/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 437 by jonathan, Thu Feb 27 15:53:21 2003 UTC revision 1558 by bh, Thu Aug 7 17:31:54 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    
11  import os  import warnings
 from math import log, ceil  
12    
13  from Thuban import _  from Thuban import _
14    
15  import shapelib, shptree  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
16         LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
 from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  
      LAYER_VISIBILITY_CHANGED  
   
 from color import Color  
17    
18  import classification  import classification
19    
20  from table import Table  from color import Transparent, Black
   
21  from base import TitledObject, Modifiable  from base import TitledObject, Modifiable
22    from data import SHAPETYPE_POLYGON, SHAPETYPE_ARC, SHAPETYPE_POINT
23    
24  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  
   
   
25    
 # 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}  
26    
27  shapetype_names = {SHAPETYPE_POINT: "Point",  shapetype_names = {SHAPETYPE_POINT: "Point",
28                     SHAPETYPE_ARC: "Arc",                     SHAPETYPE_ARC: "Arc",
# Line 68  class BaseLayer(TitledObject, Modifiable Line 32  class BaseLayer(TitledObject, Modifiable
32    
33      """Base class for the layers."""      """Base class for the layers."""
34    
35      def __init__(self, title, visible = 1):      def __init__(self, title, visible = True, projection = None):
36          """Initialize the layer.          """Initialize the layer.
37    
38          title -- the title          title -- the title
# Line 77  class BaseLayer(TitledObject, Modifiable Line 41  class BaseLayer(TitledObject, Modifiable
41          TitledObject.__init__(self, title)          TitledObject.__init__(self, title)
42          Modifiable.__init__(self)          Modifiable.__init__(self)
43          self.visible = visible          self.visible = visible
44            self.projection = projection
45    
46      def Visible(self):      def Visible(self):
47          """Return true if layer is visible"""          """Return true if layer is visible"""
# Line 87  class BaseLayer(TitledObject, Modifiable Line 52  class BaseLayer(TitledObject, Modifiable
52          self.visible = visible          self.visible = visible
53          self.issue(LAYER_VISIBILITY_CHANGED, self)          self.issue(LAYER_VISIBILITY_CHANGED, self)
54    
55        def HasClassification(self):
56            """Determine if this layer support classifications."""
57            return False
58    
59        def HasShapes(self):
60            """Determine if this layer supports shapes."""
61            return False
62    
63        def GetProjection(self):
64            """Return the layer's projection."""
65            return self.projection
66    
67        def SetProjection(self, projection):
68            """Set the layer's projection"""
69            self.projection = projection
70            self.changed(LAYER_PROJECTION_CHANGED, self)
71    
72  class Layer(BaseLayer):  class Layer(BaseLayer):
73    
# Line 95  class Layer(BaseLayer): Line 76  class Layer(BaseLayer):
76      All children of the layer have the same type.      All children of the layer have the same type.
77    
78      A layer has fill and stroke colors. Colors should be instances of      A layer has fill and stroke colors. Colors should be instances of
79      Color. They can also be None, indicating no fill or no stroke.      Color. They can also be Transparent, indicating no fill or no stroke.
80    
81      The layer objects send the following events, all of which have the      The layer objects send the following events, all of which have the
82      layer object as parameter:      layer object as parameter:
83    
84          TITLE_CHANGED -- The title has changed.          TITLE_CHANGED -- The title has changed.
85          LAYER_PROJECTION_CHANGED -- the projection has changed.          LAYER_PROJECTION_CHANGED -- the projection has changed.
         LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed  
   
