/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 276 by bh, Fri Aug 23 15:25:07 2002 UTC revision 2614 by jonathan, Fri May 6 14:16:38 2005 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001, 2002 by Intevation GmbH  # Copyright (c) 2001, 2002, 2003, 2004 by Intevation GmbH
2  # Authors:  # Authors:
3  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
4    # 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.
# Line 8  Line 10 
10  __version__ = "$Revision$"  __version__ = "$Revision$"
11    
12  import os  import os
13  from math import log, ceil  import warnings
14    
15  import shapelib, shptree  from Thuban import _
16    
17  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18       LAYER_VISIBILITY_CHANGED       LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
   
 from color import Color  
 # Some predefined colors for internal use  
 _black = Color(0, 0, 0)  
19    
20    import classification
21    
22  from table import Table  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  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  
   
   
27    
28  # Shape type constants  from color import Color
 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 = 1):      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:
89    
90          TITLE_CHANGED -- The title has changed.          TITLE_CHANGED -- The title has changed.
91          LAYER_PROJECTION_CHANGED -- the projection has changed.          LAYER_PROJECTION_CHANGED -- the projection has changed.
         LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed  
   
92      """      """
93    
94      def __init__(self, title, filename, projection = None,      def __init__(self, title, data, projection = None,
95                   fill = None, stroke = _black, stroke_width = 1, visible = 1):                   fill = Transparent,
96                     stroke = Black,
97                     lineWidth = 1,
98                     visible = True):
99          """Initialize the layer.          """Initialize the layer.
100    
101          title -- the title          title -- the title
102          filename -- the name of the shapefile          data -- datastore object for the shape data shown by the layer
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 None if the shapes are not filled          fill -- the fill color or Transparent if the shapes are
107          stroke -- the stroke color or None if the shapes are not stroked                  not filled
108            stroke -- the stroke color or Transparent if the shapes
109                    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    
118            self.__classification = None
119            self.store = None
120    
121            self.SetShapeStore(data)
122    
123            self.classification_column = None
124            self.SetClassificationColumn(None)
125            self.SetClassification(None)
126    
127            self.__classification.SetDefaultLineColor(stroke)
128            self.__classification.SetDefaultLineWidth(lineWidth)
129            self.__classification.SetDefaultFill(fill)
130    
131            self.UnsetModified()
132    
133        def SetShapeStore(self, store):
134            # Set the classification to None if there is a classification
135            # and the new shapestore doesn't have a table with a suitable
136            # column, i.e one with the same name and type as before
137            # FIXME: Maybe we should keep it the same if the type is
138            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
139            if self.__classification is not None:
140                columnname = self.classification_column
141                columntype = self.GetFieldType(columnname)
142                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)
147    
148          # Make the filename absolute. The filename will be          self.store = store
         # interpreted relative to that anyway, but when saving a  
         # session we need to compare absolute paths and it's usually  
         # safer to always work with absolute paths.  
         self.filename = os.path.abspath(filename)  
149    
150          self.projection = projection          self.changed(LAYER_SHAPESTORE_REPLACED, self)
         self.fill = fill  
         self.stroke = stroke  
         self.stroke_width = stroke_width  
         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  
   
     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]  
   
