/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 412 by jonathan, Wed Feb 19 16:51:50 2003 UTC revision 1599 by bh, Mon Aug 18 12:45:28 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
18    
19  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  import classification
      LAYER_VISIBILITY_CHANGED  
   
 from color import Color  
   
 from classification import Classification  
   
 from table import Table  
20    
21    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.None,                   fill = Transparent,
91                   stroke = Color.Black,                   stroke = Black,
92                   stroke_width = 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 None if the shapes are not filled          fill -- the fill color or Transparent if the shapes are
102          stroke -- the stroke color or None if the shapes are not stroked                  not filled
103            stroke -- the stroke color or Transparent if the shapes
104                    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                                     projection = projection)
112    
113          # Make the filename absolute. The filename will be          self.__classification = None
114          # 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)  
115    
116          self.projection = projection          self.SetShapeStore(data)
117          self.shapefile = None  
118          self.shapetree = None          self.classification_column = None
119          self.open_shapefile()          self.SetClassificationColumn(None)
120          # shapetable is the table associated with the shapefile, while          self.SetClassification(None)
121          # table is the default table used to look up attributes for  
122          # display          self.__classification.SetDefaultLineColor(stroke)
123          self.shapetable = Table(filename)          self.__classification.SetDefaultLineWidth(lineWidth)
         self.table = self.shapetable  
   
         self.__classification = Classification(self)  
         self.__classification.SetDefaultStroke(stroke)  
         self.__classification.SetDefaultStrokeWidth(stroke_width)  
124          self.__classification.SetDefaultFill(fill)          self.__classification.SetDefaultFill(fill)
125    
126          self.UnsetModified()          self.UnsetModified()
127    
128      def open_shapefile(self):      def __getattr__(self, attr):
129          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  
130    
131              # estimate a good depth for the quad tree. Each depth          The attributes implemented here are now held by the shapestore
132              # multiplies the number of nodes by four, therefore we          if at all. For backwards compatibility pretend that they are
133              # basically take the base 4 logarithm of the number of          still there but issue a DeprecationWarning when they are
134              # shapes.          accessed.
135              if self.numshapes < 4:          """
136                  maxdepth = 1          if attr in ("table", "shapetable"):
137              else:              value = self.store.Table()
138                  maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))          elif attr == "shapefile":
139                value = self.store.Shapefile()
140            elif attr == "filename":
141                value = self.store.FileName()
142            else:
143                raise AttributeError, attr
144            warnings.warn("The Layer attribute %r is deprecated."
145                          " It's value can be accessed through the shapestore"
146                          % attr, DeprecationWarning, stacklevel = 2)
147            return value
148    
149        def SetShapeStore(self, store):
150            # Set the classification to None if there is a classification
151            # and the new shapestore doesn't have a table with a suitable
152            # column, i.e one with the same name and type as before
153            # FIXME: Maybe we should keep it the same if the type is
154            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
155            if self.__classification is not None:
156                columnname = self.classification_column
157                columntype = self.GetFieldType(columnname)
158                table = store.Table()
159                if (columnname is not None
160                    and (not table.HasColumn(columnname)
161                         or table.Column(columnname).type != columntype)):
162                    self.SetClassification(None)
163    
164            self.store = store
165    
166              self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,          self.changed(LAYER_SHAPESTORE_REPLACED, self)
167                                               maxdepth)  
168        def ShapeStore(self):
169            return self.store
170    
171      def Destroy(self):      def Destroy(self):
172          BaseLayer.Destroy(self)          BaseLayer.Destroy(self)
173          if self.shapefile is not None:          if self.__classification is not None:
174              self.shapefile.close()              self.__classification.Unsubscribe(CLASS_CHANGED,
175              self.shapefile = None                                                self._classification_changed)
             self.shapetree = None  
         self.table.Destroy()  
176    
177      def BoundingBox(self):      def BoundingBox(self):
178          """Return the layer's bounding box in the intrinsic coordinate system.          """Return the layer's bounding box in the intrinsic coordinate system.
179    
180          If the layer has no shapes, return None.          If the layer has no shapes, return None.
181          """          """
182          # The bbox will be set by open_shapefile just as we need it          return self.store.BoundingBox()
         # here.  
         self.open_shapefile()  
         return self.bbox  
183    
184      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
185          """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 196  class Layer(BaseLayer):
196          else:          else:
197              return None              return None
198    
199        def ShapesBoundingBox(self, shapes):
200            """Return a bounding box in lat/long coordinates for the given
201            list of shape ids.
