/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 610 by jonathan, Fri Apr 4 13:56:59 2003 UTC revision 1978 by bh, Tue Nov 25 14:30:34 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 9  Line 9 
9  __version__ = "$Revision$"  __version__ = "$Revision$"
10    
11  import os  import os
12  from math import log, ceil  import warnings
13    
14  from Thuban import _  from Thuban import _
15    
16  import shapelib, shptree  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
17         LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
 from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  
      LAYER_VISIBILITY_CHANGED, LAYER_CHANGED  
   
 from color import Color  
18    
19  import classification  import classification
20    
21  from table import Table  from color import Transparent, Black
   
22  from base import TitledObject, Modifiable  from base import TitledObject, Modifiable
23    from data import SHAPETYPE_POLYGON, SHAPETYPE_ARC, SHAPETYPE_POINT
24    
25  class Shape:  import resource
   
     """Represent one shape"""  
   
     def __init__(self, points):  
         self.points = points  
         #self.compute_bbox()  
   
     def compute_bbox(self):  
         xs = []  
         ys = []  
         for x, y in self.points:  
             xs.append(x)  
             ys.append(y)  
         self.llx = min(xs)  
         self.lly = min(ys)  
         self.urx = max(xs)  
         self.ury = max(ys)  
   
     def Points(self):  
         return self.points  
   
   
26    
 # Shape type constants  
 SHAPETYPE_POLYGON = "polygon"  
 SHAPETYPE_ARC = "arc"  
 SHAPETYPE_POINT = "point"  
   
 # mapping from shapelib shapetype constants to our constants  
 shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,  
                        shapelib.SHPT_ARC: SHAPETYPE_ARC,  
                        shapelib.SHPT_POINT: SHAPETYPE_POINT}  
27    
28  shapetype_names = {SHAPETYPE_POINT: "Point",  shapetype_names = {SHAPETYPE_POINT: "Point",
29                     SHAPETYPE_ARC: "Arc",                     SHAPETYPE_ARC: "Arc",
# Line 68  class BaseLayer(TitledObject, Modifiable Line 33  class BaseLayer(TitledObject, Modifiable
33    
34      """Base class for the layers."""      """Base class for the layers."""
35    
36      def __init__(self, title, visible = 1):      def __init__(self, title, visible = True, projection = None):
37          """Initialize the layer.          """Initialize the layer.
38    
39          title -- the title          title -- the title
# Line 77  class BaseLayer(TitledObject, Modifiable Line 42  class BaseLayer(TitledObject, Modifiable
42          TitledObject.__init__(self, title)          TitledObject.__init__(self, title)
43          Modifiable.__init__(self)          Modifiable.__init__(self)
44          self.visible = visible          self.visible = visible
45            self.projection = projection
46    
47      def Visible(self):      def Visible(self):
48          """Return true if layer is visible"""          """Return true if layer is visible"""
# Line 87  class BaseLayer(TitledObject, Modifiable Line 53  class BaseLayer(TitledObject, Modifiable
53          self.visible = visible          self.visible = visible
54          self.issue(LAYER_VISIBILITY_CHANGED, self)          self.issue(LAYER_VISIBILITY_CHANGED, self)
55    
56        def HasClassification(self):
57            """Determine if this layer support classifications."""
58            return False
59    
60        def HasShapes(self):
61            """Determine if this layer supports shapes."""
62            return False
63    
64        def GetProjection(self):
65            """Return the layer's projection."""
66            return self.projection
67    
68        def SetProjection(self, projection):
69            """Set the layer's projection"""
70            self.projection = projection
71            self.changed(LAYER_PROJECTION_CHANGED, self)
72    
73  class Layer(BaseLayer):  class Layer(BaseLayer):
74    
# Line 95  class Layer(BaseLayer): Line 77  class Layer(BaseLayer):
77      All children of the layer have the same type.      All children of the layer have the same type.
78    
79      A layer has fill and stroke colors. Colors should be instances of      A layer has fill and stroke colors. Colors should be instances of
80      Color. They can also be None, indicating no fill or no stroke.      Color. They can also be Transparent, indicating no fill or no stroke.
81    
82      The layer objects send the following events, all of which have the      The layer objects send the following events, all of which have the
83      layer object as parameter:      layer object as parameter:
84    
85          TITLE_CHANGED -- The title has changed.          TITLE_CHANGED -- The title has changed.
86          LAYER_PROJECTION_CHANGED -- the projection has changed.          LAYER_PROJECTION_CHANGED -- the projection has changed.
         LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed  
   
