/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/classification.py
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revision 378 by jonathan, Tue Jan 28 12:13:28 2003 UTC revision 544 by jonathan, Thu Mar 20 09:43:48 2003 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001 by Intevation GmbH  # Copyright (c) 2001, 2003 by Intevation GmbH
2  # Authors:  # Authors:
3  # Jonathan Coles <[email protected]>  # Jonathan Coles <[email protected]>
4  #  #
# Line 13  to data. This mapping can be specified i Line 13  to data. This mapping can be specified i
13  First, specific values can be associated with data.  First, specific values can be associated with data.
14  Second, ranges can be associated with data such that if  Second, ranges can be associated with data such that if
15  an input value falls with a range that data is returned.  an input value falls with a range that data is returned.
16  If no mapping can be found then a NullData data will  If no mapping can be found then default data will
17  be returned. Input values must be hashable objects  be returned. Input values must be hashable objects
18    
19  See the description of getProperties() for more information  See the description of GetGroup() for more information
20  on the mapping algorithm.  on the mapping algorithm.
21  """  """
22        
23    # fix for people using python2.1
24    from __future__ import nested_scopes
25    
26    import copy
27    
28    from types import *
29    
30    from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
31         LAYER_VISIBILITY_CHANGED
32    
33  from Thuban import _  from Thuban import _
34    from Thuban.Model.color import Color
35    
36    import Thuban.Model.layer
37    
38  # constants  # constants
39  RANGE_MIN  = 0  RANGE_MIN  = 0
# Line 28  RANGE_MAX  = 1 Line 41  RANGE_MAX  = 1
41  RANGE_DATA = 2  RANGE_DATA = 2
42    
43  class Classification:  class Classification:
44        """Encapsulates the classification of layer. The Classification
45        divides some kind of data into Groups which are associated with
46        properties. Later the properties can be retrieved by matching
47        data values to the appropriate group."""
48    
49        def __init__(self, layer = None, field = None):
     def __init__(self, field = None):  
50          """Initialize a classification.          """Initialize a classification.
51    
52               layer -- the Layer object who owns this classification
53    
54             field -- the name of the data table field that             field -- the name of the data table field that
55                      is to be used to classify layer properties                      is to be used to classify layer properties
56          """          """
57    
58          self.points = {}          self.layer = None
59          self.ranges = []          self.field = None
60          self.setField(field)          self.fieldType = None
61          self.setNull(None)          self.groups = []
62            
63      def setField(self, field):          self.__setLayerLock = False
64    
65            self.SetDefaultGroup(ClassGroupDefault())
66    
67            self.SetLayer(layer)
68            self.SetField(field)
69    
70        def __iter__(self):
71            return ClassIterator(self.groups)
72    
73        def __SendNotification(self):
74            """Notify the layer that this class has changed."""
75            if self.layer is not None:
76                self.layer.ClassChanged()
77        
78        def SetField(self, field):
79          """Set the name of the data table field to use.          """Set the name of the data table field to use.
80                    
81             field -- if None then all values map to NullData             If there is no layer then the field type is set to None,
82               otherwise the layer is queried to find the type of the
83               field data
84    
85               field -- if None then all values map to the default data
86          """          """
87    
88            if field == "":
89                field = None
90    
91    
92            if field is None:
93                if self.layer is not None:
94                    self.fieldType = None
95            else:
96                if self.layer is not None:
97                    fieldType = self.layer.GetFieldType(field)
98                    if fieldType is None:
99                        raise ValueError("'%s' was not found in the layer's table."
100                                         % self.field)
101    
102                    #
103                    # unfortunately we cannot call SetFieldType() because it
104                    # requires the layer to be None
105                    #
106                    self.fieldType = fieldType
107                    #self.SetFieldType(fieldType)
108    
109          self.field = field          self.field = field
110    
111      def setNull(self, data):          self.__SendNotification()
112          """Set the data to be used when a value can't be classified.  
113        def GetField(self):
114            """Return the name of the field."""
115            return self.field
116    
117        def GetFieldType(self):
118            """Return the field type."""
