/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 6 by bh, Tue Aug 28 15:41:52 2001 UTC revision 1338 by jonathan, Tue Jul 1 16:10:00 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
16    
17  from color import Color  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18  # Some predefined colors for internal use       LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED
 _black = Color(0, 0, 0)  
19    
20    import classification
21    
22  from table import Table  from color import Transparent, Black
   
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 90  class Layer(BaseLayer): Line 119  class Layer(BaseLayer):
119      All children of the layer have the same type.      All children of the layer have the same type.
120    
121      A layer has fill and stroke colors. Colors should be instances of      A layer has fill and stroke colors. Colors should be instances of
122      Color. They can also be None, indicating no fill or no stroke.      Color. They can also be Transparent, indicating no fill or no stroke.
123    
124      The layer objects send the following events, all of which have the      The layer objects send the following events, all of which have the
125      layer object as parameter:      layer object as parameter:
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 = Transparent,
133                     stroke = 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 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 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)  
161          self.table = self.shapetable          self.SetShapeStore(data)
162    
163      def open_shapefile(self):          self.SetClassification(None)
164          if self.shapefile is None:  
165              self.shapefile = shapelib.ShapeFile(self.filename)          self.__classification.SetDefaultLineColor(stroke)
166              numshapes, shapetype, mins, maxs = self.shapefile.info()          self.__classification.SetDefaultLineWidth(lineWidth)
167              self.numshapes = numshapes          self.__classification.SetDefaultFill(fill)
168              self.shapetype = shapelib_shapetypes[shapetype]  
169            self.UnsetModified()
170    
171        def __getattr__(self, attr):
172            """Access to some attributes for backwards compatibility
173    
174            The attributes implemented here are now held by the shapestore
175            if at all. For backwards compatibility pretend that they are
176            still there but issue a DeprecationWarning when they are
177            accessed.
178            """
179            if attr in ("table", "shapetable"):
180                value = self.store.Table()
181            elif attr == "shapefile":
182                value = self.store.Shapefile()
183            elif attr == "filename":
184                value = self.store.FileName()
185            else:
186                raise AttributeError, attr
187            warnings.warn("The Layer attribute %r is deprecated."
188                          " It's value can be accessed through the shapestore"
189                          % attr, DeprecationWarning, stacklevel = 2)
190            return value
191    
192        def SetShapeStore(self, store):
193            self.store = store
194            shapefile = self.store.Shapefile()
195    
196            numshapes, shapetype, mins, maxs = shapefile.info()
197            self.numshapes = numshapes
198            self.shapetype = shapelib_shapetypes[shapetype]
199    
200            # if there are shapes, set the bbox accordingly. Otherwise
201            # set it to None.
202            if self.numshapes:
203              self.bbox = mins[:2] + maxs[:2]              self.bbox = mins[:2] + maxs[:2]
204            else:
205                self.bbox = None
206    
207            # estimate a good depth for the quad tree. Each depth
208            # multiplies the number of nodes by four, therefore we
209            # basically take the base 4 logarithm of the number of
210            # shapes.
211            if self.numshapes < 4:
212                maxdepth = 1
213            else:
214                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
215    
216            self.shapetree = shptree.SHPTree(shapefile.cobject(), 2,
217                                             maxdepth)
218            # Set the classification to None if there is a classification
219            # and the new shapestore doesn't have a table with a suitable
220            # column, i.e one with the same name and type as before
221            # FIXME: Maybe we should keep it the same if the type is
222            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
223            if self.__classification is not None:
224                fieldname = self.__classification.GetField()
225                fieldtype = self.__classification.GetFieldType()
226                table = self.store.Table()
227                if (fieldname is not None
228                    and (not table.HasColumn(fieldname)
229                         or table.Column(fieldname).type != fieldtype)):
230                    self.SetClassification(None)
231            self.changed(LAYER_SHAPESTORE_REPLACED, self)
232    
233        def ShapeStore(self):
234            return self.store
235    
236        def Destroy(self):
237            BaseLayer.Destroy(self)
238            self.GetClassification()._set_layer(None)
239    
240      def BoundingBox(self):      def BoundingBox(self):
241          """Return the bounding box of the layer's shapes in their default          """Return the layer's bounding box in the intrinsic coordinate system.
242          coordinate system"""  
243          self.open_shapefile()          If the layer has no shapes, return None.
244            """
245          return self.bbox          return self.bbox
246    
247      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
248          """Return the layer's bounding box in lat/long coordinates"""          """Return the layer's bounding box in lat/long coordinates.
249          llx, lly, urx, ury = self.BoundingBox()  
250            Return None, if the layer doesn't contain any shapes.
251            """
252            bbox = self.BoundingBox()
253            if bbox is not None:
254                llx, lly, urx, ury = bbox
255                if self.projection is not None:
256                    llx, lly = self.projection.Inverse(llx, lly)
257                    urx, ury = self.projection.Inverse(urx, ury)
258                return llx, lly, urx, ury
259            else:
260                return None
261    
262        def ShapesBoundingBox(self, shapes):
263            """Return a bounding box in lat/long coordinates for the given
264            list of shape ids.
