/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 791 by jan, Wed Apr 30 12:26:33 2003 UTC revision 2644 by bh, Tue Jul 5 16:30:51 2005 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001, 2002, 2003 by Intevation GmbH  # Copyright (c) 2001, 2002, 2003, 2004, 2005 by Intevation GmbH
2  # Authors:  # Authors:
3  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
4  # Jonathan Coles <[email protected]>  # Jonathan Coles <[email protected]>
5    # Silke Reimer <[email protected]>
6  #  #
7  # This program is free software under the GPL (>=v2)  # This program is free software under the GPL (>=v2)
8  # Read the file COPYING coming with Thuban for details.  # Read the file COPYING coming with Thuban for details.
9    
10  __version__ = "$Revision$"  __version__ = "$Revision$"
11    
12  from math import log, ceil  import os
13    import warnings
14    
15  from Thuban import _  from Thuban import _
16    
 import shapelib, shptree  
   
17  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18       LAYER_CHANGED       LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
   
 from color import Color  
19    
20  import classification  import classification
21    
22    from color import Transparent, Black
23  from base import TitledObject, Modifiable  from base import TitledObject, Modifiable
24    from data import SHAPETYPE_POLYGON, SHAPETYPE_ARC, SHAPETYPE_POINT
25    
26    import resource
27    
28  class Shape:  from color import Color
   
     """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  
   
   
   
 # 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}  
29    
30  shapetype_names = {SHAPETYPE_POINT: "Point",  shapetype_names = {SHAPETYPE_POINT: "Point",
31                     SHAPETYPE_ARC: "Arc",                     SHAPETYPE_ARC: "Arc",
# Line 66  class BaseLayer(TitledObject, Modifiable Line 35  class BaseLayer(TitledObject, Modifiable
35    
36      """Base class for the layers."""      """Base class for the layers."""
37    
38      def __init__(self, title, visible = True):      def __init__(self, title, visible = True, projection = None):
39          """Initialize the layer.          """Initialize the layer.
40    
41          title -- the title          title -- the title
# Line 75  class BaseLayer(TitledObject, Modifiable Line 44  class BaseLayer(TitledObject, Modifiable
44          TitledObject.__init__(self, title)          TitledObject.__init__(self, title)
45          Modifiable.__init__(self)          Modifiable.__init__(self)
46          self.visible = visible          self.visible = visible
47            self.projection = projection
48    
49      def Visible(self):      def Visible(self):
50          """Return true if layer is visible"""          """Return true if layer is visible"""
# Line 85  class BaseLayer(TitledObject, Modifiable Line 55  class BaseLayer(TitledObject, Modifiable
55          self.visible = visible          self.visible = visible
56          self.issue(LAYER_VISIBILITY_CHANGED, self)          self.issue(LAYER_VISIBILITY_CHANGED, self)
57    
58        def HasClassification(self):
59            """Determine if this layer supports classifications."""
60            return False
61    
62        def HasShapes(self):
63            """Determine if this layer supports shapes."""
64            return False
65    
66        def GetProjection(self):
67            """Return the layer's projection."""
68            return self.projection
69    
70        def SetProjection(self, projection):
71            """Set the layer's projection."""
72            self.projection = projection
73            self.changed(LAYER_PROJECTION_CHANGED, self)
74    
75        def Type(self):
76            return "Unknown"
77    
78  class Layer(BaseLayer):  class Layer(BaseLayer):
79    
# Line 93  class Layer(BaseLayer): Line 82  class Layer(BaseLayer):
82      All children of the layer have the same type.      All children of the layer have the same type.
83    
84      A layer has fill and stroke colors. Colors should be instances of      A layer has fill and stroke colors. Colors should be instances of
85      Color. They can also be None, indicating no fill or no stroke.      Color. They can also be Transparent, indicating no fill or no stroke.
86    
87      The layer objects send the following events, all of which have the      The layer objects send the following events, all of which have the
88      layer object as parameter:      layer object as parameter:
# Line 103  class Layer(BaseLayer): Line 92  class Layer(BaseLayer):
92      """      """
93    
94      def __init__(self, title, data, projection = None,      def __init__(self, title, data, projection = None,
95                   fill = Color.Transparent,                   fill = Transparent,
96                   stroke = Color.Black,                   stroke = Black,
97                   lineWidth = 1,                   lineWidth = 1,
98                   visible = True):                   visible = True):
99          """Initialize the layer.          """Initialize the layer.
# Line 114  class Layer(BaseLayer): Line 103  class Layer(BaseLayer):
103          projection -- the projection object. Its Inverse method is          projection -- the projection object. Its Inverse method is
104                 assumed to map the layer's coordinates to lat/long                 assumed to map the layer's coordinates to lat/long
105                 coordinates                 coordinates
106          fill -- the fill color or Color.Transparent if the shapes are          fill -- the fill color or Transparent if the shapes are
107                  not filled                  not filled
108          stroke -- the stroke color or Color.Transparent if the shapes          stroke -- the stroke color or Transparent if the shapes
109                  are not stroked                  are not stroked
110          visible -- boolean. If true the layer is visible.          visible -- boolean. If true the layer is visible.
111    
112          colors are expected to be instances of Color class          colors are expected to be instances of Color class
113          """          """
114          BaseLayer.__init__(self, title, visible = visible)          BaseLayer.__init__(self, title,
115                                     visible = visible,
116                                     projection = projection)
117    
         self.projection = projection  
   