119            return self.fieldType
120    
121             data -- data that the value maps to. See class description.      def SetFieldType(self, type):
122            """Set the type of the field used by this classification.
123    
124            A ValueError is raised if the owning layer is not None and
125            'type' is different from the current field type.
126          """          """
127    
128          self.NullData = data          if type != self.fieldType:
129                if self.layer is not None:
130                    raise ValueError()
131                else:
132                    self.fieldType = type
133                    self.__SendNotification()
134    
135      def addRange(self, min, max, data):      def SetLayer(self, layer):
136          """Add a new range to the classification.          """Set the owning Layer of this classification.
137    
138               A ValueError exception will be thrown either the field or
139               field type mismatch the information in the layer's table.
140            """
141    
142             A range allows a value to be classified if it falls between          # prevent infinite recursion when calling SetClassification()
143             min and max. Specifically, min <= value < max          if self.__setLayerLock: return
144            
145             min -- the lower bound.          self.__setLayerLock = True
146    
147            if layer is None:
148                if self.layer is not None:
149                    l = self.layer
150                    self.layer = None
151                    l.SetClassification(None)
152            else:
153                assert(isinstance(layer, Thuban.Model.layer.Layer))
154    
155                old_layer = self.layer
156    
157                self.layer = layer
158    
159                try:
160                    self.SetField(self.GetField()) # this sync's the fieldType
161                except ValueError:
162                    self.layer = old_layer
163                    self.__setLayerLock = False
164                    raise ValueError
165                else:
166                    self.layer.SetClassification(self)
167    
168            self.__setLayerLock = False
169    
170        def GetLayer(self):
171            """Return the parent layer."""
172            return self.layer
173    
174             max -- the upper bound.      def SetDefaultGroup(self, group):
175            """Set the group to be used when a value can't be classified.
176    
177             data -- data that the value maps to. See class description.             group -- group that the value maps to.
178          """          """
179    
180          if min >= max:          assert(isinstance(group, ClassGroupDefault))
181              raise ValueError(_("Range minimum >= maximum!"))          self.AddGroup(group)
182          self.ranges.append([min, max, data])  
183        def GetDefaultGroup(self):
184            """Return the default group."""
185            return self.groups[0]
186    
187        #
188        # these SetDefault* methods are really only provided for
189        # some backward compatibility. they should be considered
190        # for removal once all the classification code is finished.
191        #
192    
193        def SetDefaultFill(self, fill):
194            """Set the default fill color.
195    
196            fill -- a Color object.
197            """
198            assert(isinstance(fill, Color))
199            self.GetDefaultGroup().GetProperties().SetFill(fill)
200            self.__SendNotification()
201            
202        def GetDefaultFill(self):
203            """Return the default fill color."""
204            return self.GetDefaultGroup().GetProperties().GetFill()
205            
206        def SetDefaultLineColor(self, color):
207            """Set the default line color.
208    
209            color -- a Color object.
210            """
211            assert(isinstance(color, Color))
212            self.GetDefaultGroup().GetProperties().SetLineColor(color)
213            self.__SendNotification()
214            
215        def GetDefaultLineColor(self):
216            """Return the default line color."""
217            return self.GetDefaultGroup().GetProperties().GetLineColor()
218            
219        def SetDefaultLineWidth(self, lineWidth):
220            """Set the default line width.
221    
222            lineWidth -- an integer > 0.
223            """
224            assert(isinstance(lineWidth, IntType))
225            self.GetDefaultGroup().GetProperties().SetLineWidth(lineWidth)
226            self.__SendNotification()
227            
228        def GetDefaultLineWidth(self):
229            """Return the default line width."""
230            return self.GetDefaultGroup().GetProperties().GetLineWidth()
231            
232        def AddGroup(self, item):
233            """Add a new ClassGroup item to the classification.
