/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 6 by bh, Tue Aug 28 15:41:52 2001 UTC revision 1452 by bh, Fri Jul 18 12:57:59 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, CLASS_CHANGED
 _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          self.__classification = None
156          self.shapefile = None          self.store = None
157          # shapetable is the table associated with the shapefile, while  
158          # table is the default table used to look up attributes for          self.SetShapeStore(data)
159          # display  
160          self.shapetable = Table(filename)          self.classification_column = None
161          self.table = self.shapetable          self.SetClassificationColumn(None)
162            self.SetClassification(None)
163      def open_shapefile(self):  
164          if self.shapefile is None:          self.__classification.SetDefaultLineColor(stroke)
165              self.shapefile = shapelib.ShapeFile(self.filename)          self.__classification.SetDefaultLineWidth(lineWidth)
166              numshapes, shapetype, mins, maxs = self.shapefile.info()          self.__classification.SetDefaultFill(fill)
167              self.numshapes = numshapes  
168              self.shapetype = shapelib_shapetypes[shapetype]          self.UnsetModified()
169    
170        def __getattr__(self, attr):
171            """Access to some attributes for backwards compatibility
172    
173            The attributes implemented here are now held by the shapestore
174            if at all. For backwards compatibility pretend that they are
175            still there but issue a DeprecationWarning when they are
176            accessed.
177            """
178            if attr in ("table", "shapetable"):
179                value = self.store.Table()
180            elif attr == "shapefile":
181                value = self.store.Shapefile()
182            elif attr == "filename":
183                value = self.store.FileName()
184            else:
185                raise AttributeError, attr
186            warnings.warn("The Layer attribute %r is deprecated."
187                          " It's value can be accessed through the shapestore"
188                          % attr, DeprecationWarning, stacklevel = 2)
189            return value
190    
191        def SetShapeStore(self, store):
192            # Set the classification to None if there is a classification
193            # and the new shapestore doesn't have a table with a suitable
194            # column, i.e one with the same name and type as before
195            # FIXME: Maybe we should keep it the same if the type is
196            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
197            if self.__classification is not None:
198                columnname = self.classification_column
199                columntype = self.GetFieldType(columnname)
200                table = store.Table()
201                if (columnname is not None
202                    and (not table.HasColumn(columnname)
203                         or table.Column(columnname).type != columntype)):
204                    self.SetClassification(None)
205    
206            self.store = store
207            shapefile = self.store.Shapefile()
208    
209            numshapes, shapetype, mins, maxs = shapefile.info()
210            self.numshapes = numshapes
211            self.shapetype = shapelib_shapetypes[shapetype]
212    
213            # if there are shapes, set the bbox accordingly. Otherwise
214            # set it to None.
215            if self.numshapes:
216              self.bbox = mins[:2] + maxs[:2]              self.bbox = mins[:2] + maxs[:2]
217            else:
218                self.bbox = None
219    
220            # estimate a good depth for the quad tree. Each depth
221            # multiplies the number of nodes by four, therefore we
222            # basically take the base 4 logarithm of the number of
223            # shapes.
224            if self.numshapes < 4:
225                maxdepth = 1
226            else:
227                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
228    
229            self.shapetree = shptree.SHPTree(shapefile.cobject(), 2,
230                                             maxdepth)
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            if self.__classification is not None:
239                self.__classification.Unsubscribe(CLASS_CHANGED,
240                                                  self._classification_changed)
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            if self.store:
298                table = self.store.Table()
299                if table.HasColumn(fieldName):
300                    return table.Column(fieldName).type
301            return None
302    
303        def HasShapes(self):
304            return True
305    
306      def NumShapes(self):      def NumShapes(self):
307          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
         self.open_shapefile()  
308          return self.numshapes          return self.numshapes
309    
310      def ShapeType(self):      def ShapeType(self):
311          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
312          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
313          """          """
         self.open_shapefile()  
314          return self.shapetype          return self.shapetype
315    
316      def Shape(self, index):      def Shape(self, index):
317          """Return the shape with index index"""          """Return the shape with index index"""
318          self.open_shapefile()          shape = self.store.Shapefile().read_object(index)
319          shape = self.shapefile.read_object(index)  
320          if self.shapetype == SHAPETYPE_POINT:          if self.shapetype == SHAPETYPE_POINT:
321              points = shape.vertices()              points = shape.vertices()
322          else:          else:
# Line 173  class Layer(BaseLayer): Line 324  class Layer(BaseLayer):
324              poly = shape.vertices()[0]              poly = shape.vertices()[0]
325              points = []              points = []
326              for x, y in poly:              for x, y in poly:
327                  points.append(x, y)                  points.append((x, y))
328    
329          return Shape(points)          return Shape(points)
330    
331      def SetProjection(self, projection):      def ShapesInRegion(self, box):
332          """Set the layer's projection"""          """Return the ids of the shapes that overlap the box.
333    
334            Box is a tuple (left, bottom, right, top) in unprojected coordinates.
335            """
336            left, bottom, right, top = box
337    
338            if self.projection is not None:
339                left,  bottom = self.projection.Forward(left, bottom)
340                right, top    = self.projection.Forward(right, top)
341    
342            return self.shapetree.find_shapes((left, bottom), (right, top))
343    
344        def GetClassificationColumn(self):
345            return self.classification_column
346    
347        def SetClassificationColumn(self, column):
348            """Set the column to classifiy on, or None. If column is not None
349            and the column does not exist in the table, raise a ValueError.
