/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 6 by bh, Tue Aug 28 15:41:52 2001 UTC revision 1273 by jonathan, Fri Jun 20 17:45:49 2003 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001 by Intevation GmbH  # Copyright (c) 2001, 2002, 2003 by Intevation GmbH
2  # Authors:  # Authors:
3  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
4    # Jonathan Coles <[email protected]>
5  #  #
6  # This program is free software under the GPL (>=v2)  # This program is free software under the GPL (>=v2)
7  # Read the file COPYING coming with Thuban for details.  # Read the file COPYING coming with Thuban for details.
8    
9  __version__ = "$Revision$"  __version__ = "$Revision$"
10    
11  import shapelib  from math import log, ceil
12    import warnings
13    
14  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  from Thuban import _
15       LAYER_VISIBILITY_CHANGED  import shapelib, shptree
   
 from color import Color  
 # Some predefined colors for internal use  
 _black = Color(0, 0, 0)  
16    
17    from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18         LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED
19    
20  from table import Table  import classification
21    
22    from color import Color
23  from base import TitledObject, Modifiable  from base import TitledObject, Modifiable
24    
25    import resource
26    
27    
28  class Shape:  class Shape:
29    
30      """Represent one shape"""      """Represent one shape"""
# Line 28  class Shape: Line 32  class Shape:
32      def __init__(self, points):      def __init__(self, points):
33          self.points = points          self.points = points
34          #self.compute_bbox()          #self.compute_bbox()
35            self.bbox = None
36    
37      def compute_bbox(self):      def compute_bbox(self):
38            if self.bbox is not None:
39                return self.bbox
40    
41          xs = []          xs = []
42          ys = []          ys = []
43          for x, y in self.points:          for x, y in self.points:
# Line 40  class Shape: Line 48  class Shape:
48          self.urx = max(xs)          self.urx = max(xs)
49          self.ury = max(ys)          self.ury = max(ys)
50    
51            self.bbox = (self.llx, self.lly, self.urx, self.ury)
52    
53            return self.bbox
54    
55      def Points(self):      def Points(self):
56          return self.points          return self.points
57    
# Line 63  class BaseLayer(TitledObject, Modifiable Line 75  class BaseLayer(TitledObject, Modifiable
75    
76      """Base class for the layers."""      """Base class for the layers."""
77    
78      def __init__(self, title, visible = 1):      def __init__(self, title, visible = True, projection = None):
79          """Initialize the layer.          """Initialize the layer.
80    
81          title -- the title          title -- the title
# Line 72  class BaseLayer(TitledObject, Modifiable Line 84  class BaseLayer(TitledObject, Modifiable
84          TitledObject.__init__(self, title)          TitledObject.__init__(self, title)
85          Modifiable.__init__(self)          Modifiable.__init__(self)
86          self.visible = visible          self.visible = visible
87            self.projection = projection
88    
89      def Visible(self):      def Visible(self):
90          """Return true if layer is visible"""          """Return true if layer is visible"""
# Line 81  class BaseLayer(TitledObject, Modifiable Line 94  class BaseLayer(TitledObject, Modifiable
94          """Set the layer's visibility."""          """Set the layer's visibility."""
95          self.visible = visible          self.visible = visible
96          self.issue(LAYER_VISIBILITY_CHANGED, self)          self.issue(LAYER_VISIBILITY_CHANGED, self)
97            
98                def HasClassification(self):
99            """Determine if this layer support classifications."""
100            return False
101    
102        def HasShapes(self):
103            """Determine if this layer supports shapes."""
104            return False
105    
106        def GetProjection(self):
107            """Return the layer's projection."""
108            return self.projection
109    
110        def SetProjection(self, projection):
111            """Set the layer's projection"""
112            self.projection = projection
113            self.changed(LAYER_PROJECTION_CHANGED, self)
114    
115  class Layer(BaseLayer):  class Layer(BaseLayer):
116    
117      """Represent the information of one geodata file (currently a shapefile)      """Represent the information of one geodata file (currently a shapefile)
# Line 97  class Layer(BaseLayer): Line 126  class Layer(BaseLayer):
126    
127          TITLE_CHANGED -- The title has changed.          TITLE_CHANGED -- The title has changed.
128          LAYER_PROJECTION_CHANGED -- the projection has changed.          LAYER_PROJECTION_CHANGED -- the projection has changed.
         LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed  
   
129      """      """
130    
131      def __init__(self, title, filename, projection = None,      def __init__(self, title, data, projection = None,
132                   fill = None, stroke = _black, visible = 1):                   fill = Color.Transparent,
133                     stroke = Color.Black,
134                     lineWidth = 1,
135                     visible = True):
136          """Initialize the layer.          """Initialize the layer.