234    
235            item -- this must be a valid ClassGroup object
236            """
237    
238            assert(isinstance(item, ClassGroup))
239    
240            if len(self.groups) > 0 and isinstance(item, ClassGroupDefault):
241                self.groups[0] = item
242            else:
243                self.groups.append(item)
244    
245            self.__SendNotification()
246    
247        def GetGroup(self, value):
248            """Return the associated group, or the default group.
249    
250               Groups are checked in the order the were added to the
251               Classification.
252    
253               value -- the value to classify. If there is no mapping,
254                        the field is None or value is None,
255                        return the default properties
256            """
257    
258            if self.GetField() is not None and value is not None:
259    
260                for i in range(1, len(self.groups)):
261                    group = self.groups[i]
262                    if group.Matches(value):
263                        return group
264    
265            return self.GetDefaultGroup()
266    
267        def GetProperties(self, value):
268            """Return the properties associated with the given value."""
269    
270            group = self.GetGroup(value)
271            if isinstance(group, ClassGroupMap):
272                return group.GetPropertiesFromValue(value)
273            else:
274                return group.GetProperties()
275    
276        def TreeInfo(self):
277            items = []
278    
279            def build_color_item(text, color):
280                if color is Color.None:
281                    return ("%s: %s" % (text, _("None")), None)
282    
283                return ("%s: (%.3f, %.3f, %.3f)" %
284                        (text, color.red, color.green, color.blue),
285                        color)
286    
287            def build_item(group, string):
288                label = group.GetLabel()
289                if label == "":
290                    label = string
291                else:
292                    label += " (%s)" % string
293    
294                props = group.GetProperties()
295                i = []
296                v = props.GetLineColor()
297                i.append(build_color_item(_("Line Color"), v))
298                v = props.GetLineWidth()
299                i.append(_("Line Width: %s") % v)
300                v = props.GetFill()
301                i.append(build_color_item(_("Fill"), v))
302                return (label, i)
303    
304            for p in self:
305                if isinstance(p, ClassGroupDefault):
306                    items.append(build_item(self.GetDefaultGroup(), _("'DEFAULT'")))
307                elif isinstance(p, ClassGroupSingleton):
308                    items.append(build_item(p, str(p.GetValue())))
309                elif isinstance(p, ClassGroupRange):
310                    items.append(build_item(p, "%s - %s" %
311                                               (p.GetMin(), p.GetMax())))
312    
313            return (_("Classification"), items)
314    
315    class ClassIterator:
316        """Allows the Groups in a Classifcation to be interated over.
317    
318        The items are returned in the following order:
319            default data, singletons, ranges, maps
320        """
321    
322        def __init__(self, data): #default, points, ranges, maps):
323            """Constructor.
324    
325            default -- the default group
326    
327            points -- a list of singleton groups
328    
329            ranges -- a list of range groups
330    
331            maps -- a list of map groups
332            """
333    
334            self.data = data #[default, points, ranges, maps]
335            self.data_index = 0
336            #self.data_iter = iter(self.data)
337            #self.iter = None
338    
339        def __iter__(self):
340            return self
341    
342        def next(self):
343            """Return the next item."""
344    
345            if self.data_index >= len(self.data):
346                raise StopIteration
347            else:
348                d = self.data[self.data_index]
349                self.data_index += 1
350                return d
351            
352    #       if self.iter is None:
353    #           try:
354    #               self.data_item = self.data_iter.next()
355    #               self.iter = iter(self.data_item)
356    #           except TypeError:
357    #               return self.data_item
358    
359    #       try:
360    #           return self.iter.next()
361    #       except StopIteration:
362    #           self.iter = None
363    #           return self.next()
364          
365    class ClassGroupProperties:
366        """Represents the properties of a single Classification Group.
367      
368        These are used when rendering a layer."""
369    
370        def __init__(self, props = None):
371            """Constructor.
372    
373            props -- a ClassGroupProperties object. The class is copied if
374                     prop is not None. Otherwise, a default set of properties
375                     is created such that: line color = Color.Black, line width = 1,
376                     and fill color = Color.None
377            """
378    
379            self.stroke = None
380            self.strokeWidth = 0
381            self.fill = None
382    
383            if props is not None:
384                self.SetProperties(props)
385            else:
386                self.SetLineColor(Color.Black)
387                self.SetLineWidth(1)
388                self.SetFill(Color.None)
389    
390        def SetProperties(self, props):
391            """Set this class's properties to those in class props."""