87      """      """
88    
89      def __init__(self, title, filename, projection = None,      def __init__(self, title, data, projection = None,
90                   fill = Color.Transparent,                   fill = Transparent,
91                   stroke = Color.Black,                   stroke = Black,
92                   lineWidth = 1,                   lineWidth = 1,
93                   visible = 1):                   visible = True):
94          """Initialize the layer.          """Initialize the layer.
95    
96          title -- the title          title -- the title
97          filename -- the name of the shapefile          data -- datastore object for the shape data shown by the layer
98          projection -- the projection object. Its Inverse method is          projection -- the projection object. Its Inverse method is
99                 assumed to map the layer's coordinates to lat/long                 assumed to map the layer's coordinates to lat/long
100                 coordinates                 coordinates
101          fill -- the fill color or Color.Transparent if the shapes are          fill -- the fill color or Transparent if the shapes are
102                  not filled                  not filled
103          stroke -- the stroke color or Color.Transparent if the shapes          stroke -- the stroke color or Transparent if the shapes
104                  are not stroked                  are not stroked
105          visible -- boolean. If true the layer is visible.          visible -- boolean. If true the layer is visible.
106    
107          colors are expected to be instances of Color class          colors are expected to be instances of Color class
108          """          """
109          BaseLayer.__init__(self, title, visible = visible)          BaseLayer.__init__(self, title,
110                                     visible = visible,
111          # Make the filename absolute. The filename will be                                   projection = projection)
         # 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)  
112    
113          self.projection = projection          self.__classification = None
114          self.shapefile = None          self.store = None
         self.shapetree = None  
         self.open_shapefile()  
         # 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  
   
