/[thuban]/trunk/thuban/Thuban/Model/layer.py
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revision 6 by bh, Tue Aug 28 15:41:52 2001 UTC revision 2614 by jonathan, Fri May 6 14:16:38 2005 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001 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  import shapelib  import os
13    import warnings
14    
15  from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \  from Thuban import _
      LAYER_VISIBILITY_CHANGED  
   
 from color import Color  
 # Some predefined colors for internal use  
 _black = Color(0, 0, 0)  
16    
17    from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18         LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED, CLASS_CHANGED
19    
20  from table import Table  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  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 63  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 72  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 81  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 90  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, 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.shapefile = None          self.store = None
120          # shapetable is the table associated with the shapefile, while  
121          # table is the default table used to look up attributes for          self.SetShapeStore(data)
122          # display  
123          self.shapetable = Table(filename)          self.classification_column = None
124          self.table = self.shapetable          self.SetClassificationColumn(None)
125            self.SetClassification(None)
126      def open_shapefile(self):  
127          if self.shapefile is None:          self.__classification.SetDefaultLineColor(stroke)
128              self.shapefile = shapelib.ShapeFile(self.filename)          self.__classification.SetDefaultLineWidth(lineWidth)
129              numshapes, shapetype, mins, maxs = self.shapefile.info()          self.__classification.SetDefaultFill(fill)
130              self.numshapes = numshapes  
131              self.shapetype = shapelib_shapetypes[shapetype]          self.UnsetModified()
132              self.bbox = mins[:2] + maxs[:2]  
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            self.store = store
149    
150            self.changed(LAYER_SHAPESTORE_REPLACED, self)
151    
152        def ShapeStore(self):
153            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 bounding box of the layer's shapes in their default          """Return the layer's bounding box in the intrinsic coordinate system.
163          coordinate system"""  
164          self.open_shapefile()          If the layer has no shapes, return None.
165          return self.bbox          """
166            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.
170          llx, lly, urx, ury = self.BoundingBox()  
171          if self.projection is not None:          Return None, if the layer doesn't contain any shapes.
172              llx, lly = self.projection.Inverse(llx, lly)          """
173              urx, ury = self.projection.Inverse(urx, ury)          bbox = self.BoundingBox()
174          return llx, lly, urx, ury          if bbox is not None and self.projection is not None:
175                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:
196                    bbox = self.projection.InverseBBox(bbox)
197                left, bottom, right, top = bbox
198                xs.append(left); xs.append(right)
199                ys.append(bottom); ys.append(top)
200    
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          else:  
233              #for poly in shape.vertices():          The bbox parameter should be the bounding box as a tuple in the
234              poly = shape.vertices()[0]          form (minx, miny, maxx, maxy) in unprojected coordinates.
235              points = []          """
236              for x, y in poly:          if self.projection is not None:
237                  points.append(x, y)              # Ensure that region lies within the layer's bounding box
238          return Shape(points)              # 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,
352                     visible = True, opacity = 1, masktype = MASK_BIT):
353            """Initialize the Raster Layer.
354    
355            title -- title for the layer.
356    
357            filename -- file name of the source image.
358    
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            """
367    
368            BaseLayer.__init__(self, title, visible = visible)
369    
     def SetProjection(self, projection):  
         """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            self.bbox = -1
374    
375            self.mask_type = masktype
376            self.opacity = opacity
377    
378            self.image_info = None
379    
380            if resource.has_gdal_support():
381                #
382                # temporarily open the file so that GDAL can test if it's valid.
383                #
384                dataset = gdal.Open(self.filename, GA_ReadOnly)
385    
386                if dataset is None:
387                    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):
508            items = []
509    
510            items.append(_("Filename: %s") % self.GetImageFilename())
511    
512            if self.Visible():
513                items.append(_("Shown"))
514            else:
515                items.append(_("Hidden"))
516    
517            bbox = self.LatLongBoundingBox()
518            if bbox is not None:
519                items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
520            else:
521                items.append(_("Extent (lat-lon):"))
522    
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            return (_("Layer '%s'") % self.Title(), items)
528    
     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)  
Legend:
Removed from v.6  
changed lines
  Added in v.2614
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