/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 701 by bh, Thu Apr 17 16:18:48 2003 UTC revision 1593 by bh, Fri Aug 15 14:10:27 2003 UTC
# 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    
 import shapelib, shptree  
   
15  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
16       LAYER_CHANGED       LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_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:
# Line 104  class Layer(BaseLayer): Line 85  class Layer(BaseLayer):
85          LAYER_PROJECTION_CHANGED -- the projection has changed.          LAYER_PROJECTION_CHANGED -- the projection has changed.
86      """      """
87    
88      def __init__(self, title, filename, projection = None,      def __init__(self, title, data, projection = None,
89                   fill = Color.Transparent,                   fill = Transparent,
90                   stroke = Color.Black,                   stroke = Black,
91                   lineWidth = 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 Color.Transparent if the shapes are          fill -- the fill color or Transparent if the shapes are
101                  not filled                  not filled
102          stroke -- the stroke color or Color.Transparent if the shapes          stroke -- the stroke color or Transparent if the shapes
103                  are not stroked                  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)  
   
         self.projection = projection  
         self.shapefile = 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  
114    
115            self.SetShapeStore(data)
116    
117            self.classification_column = None
118            self.SetClassificationColumn(None)
119          self.SetClassification(None)          self.SetClassification(None)
120    
121          self.__classification.SetDefaultLineColor(stroke)          self.__classification.SetDefaultLineColor(stroke)
122          self.__classification.SetDefaultLineWidth(lineWidth)          self.__classification.SetDefaultLineWidth(lineWidth)
123          self.__classification.SetDefaultFill(fill)          self.__classification.SetDefaultFill(fill)
         self.__classification.SetLayer(self)  
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.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,          self.store = store
164                                               maxdepth)  
165            self.changed(LAYER_SHAPESTORE_REPLACED, self)
166    
167        def ShapeStore(self):
168            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.SetClassification(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          return self.bbox          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.
# Line 216  class Layer(BaseLayer): Line 195  class Layer(BaseLayer):
195          else:          else:
196              return None              return None
197    
198      def GetFieldType(self, fieldName):      def ShapesBoundingBox(self, shapes):
199          info = self.table.field_info_by_name(fieldName)          """Return a bounding box in lat/long coordinates for the given
200          if info is not None:          list of shape ids.
201              return info[0]  
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:          else:
215              return None              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          return self.numshapes          return self.store.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          return self.shapetype          return self.store.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          shape = self.shapefile.read_object(index)          return self.store.Shape(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 SetProjection(self, projection):      def HasClassification(self):
291          """Set the layer's projection"""          return True
         self.projection = projection  
         self.changed(LAYER_PROJECTION_CHANGED, self)  
292    
293      def GetClassification(self):      def GetClassification(self):
294          return self.__classification          return self.__classification
295    
296      def SetClassification(self, clazz):      def SetClassification(self, clazz):
297          """Set the classification to 'clazz'          """Set the classification used by this layer to 'clazz'
298    
299          If 'clazz' is None a default classification is created          If 'clazz' is None a default classification is created.
         """  
300    
301          # prevent infinite recursion when calling SetLayer()          This issues a LAYER_CHANGED event.
302          if self.__setClassLock: return          """
303    
304          self.__setClassLock = True          if self.__classification is not None:
305                self.__classification.Unsubscribe(CLASS_CHANGED,
306                                                  self._classification_changed)
307    
308          if clazz is None:          if clazz is None:
309              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  
310    
311          self.changed(LAYER_CHANGED, self)          self.__classification = clazz
312            self.__classification.Subscribe(CLASS_CHANGED,
313                                            self._classification_changed)
314    
315          self.__setClassLock = False          self._classification_changed()
316    
317      def ClassChanged(self):      def _classification_changed(self):
318          """Called from the classification object when it has changed."""          """Called from the classification object when it has changed."""
319          self.changed(LAYER_CHANGED, self)          self.changed(LAYER_CHANGED, self)
320    
321      def TreeInfo(self):      def TreeInfo(self):
322          items = []          items = []
323    
324            items.append(_("Filename: %s") % self.ShapeStore().FileName())
325    
326          if self.Visible():          if self.Visible():
327              items.append(_("Shown"))              items.append(_("Shown"))
328          else:          else:
# Line 312  class Layer(BaseLayer): Line 336  class Layer(BaseLayer):
336              items.append(_("Extent (lat-lon):"))              items.append(_("Extent (lat-lon):"))
337          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])          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)          items.append(self.__classification)
344    
345          return (_("Layer '%s'") % self.Title(), items)          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    
372            self.projection = projection
373            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    
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