86      """      """
87    
88      def __init__(self, title, filename, projection = None,      def __init__(self, title, data, projection = None,
89                   fill = Color.None,                   fill = Transparent,
90                   stroke = Color.Black,                   stroke = Black,
91                   stroke_width = 1,                   lineWidth = 1,
92                   visible = 1):                   visible = True):
93          """Initialize the layer.          """Initialize the layer.
94    
95          title -- the title          title -- the title
96          filename -- the name of the shapefile          data -- datastore object for the shape data shown by the layer
97          projection -- the projection object. Its Inverse method is          projection -- the projection object. Its Inverse method is
98                 assumed to map the layer's coordinates to lat/long                 assumed to map the layer's coordinates to lat/long
99                 coordinates                 coordinates
100          fill -- the fill color or None if the shapes are not filled          fill -- the fill color or Transparent if the shapes are
101          stroke -- the stroke color or None if the shapes are not stroked                  not filled
102            stroke -- the stroke color or Transparent if the shapes
103                    are not stroked
104          visible -- boolean. If true the layer is visible.          visible -- boolean. If true the layer is visible.
105    
106          colors are expected to be instances of Color class          colors are expected to be instances of Color class
107          """          """
108          BaseLayer.__init__(self, title, visible = visible)          BaseLayer.__init__(self, title,
109                                     visible = visible,
110                                     projection = projection)
111    
112          # Make the filename absolute. The filename will be          self.__classification = None
113          # interpreted relative to that anyway, but when saving a          self.store = None
         # session we need to compare absolute paths and it's usually  
         # safer to always work with absolute paths.  
         self.filename = os.path.abspath(filename)  
114    
115          self.projection = projection          self.SetShapeStore(data)
116          self.shapefile = None  
117          self.shapetree = None          self.classification_column = None
118          self.open_shapefile()          self.SetClassificationColumn(None)
119          # shapetable is the table associated with the shapefile, while          self.SetClassification(None)
120          # table is the default table used to look up attributes for  
121          # display          self.__classification.SetDefaultLineColor(stroke)
122          self.shapetable = Table(filename)          self.__classification.SetDefaultLineWidth(lineWidth)
         self.table = self.shapetable  
   
         self.__classification = classification.Classification(self)  
         self.__classification.SetDefaultStroke(stroke)  
         self.__classification.SetDefaultStrokeWidth(stroke_width)  
123          self.__classification.SetDefaultFill(fill)          self.__classification.SetDefaultFill(fill)
124    
125          self.UnsetModified()          self.UnsetModified()
126    
127      def open_shapefile(self):      def __getattr__(self, attr):
128          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  
129    
130              # estimate a good depth for the quad tree. Each depth          The attributes implemented here are now held by the shapestore
131              # multiplies the number of nodes by four, therefore we          if at all. For backwards compatibility pretend that they are
132              # basically take the base 4 logarithm of the number of          still there but issue a DeprecationWarning when they are
133              # shapes.          accessed.
134              if self.numshapes < 4:          """
135                  maxdepth = 1          if attr in ("table", "shapetable"):
136              else:              value = self.store.Table()
137                  maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))          elif attr == "shapefile":
138                value = self.store.Shapefile()
139            elif attr == "filename":
140                value = self.store.FileName()
141            else:
142                raise AttributeError, attr
143            warnings.warn("The Layer attribute %r is deprecated."
144                          " It's value can be accessed through the shapestore"
145                          % attr, DeprecationWarning, stacklevel = 2)
146            return value
147    
148        def SetShapeStore(self, store):
149            # Set the classification to None if there is a classification