         #  
         # this is really important so that when the classification class  
         # tries to set its parent layer the variable will exist  
         #  
118          self.__classification = None          self.__classification = None
119          self.__setClassLock = False          self.store = None
120    
121          self.SetShapeStore(data)          self.SetShapeStore(data)
122    
123            self.classification_column = None
124            self.SetClassificationColumn(None)
125          self.SetClassification(None)          self.SetClassification(None)
126    
127          self.__classification.SetDefaultLineColor(stroke)          self.__classification.SetDefaultLineColor(stroke)
128          self.__classification.SetDefaultLineWidth(lineWidth)          self.__classification.SetDefaultLineWidth(lineWidth)
129          self.__classification.SetDefaultFill(fill)          self.__classification.SetDefaultFill(fill)
         self.__classification.SetLayer(self)  
130    
131          self.UnsetModified()          self.UnsetModified()
132    
   
133      def SetShapeStore(self, store):      def SetShapeStore(self, store):
134          self.store = store          # Set the classification to None if there is a classification
135          self.shapefile = self.store.Shapefile()          # and the new shapestore doesn't have a table with a suitable
136          self.shapetable = self.store.Table()          # column, i.e one with the same name and type as before
137          self.filename = self.store.filename          # FIXME: Maybe we should keep it the same if the type is
138          self.table = self.shapetable          # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
   
         numshapes, shapetype, mins, maxs = self.shapefile.info()  
         self.numshapes = numshapes  
         self.shapetype = shapelib_shapetypes[shapetype]  
   
         # if there are shapes, set the bbox accordingly. Otherwise  
         # set it to None.  
         if self.numshapes:  
             self.bbox = mins[:2] + maxs[:2]  
         else:  
             self.bbox = None  
   