137    
138          title -- the title          title -- the title
139          filename -- the name of the shapefile          data -- datastore object for the shape data shown by the layer
140          projection -- the projection object. Its Inverse method is          projection -- the projection object. Its Inverse method is
141                 assumed to map the layer's coordinates to lat/long                 assumed to map the layer's coordinates to lat/long
142                 coordinates                 coordinates
143          fill -- the fill color or None if the shapes are not filled          fill -- the fill color or Color.Transparent if the shapes are
144          stroke -- the stroke color or None if the shapes are not stroked                  not filled
145            stroke -- the stroke color or Color.Transparent if the shapes
146                    are not stroked
147          visible -- boolean. If true the layer is visible.          visible -- boolean. If true the layer is visible.
148    
149          colors are expected to be instances of Color class          colors are expected to be instances of Color class
150          """          """
151          BaseLayer.__init__(self, title, visible = visible)          BaseLayer.__init__(self, title,
152          self.filename = filename                                   visible = visible,
153          self.projection = projection                                   projection = projection)
154          self.fill = fill  
155          self.stroke = stroke          #
156          self.shapefile = None          # this is really important so that when the classification class
157          # shapetable is the table associated with the shapefile, while          # tries to set its parent layer the variable will exist
158          # table is the default table used to look up attributes for          #
159          # display          self.__classification = None
160          self.shapetable = Table(filename)          self.__setClassLock = False
161          self.table = self.shapetable  
162            self.SetShapeStore(data)
163      def open_shapefile(self):  
164          if self.shapefile is None:          self.SetClassification(None)
165              self.shapefile = shapelib.ShapeFile(self.filename)  
166              numshapes, shapetype, mins, maxs = self.shapefile.info()          self.__classification.SetDefaultLineColor(stroke)
167              self.numshapes = numshapes          self.__classification.SetDefaultLineWidth(lineWidth)
168              self.shapetype = shapelib_shapetypes[shapetype]          self.__classification.SetDefaultFill(fill)
169            self.__classification.SetLayer(self)
170    
171            self.UnsetModified()
172    
173        def __getattr__(self, attr):
174            """Access to some attributes for backwards compatibility
175    
176            The attributes implemented here are now held by the shapestore
177            if at all. For backwards compatibility pretend that they are
178            still there but issue a DeprecationWarning when they are
179            accessed.
180            """
181            if attr in ("table", "shapetable"):
182                value = self.store.Table()
183            elif attr == "shapefile":
184                value = self.store.Shapefile()
185            elif attr == "filename":
186                value = self.store.FileName()
187            else:
188                raise AttributeError, attr
189            warnings.warn("The Layer attribute %r is deprecated."
190                          " It's value can be accessed through the shapestore"
191                          % attr, DeprecationWarning, stacklevel = 2)
192            return value
193    
194        def SetShapeStore(self, store):
195            self.store = store
196            shapefile = self.store.Shapefile()
197    
198            numshapes, shapetype, mins, maxs = shapefile.info()
199            self.numshapes = numshapes
200            self.shapetype = shapelib_shapetypes[shapetype]
201    
202            # if there are shapes, set the bbox accordingly. Otherwise
203            # set it to None.
204            if self.numshapes:
205              self.bbox = mins[:2] + maxs[:2]              self.bbox = mins[:2] + maxs[:2]
206            else:
207                self.bbox = None
208    
209            # estimate a good depth for the quad tree. Each depth
210            # multiplies the number of nodes by four, therefore we
211            # basically take the base 4 logarithm of the number of
212            # shapes.
213            if self.numshapes < 4:
214                maxdepth = 1
215            else:
216                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
217    
218            self.shapetree = shptree.SHPTree(shapefile.cobject(), 2,
219                                             maxdepth)
220            # Set the classification to None if there is a classification
221            # and the new shapestore doesn't have a table with a suitable
222            # column, i.e one with the same name and type as before
223            # FIXME: Maybe we should keep it the same if the type is
224            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
225            if self.__classification is not None:
226                fieldname = self.__classification.GetField()
227                fieldtype = self.__classification.GetFieldType()
228                table = self.store.Table()
229                if (fieldname is not None
230                    and (not table.HasColumn(fieldname)
231                         or table.Column(fieldname).type != fieldtype)):
232                    self.SetClassification(None)
233            self.changed(LAYER_SHAPESTORE_REPLACED, self)
234    
235        def ShapeStore(self):
236            return self.store
237    
238        def Destroy(self):
239            BaseLayer.Destroy(self)
240            self.SetClassification(None)
241    
242      def BoundingBox(self):      def BoundingBox(self):
243          """Return the bounding box of the layer's shapes in their default          """Return the layer's bounding box in the intrinsic coordinate system.
