/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 6 by bh, Tue Aug 28 15:41:52 2001 UTC revision 1427 by jonathan, Wed Jul 16 13:22:48 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.SetClassificationField(None)
161          self.table = self.shapetable          self.SetClassification(None)
162    
163      def open_shapefile(self):          self.__classification.SetDefaultLineColor(stroke)
164          if self.shapefile is None:          self.__classification.SetDefaultLineWidth(lineWidth)
165              self.shapefile = shapelib.ShapeFile(self.filename)          self.__classification.SetDefaultFill(fill)
166              numshapes, shapetype, mins, maxs = self.shapefile.info()  
167              self.numshapes = numshapes          self.UnsetModified()
168              self.shapetype = shapelib_shapetypes[shapetype]  
169        def __getattr__(self, attr):
170            """Access to some attributes for backwards compatibility
171    
172            The attributes implemented here are now held by the shapestore
173            if at all. For backwards compatibility pretend that they are
174            still there but issue a DeprecationWarning when they are
175            accessed.
176            """
177            if attr in ("table", "shapetable"):
178                value = self.store.Table()
179            elif attr == "shapefile":
180                value = self.store.Shapefile()
181            elif attr == "filename":
182                value = self.store.FileName()
183            else:
184                raise AttributeError, attr
185            warnings.warn("The Layer attribute %r is deprecated."
186                          " It's value can be accessed through the shapestore"
187                          % attr, DeprecationWarning, stacklevel = 2)
188            return value
189    
190        def SetShapeStore(self, store):
191            # Set the classification to None if there is a classification
192            # and the new shapestore doesn't have a table with a suitable
193            # column, i.e one with the same name and type as before
194            # FIXME: Maybe we should keep it the same if the type is
195            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
196            if self.__classification is not None:
197                fieldname = self.classificationField
198                fieldtype = self.GetFieldType(fieldname)
199                table = store.Table()
200                if (fieldname is not None
201                    and (not table.HasColumn(fieldname)
202                         or table.Column(fieldname).type != fieldtype)):
203                    self.SetClassification(None)
204    
205            self.store = store
206            shapefile = self.store.Shapefile()
207    
208            numshapes, shapetype, mins, maxs = shapefile.info()
209            self.numshapes = numshapes
210            self.shapetype = shapelib_shapetypes[shapetype]
211    
212            # if there are shapes, set the bbox accordingly. Otherwise
213            # set it to None.
214            if self.numshapes:
215              self.bbox = mins[:2] + maxs[:2]              self.bbox = mins[:2] + maxs[:2]
216            else:
217                self.bbox = None
218    
219            # estimate a good depth for the quad tree. Each depth
220            # multiplies the number of nodes by four, therefore we
221            # basically take the base 4 logarithm of the number of
222            # shapes.
223            if self.numshapes < 4:
224                maxdepth = 1
225            else:
226                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
227    
228            self.shapetree = shptree.SHPTree(shapefile.cobject(), 2,
229                                             maxdepth)
230            self.changed(LAYER_SHAPESTORE_REPLACED, self)
231    
232        def ShapeStore(self):
233            return self.store
234    
235        def Destroy(self):
236            BaseLayer.Destroy(self)
237            if self.__classification is not None:
238                self.__classification.Unsubscribe(CLASS_CHANGED, self.ClassChanged)
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            if self.store:
296                table = self.store.Table()
297                if table.HasColumn(fieldName):
298                    return table.Column(fieldName).type
299            return None
300    
301        def HasShapes(self):
302            return True
303    
304      def NumShapes(self):      def NumShapes(self):
305          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
         self.open_shapefile()  
306          return self.numshapes          return self.numshapes
307    
308      def ShapeType(self):      def ShapeType(self):
309          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
310          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
311          """          """
         self.open_shapefile()  
312          return self.shapetype          return self.shapetype
313    
314      def Shape(self, index):      def Shape(self, index):
315          """Return the shape with index index"""          """Return the shape with index index"""
316          self.open_shapefile()          shape = self.store.Shapefile().read_object(index)
317          shape = self.shapefile.read_object(index)  
318          if self.shapetype == SHAPETYPE_POINT:          if self.shapetype == SHAPETYPE_POINT:
319              points = shape.vertices()              points = shape.vertices()
320          else:          else:
# Line 173  class Layer(BaseLayer): Line 322  class Layer(BaseLayer):
322              poly = shape.vertices()[0]              poly = shape.vertices()[0]
323              points = []              points = []
324              for x, y in poly:              for x, y in poly:
325                  points.append(x, y)                  points.append((x, y))
326    
327          return Shape(points)          return Shape(points)
328    
329      def SetProjection(self, projection):      def ShapesInRegion(self, box):
330          """Set the layer's projection"""          """Return the ids of the shapes that overlap the box.
331    
332            Box is a tuple (left, bottom, right, top) in unprojected coordinates.
333            """
334            left, bottom, right, top = box
335    
336            if self.projection is not None:
337                left,  bottom = self.projection.Forward(left, bottom)
338                right, top    = self.projection.Forward(right, top)
339    
340            return self.shapetree.find_shapes((left, bottom), (right, top))
341    
342        def GetClassificationField(self):
343            return self.classificationField
344    
345        def SetClassificationField(self, field):
346            """Set the field to classifiy on, or None. If field is not None
347            and the field does not exist in the table, raise a ValueError.