         # 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)))  
   
         self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,  
                                          maxdepth)  
139          if self.__classification is not None:          if self.__classification is not None:
140              fieldname = self.__classification.GetField()              columnname = self.classification_column
141              if fieldname is not None and \              columntype = self.GetFieldType(columnname)
142                 not self.store.Table().field_info_by_name(fieldname):              table = store.Table()
143                if (columnname is not None
144                    and (not table.HasColumn(columnname)
145                         or table.Column(columnname).type != columntype)):
146                  self.SetClassification(None)                  self.SetClassification(None)
147          self.changed(LAYER_CHANGED, self)  
148            self.store = store
149    
150            self.changed(LAYER_SHAPESTORE_REPLACED, self)
151    
152      def ShapeStore(self):      def ShapeStore(self):
153          return self.store          return self.store
154    
155      def Destroy(self):      def Destroy(self):
156          BaseLayer.Destroy(self)          BaseLayer.Destroy(self)
157          self.SetClassification(None)          if self.__classification is not None:
158                self.__classification.Unsubscribe(CLASS_CHANGED,
159                                                  self._classification_changed)
160    
161      def BoundingBox(self):      def BoundingBox(self):
162          """Return the layer's bounding box in the intrinsic coordinate system.          """Return the layer's bounding box in the intrinsic coordinate system.
163    
164          If the layer has no shapes, return None.          If the layer has no shapes, return None.
165          """          """
166          return self.bbox          return self.store.BoundingBox()
167    
168      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
169          """Return the layer's bounding box in lat/long coordinates.          """Return the layer's bounding box in lat/long coordinates.
# Line 201  class Layer(BaseLayer): Line 171  class Layer(BaseLayer):
171          Return None, if the layer doesn't contain any shapes.          Return None, if the layer doesn't contain any shapes.
172          """          """
173          bbox = self.BoundingBox()          bbox = self.BoundingBox()
174          if bbox is not None:          if bbox is not None and self.projection is not None:
175              llx, lly, urx, ury = bbox              bbox = self.projection.InverseBBox(bbox)
176            return bbox
177    
178        def Type(self):
179            return self.ShapeType();
180    
181        def ShapesBoundingBox(self, shapes):
182            """Return a bounding box in lat/long coordinates for the given
183            list of shape ids.
184    
185            If shapes is None or empty, return None.
186            """
187    
188            if shapes is None or len(shapes) == 0: return None
189    
190            xs = []
191            ys = []
192    
193            for id in shapes:
194                bbox = self.Shape(id).compute_bbox()
195              if self.projection is not None:              if self.projection is not None:
196                  llx, lly = self.projection.Inverse(llx, lly)                  bbox = self.projection.InverseBBox(bbox)
197                  urx, ury = self.projection.Inverse(urx, ury)              left, bottom, right, top = bbox
198              return llx, lly, urx, ury              xs.append(left); xs.append(right)
199          else:              ys.append(bottom); ys.append(top)
200              return None  
201            return (min(xs), min(ys), max(xs), max(ys))
202    
203    
204      def GetFieldType(self, fieldName):      def GetFieldType(self, fieldName):
205          info = self.table.field_info_by_name(fieldName)          if self.store:
206          if info is not None:              table = self.store.Table()
207              return info[0]              if table.HasColumn(fieldName):
208          else:                  return table.Column(fieldName).type
209              return None          return None
210    
211        def HasShapes(self):
212            return True
213    
214      def NumShapes(self):      def NumShapes(self):
215          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
216          return self.numshapes          return self.store.NumShapes()
217    
218      def ShapeType(self):      def ShapeType(self):
219          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
220          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.  
221            The return value is one of the SHAPETYPE_* constants defined in
222            Thuban.Model.data.
223          """          """
224          return self.shapetype          return self.store.ShapeType()
225    
226      def Shape(self, index):      def Shape(self, index):
227          """Return the shape with index index"""          """Return the shape with index index"""
228          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)  
229    
230      def ShapesInRegion(self, box):      def ShapesInRegion(self, bbox):
231          """Return the ids of the shapes that overlap the box.          """Return an iterable over the shapes that overlap the bounding box.
232    
233          Box is a tuple (left, bottom, right, top) in the coordinate          The bbox parameter should be the bounding box as a tuple in the
234          system used by the layer's shapefile.          form (minx, miny, maxx, maxy) in unprojected coordinates.
235          """          """
236          left, bottom, right, top = box          if self.projection is not None:
237          return self.shapetree.find_shapes((left, bottom), (right, top))              # Ensure that region lies within the layer's bounding box
238                # Otherwise projection of the region would lead to incorrect
239      def GetProjection(self):              # values.
240          return self.projection              clipbbox = self.__mangle_bounding_box(bbox)
