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trunk/thuban/Thuban/Model/layer.py revision 82 by bh, Fri Feb 15 17:11:04 2002 UTC branches/WIP-pyshapelib-bramz/Thuban/Model/layer.py revision 2734 by bramz, Thu Mar 1 12:42:59 2007 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001, 2002 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]>
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  import shapelib  import os
13    import warnings
14    
15  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  from wxproj import point_in_polygon_shape, shape_centroid
      LAYER_VISIBILITY_CHANGED  
16    
17  from color import Color  from Thuban import _
 # Some predefined colors for internal use  
 _black = Color(0, 0, 0)  
18    
19    from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
20         LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
21    
22  from table import Table  import classification
23    
24    from color import Transparent, Black
25  from base import TitledObject, Modifiable  from base import TitledObject, Modifiable
26    from data import SHAPETYPE_POLYGON, SHAPETYPE_ARC, SHAPETYPE_POINT
27    from label import ALIGN_CENTER, ALIGN_TOP, ALIGN_BOTTOM, \
28         ALIGN_LEFT, ALIGN_RIGHT
29    
30  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  
   
   
31    
32  # 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}  
33    
34  shapetype_names = {SHAPETYPE_POINT: "Point",  shapetype_names = {SHAPETYPE_POINT: "Point",
35                     SHAPETYPE_ARC: "Arc",                     SHAPETYPE_ARC: "Arc",
# Line 63  class BaseLayer(TitledObject, Modifiable Line 39  class BaseLayer(TitledObject, Modifiable
39    
40      """Base class for the layers."""      """Base class for the layers."""
41    
42      def __init__(self, title, visible = 1):      def __init__(self, title, visible = True, projection = None):
43          """Initialize the layer.          """Initialize the layer.
44    
45          title -- the title          title -- the title
# Line 72  class BaseLayer(TitledObject, Modifiable Line 48  class BaseLayer(TitledObject, Modifiable
48          TitledObject.__init__(self, title)          TitledObject.__init__(self, title)
49          Modifiable.__init__(self)          Modifiable.__init__(self)
50          self.visible = visible          self.visible = visible
51            self.projection = projection
52    
53      def Visible(self):      def Visible(self):
54          """Return true if layer is visible"""          """Return true if layer is visible"""
# Line 81  class BaseLayer(TitledObject, Modifiable Line 58  class BaseLayer(TitledObject, Modifiable
58          """Set the layer's visibility."""          """Set the layer's visibility."""
59          self.visible = visible          self.visible = visible
60          self.issue(LAYER_VISIBILITY_CHANGED, self)          self.issue(LAYER_VISIBILITY_CHANGED, self)
61            
62                def HasClassification(self):
63            """Determine if this layer supports classifications."""
64            return False
65    
66        def HasShapes(self):
67            """Determine if this layer supports shapes."""
68            return False
69    
70        def GetProjection(self):
71            """Return the layer's projection."""
72            return self.projection
73    
74        def SetProjection(self, projection):
75            """Set the layer's projection."""
76            self.projection = projection
77            self.changed(LAYER_PROJECTION_CHANGED, self)
78    
79        def Type(self):
80            return "Unknown"
81    
82  class Layer(BaseLayer):  class Layer(BaseLayer):
83    
84      """Represent the information of one geodata file (currently a shapefile)      """Represent the information of one geodata file (currently a shapefile)
# Line 90  class Layer(BaseLayer): Line 86  class Layer(BaseLayer):
86      All children of the layer have the same type.      All children of the layer have the same type.
87    
88      A layer has fill and stroke colors. Colors should be instances of      A layer has fill and stroke colors. Colors should be instances of
89      Color. They can also be None, indicating no fill or no stroke.      Color. They can also be Transparent, indicating no fill or no stroke.
90    
91      The layer objects send the following events, all of which have the      The layer objects send the following events, all of which have the
92      layer object as parameter:      layer object as parameter:
93    
94          TITLE_CHANGED -- The title has changed.          TITLE_CHANGED -- The title has changed.
95          LAYER_PROJECTION_CHANGED -- the projection has changed.          LAYER_PROJECTION_CHANGED -- the projection has changed.
         LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed  
   
96      """      """
97    
98      def __init__(self, title, filename, projection = None,      def __init__(self, title, data, projection = None,
99                   fill = None, stroke = _black, stroke_width = 1, visible = 1):                   fill = Transparent,
100                     stroke = Black,
101                     lineWidth = 1,
102                     visible = True):
103          """Initialize the layer.          """Initialize the layer.