150            # and the new shapestore doesn't have a table with a suitable
151            # column, i.e one with the same name and type as before
152            # FIXME: Maybe we should keep it the same if the type is
153            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
154            if self.__classification is not None:
155                columnname = self.classification_column
156                columntype = self.GetFieldType(columnname)
157                table = store.Table()
158                if (columnname is not None
159                    and (not table.HasColumn(columnname)
160                         or table.Column(columnname).type != columntype)):
161                    self.SetClassification(None)
162    
163            self.store = store
164    
165            self.changed(LAYER_SHAPESTORE_REPLACED, self)
166    
167              self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,      def ShapeStore(self):
168                                               maxdepth)          return self.store
169    
170      def Destroy(self):      def Destroy(self):
171          BaseLayer.Destroy(self)          BaseLayer.Destroy(self)
172          if self.shapefile is not None:          if self.__classification is not None:
173              self.shapefile.close()              self.__classification.Unsubscribe(CLASS_CHANGED,
174              self.shapefile = None                                                self._classification_changed)
             self.shapetree = None  
         self.table.Destroy()  
175    
176      def BoundingBox(self):      def BoundingBox(self):
177          """Return the layer's bounding box in the intrinsic coordinate system.          """Return the layer's bounding box in the intrinsic coordinate system.
178    
179          If the layer has no shapes, return None.          If the layer has no shapes, return None.
180          """          """
181          # The bbox will be set by open_shapefile just as we need it          return self.store.BoundingBox()
         # here.  
         self.open_shapefile()  
         return self.bbox  
182    
183      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
184          """Return the layer's bounding box in lat/long coordinates.          """Return the layer's bounding box in lat/long coordinates.
# Line 208  class Layer(BaseLayer): Line 195  class Layer(BaseLayer):
195          else:          else:
196              return None              return None
197    
198        def ShapesBoundingBox(self, shapes):
199            """Return a bounding box in lat/long coordinates for the given
200            list of shape ids.
201    
202            If shapes is None or empty, return None.
203            """
204    
205            if shapes is None or len(shapes) == 0: return None
206    
207            llx = []
208            lly = []
209            urx = []
210            ury = []
211    
212            if self.projection is not None:
213                inverse = lambda x, y: self.projection.Inverse(x, y)
214            else:
215                inverse = lambda x, y: (x, y)
216    
217            for id in shapes:
218                left, bottom, right, top = self.Shape(id).compute_bbox()
219    
220                left, bottom = inverse(left, bottom)
221                right, top   = inverse(right, top)
222    
223                llx.append(left)
224                lly.append(bottom)
225                urx.append(right)
226                ury.append(top)
227    
228            return (min(llx), min(lly), max(urx), max(ury))
229    
230        def GetFieldType(self, fieldName):
231            if self.store:
232                table = self.store.Table()
233                if table.HasColumn(fieldName):
234                    return table.Column(fieldName).type
235            return None
236    
237        def HasShapes(self):
238            return True
239    
240      def NumShapes(self):      def NumShapes(self):
241          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
242          self.open_shapefile()          return self.store.NumShapes()
         return self.numshapes  
243    
244      def ShapeType(self):      def ShapeType(self):
245          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
246          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.  
247            The return value is one of the SHAPETYPE_* constants defined in
248            Thuban.Model.data.
249          """          """
250          self.open_shapefile()          return self.store.ShapeType()
         return self.shapetype  
251    
252      def Shape(self, index):      def Shape(self, index):
253          """Return the shape with index index"""          """Return the shape with index index"""
254          self.open_shapefile()          return self.store.Shape(index)
         shape = self.shapefile.read_object(index)  
   
