/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/layer.py
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revision 179 by bh, Wed May 15 14:02:49 2002 UTC revision 2562 by jonathan, Wed Feb 16 21:14:47 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.
9    
10  __version__ = "$Revision$"  __version__ = "$Revision$"
11    
12  from math import log, ceil  import os
13    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
19    
20  from color import Color  import classification
 # Some predefined colors for internal use  
 _black = Color(0, 0, 0)  
   
   
 from table import Table  
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  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    from color import Color
 # 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 65  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 74  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 83  class BaseLayer(TitledObject, Modifiable Line 54  class BaseLayer(TitledObject, Modifiable
54          """Set the layer's visibility."""          """Set the layer's visibility."""
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    
80      """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 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          self.filename = filename                                   visible = visible,
116          self.projection = projection                                   projection = projection)
117          self.fill = fill  
118          self.stroke = stroke          self.__classification = None
119          self.stroke_width = stroke_width          self.store = None
120          self.shapefile = None  
121          self.shapetree = None          self.SetShapeStore(data)
122          self.open_shapefile()  
123          # shapetable is the table associated with the shapefile, while          self.classification_column = None
124          # table is the default table used to look up attributes for          self.SetClassificationColumn(None)
125          # display          self.SetClassification(None)
126          self.shapetable = Table(filename)  
127          self.table = self.shapetable          self.__classification.SetDefaultLineColor(stroke)
128            self.__classification.SetDefaultLineWidth(lineWidth)
129      def open_shapefile(self):          self.__classification.SetDefaultFill(fill)
130          if self.shapefile is None:  
131              self.shapefile = shapelib.ShapeFile(self.filename)          self.UnsetModified()
132              numshapes, shapetype, mins, maxs = self.shapefile.info()  
133              self.numshapes = numshapes      def SetShapeStore(self, store):
134              self.shapetype = shapelib_shapetypes[shapetype]          # Set the classification to None if there is a classification
135            # and the new shapestore doesn't have a table with a suitable
136              # if there are shapes, set the bbox accordinly. Otherwise          # column, i.e one with the same name and type as before
137              # set it to None.          # FIXME: Maybe we should keep it the same if the type is
138              if self.numshapes:          # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
139                  self.bbox = mins[:2] + maxs[:2]          if self.__classification is not None:
140              else:              columnname = self.classification_column
141                  self.bbox = None              columntype = self.GetFieldType(columnname)
142                table = store.Table()
143              # estimate a good depth for the quad tree. Each depth              if (columnname is not None
144              # multiplies the number of nodes by four, therefore we                  and (not table.HasColumn(columnname)
145              # basically take the base 4 logarithm of the number of                       or table.Column(columnname).type != columntype)):
146              # shapes.                  self.SetClassification(None)
147              if self.numshapes < 4:  
148                  maxdepth = 1          self.store = store
149              else:  
150                  maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))          self.changed(LAYER_SHAPESTORE_REPLACED, self)
151    
152              self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,      def ShapeStore(self):
153                                               maxdepth)          return self.store
154    
155        def Destroy(self):
156            BaseLayer.Destroy(self)
157            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          # 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 175  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)
         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)  
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                # 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:
330                left = max(lminx, bminx)
331                right = min(lmaxx, bmaxx)
332            if bminy > lmaxy or bmaxy < lminy:
333                bottom, top = bminy, bmaxy
334            else:
335                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, visible = True):
352            """Initialize the Raster Layer.
353    
354            title -- title for the layer.
355    
356            filename -- file name of the source image.
357    
358            projection -- Projection object describing the projection which
359                          the source image is in.
360    
361            visible -- True is the layer should initially be visible.
362    
363            Throws IOError if the filename is invalid or points to a file that
364            is not in a format GDAL can use.
365            """
366    
367            BaseLayer.__init__(self, title, visible = visible)
368    
     def SetProjection(self, projection):  
         """Set the layer's projection"""  
369          self.projection = projection          self.projection = projection
370          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = os.path.abspath(filename)
371    
372            self.bbox = -1
373    
374            self.mask_type = self.MASK_BIT
375            self.alpha_opacity = 1
376    
377            self.image_info = None
378    
379            if resource.has_gdal_support():
380                #
381                # temporarily open the file so that GDAL can test if it's valid.