202    
203            If shapes is None or empty, return None.
204            """
205    
206            if shapes is None or len(shapes) == 0: return None
207    
208            llx = []
209            lly = []
210            urx = []
211            ury = []
212    
213            if self.projection is not None:
214                inverse = lambda x, y: self.projection.Inverse(x, y)
215            else:
216                inverse = lambda x, y: (x, y)
217    
218            for id in shapes:
219                left, bottom, right, top = self.Shape(id).compute_bbox()
220    
221                left, bottom = inverse(left, bottom)
222                right, top   = inverse(right, top)
223    
224                llx.append(left)
225                lly.append(bottom)
226                urx.append(right)
227                ury.append(top)
228    
229            return (min(llx), min(lly), max(urx), max(ury))
230    
231        def GetFieldType(self, fieldName):
232            if self.store:
233                table = self.store.Table()
234                if table.HasColumn(fieldName):
235                    return table.Column(fieldName).type
236            return None
237    
238        def HasShapes(self):
239            return True
240    
241      def NumShapes(self):      def NumShapes(self):
242          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
243          self.open_shapefile()          return self.store.NumShapes()
         return self.numshapes  
244    
245      def ShapeType(self):      def ShapeType(self):
246          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
247          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.  
248            The return value is one of the SHAPETYPE_* constants defined in
249            Thuban.Model.data.
250          """          """
251          self.open_shapefile()          return self.store.ShapeType()
         return self.shapetype  
252    
253      def Shape(self, index):      def Shape(self, index):
254          """Return the shape with index index"""          """Return the shape with index index"""
255          self.open_shapefile()          return self.store.Shape(index)
         shape = self.shapefile.read_object(index)  
256    
257          if self.shapetype == SHAPETYPE_POINT:      def ShapesInRegion(self, bbox):
258              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.  
259    
260          Box is a tuple (left, bottom, right, top) in the coordinate          The bbox parameter should be the bounding box as a tuple in the
261          system used by the layer's shapefile.          form (minx, miny, maxx, maxy) in unprojected coordinates.
262            """
263            if self.projection is not None:
264                left, bottom, right, top = bbox
265                xs = []; ys = []
266                for x, y in [(left, bottom), (left, top), (right, top),
267                             (right, bottom)]:
268                    x, y = self.projection.Forward(x, y)
269                    xs.append(x)
270                    ys.append(y)
271                bbox = (min(xs), min(ys), max(xs), max(ys))
272    
273            return self.store.ShapesInRegion(bbox)
274    
275        def GetClassificationColumn(self):
276            return self.classification_column
277    
278        def SetClassificationColumn(self, column):
279            """Set the column to classifiy on, or None. If column is not None
280            and the column does not exist in the table, raise a ValueError.
281          """          """
282          left, bottom, right, top = box          if column:
283          return self.shapetree.find_shapes((left, bottom), (right, top))              columnType = self.GetFieldType(column)
284                if columnType is None:
285                    raise ValueError()
286            changed = self.classification_column != column
287            self.classification_column = column
288            if changed:
289                self.changed(LAYER_CHANGED, self)
290    
291      def SetProjection(self, projection):      def HasClassification(self):
292          """Set the layer's projection"""          return True
         self.projection = projection  
         self.changed(LAYER_PROJECTION_CHANGED, self)  
293    
294      def GetClassification(self):      def GetClassification(self):
295          return self.__classification          return self.__classification
296    
297      def SetClassification(self, clazz):      def SetClassification(self, clazz):
298            """Set the classification used by this layer to 'clazz'
299    
300            If 'clazz' is None a default classification is created.
301    
302            This issues a LAYER_CHANGED event.
303            """
304    
305            if self.__classification is not None:
306                self.__classification.Unsubscribe(CLASS_CHANGED,
307                                                  self._classification_changed)
308    
309            if clazz is None:
310                clazz = classification.Classification()
311    
312          self.__classification = clazz          self.__classification = clazz
313          self.changed(LAYER_LEGEND_CHANGED, self)          self.__classification.Subscribe(CLASS_CHANGED,
314                                            self._classification_changed)
315    
316            self._classification_changed()
317    
318        def _classification_changed(self):
319            """Called from the classification object when it has changed."""
