/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 437 by jonathan, Thu Feb 27 15:53:21 2003 UTC revision 1355 by jonathan, Wed Jul 2 09:37:23 2003 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001, 2002 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]>  # Jonathan Coles <[email protected]>
# Line 8  Line 8 
8    
9  __version__ = "$Revision$"  __version__ = "$Revision$"
10    
 import os  
11  from math import log, ceil  from math import log, ceil
12    import warnings
13    
14  from Thuban import _  from Thuban import _
   
15  import shapelib, shptree  import shapelib, shptree
16    
17  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18       LAYER_VISIBILITY_CHANGED       LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED
   
 from color import Color  
19    
20  import classification  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 33  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 45  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 68  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 77  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 87  class BaseLayer(TitledObject, Modifiable Line 95  class BaseLayer(TitledObject, Modifiable
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    
# Line 95  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 = Color.None,                   fill = Transparent,
133                   stroke = Color.Black,                   stroke = Black,
134                   stroke_width = 1,                   lineWidth = 1,
135                   visible = 1):                   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                                     visible = visible,
153                                     projection = projection)
154    
155            #
156            # this is really important so that when the classification class
157            # tries to set its parent layer the variable will exist
158            #
159            self.__classification = None
160    
161          # Make the filename absolute. The filename will be          self.SetShapeStore(data)
         # 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)  
162    
163          self.projection = projection          self.SetClassification(None)
164          self.shapefile = None  
165          self.shapetree = None          self.__classification.SetDefaultLineColor(stroke)
166          self.open_shapefile()          self.__classification.SetDefaultLineWidth(lineWidth)
         # shapetable is the table associated with the shapefile, while  
         # table is the default table used to look up attributes for  
         # display  
         self.shapetable = Table(filename)  
         self.table = self.shapetable  
   
         self.__classification = classification.Classification(self)  
         self.__classification.SetDefaultStroke(stroke)  
         self.__classification.SetDefaultStrokeWidth(stroke_width)  
167          self.__classification.SetDefaultFill(fill)          self.__classification.SetDefaultFill(fill)
168    
169          self.UnsetModified()          self.UnsetModified()
170    
171      def open_shapefile(self):      def __getattr__(self, attr):
172          if self.shapefile is None:          """Access to some attributes for backwards compatibility
             self.shapefile = shapelib.ShapeFile(self.filename)  
             numshapes, shapetype, mins, maxs = self.shapefile.info()  
             self.numshapes = numshapes  
             self.shapetype = shapelib_shapetypes[shapetype]  
   