382                #
383                dataset = gdal.Open(self.filename, GA_ReadOnly)
384    
385                if dataset is None:
386                    raise IOError()
387    
388                #
389                # while we have the file, extract some basic information
390                # that we can display later
391                #
392                self.image_info = {}
393    
394                self.image_info["nBands"] = dataset.RasterCount
395                self.image_info["Size"] = (dataset.RasterXSize, dataset.RasterYSize)
396                self.image_info["Driver"] = dataset.GetDriver().ShortName
397    
398                # store some information about the individual bands
399                # [min_value, max_value]
400                a = self.image_info["BandData"] = []
401    
402                for i in range(1, dataset.RasterCount+1):
403                    band = dataset.GetRasterBand(i)
404                    a.append(band.ComputeRasterMinMax())
405    
406            self.UnsetModified()
407    
408        def BoundingBox(self):
409            """Return the layer's bounding box in the intrinsic coordinate system.
410    
411            If the there is no support for images, or the file cannot
412            be read, or there is no geographics information available, return None.
413            """
414            if not resource.has_gdal_support():
415                return None
416    
417            if self.bbox == -1:
418                dataset = gdal.Open(self.filename, GA_ReadOnly)
419                if dataset is None:
420                    self.bbox = None
421                else:
422                    geotransform = dataset.GetGeoTransform()
423                    if geotransform is None:
424                        return None
425    
426                    x = 0
427                    y = dataset.RasterYSize
428                    left = geotransform[0] +        \
429                           geotransform[1] * x +    \
430                           geotransform[2] * y
431    
432                    bottom = geotransform[3] +      \
433                             geotransform[4] * x +  \
434                             geotransform[5] * y
435    
436                    x = dataset.RasterXSize
437                    y = 0
438                    right = geotransform[0] +       \
439                            geotransform[1] * x +   \
440                            geotransform[2] * y
441    
442                    top = geotransform[3] +         \
443                          geotransform[4] * x +     \
444                          geotransform[5] * y
445    
446                    self.bbox = (left, bottom, right, top)
447    
448            return self.bbox
449    
450        def LatLongBoundingBox(self):
451            bbox = self.BoundingBox()
452            if bbox is None:
453                return None
454    
455            if self.projection is not None:
456                bbox = self.projection.InverseBBox(bbox)
457    
458            return bbox
459    
460        def Type(self):
461            return "Image"
462    
463        def GetImageFilename(self):
464            return self.filename
465    
466        def MaskType(self):
467            """Return True if the mask should be used when rendering the layer."""
468            return self.mask_type
469    
470        def SetMaskType(self, type):
471            """Set the type of mask to use.
472    
473            type can be one of MASK_NONE, MASK_BIT, MASK_ALPHA
474    
475            If the state changes, a LAYER_CHANGED message is sent.
476            """
477            if type not in (self.MASK_NONE, self.MASK_BIT, self.MASK_ALPHA):
478                raise ValueError("type is invalid")
479    
480            if type != self.mask_type:
481                self.mask_type = type
482                self.changed(LAYER_CHANGED, self)
483    
484        def AlphaOpacity(self):
485            """Return the level of opacity used in alpha blending, or None
486            if mask type is not MASK_ALPHA.
487            """
488            if self.mask_type == self.MASK_ALPHA:
489                return self.alpha_opacity
490            else:
491                return None
492    
493        def SetAlphaOpacity(self, op):
494            """Set the level of alpha opacity.
495    
496            0 <= op <= 1.
497    
498            The layer is fully opaque when op = 1.
499            """
500            if not (0 <= op <= 1):
501                raise ValueError("op out of range")
502    
503            self.alpha_opacity = op
504    
505        def ImageInfo(self):
506            return self.image_info
507    
508        def TreeInfo(self):
509            items = []
510    
511            items.append(_("Filename: %s") % self.GetImageFilename())
512    
513            if self.Visible():
514                items.append(_("Shown"))
515            else:
516                items.append(_("Hidden"))
517    
518            bbox = self.LatLongBoundingBox()
519            if bbox is not None:
520                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
521            else:
522                items.append(_("Extent (lat-lon):"))
523    
524            if self.projection and len(self.projection.params) > 0:
525                items.append((_("Projection"),
526                            [str(param) for param in self.projection.params]))
527    
528            return (_("Layer '%s'") % self.Title(), items)
529    
     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.179  
changed lines
  Added in v.2562
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