244          coordinate system"""  
245          self.open_shapefile()          If the layer has no shapes, return None.
246            """
247          return self.bbox          return self.bbox
248    
249      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
250          """Return the layer's bounding box in lat/long coordinates"""          """Return the layer's bounding box in lat/long coordinates.
251          llx, lly, urx, ury = self.BoundingBox()  
252            Return None, if the layer doesn't contain any shapes.
253            """
254            bbox = self.BoundingBox()
255            if bbox is not None:
256                llx, lly, urx, ury = bbox
257                if self.projection is not None:
258                    llx, lly = self.projection.Inverse(llx, lly)
259                    urx, ury = self.projection.Inverse(urx, ury)
260                return llx, lly, urx, ury
261            else:
262                return None
263    
264        def ShapesBoundingBox(self, shapes):
265            """Return a bounding box in lat/long coordinates for the given
266            list of shape ids.
267    
268            If shapes is None or empty, return None.
269            """
270    
271            if shapes is None or len(shapes) == 0: return None
272    
273            llx = []
274            lly = []
275            urx = []
276            ury = []
277    
278          if self.projection is not None:          if self.projection is not None:
279              llx, lly = self.projection.Inverse(llx, lly)              inverse = lambda x, y: self.projection.Inverse(x, y)
280              urx, ury = self.projection.Inverse(urx, ury)          else:
281          return llx, lly, urx, ury              inverse = lambda x, y: (x, y)
282    
283            for id in shapes:
284                left, bottom, right, top = self.Shape(id).compute_bbox()
285    
286                left, bottom = inverse(left, bottom)
287                right, top   = inverse(right, top)
288    
289                llx.append(left)
290                lly.append(bottom)
291                urx.append(right)
292                ury.append(top)
293    
294            return (min(llx), min(lly), max(urx), max(ury))
295    
296        def GetFieldType(self, fieldName):
297            table = self.store.Table()
298            if table.HasColumn(fieldName):
299                return table.Column(fieldName).type
300            return None
301    
302        def HasShapes(self):
303            return True
304    
305      def NumShapes(self):      def NumShapes(self):
306          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
         self.open_shapefile()  
307          return self.numshapes          return self.numshapes
308    
309      def ShapeType(self):      def ShapeType(self):
310          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
311          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
312          """          """
         self.open_shapefile()  
313          return self.shapetype          return self.shapetype
314    
315      def Shape(self, index):      def Shape(self, index):
316          """Return the shape with index index"""          """Return the shape with index index"""
317          self.open_shapefile()          shape = self.store.Shapefile().read_object(index)
318          shape = self.shapefile.read_object(index)  
319          if self.shapetype == SHAPETYPE_POINT:          if self.shapetype == SHAPETYPE_POINT:
320              points = shape.vertices()              points = shape.vertices()
321          else:          else:
# Line 173  class Layer(BaseLayer): Line 323  class Layer(BaseLayer):
323              poly = shape.vertices()[0]              poly = shape.vertices()[0]
324              points = []              points = []
325              for x, y in poly:              for x, y in poly:
326                  points.append(x, y)                  points.append((x, y))
327    
328          return Shape(points)          return Shape(points)
329    
330      def SetProjection(self, projection):      def ShapesInRegion(self, box):
331          """Set the layer's projection"""          """Return the ids of the shapes that overlap the box.
332    
333            Box is a tuple (left, bottom, right, top) in unprojected coordinates.
334            """
335            left, bottom, right, top = box
336    
337            if self.projection is not None:
338                left,  bottom = self.projection.Forward(left, bottom)
339                right, top    = self.projection.Forward(right, top)
340    
341            return self.shapetree.find_shapes((left, bottom), (right, top))
342    
343        def HasClassification(self):
344            return True
345    
346        def GetClassification(self):
347            return self.__classification
348    
349        def SetClassification(self, clazz):
350            """Set the classification to 'clazz'
351    
352            If 'clazz' is None a default classification is created
353            """
354    
355            # prevent infinite recursion when calling SetLayer()
356            if self.__setClassLock: return
357    
358            self.__setClassLock = True
359    
360            if clazz is None:
361                if self.__classification is not None:
362                    self.__classification.SetLayer(None)
363                self.__classification = classification.Classification()
364            else:
365                self.__classification = clazz
366                try:
367                    self.__classification.SetLayer(self)
368                except ValueError:
369                    self.__setClassLock = False
370                    raise ValueError
371    
372            self.changed(LAYER_CHANGED, self)
373    
374            self.__setClassLock = False
375    
376        def ClassChanged(self):
377            """Called from the classification object when it has changed."""