104    
105          title -- the title          title -- the title
106          filename -- the name of the shapefile          data -- datastore object for the shape data shown by the layer
107          projection -- the projection object. Its Inverse method is          projection -- the projection object. Its Inverse method is
108                 assumed to map the layer's coordinates to lat/long                 assumed to map the layer's coordinates to lat/long
109                 coordinates                 coordinates
110          fill -- the fill color or None if the shapes are not filled          fill -- the fill color or Transparent if the shapes are
111          stroke -- the stroke color or None if the shapes are not stroked                  not filled
112            stroke -- the stroke color or Transparent if the shapes
113                    are not stroked
114          visible -- boolean. If true the layer is visible.          visible -- boolean. If true the layer is visible.
115    
116          colors are expected to be instances of Color class          colors are expected to be instances of Color class
117          """          """
118          BaseLayer.__init__(self, title, visible = visible)          BaseLayer.__init__(self, title,
119          self.filename = filename                                   visible = visible,
120          self.projection = projection                                   projection = projection)
121          self.fill = fill  
122          self.stroke = stroke          self.__classification = None
123          self.stroke_width = stroke_width          self.store = None
124          self.shapefile = None  
125          self.open_shapefile()          self.SetShapeStore(data)
126          # shapetable is the table associated with the shapefile, while  
127          # table is the default table used to look up attributes for          self.classification_column = None
128          # display          self.SetClassificationColumn(None)
129          self.shapetable = Table(filename)          self.SetClassification(None)
130          self.table = self.shapetable  
131            self.__classification.SetDefaultLineColor(stroke)
132      def open_shapefile(self):          self.__classification.SetDefaultLineWidth(lineWidth)
133          if self.shapefile is None:          self.__classification.SetDefaultFill(fill)
134              self.shapefile = shapelib.ShapeFile(self.filename)  
135              numshapes, shapetype, mins, maxs = self.shapefile.info()          self.UnsetModified()
136              self.numshapes = numshapes  
137              self.shapetype = shapelib_shapetypes[shapetype]      def SetShapeStore(self, store):
138              self.bbox = mins[:2] + maxs[:2]          # Set the classification to None if there is a classification
139            # and the new shapestore doesn't have a table with a suitable
140            # column, i.e one with the same name and type as before
141            # FIXME: Maybe we should keep it the same if the type is
142            # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
143            if self.__classification is not None:
144                columnname = self.classification_column
145                columntype = self.GetFieldType(columnname)
146                table = store.Table()
147                if (columnname is not None
148                    and (not table.HasColumn(columnname)
149                         or table.Column(columnname).type != columntype)):
150                    self.SetClassification(None)
151    
152            self.store = store
153    
154            self.changed(LAYER_SHAPESTORE_REPLACED, self)
155    
156        def ShapeStore(self):
157            return self.store
158    
159        def Destroy(self):
160            BaseLayer.Destroy(self)
161            if self.__classification is not None:
162                self.__classification.Unsubscribe(CLASS_CHANGED,
163                                                  self._classification_changed)
164    
165      def BoundingBox(self):      def BoundingBox(self):
166          """Return the bounding box of the layer's shapes in their default          """Return the layer's bounding box in the intrinsic coordinate system.
167          coordinate system"""  
168          self.open_shapefile()          If the layer has no shapes, return None.
169          return self.bbox          """
170            return self.store.BoundingBox()
171    
172      def LatLongBoundingBox(self):      def LatLongBoundingBox(self):
173          """Return the layer's bounding box in lat/long coordinates"""          """Return the layer's bounding box in lat/long coordinates.
174          llx, lly, urx, ury = self.BoundingBox()  
175          if self.projection is not None:          Return None, if the layer doesn't contain any shapes.
176              llx, lly = self.projection.Inverse(llx, lly)          """
177              urx, ury = self.projection.Inverse(urx, ury)          bbox = self.BoundingBox()
178          return llx, lly, urx, ury          if bbox is not None and self.projection is not None:
179                bbox = self.projection.InverseBBox(bbox)
180            return bbox
181    
182        def Type(self):
183            return self.ShapeType();
184    
185        def ShapesBoundingBox(self, shapes):
186            """Return a bounding box in lat/long coordinates for the given
187            list of shape ids.