             # if there are shapes, set the bbox accordinly. Otherwise  
             # set it to None.  
             if self.numshapes:  
                 self.bbox = mins[:2] + maxs[:2]  
             else:  
                 self.bbox = None  
173    
174              # estimate a good depth for the quad tree. Each depth          The attributes implemented here are now held by the shapestore
175              # multiplies the number of nodes by four, therefore we          if at all. For backwards compatibility pretend that they are
176              # basically take the base 4 logarithm of the number of          still there but issue a DeprecationWarning when they are
177              # shapes.          accessed.
178              if self.numshapes < 4:          """
179                  maxdepth = 1          if attr in ("table", "shapetable"):
180              else:              value = self.store.Table()
181                  maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))          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]
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              self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,      def ShapeStore(self):
234                                               maxdepth)          return self.store
235    
236      def Destroy(self):      def Destroy(self):
237          BaseLayer.Destroy(self)          BaseLayer.Destroy(self)
238          if self.shapefile is not None:          self.GetClassification()._set_layer(None)
             self.shapefile.close()  
             self.shapefile = None  
             self.shapetree = None  
         self.table.Destroy()  
239    
240      def BoundingBox(self):      def BoundingBox(self):
241          """Return the layer's bounding box in the intrinsic coordinate system.          """Return the layer's bounding box in the intrinsic coordinate system.
242    
243          If the layer has no shapes, return None.          If the layer has no shapes, return None.
244          """          """
         # The bbox will be set by open_shapefile just as we need it  
         # here.  
         self.open_shapefile()  
245          return self.bbox          return self.bbox
246    
247      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
# Line 208  class Layer(BaseLayer): Line 259  class Layer(BaseLayer):
259          else:          else:
260              return None              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:
277                inverse = lambda x, y: self.projection.Inverse(x, y)
278            else:
279                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)
         shape = self.shapefile.read_object(index)  
316    
317          if self.shapetype == SHAPETYPE_POINT:          if self.shapetype == SHAPETYPE_POINT:
318              points = shape.vertices()              points = shape.vertices()
# Line 239  class Layer(BaseLayer): Line 328  class Layer(BaseLayer):
328      def ShapesInRegion(self, box):      def ShapesInRegion(self, box):
329          """Return the ids of the shapes that overlap the box.          """Return the ids of the shapes that overlap the box.
330    
331          Box is a tuple (left, bottom, right, top) in the coordinate          Box is a tuple (left, bottom, right, top) in unprojected coordinates.
         system used by the layer's shapefile.  
332          """          """
333          left, bottom, right, top = box          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))          return self.shapetree.find_shapes((left, bottom), (right, top))
340    
341      def SetProjection(self, projection):      def HasClassification(self):
342          """Set the layer's projection"""          return True
         self.projection = projection  
         self.changed(LAYER_PROJECTION_CHANGED, self)  
343    
344      def GetClassification(self):      def GetClassification(self):
345          return self.__classification          return self.__classification
346    
347      def SetClassification(self, clazz):      def SetClassification(self, clazz):
348          self.__classification = clazz          """Set the classification used by this layer to 'clazz'
349          self.changed(LAYER_LEGEND_CHANGED, self)  
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                self.__classification = clazz
365                clazz._set_layer(self)
366    
367                # only change things after a successful call
368                if old_class is not None:
369                    old_class._set_layer(None)
370            except ValueError:
371                self.__classification = old_class
372                raise ValueError
373    
374            # we don't need this since a message will be sent
375            # after calling _set_layer()
376            #self.changed(LAYER_CHANGED, self)
377    
378        def ClassChanged(self):
379            """Called from the classification object when it has changed."""
380            self.changed(LAYER_CHANGED, self)
381    
382      def TreeInfo(self):      def TreeInfo(self):
383          items = []          items = []
384    
385            items.append(_("Filename: %s") % self.ShapeStore().FileName())
386    
387          if self.Visible():          if self.Visible():
388              items.append(_("Shown"))              items.append(_("Shown"))
389          else:          else:
# Line 273  class Layer(BaseLayer): Line 397  class Layer(BaseLayer):
397              items.append(_("Extent (lat-lon):"))              items.append(_("Extent (lat-lon):"))
398          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
399    
400            if self.projection and len(self.projection.params) > 0:
401                items.append((_("Projection"),
402                            [str(param) for param in self.projection.params]))
403    
404          items.append(self.__classification)          items.append(self.__classification)
405    
406          return (_("Layer '%s'") % self.Title(), items)          return (_("Layer '%s'") % self.Title(), items)
407    
408    
409    if resource.has_gdal_support():
410        import gdal
411        from gdalconst import GA_ReadOnly
412    
413    class RasterLayer(BaseLayer):
414    
415        def __init__(self, title, filename, projection = None, visible = True):
416            """Initialize the Raster Layer.
417    
418            title -- title for the layer.
419    
420            filename -- file name of the source image.
421    
422            projection -- Projection object describing the projection which
423                          the source image is in.
424    
425            visible -- True is the layer should initially be visible.
426    
427            Throws IOError if the filename is invalid or points to a file that
428            is not in a format GDAL can use.
429            """
430    
431            BaseLayer.__init__(self, title, visible = visible)
432    
433            self.projection = projection
434            self.filename = filename
435    
436            self.bbox = -1
437    
438            if resource.has_gdal_support():
439                #
440                # temporarily open the file so that GDAL can test if it's valid.
441                #
442                dataset = gdal.Open(self.filename, GA_ReadOnly)
443    
444                if dataset is None:
445                    raise IOError()
446    
447            self.UnsetModified()
448    
449        def BoundingBox(self):
450            """Return the layer's bounding box in the intrinsic coordinate system.
451    
452            If the there is no support for images, or the file cannot
453            be read, or there is no geographics information available, return None.
454            """
455            if not resource.has_gdal_support():
456                return None
457    
458            if self.bbox == -1:
459                dataset = gdal.Open(self.filename, GA_ReadOnly)
460                if dataset is None:
461                    self.bbox = None
462                else:
463                    geotransform = dataset.GetGeoTransform()
464                    if geotransform is None:
465                        return None
466    
467                    x = 0
468                    y = dataset.RasterYSize
469                    left = geotransform[0] +        \
470                           geotransform[1] * x +    \
471                           geotransform[2] * y
472    
473                    bottom = geotransform[3] +      \
474                             geotransform[4] * x +  \
475                             geotransform[5] * y
476    
477                    x = dataset.RasterXSize
478                    y = 0
479                    right = geotransform[0] +       \
480                            geotransform[1] * x +   \
481                            geotransform[2] * y
482    
483                    top = geotransform[3] +         \
484                          geotransform[4] * x +     \
485                          geotransform[5] * y
486    
487                    self.bbox = (left, bottom, right, top)
488    
489            return self.bbox
490    
491        def LatLongBoundingBox(self):
492            bbox = self.BoundingBox()
493            if bbox is None:
494                return None
495    
496            llx, lly, urx, ury = bbox
497            if self.projection is not None:
498                llx, lly = self.projection.Inverse(llx, lly)
499                urx, ury = self.projection.Inverse(urx, ury)
500    
501            return llx, lly, urx, ury
502    
503        def GetImageFilename(self):
504            return self.filename
505    
506        def TreeInfo(self):
507            items = []
508    
509            items.append(_("Filename: %s") % self.GetImageFilename())
510    
511            if self.Visible():
512                items.append(_("Shown"))
513            else:
514                items.append(_("Hidden"))
515    
516            bbox = self.LatLongBoundingBox()
517            if bbox is not None:
518                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
519            else:
520                items.append(_("Extent (lat-lon):"))
521    
522            if self.projection and len(self.projection.params) > 0:
523                items.append((_("Projection"),
524                            [str(param) for param in self.projection.params]))
525    
526            return (_("Layer '%s'") % self.Title(), items)
527    
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