320            self.changed(LAYER_CHANGED, self)
321    
322      def TreeInfo(self):      def TreeInfo(self):
323          items = []          items = []
324    
325            items.append(_("Filename: %s") % self.ShapeStore().FileName())
326    
327          if self.Visible():          if self.Visible():
328              items.append(_("Shown"))              items.append(_("Shown"))
329          else:          else:
# Line 273  class Layer(BaseLayer): Line 337  class Layer(BaseLayer):
337              items.append(_("Extent (lat-lon):"))              items.append(_("Extent (lat-lon):"))
338          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
339    
340            if self.projection and len(self.projection.params) > 0:
341                items.append((_("Projection"),
342                            [str(param) for param in self.projection.params]))
343    
344          items.append(self.__classification)          items.append(self.__classification)
345    
346          return (_("Layer '%s'") % self.Title(), items)          return (_("Layer '%s'") % self.Title(), items)
347    
348    
349    if resource.has_gdal_support():
350        import gdal
351        from gdalconst import GA_ReadOnly
352    
353    class RasterLayer(BaseLayer):
354    
355        def __init__(self, title, filename, projection = None, visible = True):
356            """Initialize the Raster Layer.
357    
358            title -- title for the layer.
359    
360            filename -- file name of the source image.
361    
362            projection -- Projection object describing the projection which
363                          the source image is in.
364    
365            visible -- True is the layer should initially be visible.
366    
367            Throws IOError if the filename is invalid or points to a file that
368            is not in a format GDAL can use.
369            """
370    
371            BaseLayer.__init__(self, title, visible = visible)
372    
373            self.projection = projection
374            self.filename = os.path.abspath(filename)
375    
376            self.bbox = -1
377    
378            if resource.has_gdal_support():
379                #
380                # temporarily open the file so that GDAL can test if it's valid.
381                #
382                dataset = gdal.Open(self.filename, GA_ReadOnly)
383    
384                if dataset is None:
385                    raise IOError()
386    
387            self.UnsetModified()
388    
389        def BoundingBox(self):
390            """Return the layer's bounding box in the intrinsic coordinate system.
391    
392            If the there is no support for images, or the file cannot
393            be read, or there is no geographics information available, return None.
394            """
395            if not resource.has_gdal_support():
396                return None
397    
398            if self.bbox == -1:
399                dataset = gdal.Open(self.filename, GA_ReadOnly)
400                if dataset is None:
401                    self.bbox = None
402                else:
403                    geotransform = dataset.GetGeoTransform()
404                    if geotransform is None:
405                        return None
406    
407                    x = 0
408                    y = dataset.RasterYSize
409                    left = geotransform[0] +        \
410                           geotransform[1] * x +    \
411                           geotransform[2] * y
412    
413                    bottom = geotransform[3] +      \
414                             geotransform[4] * x +  \
415                             geotransform[5] * y
416    
417                    x = dataset.RasterXSize
418                    y = 0
419                    right = geotransform[0] +       \
420                            geotransform[1] * x +   \
421                            geotransform[2] * y
422    
423                    top = geotransform[3] +         \
424                          geotransform[4] * x +     \
425                          geotransform[5] * y
426    
427                    self.bbox = (left, bottom, right, top)
428    
429            return self.bbox
430    
431        def LatLongBoundingBox(self):
432            bbox = self.BoundingBox()
433            if bbox is None:
434                return None
435    
436            llx, lly, urx, ury = bbox
437            if self.projection is not None:
438                llx, lly = self.projection.Inverse(llx, lly)
439                urx, ury = self.projection.Inverse(urx, ury)
440    
441            return llx, lly, urx, ury
442    
443        def GetImageFilename(self):
444            return self.filename
445    
446        def TreeInfo(self):
447            items = []
448    
449            items.append(_("Filename: %s") % self.GetImageFilename())
450    
451            if self.Visible():
452                items.append(_("Shown"))
453            else:
454                items.append(_("Hidden"))
455    
456            bbox = self.LatLongBoundingBox()
457            if bbox is not None:
458                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
459            else:
460                items.append(_("Extent (lat-lon):"))
461    
462            if self.projection and len(self.projection.params) > 0:
463                items.append((_("Projection"),
464                            [str(param) for param in self.projection.params]))
465    
466            return (_("Layer '%s'") % self.Title(), items)
467    
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