188    
189            If shapes is None or empty, return None.
190            """
191    
192            if shapes is None or len(shapes) == 0: return None
193    
194            xs = []
195            ys = []
196    
197            for id in shapes:
198                bbox = self.Shape(id).compute_bbox()
199                if self.projection is not None:
200                    bbox = self.projection.InverseBBox(bbox)
201                left, bottom, right, top = bbox
202                xs.append(left); xs.append(right)
203                ys.append(bottom); ys.append(top)
204    
205            return (min(xs), min(ys), max(xs), max(ys))
206    
207    
208        def GetFieldType(self, fieldName):
209            if self.store:
210                table = self.store.Table()
211                if table.HasColumn(fieldName):
212                    return table.Column(fieldName).type
213            return None
214    
215        def HasShapes(self):
216            return True
217    
218      def NumShapes(self):      def NumShapes(self):
219          """Return the number of shapes in the layer"""          """Return the number of shapes in the layer"""
220          self.open_shapefile()          return self.store.NumShapes()
         return self.numshapes  
221    
222      def ShapeType(self):      def ShapeType(self):
223          """Return the type of the shapes in the layer.          """Return the type of the shapes in the layer.
224          This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.  
225            The return value is one of the SHAPETYPE_* constants defined in
226            Thuban.Model.data.
227          """          """
228          self.open_shapefile()          return self.store.ShapeType()
         return self.shapetype  
229    
230      def Shape(self, index):      def Shape(self, index):
231          """Return the shape with index index"""          """Return the shape with index index"""
232          self.open_shapefile()          return self.store.Shape(index)
233          shape = self.shapefile.read_object(index)  
234          if self.shapetype == SHAPETYPE_POINT:      def ShapesInRegion(self, bbox):
235              points = shape.vertices()          """Return an iterable over the shapes that overlap the bounding box.
236          else:  
237              #for poly in shape.vertices():          The bbox parameter should be the bounding box as a tuple in the
238              poly = shape.vertices()[0]          form (minx, miny, maxx, maxy) in unprojected coordinates.
239              points = []          """
240              for x, y in poly:          if self.projection is not None:
241                  points.append((x, y))              # Ensure that region lies within the layer's bounding box
242          return Shape(points)              # Otherwise projection of the region would lead to incorrect
243                # values.
244                clipbbox = self.__mangle_bounding_box(bbox)
245                bbox = self.projection.ForwardBBox(clipbbox)
246            return self.store.ShapesInRegion(bbox)
247    
248        def GetClassificationColumn(self):
249            return self.classification_column
250    
251        def SetClassificationColumn(self, column):
252            """Set the column to classifiy on, or None. If column is not None
253            and the column does not exist in the table, raise a ValueError.
254            """
255            if column:
256                columnType = self.GetFieldType(column)
257                if columnType is None:
258                    raise ValueError()
259            changed = self.classification_column != column
260            self.classification_column = column
261            if changed:
262                self.changed(LAYER_CHANGED, self)
263    
264        def HasClassification(self):
265            return True
266    
267        def GetClassification(self):
268            return self.__classification
269    
270        def SetClassification(self, clazz):
271            """Set the classification used by this layer to 'clazz'
272    
273            If 'clazz' is None a default classification is created.
274    
275            This issues a LAYER_CHANGED event.
276            """
277    
278            if self.__classification is not None:
279                self.__classification.Unsubscribe(CLASS_CHANGED,
280                                                  self._classification_changed)
281    
282            if clazz is None:
283                clazz = classification.Classification()
284    
285            self.__classification = clazz
286            self.__classification.Subscribe(CLASS_CHANGED,
287                                            self._classification_changed)
288    
289            self._classification_changed()
290    
291        def _classification_changed(self):
292            """Called from the classification object when it has changed."""
293            self.changed(LAYER_CHANGED, self)
294    
295        def TreeInfo(self):
296            items = []
297    
298            items.append(_("Filename: %s") % self.ShapeStore().FileName())
299    
300            if self.Visible():
301                items.append(_("Shown"))
302            else:
303                items.append(_("Hidden"))
304            items.append(_("Shapes: %d") % self.NumShapes())
305    
306            bbox = self.LatLongBoundingBox()
307            if bbox is not None:
308                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % tuple(bbox))
309            else:
310                items.append(_("Extent (lat-lon):"))
311            items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
312    
313            if self.projection and len(self.projection.params) > 0:
314                items.append((_("Projection"),
315                            [str(param) for param in self.projection.params]))
316    
317            items.append(self.__classification)
318    
319            return (_("Layer '%s'") % self.Title(), items)
320    
321        def __mangle_bounding_box(self, bbox):
322            # FIXME: This method doesn't make much sense.