350            """
351            if column:
352                columnType = self.GetFieldType(column)
353                if columnType is None:
354                    raise ValueError()
355            changed = self.classification_column != column
356            self.classification_column = column
357            if changed:
358                self.changed(LAYER_CHANGED, self)
359    
360        def HasClassification(self):
361            return True
362    
363        def GetClassification(self):
364            return self.__classification
365    
366        def SetClassification(self, clazz):
367            """Set the classification used by this layer to 'clazz'
368    
369            If 'clazz' is None a default classification is created.
370    
371            This issues a LAYER_CHANGED event.
372            """
373    
374            if self.__classification is not None:
375                self.__classification.Unsubscribe(CLASS_CHANGED,
376                                                  self._classification_changed)
377    
378            if clazz is None:
379                clazz = classification.Classification()
380    
381            self.__classification = clazz
382            self.__classification.Subscribe(CLASS_CHANGED,
383                                            self._classification_changed)
384    
385            self._classification_changed()
386    
387        def _classification_changed(self):
388            """Called from the classification object when it has changed."""
389            self.changed(LAYER_CHANGED, self)
390    
391        def TreeInfo(self):
392            items = []
393    
394            items.append(_("Filename: %s") % self.ShapeStore().FileName())
395    
396            if self.Visible():
397                items.append(_("Shown"))
398            else:
399                items.append(_("Hidden"))
400            items.append(_("Shapes: %d") % self.NumShapes())
401    
402            bbox = self.LatLongBoundingBox()
403            if bbox is not None:
404                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
405            else:
406                items.append(_("Extent (lat-lon):"))
407            items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
408    
409            if self.projection and len(self.projection.params) > 0:
410                items.append((_("Projection"),
411                            [str(param) for param in self.projection.params]))
412    
413            items.append(self.__classification)
414    
415            return (_("Layer '%s'") % self.Title(), items)
416    
417    
418    if resource.has_gdal_support():
419        import gdal
420        from gdalconst import GA_ReadOnly
421    
422    class RasterLayer(BaseLayer):
423    
424        def __init__(self, title, filename, projection = None, visible = True):
425            """Initialize the Raster Layer.
426    
427            title -- title for the layer.
428    
429            filename -- file name of the source image.
430    
431            projection -- Projection object describing the projection which
432                          the source image is in.
433    
434            visible -- True is the layer should initially be visible.
435    
436            Throws IOError if the filename is invalid or points to a file that
437            is not in a format GDAL can use.
438            """
439    
440            BaseLayer.__init__(self, title, visible = visible)
441    
442          self.projection = projection          self.projection = projection
443          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = filename
444    
445            self.bbox = -1
446    
447            if resource.has_gdal_support():
448                #
449                # temporarily open the file so that GDAL can test if it's valid.
450                #
451                dataset = gdal.Open(self.filename, GA_ReadOnly)
452    
453                if dataset is None:
454                    raise IOError()
455    
456            self.UnsetModified()
457    
458        def BoundingBox(self):
459            """Return the layer's bounding box in the intrinsic coordinate system.
460    
461            If the there is no support for images, or the file cannot
462            be read, or there is no geographics information available, return None.
463            """
464            if not resource.has_gdal_support():
465                return None
466    
467            if self.bbox == -1:
468                dataset = gdal.Open(self.filename, GA_ReadOnly)
469                if dataset is None:
470                    self.bbox = None
471                else:
472                    geotransform = dataset.GetGeoTransform()
473                    if geotransform is None:
474                        return None
475    
476                    x = 0
477                    y = dataset.RasterYSize
478                    left = geotransform[0] +        \
479                           geotransform[1] * x +    \
480                           geotransform[2] * y
481    
482                    bottom = geotransform[3] +      \
483                             geotransform[4] * x +  \
484                             geotransform[5] * y
485    
486                    x = dataset.RasterXSize
487                    y = 0
488                    right = geotransform[0] +       \
489                            geotransform[1] * x +   \
490                            geotransform[2] * y
491    
492                    top = geotransform[3] +         \
493                          geotransform[4] * x +     \
494                          geotransform[5] * y
495    
496                    self.bbox = (left, bottom, right, top)
497    
498            return self.bbox
499    
500        def LatLongBoundingBox(self):
501            bbox = self.BoundingBox()
502            if bbox is None:
503                return None
504    
505            llx, lly, urx, ury = bbox
506            if self.projection is not None:
507                llx, lly = self.projection.Inverse(llx, lly)
508                urx, ury = self.projection.Inverse(urx, ury)
509    
510            return llx, lly, urx, ury
511    
512        def GetImageFilename(self):
513            return self.filename
514    
515        def TreeInfo(self):
516            items = []
517    
518            items.append(_("Filename: %s") % self.GetImageFilename())
519    
520            if self.Visible():
521                items.append(_("Shown"))
522            else:
523                items.append(_("Hidden"))
524    
525            bbox = self.LatLongBoundingBox()
526            if bbox is not None:
527                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
528            else:
529                items.append(_("Extent (lat-lon):"))
530    
531            if self.projection and len(self.projection.params) > 0:
532                items.append((_("Projection"),
533                            [str(param) for param in self.projection.params]))
534    
535            return (_("Layer '%s'") % self.Title(), items)
536    
     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.1452
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