392    
393            assert(isinstance(props, ClassGroupProperties))
394            self.SetLineColor(props.GetLineColor())
395            self.SetLineWidth(props.GetLineWidth())
396            self.SetFill(props.GetFill())
397            
398        def GetLineColor(self):
399            """Return the line color as a Color object."""
400            return self.stroke
401    
402        def SetLineColor(self, color):
403            """Set the line color.
404    
405            color -- the color of the line. This must be a Color object.
406            """
407    
408            assert(isinstance(color, Color))
409            self.stroke = color
410    
411        def GetLineWidth(self):
412            """Return the line width."""
413            return self.strokeWidth
414    
415        def SetLineWidth(self, lineWidth):
416            """Set the line width.
417    
418            lineWidth -- the new line width. This must be > 0.
419            """
420            assert(isinstance(lineWidth, IntType))
421            if (lineWidth < 1):
422                raise ValueError(_("lineWidth < 1"))
423    
424            self.strokeWidth = lineWidth
425    
426        def GetFill(self):
427            """Return the fill color as a Color object."""
428            return self.fill
429    
430        def SetFill(self, fill):
431            """Set the fill color.
432    
433            fill -- the color of the fill. This must be a Color object.
434            """
435    
436            assert(isinstance(fill, Color))
437            self.fill = fill
438    
439        def __eq__(self, other):
440            """Return true if 'props' has the same attributes as this class"""
441    
442            return isinstance(other, ClassGroupProperties)   \
443                and self.stroke      == other.GetLineColor() \
444                and self.strokeWidth == other.GetLineWidth() \
445                and self.fill        == other.GetFill()
446    
447        def __ne__(self, other):
448            return not self.__eq__(other)
449    
450        def __copy__(self):
451            return ClassGroupProperties(self)
452    
453    class ClassGroup:
454        """A base class for all Groups within a Classification"""
455    
456        def __init__(self, label = ""):
457            """Constructor.
458    
459            label -- A string representing the Group's label
460            """
461    
462            self.label = None
463    
464            self.SetLabel(label)
465    
466      def addPoint(self, value, data):      def GetLabel(self):
467          """Associate a single value with data.          """Return the Group's label."""
468            return self.label
469    
470        def SetLabel(self, label):
471            """Set the Group's label.
472    
473            label -- a string representing the Group's label. This must
474                     not be None.
475            """
476            assert(isinstance(label, StringType))
477            self.label = label
478    
479        def GetDisplayText(self):
480            assert(False, "GetDisplay must be overridden by subclass!")
481            return ""
482    
483        def Matches(self, value):
484            """Determines if this Group is associated with the given value.
485    
486            Returns False. This needs to be overridden by all subclasses.
487            """
488            assert(False, "GetMatches must be overridden by subclass!")
489            return False
490    
491        def GetProperties(self):
492            """Return the properties associated with the given value.
493    
494            Returns None. This needs to be overridden by all subclasses.
495            """
496            assert(False, "GetProperties must be overridden by subclass!")
497            return None
498    
499        
500    class ClassGroupSingleton(ClassGroup):
501        """A Group that is associated with a single value."""
502    
503             When this value is to be classified data will be returned.      def __init__(self, value = 0, prop = None, label = ""):
504            """Constructor.
505    
506             value -- classification value.          value -- the associated value.
507    
508             data  -- data that the value maps to. See class description.          prop -- a ClassGroupProperites object. If prop is None a default
509                     set of properties is created.
510    
511            label -- a label for this group.