265    
266            If shapes is None or empty, return None.
267            """
268    
269            if shapes is None or len(shapes) == 0: return None
270    
271            llx = []
272            lly = []
273            urx = []
274            ury = []
275    
276          if self.projection is not None:          if self.projection is not None:
277              llx, lly = self.projection.Inverse(llx, lly)              inverse = lambda x, y: self.projection.Inverse(x, y)
278              urx, ury = self.projection.Inverse(urx, ury)          else:
279          return llx, lly, urx, ury              inverse = lambda x, y: (x, y)
280    
281            for id in shapes:
282                left, bottom, right, top = self.Shape(id).compute_bbox()
283    
284                left, bottom = inverse(left, bottom)
285                right, top   = inverse(right, top)
286    
287                llx.append(left)
288                lly.append(bottom)
289                urx.append(right)
290                ury.append(top)
291    
292            return (min(llx), min(lly), max(urx), max(ury))
293    
294        def GetFieldType(self, fieldName):
295            table = self.store.Table()
296            if table.HasColumn(fieldName):
297                return table.Column(fieldName).type
298            return None
299    
300        def HasShapes(self):
301            return True
302    
303      def NumShapes(self):      def NumShapes(self):
304          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
         self.open_shapefile()  
305          return self.numshapes          return self.numshapes
306    
307      def ShapeType(self):      def ShapeType(self):
308          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
309          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
310          """          """
         self.open_shapefile()  
311          return self.shapetype          return self.shapetype
312    
313      def Shape(self, index):      def Shape(self, index):
314          """Return the shape with index index"""          """Return the shape with index index"""
315          self.open_shapefile()          shape = self.store.Shapefile().read_object(index)
316          shape = self.shapefile.read_object(index)  
317          if self.shapetype == SHAPETYPE_POINT:          if self.shapetype == SHAPETYPE_POINT:
318              points = shape.vertices()              points = shape.vertices()
319          else:          else:
# Line 173  class Layer(BaseLayer): Line 321  class Layer(BaseLayer):
321              poly = shape.vertices()[0]              poly = shape.vertices()[0]
322              points = []              points = []
323              for x, y in poly:              for x, y in poly:
324                  points.append(x, y)                  points.append((x, y))
325    
326          return Shape(points)          return Shape(points)
327    
328      def SetProjection(self, projection):      def ShapesInRegion(self, box):
329          """Set the layer's projection"""          """Return the ids of the shapes that overlap the box.
330    
331            Box is a tuple (left, bottom, right, top) in unprojected coordinates.
332            """
333            left, bottom, right, top = box
334    
335            if self.projection is not None:
336                left,  bottom = self.projection.Forward(left, bottom)
337                right, top    = self.projection.Forward(right, top)
338    
339            return self.shapetree.find_shapes((left, bottom), (right, top))
340    
341        def HasClassification(self):
342            return True
343    
344        def GetClassification(self):
345            return self.__classification
346    
347        def SetClassification(self, clazz):
348            """Set the classification used by this layer to 'clazz'
349    
350            If 'clazz' is None a default classification is created.
351    
352            ValueError is raised if the classification's field name
353            and type are different (if they aren't None) than what
354            is in the shapestore. The Layer will not be changed in
355            this case.
356            """
357    
358            old_class = self.__classification
359    
360            if clazz is None:
361                clazz = classification.Classification()
362    
363            try:
364                clazz._set_layer(self)
365    
366                # only change things after a successful call
367                if old_class is not None:
368                    old_class._set_layer(None)
369                self.__classification = clazz
370            except ValueError:
371                raise ValueError
372    
373            # we don't need this since a message will be sent
374            # after calling _set_layer()
375            #self.changed(LAYER_CHANGED, self)
376    
377        def ClassChanged(self):
378            """Called from the classification object when it has changed."""
379            self.changed(LAYER_CHANGED, self)
380    
381        def TreeInfo(self):
382            items = []
383    
384            items.append(_("Filename: %s") % self.ShapeStore().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 there is no support for images, or the file cannot
452            be read, or there is no geographics information available, return None.
453            """
454            if not resource.has_gdal_support():
455                return None
456    
457            if self.bbox == -1:
458                dataset = gdal.Open(self.filename, GA_ReadOnly)
459                if dataset is None:
460                    self.bbox = None
461                else:
462                    geotransform = dataset.GetGeoTransform()
463                    if geotransform is None:
464                        return None
465    
466                    x = 0
467                    y = dataset.RasterYSize
468                    left = geotransform[0] +        \
469                           geotransform[1] * x +    \
470                           geotransform[2] * y
471    
472                    bottom = geotransform[3] +      \
473                             geotransform[4] * x +  \
474                             geotransform[5] * y
475    
476                    x = dataset.RasterXSize
477                    y = 0
478                    right = geotransform[0] +       \
479                            geotransform[1] * x +   \
480                            geotransform[2] * y
481    
482                    top = geotransform[3] +         \
483                          geotransform[4] * x +     \
484                          geotransform[5] * y
485    
486                    self.bbox = (left, bottom, right, top)
487    
488            return self.bbox
489    
490        def LatLongBoundingBox(self):
491            bbox = self.BoundingBox()
492            if bbox is None:
493                return None
494    
495            llx, lly, urx, ury = bbox
496            if self.projection is not None:
497                llx, lly = self.projection.Inverse(llx, lly)
498                urx, ury = self.projection.Inverse(urx, ury)
499    
500            return llx, lly, urx, ury
501    
502        def GetImageFilename(self):
503            return self.filename
504    
505        def TreeInfo(self):
506            items = []
507    
508            items.append(_("Filename: %s") % self.GetImageFilename())
509    
510            if self.Visible():
511                items.append(_("Shown"))
512            else:
513                items.append(_("Hidden"))
514    
515            bbox = self.LatLongBoundingBox()
516            if bbox is not None:
517                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
518            else:
519                items.append(_("Extent (lat-lon):"))
520    
521            if self.projection and len(self.projection.params) > 0:
522                items.append((_("Projection"),
523                            [str(param) for param in self.projection.params]))
524    
525            return (_("Layer '%s'") % self.Title(), items)
526    
     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.1338
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