             # 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  
151    
152              # estimate a good depth for the quad tree. Each depth      def ShapeStore(self):
153              # multiplies the number of nodes by four, therefore we          return self.store
             # 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)  
154    
155      def Destroy(self):      def Destroy(self):
156          BaseLayer.Destroy(self)          BaseLayer.Destroy(self)
157          if self.shapefile is not None:          if self.__classification is not None:
158              self.shapefile.close()              self.__classification.Unsubscribe(CLASS_CHANGED,
159              self.shapefile = None                                                self._classification_changed)
             self.shapetree = None  
         self.table.Destroy()  
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          # The bbox will be set by open_shapefile just as we need it          return self.store.BoundingBox()
         # here.  
         self.open_shapefile()  
         return self.bbox  
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 190  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):
205            if self.store:
206                table = self.store.Table()
207                if table.HasColumn(fieldName):
208                    return table.Column(fieldName).type
209            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          self.open_shapefile()          return self.store.NumShapes()
         return self.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          self.open_shapefile()          return self.store.ShapeType()
         return self.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          self.open_shapefile()          return self.store.Shape(index)
229          shape = self.shapefile.read_object(index)  
230          if self.shapetype == SHAPETYPE_POINT:      def ShapesInRegion(self, bbox):
231              points = shape.vertices()          """Return an iterable over the shapes that overlap the bounding box.
232    
233            The bbox parameter should be the bounding box as a tuple in the
234            form (minx, miny, maxx, maxy) in unprojected coordinates.
235            """
236            if self.projection is not None:
237                # Ensure that region lies within the layer's bounding box
238                # Otherwise projection of the region would lead to incorrect
239                # values.
240                clipbbox = self.ClipBoundingBox(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 HasClassification(self):
261            return True
262    
263        def GetClassification(self):
264            return self.__classification
265    
266        def SetClassification(self, clazz):
267            """Set the classification used by this layer to 'clazz'
268    
269            If 'clazz' is None a default classification is created.
270    
271            This issues a LAYER_CHANGED event.
272            """
273    
274            if self.__classification is not None:
275                self.__classification.Unsubscribe(CLASS_CHANGED,
276                                                  self._classification_changed)
277    
278            if clazz is None:
279                clazz = classification.Classification()
280    
281            self.__classification = clazz
282            self.__classification.Subscribe(CLASS_CHANGED,
283                                            self._classification_changed)
284    
285            self._classification_changed()
286    
287        def _classification_changed(self):
288            """Called from the classification object when it has changed."""
289            self.changed(LAYER_CHANGED, self)
290    
291        def TreeInfo(self):
292            items = []
293    
294            items.append(_("Filename: %s") % self.ShapeStore().FileName())
295    
296            if self.Visible():
297                items.append(_("Shown"))
298            else:
299                items.append(_("Hidden"))
300            items.append(_("Shapes: %d") % self.NumShapes())
301    
302            bbox = self.LatLongBoundingBox()
303            if bbox is not None:
304                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % tuple(bbox))
305            else:
306                items.append(_("Extent (lat-lon):"))
307            items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
308    
309            if self.projection and len(self.projection.params) > 0:
310                items.append((_("Projection"),
311                            [str(param) for param in self.projection.params]))
312    
313            items.append(self.__classification)
314    
315            return (_("Layer '%s'") % self.Title(), items)
316    
317        def ClipBoundingBox(self, bbox):
318            """ Clip bbox to layer's bounding box.
319    
320            Returns that part of bbox that lies within the layers bounding box.
321            If bbox is completely outside of the layers bounding box, bbox is
322            returned.  It is assumed that bbox has sensible values, i.e. bminx
323            < bmaxx and bminy < bmaxy.
324            """
325            bminx, bminy, bmaxx, bmaxy = bbox
326            lminx, lminy, lmaxx, lmaxy = self.LatLongBoundingBox()
327            if bminx > lmaxx or bmaxx < lminx:
328                left, right = bminx, bmaxx
329          else:          else:
330              #for poly in shape.vertices():              left = max(lminx, bminx)
331              poly = shape.vertices()[0]              right = min(lmaxx, bmaxx)
332              points = []          if bminy > lmaxy or bmaxy < lminy:
333              for x, y in poly:              bottom, top = bminy, bmaxy
334                  points.append((x, y))          else:
335          return Shape(points)              bottom = max(lminy, bminy)
336                top = min(lmaxy, bmaxy)
337            
338            return (left, bottom, right, top)
339    
340    
341    if resource.has_gdal_support():
342        import gdal
343        from gdalconst import GA_ReadOnly
344    
345    class RasterLayer(BaseLayer):
346    
347        MASK_NONE  = 0
348        MASK_BIT   = 1
349        MASK_ALPHA = 2
350    
351        def __init__(self, title, filename, projection = None,
352                     visible = True, opacity = 1, masktype = MASK_BIT):
353            """Initialize the Raster Layer.
354    
355      def ShapesInRegion(self, box):          title -- title for the layer.
         """Return the ids of the shapes that overlap the box.  
356    
357          Box is a tuple (left, bottom, right, top) in the coordinate          filename -- file name of the source image.
358          system used by the layer's shapefile.  
359            projection -- Projection object describing the projection which
360                          the source image is in.
361    
362            visible -- True is the layer should initially be visible.
363    
364            Throws IOError if the filename is invalid or points to a file that
365            is not in a format GDAL can use.
366          """          """
         left, bottom, right, top = box  
         return self.shapetree.find_shapes((left, bottom), (right, top))  
367    
368      def SetProjection(self, projection):          BaseLayer.__init__(self, title, visible = visible)