512          """          """
513            ClassGroup.__init__(self, label)
514    
515            self.prop = None
516            self.value = None
517    
518            self.SetValue(value)
519            self.SetProperties(prop)
520    
521        def __copy__(self):
522            return ClassGroupSingleton(self.GetValue(),
523                                       self.GetProperties(),
524                                       self.GetLabel())
525    
526        def __deepcopy__(self, memo):
527            return ClassGroupSingleton(copy.copy(self.GetValue()),
528                                       copy.copy(self.GetProperties()),
529                                       copy.copy(self.GetLabel()))
530    
531        def GetValue(self):
532            """Return the associated value."""
533            return self.value
534    
535          self.points[value] = data      def SetValue(self, value):
536            """Associate this Group with the given value."""
537            self.value = value
538    
539      def getProperties(self, value):      def Matches(self, value):
540          """Return the associated data, or the NullData.          """Determine if the given value matches the associated Group value."""
541    
542             The following search technique is used:          """Returns True if the value matches, False otherwise."""
                (1) if the field is None, return NullData  
                (2) check if the value exists as a single value  
                (3) check if the value falls within a range. Ranges  
                    are checked in the order they were added to  
                    the classification.  
543    
544             value -- the value to classify. If there is no mapping          return self.value == value
545                      return the NullData (which may be None)  
546        def GetProperties(self):
547            """Return the Properties associated with this Group."""
548    
549            return self.prop
550    
551        def SetProperties(self, prop):
552            """Set the properties associated with this Group.
553    
554            prop -- a ClassGroupProperties object. if prop is None,
555                    a default set of properties is created.
556          """          """
557    
558          if self.field is not None:          if prop is None: prop = ClassGroupProperties()
559              #          assert(isinstance(prop, ClassGroupProperties))
560              # first check the discrete values          self.prop = prop
561              #  
562              if self.points.has_key(value):      def GetDisplayText(self):
563                  return self.points[value]          label = self.GetLabel()
564    
565            if label != "": return label
566    
567            return str(self.GetValue())
568    
569        def __eq__(self, other):
570            return isinstance(other, ClassGroupSingleton) \
571                and self.GetProperties() == other.GetProperties() \
572                and self.GetValue() == other.GetValue()
573    
574        def __ne__(self, other):
575            return not self.__eq__(other)
576    
577    class ClassGroupDefault(ClassGroup):
578        """The default Group. When values do not match any other
579           Group within a Classification, the properties from this
580           class are used."""
581    
582        def __init__(self, prop = None, label = ""):
583            """Constructor.
584    
585            prop -- a ClassGroupProperites object. If prop is None a default
586                     set of properties is created.
587    
588            label -- a label for this group.
589            """
590    
591            ClassGroup.__init__(self, label)
592            self.SetProperties(prop)
593    
594        def __copy__(self):
595            return ClassGroupDefault(self.GetProperties(), self.GetLabel())
596    
597        def __deepcopy__(self, memo):
598            return ClassGroupDefault(copy.copy(self.GetProperties()),
599                                     copy.copy(self.GetLabel()))
600    
601        def Matches(self, value):
602            return True
603    
604        def GetProperties(self):
605            """Return the Properties associated with this Group."""
606            return self.prop
607    
608        def SetProperties(self, prop):
609            """Set the properties associated with this Group.
610    
611            prop -- a ClassGroupProperties object. if prop is None,
612                    a default set of properties is created.
613            """
614    
615            if prop is None: prop = ClassGroupProperties()
616            assert(isinstance(prop, ClassGroupProperties))
617            self.prop = prop
618    
619        def GetDisplayText(self):
620            label = self.GetLabel()
621    
622            if label != "": return label
623    
624            return "DEFAULT"
625    
626        def __eq__(self, other):
627            return isinstance(other, ClassGroupDefault) \
628                and self.GetProperties() == other.GetProperties()
629    
630        def __ne__(self, other):
631            return not self.__eq__(other)
632    
633    class ClassGroupRange(ClassGroup):
634        """A Group that represents a range of values that map to the same
635           set of properties."""
636    
637        def __init__(self, min = 0, max = 1, prop = None, label = ""):
638            """Constructor.
639    
640            The minumum value must be strictly less than the maximum.
641    
642            min -- the minimum range value
643    
644            max -- the maximum range value
645    
646            prop -- a ClassGroupProperites object. If prop is None a default
647                     set of properties is created.