         #  
         # this is really important so that when the classification class  
         # tries to set its parent layer the variable will exist  
         #  
         self.__classification = None  
         self.__setClassLock = False  
115    
116            self.SetShapeStore(data)
117    
118            self.classification_column = None
119            self.SetClassificationColumn(None)
120          self.SetClassification(None)          self.SetClassification(None)
121    
122          self.__classification.SetDefaultLineColor(stroke)          self.__classification.SetDefaultLineColor(stroke)
123          self.__classification.SetDefaultLineWidth(lineWidth)          self.__classification.SetDefaultLineWidth(lineWidth)
124          self.__classification.SetDefaultFill(fill)          self.__classification.SetDefaultFill(fill)
         self.__classification.SetLayer(self)  
125    
126          self.UnsetModified()          self.UnsetModified()
127    
128      def open_shapefile(self):      def SetShapeStore(self, store):
129          if self.shapefile is None:          # Set the classification to None if there is a classification
130              self.shapefile = shapelib.ShapeFile(self.filename)          # and the new shapestore doesn't have a table with a suitable
131              numshapes, shapetype, mins, maxs = self.shapefile.info()          # column, i.e one with the same name and type as before
132              self.numshapes = numshapes          # FIXME: Maybe we should keep it the same if the type is
133              self.shapetype = shapelib_shapetypes[shapetype]          # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
134            if self.__classification is not None:
135              # if there are shapes, set the bbox accordinly. Otherwise              columnname = self.classification_column
136              # set it to None.              columntype = self.GetFieldType(columnname)
137              if self.numshapes:              table = store.Table()
138                  self.bbox = mins[:2] + maxs[:2]              if (columnname is not None
139              else:                  and (not table.HasColumn(columnname)
140                  self.bbox = None                       or table.Column(columnname).type != columntype)):
141                    self.SetClassification(None)
142    
143              # estimate a good depth for the quad tree. Each depth          self.store = store
             # multiplies the number of nodes by four, therefore we  
             # basically take the base 4 logarithm of the number of  
             # shapes.  
             if self.numshapes < 4:  
                 maxdepth = 1  
             else:  
                 maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))  
144    
145              self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,          self.changed(LAYER_SHAPESTORE_REPLACED, self)
146                                               maxdepth)  
147        def ShapeStore(self):
148            return self.store
149    
150      def Destroy(self):      def Destroy(self):
151          BaseLayer.Destroy(self)          BaseLayer.Destroy(self)
152          if self.shapefile is not None:          if self.__classification is not None:
153              self.shapefile.close()              self.__classification.Unsubscribe(CLASS_CHANGED,
154              self.shapefile = None                                                self._classification_changed)
             self.shapetree = None  
         self.SetClassification(None)  
         self.table.Destroy()  
155    
156      def BoundingBox(self):      def BoundingBox(self):
157          """Return the layer's bounding box in the intrinsic coordinate system.          """Return the layer's bounding box in the intrinsic coordinate system.
158    
159          If the layer has no shapes, return None.          If the layer has no shapes, return None.
160          """          """
161          # The bbox will be set by open_shapefile just as we need it          return self.store.BoundingBox()
         # here.  
         self.open_shapefile()  
         return self.bbox  
162    
163      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
164          """Return the layer's bounding box in lat/long coordinates.          """Return the layer's bounding box in lat/long coordinates.
# Line 221  class Layer(BaseLayer): Line 175  class Layer(BaseLayer):
175          else:          else:
176              return None              return None
177    
178      def GetFieldType(self, fieldName):      def ShapesBoundingBox(self, shapes):
179          self.open_shapefile()          """Return a bounding box in lat/long coordinates for the given
180          info = self.table.field_info_by_name(fieldName)          list of shape ids.
181          if info is not None:  
182              return info[0]          If shapes is None or empty, return None.
183            """
184    
185            if shapes is None or len(shapes) == 0: return None
186    
187            llx = []
188            lly = []
189            urx = []
190            ury = []
191    
192            if self.projection is not None:
193                inverse = lambda x, y: self.projection.Inverse(x, y)
194          else:          else:
195              return None              inverse = lambda x, y: (x, y)
196    
197            for id in shapes:
198                left, bottom, right, top = self.Shape(id).compute_bbox()
199    
200                left, bottom = inverse(left, bottom)
201                right, top   = inverse(right, top)
202    
203                llx.append(left)
204                lly.append(bottom)
205                urx.append(right)
206                ury.append(top)
207    
208            return (min(llx), min(lly), max(urx), max(ury))
209    
210        def GetFieldType(self, fieldName):
211            if self.store:
212                table = self.store.Table()
213                if table.HasColumn(fieldName):
214                    return table.Column(fieldName).type
215            return None
216    
217        def HasShapes(self):
218            return True
219    
220      def NumShapes(self):      def NumShapes(self):
221          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
222          self.open_shapefile()          return self.store.NumShapes()
         return self.numshapes  
223    
224      def ShapeType(self):      def ShapeType(self):
225          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
226          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.  
227            The return value is one of the SHAPETYPE_* constants defined in
228            Thuban.Model.data.
229          """          """
230          self.open_shapefile()          return self.store.ShapeType()
         return self.shapetype  
231    
232      def Shape(self, index):      def Shape(self, index):
233          """Return the shape with index index"""          """Return the shape with index index"""
234          self.open_shapefile()          return self.store.Shape(index)
         shape = self.shapefile.read_object(index)  
235    
236          if self.shapetype == SHAPETYPE_POINT:      def ShapesInRegion(self, bbox):
237              points = shape.vertices()          """Return an iterable over the shapes that overlap the bounding box.
         else:  
             #for poly in shape.vertices():  
             poly = shape.vertices()[0]  
             points = []  
             for x, y in poly:  
                 points.append((x, y))  
   