241                bbox = self.projection.ForwardBBox(clipbbox)
242            return self.store.ShapesInRegion(bbox)
243    
244        def GetClassificationColumn(self):
245            return self.classification_column
246    
247        def SetClassificationColumn(self, column):
248            """Set the column to classifiy on, or None. If column is not None
249            and the column does not exist in the table, raise a ValueError.
250            """
251            if column:
252                columnType = self.GetFieldType(column)
253                if columnType is None:
254                    raise ValueError()
255            changed = self.classification_column != column
256            self.classification_column = column
257            if changed:
258                self.changed(LAYER_CHANGED, self)
259    
260      def SetProjection(self, projection):      def HasClassification(self):
261          """Set the layer's projection"""          return True
         self.projection = projection  
         self.changed(LAYER_PROJECTION_CHANGED, self)  
262    
263      def GetClassification(self):      def GetClassification(self):
264          return self.__classification          return self.__classification
265    
266      def SetClassification(self, clazz):      def SetClassification(self, clazz):
267          """Set the classification to 'clazz'          """Set the classification used by this layer to 'clazz'
268    
269          If 'clazz' is None a default classification is created          If 'clazz' is None a default classification is created.
         """  
270    
271          # prevent infinite recursion when calling SetLayer()          This issues a LAYER_CHANGED event.
272          if self.__setClassLock: return          """
273    
274          self.__setClassLock = True          if self.__classification is not None:
275                self.__classification.Unsubscribe(CLASS_CHANGED,
276                                                  self._classification_changed)
277    
278          if clazz is None:          if clazz is None:
279              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  
280    
281          self.changed(LAYER_CHANGED, self)          self.__classification = clazz
282            self.__classification.Subscribe(CLASS_CHANGED,
283                                            self._classification_changed)
284    
285          self.__setClassLock = False          self._classification_changed()
286    
287      def ClassChanged(self):      def _classification_changed(self):
288          """Called from the classification object when it has changed."""          """Called from the classification object when it has changed."""
289          self.changed(LAYER_CHANGED, self)          self.changed(LAYER_CHANGED, self)
290    
291      def TreeInfo(self):      def TreeInfo(self):
292          items = []          items = []
293    
294            items.append(_("Filename: %s") % self.ShapeStore().FileName())
295    
296          if self.Visible():          if self.Visible():
297              items.append(_("Shown"))              items.append(_("Shown"))
298          else:          else:
# Line 304  class Layer(BaseLayer): Line 301  class Layer(BaseLayer):
301    
302          bbox = self.LatLongBoundingBox()          bbox = self.LatLongBoundingBox()
303          if bbox is not None:          if bbox is not None:
304              items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)              items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % tuple(bbox))
305          else:          else:
306              items.append(_("Extent (lat-lon):"))              items.append(_("Extent (lat-lon):"))
307          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])          items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
# Line 317  class Layer(BaseLayer): Line 314  class Layer(BaseLayer):
314    
315          return (_("Layer '%s'") % self.Title(), items)          return (_("Layer '%s'") % self.Title(), items)
316    
317        def __mangle_bounding_box(self, bbox):
318            # FIXME: This method doesn't make much sense.
319            # See RT #2845 which effectively says:
320            #
321            # If this method, which was originally called ClipBoundingBox,
322            # is supposed to do clipping it shouldn't return the parameter
323            # unchanged when it lies completely outside of the bounding box.
324            # It would be better to return None and return an empty list in
325            # ShapesInRegion (the only caller) in that case.
326            #
327            # This method was introduced to fix a bug that IIRC had
328            # something todo with projections and bounding boxes containing
329            # NaN or INF when the parameter to ShapesInRegion covered the
330            # entire earth or something similarly large).
331            bminx, bminy, bmaxx, bmaxy = bbox
332            lminx, lminy, lmaxx, lmaxy = self.LatLongBoundingBox()
333            if bminx > lmaxx or bmaxx < lminx:
334                left, right = bminx, bmaxx
335            else:
336                left = max(lminx, bminx)
337                right = min(lmaxx, bmaxx)
338            if bminy > lmaxy or bmaxy < lminy:
339                bottom, top = bminy, bmaxy
340            else:
341                bottom = max(lminy, bminy)
342                top = min(lmaxy, bmaxy)
343    
344            return (left, bottom, right, top)
345    
346    
347    if resource.has_gdal_support():
348        import gdal
349        from gdalconst import GA_ReadOnly
350    
351    class RasterLayer(BaseLayer):
352    
353        MASK_NONE  = 0
354        MASK_BIT   = 1
355        MASK_ALPHA = 2
356    
357        def __init__(self, title, filename, projection = None,
358                     visible = True, opacity = 1, masktype = MASK_BIT):
359            """Initialize the Raster Layer.
360    
361            title -- title for the layer.
362    
363            filename -- file name of the source image.
364    
365            projection -- Projection object describing the projection which
366                          the source image is in.