323            # See RT #2845 which effectively says:
324            #
325            # If this method, which was originally called ClipBoundingBox,
326            # is supposed to do clipping it shouldn't return the parameter
327            # unchanged when it lies completely outside of the bounding box.
328            # It would be better to return None and return an empty list in
329            # ShapesInRegion (the only caller) in that case.
330            #
331            # This method was introduced to fix a bug that IIRC had
332            # something todo with projections and bounding boxes containing
333            # NaN or INF when the parameter to ShapesInRegion covered the
334            # entire earth or something similarly large).
335            bminx, bminy, bmaxx, bmaxy = bbox
336            lminx, lminy, lmaxx, lmaxy = self.LatLongBoundingBox()
337            if bminx > lmaxx or bmaxx < lminx:
338                left, right = bminx, bmaxx
339            else:
340                left = max(lminx, bminx)
341                right = min(lmaxx, bmaxx)
342            if bminy > lmaxy or bmaxy < lminy:
343                bottom, top = bminy, bmaxy
344            else:
345                bottom = max(lminy, bminy)
346                top = min(lmaxy, bmaxy)
347    
348            return (left, bottom, right, top)
349    
350        def GetLabelPosFromShape(self, cmap, shape_index):
351            '''
352            Return the label position parameters (x, y, halign, valign) from the
353            shape object
354            '''
355            proj = cmap.projection
356            if proj is not None:
357                map_proj = proj
358            else:
359                map_proj = None
360            proj = self.projection
361            if proj is not None:
362                layer_proj = proj
363            else:
364                layer_proj = None
365    
366            shapetype = self.ShapeType()
367            if shapetype == SHAPETYPE_POLYGON:
368                shapefile = self.ShapeStore().Shapefile().cobject()
369                x, y = shape_centroid(shapefile, shape_index,
370                                      map_proj, layer_proj, 1, 1, 0, 0)
371                if map_proj is not None:
372                    x, y = map_proj.Inverse(x, y)
373            else:
374                shape = self.Shape(shape_index)
375                if shapetype == SHAPETYPE_POINT:
376                    x, y = shape.Points()[0][0]
377                else:
378                    # assume SHAPETYPE_ARC
379                    points = shape.Points()[0]
380                    x, y = points[len(points) / 2]
381                if layer_proj is not None:
382                    x, y = layer_proj.Inverse(x, y)
383            if shapetype == SHAPETYPE_POINT:
384                halign = ALIGN_LEFT
385                valign = ALIGN_CENTER
386            elif shapetype == SHAPETYPE_POLYGON:
387                halign = ALIGN_CENTER
388                valign = ALIGN_CENTER
389            elif shapetype == SHAPETYPE_ARC:
390                halign = ALIGN_LEFT
391                valign = ALIGN_CENTER
392            
393            return (x, y, halign, valign)
394    
395    
396    
397    if resource.has_gdal_support():
398        import gdal
399        from gdalconst import GA_ReadOnly
400    
401    class RasterLayer(BaseLayer):
402    
403        MASK_NONE  = 0
404        MASK_BIT   = 1
405        MASK_ALPHA = 2
406    
407        def __init__(self, title, filename, projection = None,
408                     visible = True, opacity = 1, masktype = MASK_BIT):
409            """Initialize the Raster Layer.
410    
411            title -- title for the layer.
412    
413            filename -- file name of the source image.
414    
415            projection -- Projection object describing the projection which
416                          the source image is in.
417    
418            visible -- True is the layer should initially be visible.
419    
420            Throws IOError if the filename is invalid or points to a file that
421            is not in a format GDAL can use.
422            """
423    
424            BaseLayer.__init__(self, title, visible = visible)
425    
     def SetProjection(self, projection):  
         """Set the layer's projection"""  
426          self.projection = projection          self.projection = projection
427          self.changed(LAYER_PROJECTION_CHANGED, self)          self.filename = os.path.abspath(filename)
428    
429            self.bbox = -1
430    
431            self.mask_type = masktype
432            self.opacity = opacity
433    
434            self.image_info = None
435    
436            if resource.has_gdal_support():
437                #
438                # temporarily open the file so that GDAL can test if it's valid.