         return Shape(points)  
   
     def ShapesInRegion(self, box):  
         """Return the ids of the shapes that overlap the box.  
238    
239          Box is a tuple (left, bottom, right, top) in the coordinate          The bbox parameter should be the bounding box as a tuple in the
240          system used by the layer's shapefile.          form (minx, miny, maxx, maxy) in unprojected coordinates.
241            """
242            if self.projection is not None:
243                left, bottom, right, top = bbox
244                xs = []; ys = []
245                for x, y in [(left, bottom), (left, top), (right, top),
246                             (right, bottom)]:
247                    x, y = self.projection.Forward(x, y)
248                    xs.append(x)
249                    ys.append(y)
250                bbox = (min(xs), min(ys), max(xs), max(ys))
251    
252            return self.store.ShapesInRegion(bbox)
253    
254        def GetClassificationColumn(self):
255            return self.classification_column
256    
257        def SetClassificationColumn(self, column):
258            """Set the column to classifiy on, or None. If column is not None
259            and the column does not exist in the table, raise a ValueError.
260          """          """
261          left, bottom, right, top = box          if column:
262          return self.shapetree.find_shapes((left, bottom), (right, top))              columnType = self.GetFieldType(column)
263                if columnType is None:
264                    raise ValueError()
265            changed = self.classification_column != column
266            self.classification_column = column
267            if changed:
268                self.changed(LAYER_CHANGED, self)
269    
270      def SetProjection(self, projection):      def HasClassification(self):
271          """Set the layer's projection"""          return True
         self.projection = projection  
         self.changed(LAYER_PROJECTION_CHANGED, self)  
272    
273      def GetClassification(self):      def GetClassification(self):
274          return self.__classification          return self.__classification
275    
276      def SetClassification(self, clazz):      def SetClassification(self, clazz):
277          """Set the classification to 'clazz'          """Set the classification used by this layer to 'clazz'
278    
279          If 'clazz' is None a default classification is created          If 'clazz' is None a default classification is created.
         """  
280    
281          # prevent infinite recursion when calling SetLayer()          This issues a LAYER_CHANGED event.
282          if self.__setClassLock: return          """
283    
284          self.__setClassLock = True          if self.__classification is not None:
285                self.__classification.Unsubscribe(CLASS_CHANGED,
286                                                  self._classification_changed)
287    
288          if clazz is None:          if clazz is None:
289              if self.__classification is not None:              clazz = classification.Classification()
                 self.__classification.SetLayer(None)  
             self.__classification = classification.Classification()  
         else:  
             self.__classification = clazz  
             try:  
                 self.__classification.SetLayer(self)  
             except ValueError:  
                 self.__setClassLock = False  
                 raise ValueError  
290    
291          self.changed(LAYER_CHANGED, self)          self.__classification = clazz
292            self.__classification.Subscribe(CLASS_CHANGED,
293                                            self._classification_changed)
294    
295          self.__setClassLock = False          self._classification_changed()
296    
297      def ClassChanged(self):      def _classification_changed(self):
298          """Called from the classification object when it has changed."""          """Called from the classification object when it has changed."""
299          self.changed(LAYER_CHANGED, self)          self.changed(LAYER_CHANGED, self)
300    
301      def TreeInfo(self):      def TreeInfo(self):
302          items = []          items = []
303    
304            items.append(_("Filename: %s") % self.ShapeStore().FileName())
305    
306          if self.Visible():          if self.Visible():
307              items.append(_("Shown"))              items.append(_("Shown"))
308          else:          else:
# Line 321  class Layer(BaseLayer): Line 316  class Layer(BaseLayer):
316              items.append(_("Extent (lat-lon):"))              items.append(_("Extent (lat-lon):"))
317          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
318    
319            if self.projection and len(self.projection.params) > 0:
320                items.append((_("Projection"),
321                            [str(param) for param in self.projection.params]))
322    
323          items.append(self.__classification)          items.append(self.__classification)
324    
325          return (_("Layer '%s'") % self.Title(), items)          return (_("Layer '%s'") % self.Title(), items)
326    
327    
328    if resource.has_gdal_support():
329        import gdal
330        from gdalconst import GA_ReadOnly
331    
332    class RasterLayer(BaseLayer):
333    
334        def __init__(self, title, filename, projection = None, visible = True):
335            """Initialize the Raster Layer.
336    
337            title -- title for the layer.
338    
339            filename -- file name of the source image.
340    
341            projection -- Projection object describing the projection which
342                          the source image is in.
343    
344            visible -- True is the layer should initially be visible.
345    
346            Throws IOError if the filename is invalid or points to a file that
347            is not in a format GDAL can use.
348            """
349    
350            BaseLayer.__init__(self, title, visible = visible)
351    
352            self.projection = projection
353            self.filename = os.path.abspath(filename)
354    
355            self.bbox = -1
356    
357            if resource.has_gdal_support():
358                #
359                # temporarily open the file so that GDAL can test if it's valid.
360                #
361                dataset = gdal.Open(self.filename, GA_ReadOnly)
362    
363                if dataset is None:
364                    raise IOError()
365    
366            self.UnsetModified()
367    
368        def BoundingBox(self):
369            """Return the layer's bounding box in the intrinsic coordinate system.
370    
371            If the there is no support for images, or the file cannot
372            be read, or there is no geographics information available, return None.
373            """
374            if not resource.has_gdal_support():
375                return None
376    
377            if self.bbox == -1:
378                dataset = gdal.Open(self.filename, GA_ReadOnly)
379                if dataset is None:
380                    self.bbox = None
381                else:
382                    geotransform = dataset.GetGeoTransform()
383                    if geotransform is None:
384                        return None
385    
386                    x = 0
387                    y = dataset.RasterYSize
388                    left = geotransform[0] +        \
389                           geotransform[1] * x +    \
390                           geotransform[2] * y
391    
392                    bottom = geotransform[3] +      \
393                             geotransform[4] * x +  \
394                             geotransform[5] * y
395    
396                    x = dataset.RasterXSize
397                    y = 0
398                    right = geotransform[0] +       \
399                            geotransform[1] * x +   \
400                            geotransform[2] * y
401    
402                    top = geotransform[3] +         \
403                          geotransform[4] * x +     \
404                          geotransform[5] * y
405    
406                    self.bbox = (left, bottom, right, top)
407    
408            return self.bbox
409    
410        def LatLongBoundingBox(self):
411            bbox = self.BoundingBox()
412            if bbox is None:
413                return None
414    
415            llx, lly, urx, ury = bbox
416            if self.projection is not None:
417                llx, lly = self.projection.Inverse(llx, lly)
418                urx, ury = self.projection.Inverse(urx, ury)
419    
420            return llx, lly, urx, ury
421    
422        def GetImageFilename(self):
423            return self.filename
424    
425        def TreeInfo(self):
426            items = []
427    
428            items.append(_("Filename: %s") % self.GetImageFilename())
429    
430            if self.Visible():
431                items.append(_("Shown"))
432            else:
433                items.append(_("Hidden"))
434    
435            bbox = self.LatLongBoundingBox()
436            if bbox is not None:
437                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
438            else:
439                items.append(_("Extent (lat-lon):"))
440    
441            if self.projection and len(self.projection.params) > 0:
442                items.append((_("Projection"),
443                            [str(param) for param in self.projection.params]))
444    
445            return (_("Layer '%s'") % self.Title(), items)
446    
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