETYPE_POINT = "point"
29    
30    # mapping from shapelib shapetype constants to our constants
31    shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
32                           shapelib.SHPT_ARC: SHAPETYPE_ARC,
33                           shapelib.SHPT_POINT: SHAPETYPE_POINT}
34    
35    
36    class Shape:
37    
38        """Represent one shape"""
39    
40        def __init__(self, points):
41            self.points = points
42            #self.compute_bbox()
43            self.bbox = None
44    
45        def compute_bbox(self):
46            if self.bbox is not None:
47                return self.bbox
48    
49            xs = []
50            ys = []
51            for part in self.points:
52                for x, y in part:
53                    xs.append(x)
54                    ys.append(y)
55            self.llx = min(xs)
56            self.lly = min(ys)
57            self.urx = max(xs)
58            self.ury = max(ys)
59    
60            self.bbox = (self.llx, self.lly, self.urx, self.ury)
61    
62            return self.bbox
63    
64        def Points(self):
65            return self.points
66    
67    
68    
69  class ShapeTable(transientdb.AutoTransientTable):  class ShapeTable(transientdb.AutoTransientTable):
70    
# Line 59  class ShapefileStore: Line 105  class ShapefileStore:
105          self.dbftable = table.DBFTable(filename)          self.dbftable = table.DBFTable(filename)
106          self.table = ShapeTable(self, session.TransientDB(), self.dbftable)          self.table = ShapeTable(self, session.TransientDB(), self.dbftable)
107    
108            self.numshapes, shapetype, mins, maxs = self.shapefile.info()
109            if self.numshapes:
110                self.bbox = mins[:2] + maxs[:2]
111            else:
112                self.bbox = None
113            self.shapetype = shapelib_shapetypes[shapetype]
114    
115            # estimate a good depth for the quad tree. Each depth multiplies
116            # the number of nodes by four, therefore we basically take the
117            # base 4 logarithm of the number of shapes.
118            if self.numshapes < 4:
119                maxdepth = 1
120            else:
121                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
122    
123            self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
124                                             maxdepth)
125    
126      def Table(self):      def Table(self):
127          """Return the table containing the attribute data"""          """Return the table containing the attribute data"""
128          return self.table          return self.table
# Line 75  class ShapefileStore: Line 139  class ShapefileStore:
139          """Return the filetype. This is always the string 'shapefile'"""          """Return the filetype. This is always the string 'shapefile'"""
140          return "shapefile"          return "shapefile"
141    
142        def ShapeType(self):
143            """Return the type of the shapes in the shapestore.
144    
145            This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
146            """
147            return self.shapetype
148    
149        def NumShapes(self):
150            """Return the number of shapes in the shape store"""
151            return self.numshapes
152    
153      def Dependencies(self):      def Dependencies(self):
154          """Return the empty tuple.          """Return the empty tuple.
155    
# Line 82  class ShapefileStore: Line 157  class ShapefileStore:
157          """          """
158          return ()          return ()
159    
160        def OrigShapeStore(self):
161            """Return None.
162    
163            The ShapefileStore was not derived from another shapestore.
164            """
165            return None
166    
167        def BoundingBox(self):
168            """Return the bounding box of the shapes in the shapestore.
169    
170            The coordinate system used is whatever was used in the shapefile.
171            If the shapefile is empty, return None.
172            """
173            return self.bbox
174    
175        def ShapesInRegion(self, box):
176            """Return the ids of the shapes that overlap the box.
177    
178            Box is a tuple (left, bottom, right, top) in the coordinate
179            system used used in the shapefile.
180            """
181            left, bottom, right, top = box
182            return self.shapetree.find_shapes((left, bottom), (right, top))
183    
184        def Shape(self, index):
185            """Return the shape with index index"""
186            shape = self.shapefile.read_object(index)
187    
188            if self.ShapeType() == SHAPETYPE_POINT:
189                points = [shape.vertices()]
190            else:
191                points = []
192                for poly in shape.vertices():
193                    part = []
194                    for x, y in poly:
195                        part.append((x, y))
196                    points.append(part)
197    
198            return Shape(points)
199    
200    
201    
202  class DerivedShapeStore:  class DerivedShapeStore:
203    
# Line 92  class DerivedShapeStore: Line 208  class DerivedShapeStore:
208    
209          The arguments are a shapestore for the shapedata and a table for          The arguments are a shapestore for the shapedata and a table for
210          the tabular data.          the tabular data.
211    
212            Raises ValueError if the number of shapes in the shapestore
213            is different from the number of rows in the table.
214          """          """
215    
216            numShapes = shapestore.Shapefile().info()[0]
217            if numShapes != table.NumRows():
218                raise ValueError(_("Table not compatible with shapestore."))
219    
220          self.shapestore = shapestore          self.shapestore = shapestore
221          self.table = table          self.table = table
222    
# Line 101  class DerivedShapeStore: Line 225  class DerivedShapeStore:
225          return self.table          return self.table
226    
227      def Shapefile(self):      def Shapefile(self):
228          """Return the shapefile of he underlying shapestore"""          """Return the shapefile of the underlying shapestore"""
229          return self.shapestore.Shapefile()          return self.shapestore.Shapefile()
230    
231      def Dependencies(self):      def Dependencies(self):
232          """Return a tuple containing the shapestore and the table"""          """Return a tuple containing the shapestore and the table"""
233          return (self.shapestore, self.table)          return (self.shapestore, self.table)
234    
235        def OrigShapeStore(self):
236            """
237            Return the original shapestore the derived store was instantiated with
238            """
239            return self.shapestore
240    
241  class SimpleStore:      def Shape(self, index):
242            """Return the shape with index index"""
243            return self.shapestore.Shape(index)
244    
245      """Combine a shapefile and a table object"""      def ShapesInRegion(self, bbox):
246            """Return the ids of the shapes that overlap the box.
247    
248      def __init__(self, shapefile, table):          This method is simply delegated to the shapestore the
249          warnings.warn("The SimpleStore is deprecated."          DerivedShapeStore was instantiated with.
250                        " Use DerivedShapeStore instead",          """
251                        DeprecationWarning, stacklevel = 2)          return self.shapestore.ShapesInRegion(bbox)
         self.shapefile = shapefile  
         self.table = table  
         self.filename = None  
252    
253      def Table(self):      def ShapeType(self):
254          return self.table          """Return the type of the shapes in the layer.
255    
256      def Shapefile(self):          This method is simply delegated to the shapestore the
257          return self.shapefile          DerivedShapeStore was instantiated with.
258            """
259            return self.shapestore.ShapeType()
260    
261        def NumShapes(self):
262            """Return the number of shapes in the shapestore."""
263            return self.shapestore.NumShapes()
264    
265        def BoundingBox(self):
266            """Return the bounding box of the shapes in the shapestore.
267    
268            This method is simply delegated to the shapestore the
269            DerivedShapeStore was instantiated with.
270            """
271            return self.shapestore.BoundingBox()
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