439                #
440                dataset = gdal.Open(self.filename, GA_ReadOnly)
441    
442                if dataset is None:
443                    raise IOError()
444    
445                #
446                # while we have the file, extract some basic information
447                # that we can display later
448                #
449                self.image_info = {}
450    
451                self.image_info["nBands"] = dataset.RasterCount
452                self.image_info["Size"] = (dataset.RasterXSize, dataset.RasterYSize)
453                self.image_info["Driver"] = dataset.GetDriver().ShortName
454    
455                # store some information about the individual bands
456                # [min_value, max_value]
457                a = self.image_info["BandData"] = []
458    
459                for i in range(1, dataset.RasterCount+1):
460                    band = dataset.GetRasterBand(i)
461                    a.append(band.ComputeRasterMinMax())
462    
463            self.UnsetModified()
464    
465        def BoundingBox(self):
466            """Return the layer's bounding box in the intrinsic coordinate system.
467    
468            If the there is no support for images, or the file cannot
469            be read, or there is no geographics information available, return None.
470            """
471            if not resource.has_gdal_support():
472                return None
473    
474            if self.bbox == -1:
475                dataset = gdal.Open(self.filename, GA_ReadOnly)
476                if dataset is None:
477                    self.bbox = None
478                else:
479                    geotransform = dataset.GetGeoTransform()
480                    if geotransform is None:
481                        return None
482    
483                    x = 0
484                    y = dataset.RasterYSize
485                    left = geotransform[0] +        \
486                           geotransform[1] * x +    \
487                           geotransform[2] * y
488    
489                    bottom = geotransform[3] +      \
490                             geotransform[4] * x +  \
491                             geotransform[5] * y
492    
493                    x = dataset.RasterXSize
494                    y = 0
495                    right = geotransform[0] +       \
496                            geotransform[1] * x +   \
497                            geotransform[2] * y
498    
499                    top = geotransform[3] +         \
500                          geotransform[4] * x +     \
501                          geotransform[5] * y
502    
503                    self.bbox = (left, bottom, right, top)
504    
505            return self.bbox
506    
507        def LatLongBoundingBox(self):
508            bbox = self.BoundingBox()
509            if bbox is None:
510                return None
511    
512            if self.projection is not None:
513                bbox = self.projection.InverseBBox(bbox)
514    
515            return bbox
516    
517        def Type(self):
518            return "Image"
519    
520        def GetImageFilename(self):
521            return self.filename
522    
523        def MaskType(self):
524            """Return True if the mask should be used when rendering the layer."""
525            return self.mask_type
526    
527        def SetMaskType(self, type):
528            """Set the type of mask to use.
529    
530            type can be one of MASK_NONE, MASK_BIT, MASK_ALPHA
531    
532            If the state changes, a LAYER_CHANGED message is sent.
533            """
534            if type not in (self.MASK_NONE, self.MASK_BIT, self.MASK_ALPHA):
535                raise ValueError("type is invalid")
536    
537            if type != self.mask_type:
538                self.mask_type = type
539                self.changed(LAYER_CHANGED, self)
540    
541        def Opacity(self):
542            """Return the level of opacity used in alpha blending.
543            """
544            return self.opacity
545    
546        def SetOpacity(self, op):
547            """Set the level of alpha opacity.
548    
549            0 <= op <= 1.
550    
551            The layer is fully opaque when op = 1.
552            """
553            if not (0 <= op <= 1):
554                raise ValueError("op out of range")
555    
556            if op != self.opacity:
557                self.opacity = op
558                self.changed(LAYER_CHANGED, self)
559    
560        def ImageInfo(self):
561            return self.image_info
562    
563        def TreeInfo(self):
564            items = []
565    
566            items.append(_("Filename: %s") % self.GetImageFilename())
567    
568            if self.Visible():
569                items.append(_("Shown"))
570            else:
571                items.append(_("Hidden"))
572    
573            bbox = self.LatLongBoundingBox()
574            if bbox is not None:
575                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
576            else:
577                items.append(_("Extent (lat-lon):"))
578    
579            if self.projection and len(self.projection.params) > 0:
580                items.append((_("Projection"),
581                            [str(param) for param in self.projection.params]))
582    
583            return (_("Layer '%s'") % self.Title(), items)
584    
     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.82  
changed lines
  Added in v.2734
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