348            """
349            if field:
350                fieldType = self.GetFieldType(field)
351                if fieldType is None:
352                    raise ValueError()
353            self.classificationField = field
354    
355        def HasClassification(self):
356            return True
357    
358        def GetClassification(self):
359            return self.__classification
360    
361        def SetClassification(self, clazz):
362            """Set the classification used by this layer to 'clazz'
363    
364            If 'clazz' is None a default classification is created.
365    
366            This issues a LAYER_CHANGED event.
367            """
368    
369            if self.__classification is not None:
370                self.__classification.Unsubscribe(CLASS_CHANGED, self.ClassChanged)
371    
372            if clazz is None:
373                clazz = classification.Classification()
374    
375            self.__classification = clazz
376            self.__classification.Subscribe(CLASS_CHANGED, self.ClassChanged)
377    
378            self.ClassChanged()
379    
380        def ClassChanged(self):
381            """Called from the classification object when it has changed."""
382            self.changed(LAYER_CHANGED, self)
383    
384        def TreeInfo(self):
385            items = []
386    
387            items.append(_("Filename: %s") % self.ShapeStore().FileName())
388    
389            if self.Visible():
390                items.append(_("Shown"))
391            else:
392                items.append(_("Hidden"))
393            items.append(_("Shapes: %d") % self.NumShapes())
394    
395            bbox = self.LatLongBoundingBox()
396            if bbox is not None:
397                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
398            else:
399                items.append(_("Extent (lat-lon):"))
400            items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
401    
402            if self.projection and len(self.projection.params) > 0:
403                items.append((_("Projection"),
404                            [str(param) for param in self.projection.params]))
405    
406            items.append(self.__classification)
407    
408            return (_("Layer '%s'") % self.Title(), items)
409    
410    
411    if resource.has_gdal_support():
412        import gdal
413        from gdalconst import GA_ReadOnly
414    
415    class RasterLayer(BaseLayer):
416    
417        def __init__(self, title, filename, projection = None, visible = True):
418            """Initialize the Raster Layer.
419    
420            title -- title for the layer.
421    
422            filename -- file name of the source image.
423    
424            projection -- Projection object describing the projection which
425                          the source image is in.
426    
427            visible -- True is the layer should initially be visible.
428    
429            Throws IOError if the filename is invalid or points to a file that
430            is not in a format GDAL can use.
431            """
432    
433            BaseLayer.__init__(self, title, visible = visible)
434    
435          self.projection = projection          self.projection = projection
436          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = filename
437    
438            self.bbox = -1
439    
440            if resource.has_gdal_support():
441                #
442                # temporarily open the file so that GDAL can test if it's valid.
443                #
444                dataset = gdal.Open(self.filename, GA_ReadOnly)
445    
446                if dataset is None:
447                    raise IOError()
448    
449            self.UnsetModified()
450    
451        def BoundingBox(self):
452            """Return the layer's bounding box in the intrinsic coordinate system.
453    
454            If the there is no support for images, or the file cannot
455            be read, or there is no geographics information available, return None.
456            """
457            if not resource.has_gdal_support():
458                return None
459    
460            if self.bbox == -1:
461                dataset = gdal.Open(self.filename, GA_ReadOnly)
462                if dataset is None:
463                    self.bbox = None
464                else:
465                    geotransform = dataset.GetGeoTransform()
466                    if geotransform is None:
467                        return None
468    
469                    x = 0
470                    y = dataset.RasterYSize
471                    left = geotransform[0] +        \
472                           geotransform[1] * x +    \
473                           geotransform[2] * y
474    
475                    bottom = geotransform[3] +      \
476                             geotransform[4] * x +  \
477                             geotransform[5] * y
478    
479                    x = dataset.RasterXSize
480                    y = 0
481                    right = geotransform[0] +       \
482                            geotransform[1] * x +   \
483                            geotransform[2] * y
484    
485                    top = geotransform[3] +         \
486                          geotransform[4] * x +     \
487                          geotransform[5] * y
488    
489                    self.bbox = (left, bottom, right, top)
490    
491            return self.bbox
492    
493        def LatLongBoundingBox(self):
494            bbox = self.BoundingBox()
495            if bbox is None:
496                return None
497    
498            llx, lly, urx, ury = bbox
499            if self.projection is not None:
500                llx, lly = self.projection.Inverse(llx, lly)
501                urx, ury = self.projection.Inverse(urx, ury)
502    
503            return llx, lly, urx, ury
504    
505        def GetImageFilename(self):
506            return self.filename
507    
508        def TreeInfo(self):
509            items = []
510    
511            items.append(_("Filename: %s") % self.GetImageFilename())
512    
513            if self.Visible():
514                items.append(_("Shown"))
515            else:
516                items.append(_("Hidden"))
517    
518            bbox = self.LatLongBoundingBox()
519            if bbox is not None:
520                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
521            else:
522                items.append(_("Extent (lat-lon):"))
523    
524            if self.projection and len(self.projection.params) > 0:
525                items.append((_("Projection"),
526                            [str(param) for param in self.projection.params]))
527    
528            return (_("Layer '%s'") % self.Title(), items)
529    
     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.1427
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