/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 171 by bh, Tue May 14 14:16:24 2002 UTC revision 1593 by bh, Fri Aug 15 14:10:27 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]>
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  from math import log, ceil  import warnings
12    
13  import shapelib, shptree  from Thuban import _
14    
15  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
16       LAYER_VISIBILITY_CHANGED       LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
17    
18  from color import Color  import classification
 # Some predefined colors for internal use  
 _black = Color(0, 0, 0)  
   
   
 from table import Table  
19    
20    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    
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  shapetype_names = {SHAPETYPE_POINT: "Point",  shapetype_names = {SHAPETYPE_POINT: "Point",
28                     SHAPETYPE_ARC: "Arc",                     SHAPETYPE_ARC: "Arc",
29                     SHAPETYPE_POLYGON: "Polygon"}                     SHAPETYPE_POLYGON: "Polygon"}
# Line 65  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 74  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 83  class BaseLayer(TitledObject, Modifiable Line 51  class BaseLayer(TitledObject, Modifiable
51          """Set the layer's visibility."""          """Set the layer's visibility."""
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    
74      """Represent the information of one geodata file (currently a shapefile)      """Represent the information of one geodata file (currently a shapefile)
# Line 92  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 = None, stroke = _black, stroke_width = 1, visible = 1):                   fill = Transparent,
90                     stroke = Black,
91                     lineWidth = 1,
92                     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          self.filename = filename                                   visible = visible,
110          self.projection = projection                                   projection = projection)
111          self.fill = fill  
112          self.stroke = stroke          self.__classification = None
113          self.stroke_width = stroke_width          self.store = None
114          self.shapefile = None  
115          self.shapetree = None          self.SetShapeStore(data)
         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  
   
     def open_shapefile(self):  
         if self.shapefile is None:  
             self.shapefile = shapelib.ShapeFile(self.filename)  
             numshapes, shapetype, mins, maxs = self.shapefile.info()  
             self.numshapes = numshapes  
             self.shapetype = shapelib_shapetypes[shapetype]  
             self.bbox = mins[:2] + maxs[:2]  
   