367    
368            visible -- True is the layer should initially be visible.
369    
370            Throws IOError if the filename is invalid or points to a file that
371            is not in a format GDAL can use.
372            """
373    
374            BaseLayer.__init__(self, title, visible = visible)
375    
376            self.projection = projection
377            self.filename = os.path.abspath(filename)
378    
379            self.bbox = -1
380    
381            self.mask_type = masktype
382            self.opacity = opacity
383    
384            self.image_info = None
385    
386            if resource.has_gdal_support():
387                #
388                # temporarily open the file so that GDAL can test if it's valid.
389                #
390                dataset = gdal.Open(self.filename, GA_ReadOnly)
391    
392                if dataset is None:
393                    raise IOError()
394    
395                #
396                # while we have the file, extract some basic information
397                # that we can display later
398                #
399                self.image_info = {}
400    
401                self.image_info["nBands"] = dataset.RasterCount
402                self.image_info["Size"] = (dataset.RasterXSize, dataset.RasterYSize)
403                self.image_info["Driver"] = dataset.GetDriver().ShortName
404    
405                # store some information about the individual bands
406                # [min_value, max_value]
407                a = self.image_info["BandData"] = []
408    
409                for i in range(1, dataset.RasterCount+1):
410                    band = dataset.GetRasterBand(i)
411                    a.append(band.ComputeRasterMinMax())
412    
413            self.UnsetModified()
414    
415        def BoundingBox(self):
416            """Return the layer's bounding box in the intrinsic coordinate system.
417    
418            If the there is no support for images, or the file cannot
419            be read, or there is no geographics information available, return None.
420            """
421            if not resource.has_gdal_support():
422                return None
423    
424            if self.bbox == -1:
425                dataset = gdal.Open(self.filename, GA_ReadOnly)
426                if dataset is None:
427                    self.bbox = None
428                else:
429                    geotransform = dataset.GetGeoTransform()
430                    if geotransform is None:
431                        return None
432    
433                    x = 0
434                    y = dataset.RasterYSize
435                    left = geotransform[0] +        \
436                           geotransform[1] * x +    \
437                           geotransform[2] * y
438    
439                    bottom = geotransform[3] +      \
440                             geotransform[4] * x +  \
441                             geotransform[5] * y
442    
443                    x = dataset.RasterXSize
444                    y = 0
445                    right = geotransform[0] +       \
446                            geotransform[1] * x +   \
447                            geotransform[2] * y
448    
449                    top = geotransform[3] +         \
450                          geotransform[4] * x +     \
451                          geotransform[5] * y
452    
453                    self.bbox = (left, bottom, right, top)
454    
455            return self.bbox
456    
457        def LatLongBoundingBox(self):
458            bbox = self.BoundingBox()
459            if bbox is None:
460                return None
461    
462            if self.projection is not None:
463                bbox = self.projection.InverseBBox(bbox)
464    
465            return bbox
466    
467        def Type(self):
468            return "Image"
469    
470        def GetImageFilename(self):
471            return self.filename
472    
473        def MaskType(self):
474            """Return True if the mask should be used when rendering the layer."""
475            return self.mask_type
476    
477        def SetMaskType(self, type):
478            """Set the type of mask to use.
479    
480            type can be one of MASK_NONE, MASK_BIT, MASK_ALPHA
481    
482            If the state changes, a LAYER_CHANGED message is sent.
483            """
484            if type not in (self.MASK_NONE, self.MASK_BIT, self.MASK_ALPHA):
485                raise ValueError("type is invalid")
486    
487            if type != self.mask_type:
488                self.mask_type = type
489                self.changed(LAYER_CHANGED, self)
490    
491        def Opacity(self):
492            """Return the level of opacity used in alpha blending.
493            """
494            return self.opacity
495    
496        def SetOpacity(self, op):
497            """Set the level of alpha opacity.
498    
499            0 <= op <= 1.
500    
501            The layer is fully opaque when op = 1.
502            """
503            if not (0 <= op <= 1):
504                raise ValueError("op out of range")
505    
506            if op != self.opacity:
507                self.opacity = op
508                self.changed(LAYER_CHANGED, self)
509    
510        def ImageInfo(self):
511            return self.image_info
512    
513        def TreeInfo(self):
514            items = []
515    
516            items.append(_("Filename: %s") % self.GetImageFilename())
517    
518            if self.Visible():
519                items.append(_("Shown"))
520            else:
521                items.append(_("Hidden"))
522    
523            bbox = self.LatLongBoundingBox()
524            if bbox is not None:
525                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
526            else:
527                items.append(_("Extent (lat-lon):"))
528    
529            if self.projection and len(self.projection.params) > 0:
530                items.append((_("Projection"),
531                            [str(param) for param in self.projection.params]))
532    
533            return (_("Layer '%s'") % self.Title(), items)
534    
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