648    
649            label -- a label for this group.
650            """
651    
652            ClassGroup.__init__(self, label)
653    
654            self.min = self.max = 0
655            self.prop = None
656    
657            self.SetRange(min, max)
658            self.SetProperties(prop)
659    
660        def __copy__(self):
661            return ClassGroupRange(self.GetMin(),
662                                   self.GetMax(),
663                                   self.GetProperties(),
664                                   self.GetLabel())
665    
666        def __deepcopy__(self, memo):
667            return ClassGroupRange(copy.copy(self.GetMin()),
668                                   copy.copy(self.GetMax()),
669                                   copy.copy(self.GetProperties()),
670                                   copy.copy(self.GetLabel()))
671    
672        def GetMin(self):
673            """Return the range's minimum value."""
674            return self.min
675    
676        def SetMin(self, min):
677            """Set the range's minimum value.
678        
679            min -- the new minimum. Note that this must be less than the current
680                   maximum value. Use SetRange() to change both min and max values.
681            """
682        
683            self.SetRange(min, self.max)
684    
685        def GetMax(self):
686            """Return the range's maximum value."""
687            return self.max
688    
689        def SetMax(self, max):
690            """Set the range's maximum value.
691        
692            max -- the new maximum. Note that this must be greater than the current
693                   minimum value. Use SetRange() to change both min and max values.
694            """
695            self.SetRange(self.min, max)
696    
697        def SetRange(self, min, max):
698            """Set a new range.
699    
700            Note that min must be strictly less than max.
701    
702            min -- the new minimum value
703            min -- the new maximum value
704            """
705    
706            if min >= max:
707                raise ValueError(_("ClassGroupRange: %i(min) >= %i(max)!") %
708                                 (min, max))
709            self.min = min
710            self.max = max
711    
712        def GetRange(self):
713            """Return the range as a tuple (min, max)"""
714            return (self.min, self.max)
715    
716        def Matches(self, value):
717            """Determine if the given value lies with the current range.
718    
719            The following check is used: min <= value < max.
720            """
721    
722            return self.min <= value < self.max
723    
724        def GetProperties(self):
725            """Return the Properties associated with this Group."""
726            return self.prop
727    
728        def SetProperties(self, prop):
729            """Set the properties associated with this Group.
730    
731            prop -- a ClassGroupProperties object. if prop is None,
732                    a default set of properties is created.
733            """
734            if prop is None: prop = ClassGroupProperties()
735            assert(isinstance(prop, ClassGroupProperties))
736            self.prop = prop
737    
738        def GetDisplayText(self):
739            label = self.GetLabel()
740    
741            if label != "": return label
742    
743            return _("%s - %s") % (self.GetMin(), self.GetMax())
744    
745        def __eq__(self, other):
746            return isinstance(other, ClassGroupRange) \
747                and self.GetProperties() == other.GetProperties() \
748                and self.GetRange() == other.GetRange()
749    
750        def __ne__(self, other):
751            return not self.__eq__(other)
752    
753    class ClassGroupMap(ClassGroup):
754        """Currently, this class is not used."""
755    
756        FUNC_ID = "id"
757    
758        def __init__(self, map_type = FUNC_ID, func = None, prop = None, label=""):
759            ClassGroup.__init__(self, label)
760    
761            self.map_type = map_type
762            self.func = func
763    
764            if self.func is None:
765                self.func = func_id
766    
767        def Map(self, value):
768            return self.func(value)
769    
770              #      def GetProperties(self):
771              # now check the ranges          return None
             #  
             for p in self.ranges:  
                 if (p[RANGE_MIN] <= value) and (value < p[RANGE_MAX]):  
                     return p[RANGE_DATA]  
772    
773        def GetPropertiesFromValue(self, value):
774            pass
775    
776          return self.NullData      def GetDisplayText(self):
777            return "Map: " + self.map_type
778    
779        #
780        # built-in mappings
781        #
782        def func_id(value):
783            return value
784    

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