             # estimate a good depth for the quad tree. Each depth  
             # 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)))  
116    
117              self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,          self.classification_column = None
118                                               maxdepth)          self.SetClassificationColumn(None)
119            self.SetClassification(None)
120    
121            self.__classification.SetDefaultLineColor(stroke)
122            self.__classification.SetDefaultLineWidth(lineWidth)
123            self.__classification.SetDefaultFill(fill)
124    
125            self.UnsetModified()
126    
127        def __getattr__(self, attr):
128            """Access to some attributes for backwards compatibility
129    
130            The attributes implemented here are now held by the shapestore
131            if at all. For backwards compatibility pretend that they are
132            still there but issue a DeprecationWarning when they are
133            accessed.
134            """
135            if attr in ("table", "shapetable"):
136                value = self.store.Table()
137            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        def ShapeStore(self):
168            return self.store
169    
170        def Destroy(self):
171            BaseLayer.Destroy(self)
172            if self.__classification is not None:
173                self.__classification.Unsubscribe(CLASS_CHANGED,
174                                                  self._classification_changed)
175    
176      def BoundingBox(self):      def BoundingBox(self):
177          """Return the bounding box of the layer's shapes in their default          """Return the layer's bounding box in the intrinsic coordinate system.
178          coordinate system"""  
179          self.open_shapefile()          If the layer has no shapes, return None.
180          return self.bbox          """
181            return self.store.BoundingBox()
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.
185          llx, lly, urx, ury = self.BoundingBox()  
186            Return None, if the layer doesn't contain any shapes.
187            """
188            bbox = self.BoundingBox()
189            if bbox is not None:
190                llx, lly, urx, ury = bbox
191                if self.projection is not None:
192                    llx, lly = self.projection.Inverse(llx, lly)
193                    urx, ury = self.projection.Inverse(urx, ury)
194                return llx, lly, urx, ury
195            else:
196                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:          if self.projection is not None:
213              llx, lly = self.projection.Inverse(llx, lly)              inverse = lambda x, y: self.projection.Inverse(x, y)
214              urx, ury = self.projection.Inverse(urx, ury)          else:
215          return llx, lly, urx, ury              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, bbox):
257          """Return the ids of the shapes that overlap the box.          """Return an iterable over the shapes that overlap the bounding box.
258    
259          Box is a tuple (left, bottom, right, top) in the coordinate          The bbox parameter should be the bounding box as a tuple in the
260          system used by the layer's shapefile.          form (minx, miny, maxx, maxy) in unprojected coordinates.
261          """          """
262          left, bottom, right, top = box          if self.projection is not None:
263          return self.shapetree.find_shapes((left, bottom), (right, top))              left, bottom, right, top = bbox
264                xs = []; ys = []
265                for x, y in [(left, bottom), (left, top), (right, top),
266                             (right, bottom)]:
267                    x, y = self.projection.Forward(x, y)
268                    xs.append(x)
269                    ys.append(y)
270                bbox = (min(xs), min(ys), max(xs), max(ys))
271    
272            return self.store.ShapesInRegion(bbox)
273    
274        def GetClassificationColumn(self):
275            return self.classification_column
276    
277        def SetClassificationColumn(self, column):
278            """Set the column to classifiy on, or None. If column is not None
279            and the column does not exist in the table, raise a ValueError.
280            """
281            if column:
282                columnType = self.GetFieldType(column)
283                if columnType is None:
284                    raise ValueError()
285            changed = self.classification_column != column
286            self.classification_column = column
287            if changed:
288                self.changed(LAYER_CHANGED, self)
289    
290        def HasClassification(self):
291            return True
292    
293        def GetClassification(self):
294            return self.__classification
295    
296        def SetClassification(self, clazz):
297            """Set the classification used by this layer to 'clazz'
298    
299            If 'clazz' is None a default classification is created.
300    
301            This issues a LAYER_CHANGED event.
302            """
303    
304            if self.__classification is not None:
305                self.__classification.Unsubscribe(CLASS_CHANGED,
306                                                  self._classification_changed)
307    
308            if clazz is None:
309                clazz = classification.Classification()
310    
311            self.__classification = clazz
312            self.__classification.Subscribe(CLASS_CHANGED,
313                                            self._classification_changed)
314    
315            self._classification_changed()
316    
317        def _classification_changed(self):
318            """Called from the classification object when it has changed."""
319            self.changed(LAYER_CHANGED, self)
320    
321        def TreeInfo(self):
322            items = []
323    
324            items.append(_("Filename: %s") % self.ShapeStore().FileName())
325    
326            if self.Visible():
327                items.append(_("Shown"))
328            else:
329                items.append(_("Hidden"))
330            items.append(_("Shapes: %d") % self.NumShapes())
331    
332            bbox = self.LatLongBoundingBox()
333            if bbox is not None:
334                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
335            else:
336                items.append(_("Extent (lat-lon):"))
337            items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
338    
339            if self.projection and len(self.projection.params) > 0:
340                items.append((_("Projection"),
341                            [str(param) for param in self.projection.params]))
342    
343            items.append(self.__classification)
344    
345            return (_("Layer '%s'") % self.Title(), items)
346    
347    
348    if resource.has_gdal_support():
349        import gdal
350        from gdalconst import GA_ReadOnly
351    
352    class RasterLayer(BaseLayer):
353    
354        def __init__(self, title, filename, projection = None, visible = True):
355            """Initialize the Raster Layer.
356    
357            title -- title for the layer.
358    
359            filename -- file name of the source image.
360    
361            projection -- Projection object describing the projection which
362                          the source image is in.
363    
364            visible -- True is the layer should initially be visible.
365    
366            Throws IOError if the filename is invalid or points to a file that
367            is not in a format GDAL can use.
368            """
369    
370            BaseLayer.__init__(self, title, visible = visible)
371    
     def SetProjection(self, projection):  
         """Set the layer's projection"""  
372          self.projection = projection          self.projection = projection
373          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = filename
374    
375            self.bbox = -1
376    
377            if resource.has_gdal_support():
378                #
379                # temporarily open the file so that GDAL can test if it's valid.
380                #
381                dataset = gdal.Open(self.filename, GA_ReadOnly)
382    
383                if dataset is None:
384                    raise IOError()
385    
386            self.UnsetModified()
387    
388        def BoundingBox(self):
389            """Return the layer's bounding box in the intrinsic coordinate system.
390    
391            If the there is no support for images, or the file cannot
392            be read, or there is no geographics information available, return None.
393            """
394            if not resource.has_gdal_support():
395                return None
396    
397            if self.bbox == -1:
398                dataset = gdal.Open(self.filename, GA_ReadOnly)
399                if dataset is None:
400                    self.bbox = None
401                else:
402                    geotransform = dataset.GetGeoTransform()
403                    if geotransform is None:
404                        return None
405    
406                    x = 0
407                    y = dataset.RasterYSize
408                    left = geotransform[0] +        \
409                           geotransform[1] * x +    \
410                           geotransform[2] * y
411    
412                    bottom = geotransform[3] +      \
413                             geotransform[4] * x +  \
414                             geotransform[5] * y
415    
416                    x = dataset.RasterXSize
417                    y = 0
418                    right = geotransform[0] +       \
419                            geotransform[1] * x +   \
420                            geotransform[2] * y
421    
422                    top = geotransform[3] +         \
423                          geotransform[4] * x +     \
424                          geotransform[5] * y
425    
426                    self.bbox = (left, bottom, right, top)
427    
428            return self.bbox
429    
430        def LatLongBoundingBox(self):
431            bbox = self.BoundingBox()
432            if bbox is None:
433                return None
434    
435            llx, lly, urx, ury = bbox
436            if self.projection is not None:
437                llx, lly = self.projection.Inverse(llx, lly)
438                urx, ury = self.projection.Inverse(urx, ury)
439    
440            return llx, lly, urx, ury
441    
442        def GetImageFilename(self):
443            return self.filename
444    
445        def TreeInfo(self):
446            items = []
447    
448            items.append(_("Filename: %s") % self.GetImageFilename())
449    
450            if self.Visible():
451                items.append(_("Shown"))
452            else:
453                items.append(_("Hidden"))
454    
455            bbox = self.LatLongBoundingBox()
456            if bbox is not None:
457                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
458            else:
459                items.append(_("Extent (lat-lon):"))
460    
461            if self.projection and len(self.projection.params) > 0:
462                items.append((_("Projection"),
463                            [str(param) for param in self.projection.params]))
464    
465            return (_("Layer '%s'") % self.Title(), items)
466    
     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)  
   
     def SetStrokeWidth(self, width):  
         """Set the layer's stroke width."""  
         self.stroke_width = width  
         self.changed(LAYER_LEGEND_CHANGED, self)  
Legend:
Removed from v.171  
changed lines
  Added in v.1593
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