         if self.shapetype == SHAPETYPE_POINT:  
             points = shape.vertices()  
         else:  
             #for poly in shape.vertices():  
             poly = shape.vertices()[0]  
             points = []  
             for x, y in poly:  
                 points.append((x, y))  
   
         return Shape(points)  
255    
256      def ShapesInRegion(self, box):      def ShapesInRegion(self, box):
257          """Return the ids of the shapes that overlap the box.          """Return the ids of the shapes that overlap the box.
258    
259          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.  
260          """          """
261          left, bottom, right, top = box          left, bottom, right, top = box
         return self.shapetree.find_shapes((left, bottom), (right, top))  
262    
263      def SetProjection(self, projection):          if self.projection is not None:
264          """Set the layer's projection"""              left,  bottom = self.projection.Forward(left, bottom)
265          self.projection = projection              right, top    = self.projection.Forward(right, top)
266          self.changed(LAYER_PROJECTION_CHANGED, self)  
267            return self.store.ShapesInRegion((left, bottom, right, top))
268    
269        def GetClassificationColumn(self):
270            return self.classification_column
271    
272        def SetClassificationColumn(self, column):
273            """Set the column to classifiy on, or None. If column is not None
274            and the column does not exist in the table, raise a ValueError.
275            """
276            if column:
277                columnType = self.GetFieldType(column)
278                if columnType is None:
279                    raise ValueError()
280            changed = self.classification_column != column
281            self.classification_column = column
282            if changed:
283                self.changed(LAYER_CHANGED, self)
284    
285        def HasClassification(self):
286            return True
287    
288      def GetClassification(self):      def GetClassification(self):
289          return self.__classification          return self.__classification
290    
291      def SetClassification(self, clazz):      def SetClassification(self, clazz):
292            """Set the classification used by this layer to 'clazz'
293    
294            If 'clazz' is None a default classification is created.
295    
296            This issues a LAYER_CHANGED event.
297            """
298    
299            if self.__classification is not None:
300                self.__classification.Unsubscribe(CLASS_CHANGED,
301                                                  self._classification_changed)
302    
303            if clazz is None:
304                clazz = classification.Classification()
305    
306          self.__classification = clazz          self.__classification = clazz
307          self.changed(LAYER_LEGEND_CHANGED, self)          self.__classification.Subscribe(CLASS_CHANGED,
308                                            self._classification_changed)
309    
310            self._classification_changed()
311    
312        def _classification_changed(self):
313            """Called from the classification object when it has changed."""
314            self.changed(LAYER_CHANGED, self)
315    
316      def TreeInfo(self):      def TreeInfo(self):
317          items = []          items = []
318    
319            items.append(_("Filename: %s") % self.ShapeStore().FileName())
320    
321          if self.Visible():          if self.Visible():
322              items.append(_("Shown"))              items.append(_("Shown"))
323          else:          else:
# Line 273  class Layer(BaseLayer): Line 331  class Layer(BaseLayer):
331              items.append(_("Extent (lat-lon):"))              items.append(_("Extent (lat-lon):"))
332          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
333    
334            if self.projection and len(self.projection.params) > 0:
335                items.append((_("Projection"),
336                            [str(param) for param in self.projection.params]))
337    
338          items.append(self.__classification)          items.append(self.__classification)
339    
340          return (_("Layer '%s'") % self.Title(), items)          return (_("Layer '%s'") % self.Title(), items)
341    
342    
343    if resource.has_gdal_support():
344        import gdal
345        from gdalconst import GA_ReadOnly
346    
347    class RasterLayer(BaseLayer):
348    
349        def __init__(self, title, filename, projection = None, visible = True):
350            """Initialize the Raster Layer.
351    
352            title -- title for the layer.
353    
354            filename -- file name of the source image.
355    
356            projection -- Projection object describing the projection which
357                          the source image is in.
358    
359            visible -- True is the layer should initially be visible.
360    
361            Throws IOError if the filename is invalid or points to a file that
362            is not in a format GDAL can use.
363            """
364    
365            BaseLayer.__init__(self, title, visible = visible)
366    
367            self.projection = projection
368            self.filename = filename
369    
370            self.bbox = -1
371    
372            if resource.has_gdal_support():
373                #
374                # temporarily open the file so that GDAL can test if it's valid.
375                #
376                dataset = gdal.Open(self.filename, GA_ReadOnly)
377    
378                if dataset is None:
379                    raise IOError()
380    
381            self.UnsetModified()
382    
383        def BoundingBox(self):
384            """Return the layer's bounding box in the intrinsic coordinate system.
385    
386            If the there is no support for images, or the file cannot
387            be read, or there is no geographics information available, return None.
388            """
389            if not resource.has_gdal_support():
390                return None
391    
392            if self.bbox == -1:
393                dataset = gdal.Open(self.filename, GA_ReadOnly)
394                if dataset is None:
395                    self.bbox = None
396                else:
397                    geotransform = dataset.GetGeoTransform()
398                    if geotransform is None:
399                        return None
400    
401                    x = 0
402                    y = dataset.RasterYSize
403                    left = geotransform[0] +        \
404                           geotransform[1] * x +    \
405                           geotransform[2] * y
406    
407                    bottom = geotransform[3] +      \
408                             geotransform[4] * x +  \
409                             geotransform[5] * y
410    
411                    x = dataset.RasterXSize
412                    y = 0
413                    right = geotransform[0] +       \
414                            geotransform[1] * x +   \
415                            geotransform[2] * y
416    
417                    top = geotransform[3] +         \
418                          geotransform[4] * x +     \
419                          geotransform[5] * y
420    
421                    self.bbox = (left, bottom, right, top)
422    
423            return self.bbox
424    
425        def LatLongBoundingBox(self):
426            bbox = self.BoundingBox()
427            if bbox is None:
428                return None
429    
430            llx, lly, urx, ury = bbox
431            if self.projection is not None:
432                llx, lly = self.projection.Inverse(llx, lly)
433                urx, ury = self.projection.Inverse(urx, ury)
434    
435            return llx, lly, urx, ury
436    
437        def GetImageFilename(self):
438            return self.filename
439    
440        def TreeInfo(self):
441            items = []
442    
443            items.append(_("Filename: %s") % self.GetImageFilename())
444    
445            if self.Visible():
446                items.append(_("Shown"))
447            else:
448                items.append(_("Hidden"))
449    
450            bbox = self.LatLongBoundingBox()
451            if bbox is not None:
452                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
453            else:
454                items.append(_("Extent (lat-lon):"))
455    
456            if self.projection and len(self.projection.params) > 0:
457                items.append((_("Projection"),
458                            [str(param) for param in self.projection.params]))
459    
460            return (_("Layer '%s'") % self.Title(), items)
461    
Legend:
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