378            self.changed(LAYER_CHANGED, self)
379    
380        def TreeInfo(self):
381            items = []
382    
383            if hasattr(self, 'filename'):
384                items.append(_("Filename: %s") % self.filename)
385    
386            if self.Visible():
387                items.append(_("Shown"))
388            else:
389                items.append(_("Hidden"))
390            items.append(_("Shapes: %d") % self.NumShapes())
391    
392            bbox = self.LatLongBoundingBox()
393            if bbox is not None:
394                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
395            else:
396                items.append(_("Extent (lat-lon):"))
397            items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
398    
399            if self.projection and len(self.projection.params) > 0:
400                items.append((_("Projection"),
401                            [str(param) for param in self.projection.params]))
402    
403            items.append(self.__classification)
404    
405            return (_("Layer '%s'") % self.Title(), items)
406    
407    
408    if resource.has_gdal_support():
409        import gdal
410        from gdalconst import GA_ReadOnly
411    
412    class RasterLayer(BaseLayer):
413    
414        def __init__(self, title, filename, projection = None, visible = True):
415            """Initialize the Raster Layer.
416    
417            title -- title for the layer.
418    
419            filename -- file name of the source image.
420    
421            projection -- Projection object describing the projection which
422                          the source image is in.
423    
424            visible -- True is the layer should initially be visible.
425    
426            Throws IOError if the filename is invalid or points to a file that
427            is not in a format GDAL can use.
428            """
429    
430            BaseLayer.__init__(self, title, visible = visible)
431    
432          self.projection = projection          self.projection = projection
433          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = filename
434    
435            self.bbox = -1
436    
437            if resource.has_gdal_support():
438                #
439                # temporarily open the file so that GDAL can test if it's valid.
440                #
441                dataset = gdal.Open(self.filename, GA_ReadOnly)
442    
443                if dataset is None:
444                    raise IOError()
445    
446            self.UnsetModified()
447    
448        def BoundingBox(self):
449            """Return the layer's bounding box in the intrinsic coordinate system.
450    
451            If the layer has no shapes, return None.
452            """
453            if not resource.has_gdal_support():
454                return None
455    
456            if self.bbox == -1:
457                dataset = gdal.Open(self.filename, GA_ReadOnly)
458                if dataset is None:
459                    self.bbox = None
460                else:
461                    geotransform = dataset.GetGeoTransform()
462                    if geotransform is None:
463                        return None
464    
465                    x = 0
466                    y = dataset.RasterYSize
467                    left = geotransform[0] +        \
468                           geotransform[1] * x +    \
469                           geotransform[2] * y
470    
471                    bottom = geotransform[3] +      \
472                             geotransform[4] * x +  \
473                             geotransform[5] * y
474    
475                    x = dataset.RasterXSize
476                    y = 0
477                    right = geotransform[0] +       \
478                            geotransform[1] * x +   \
479                            geotransform[2] * y
480    
481                    top = geotransform[3] +         \
482                          geotransform[4] * x +     \
483                          geotransform[5] * y
484    
485                    self.bbox = (left, bottom, right, top)
486    
487            return self.bbox
488    
489        def LatLongBoundingBox(self):
490            bbox = self.BoundingBox()
491            if bbox is None:
492                return None
493    
494            llx, lly, urx, ury = bbox
495            if self.projection is not None:
496                llx, lly = self.projection.Inverse(llx, lly)
497                urx, ury = self.projection.Inverse(urx, ury)
498    
499            return llx, lly, urx, ury
500    
501        def GetImageFilename(self):
502            return self.filename
503    
504        def TreeInfo(self):
505            items = []
506    
507            if self.Visible():
508                items.append(_("Shown"))
509            else:
510                items.append(_("Hidden"))
511            items.append(_("Shapes: %d") % self.NumShapes())
512    
513            bbox = self.LatLongBoundingBox()
514            if bbox is not None:
515                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
516            else:
517                items.append(_("Extent (lat-lon):"))
518    
519            if self.projection and len(self.projection.params) > 0:
520                items.append((_("Projection"),
521                            [str(param) for param in self.projection.params]))
522    
523            return (_("Layer '%s'") % self.Title(), items)
524    
     def SetFill(self, fill):  
         """Set the layer's fill color. None means the shapes are not filled"""  
         self.fill = fill  
         self.changed(LAYER_LEGEND_CHANGED, self)  
   
     def SetStroke(self, stroke):  
         """Set the layer's stroke color. None means the shapes are not  
         stroked."""  
         self.stroke = stroke  
         self.changed(LAYER_LEGEND_CHANGED, self)  
Legend:
Removed from v.6  
changed lines
  Added in v.1273
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