369          """Set the layer's projection"""  
370          self.projection = projection          self.projection = projection
371          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = os.path.abspath(filename)
372    
373      def SetFill(self, fill):          self.bbox = -1
374          """Set the layer's fill color. None means the shapes are not filled"""  
375          self.fill = fill          self.mask_type = masktype
376          self.changed(LAYER_LEGEND_CHANGED, self)          self.opacity = opacity
377    
378      def SetStroke(self, stroke):          self.image_info = None
379          """Set the layer's stroke color. None means the shapes are not  
380          stroked."""          if resource.has_gdal_support():
381          self.stroke = stroke              #
382          self.changed(LAYER_LEGEND_CHANGED, self)              # temporarily open the file so that GDAL can test if it's valid.
383                #
384      def SetStrokeWidth(self, width):              dataset = gdal.Open(self.filename, GA_ReadOnly)
385          """Set the layer's stroke width."""  
386          self.stroke_width = width              if dataset is None:
387          self.changed(LAYER_LEGEND_CHANGED, self)                  raise IOError()
388    
389                #
390                # while we have the file, extract some basic information
391                # that we can display later
392                #
393                self.image_info = {}
394    
395                self.image_info["nBands"] = dataset.RasterCount
396                self.image_info["Size"] = (dataset.RasterXSize, dataset.RasterYSize)
397                self.image_info["Driver"] = dataset.GetDriver().ShortName
398    
399                # store some information about the individual bands
400                # [min_value, max_value]
401                a = self.image_info["BandData"] = []
402    
403                for i in range(1, dataset.RasterCount+1):
404                    band = dataset.GetRasterBand(i)
405                    a.append(band.ComputeRasterMinMax())
406    
407            self.UnsetModified()
408    
409        def BoundingBox(self):
410            """Return the layer's bounding box in the intrinsic coordinate system.
411    
412            If the there is no support for images, or the file cannot
413            be read, or there is no geographics information available, return None.
414            """
415            if not resource.has_gdal_support():
416                return None
417    
418            if self.bbox == -1:
419                dataset = gdal.Open(self.filename, GA_ReadOnly)
420                if dataset is None:
421                    self.bbox = None
422                else:
423                    geotransform = dataset.GetGeoTransform()
424                    if geotransform is None:
425                        return None
426    
427                    x = 0
428                    y = dataset.RasterYSize
429                    left = geotransform[0] +        \
430                           geotransform[1] * x +    \
431                           geotransform[2] * y
432    
433                    bottom = geotransform[3] +      \
434                             geotransform[4] * x +  \
435                             geotransform[5] * y
436    
437                    x = dataset.RasterXSize
438                    y = 0
439                    right = geotransform[0] +       \
440                            geotransform[1] * x +   \
441                            geotransform[2] * y
442    
443                    top = geotransform[3] +         \
444                          geotransform[4] * x +     \
445                          geotransform[5] * y
446    
447                    self.bbox = (left, bottom, right, top)
448    
449            return self.bbox
450    
451        def LatLongBoundingBox(self):
452            bbox = self.BoundingBox()
453            if bbox is None:
454                return None
455    
456            if self.projection is not None:
457                bbox = self.projection.InverseBBox(bbox)
458    
459            return bbox
460    
461        def Type(self):
462            return "Image"
463    
464        def GetImageFilename(self):
465            return self.filename
466    
467        def MaskType(self):
468            """Return True if the mask should be used when rendering the layer."""
469            return self.mask_type
470    
471        def SetMaskType(self, type):
472            """Set the type of mask to use.
473    
474            type can be one of MASK_NONE, MASK_BIT, MASK_ALPHA
475    
476            If the state changes, a LAYER_CHANGED message is sent.
477            """
478            if type not in (self.MASK_NONE, self.MASK_BIT, self.MASK_ALPHA):
479                raise ValueError("type is invalid")
480    
481            if type != self.mask_type:
482                self.mask_type = type
483                self.changed(LAYER_CHANGED, self)
484    
485        def Opacity(self):
486            """Return the level of opacity used in alpha blending.
487            """
488            return self.opacity
489    
490        def SetOpacity(self, op):
491            """Set the level of alpha opacity.
492    
493            0 <= op <= 1.
494    
495            The layer is fully opaque when op = 1.
496            """
497            if not (0 <= op <= 1):
498                raise ValueError("op out of range")
499    
500            if op != self.opacity:
501                self.opacity = op
502                self.changed(LAYER_CHANGED, self)
503    
504        def ImageInfo(self):
505            return self.image_info
506    
507      def TreeInfo(self):      def TreeInfo(self):
508          items = []          items = []
509    
510            items.append(_("Filename: %s") % self.GetImageFilename())
511    
512          if self.Visible():          if self.Visible():
513              items.append("Shown")              items.append(_("Shown"))
514          else:          else:
515              items.append("Hidden")              items.append(_("Hidden"))
         items.append("Shapes: %d" % self.NumShapes())  
516    
517          bbox = self.LatLongBoundingBox()          bbox = self.LatLongBoundingBox()
518          if bbox is not None:          if bbox is not None:
519              items.append("Extent (lat-lon): (%g, %g, %g, %g)" % bbox)              items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
520          else:          else:
521              items.append("Extent (lat-lon):")              items.append(_("Extent (lat-lon):"))
522          items.append("Shapetype: %s" % shapetype_names[self.ShapeType()])  
523            if self.projection and len(self.projection.params) > 0:
524                items.append((_("Projection"),
525                            [str(param) for param in self.projection.params]))
526    
527          def color_string(color):          return (_("Layer '%s'") % self.Title(), items)
             if color is None:  
                 return "None"  
             return "(%.3f, %.3f, %.3f)" % (color.red, color.green, color.blue)  
         items.append("Fill: " + color_string(self.fill))  
         items.append("Outline: " + color_string(self.stroke))  
528    
         return ("Layer '%s'" % self.Title(), items)  
Legend:
Removed from v.276  
changed lines
  Added in v.2614
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