Thuban/Model/classification.py

# Copyright (c) 2001, 2003 by Intevation GmbH
# Authors:
# Jonathan Coles <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

"""
A Classification provides a mapping from an input value
to data. This mapping can be specified in two ways. 
First, specific values can be associated with data. 
Second, ranges can be associated with data such that if 
an input value falls with a range that data is returned. 
If no mapping can be found then default data will 
be returned. Input values must be hashable objects

See the description of GetGroup() for more information 
on the mapping algorithm.
"""
  
# fix for people using python2.1
from __future__ import nested_scopes

import copy

from types import *

from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
     LAYER_VISIBILITY_CHANGED

from Thuban import _
from Thuban.Model.color import Color

import Thuban.Model.layer

# constants
RANGE_MIN  = 0
RANGE_MAX  = 1
RANGE_DATA = 2

class Classification:
    """Encapsulates the classification of layer. The Classification
    divides some kind of data into Groups which are associated with
    properties. Later the properties can be retrieved by matching
    data values to the appropriate group."""

    def __init__(self, layer = None, field = None):
        """Initialize a classification.

           layer -- the Layer object who owns this classification

           field -- the name of the data table field that 
                    is to be used to classify layer properties
        """
 
        self.layer = None
        self.field = None
        self.fieldType = None
        self.groups = []

        self.__setLayerLock = False

        self.SetDefaultGroup(ClassGroupDefault())

        self.SetLayer(layer)
        self.SetField(field)

    def __iter__(self):
        return ClassIterator(self.groups) 

    def __SendNotification(self):
        """Notify the layer that this class has changed."""
        if self.layer is not None:
            self.layer.ClassChanged()
    
    def SetField(self, field):
        """Set the name of the data table field to use.
         
           If there is no layer then the field type is set to None, 
           otherwise the layer is queried to find the type of the
           field data

           field -- if None then all values map to the default data 
        """

        if field == "": 
            field = None


        if field is None:
            if self.layer is not None:
                self.fieldType = None
        else:
            if self.layer is not None:
                fieldType = self.layer.GetFieldType(field)
                if fieldType is None:
                    raise ValueError("'%s' was not found in the layer's table."
                                     % self.field)

                #
                # unfortunately we cannot call SetFieldType() because it
                # requires the layer to be None
                #
                self.fieldType = fieldType
                #self.SetFieldType(fieldType)

        self.field = field

        self.__SendNotification()

    def GetField(self):
        """Return the name of the field."""
        return self.field

    def GetFieldType(self):
        """Return the field type."""
        return self.fieldType

    def SetFieldType(self, type):
        """Set the type of the field used by this classification.

        A ValueError is raised if the owning layer is not None and
        'type' is different from the current field type.
        """

        if type != self.fieldType:
            if self.layer is not None:
                raise ValueError()
            else:
                self.fieldType = type
                self.__SendNotification()

    def SetLayer(self, layer):
        """Set the owning Layer of this classification.
 
           A ValueError exception will be thrown either the field or
           field type mismatch the information in the layer's table.
        """

        # prevent infinite recursion when calling SetClassification()
        if self.__setLayerLock: return

        self.__setLayerLock = True

        if layer is None:
            if self.layer is not None:
                l = self.layer
                self.layer = None
                l.SetClassification(None)
        else:
            assert isinstance(layer, Thuban.Model.layer.Layer)

            old_layer = self.layer

            self.layer = layer

            try:
                self.SetField(self.GetField()) # this sync's the fieldType
            except ValueError:
                self.layer = old_layer
                self.__setLayerLock = False
                raise ValueError
            else:
                self.layer.SetClassification(self)

        self.__setLayerLock = False

    def GetLayer(self):
        """Return the parent layer."""
        return self.layer

    def SetDefaultGroup(self, group):
        """Set the group to be used when a value can't be classified.

           group -- group that the value maps to.
        """

        assert isinstance(group, ClassGroupDefault)
        self.AddGroup(group)

    def GetDefaultGroup(self):
        """Return the default group."""
        return self.groups[0]

    #
    # these SetDefault* methods are really only provided for 
    # some backward compatibility. they should be considered
    # for removal once all the classification code is finished.
    #

    def SetDefaultFill(self, fill):
        """Set the default fill color.

        fill -- a Color object.
        """
        assert isinstance(fill, Color)
        self.GetDefaultGroup().GetProperties().SetFill(fill)
        self.__SendNotification()
        
    def GetDefaultFill(self):
        """Return the default fill color."""
        return self.GetDefaultGroup().GetProperties().GetFill()
        
    def SetDefaultLineColor(self, color):
        """Set the default line color.

        color -- a Color object.
        """
        assert isinstance(color, Color)
        self.GetDefaultGroup().GetProperties().SetLineColor(color)
        self.__SendNotification()
        
    def GetDefaultLineColor(self):
        """Return the default line color."""
        return self.GetDefaultGroup().GetProperties().GetLineColor()
        
    def SetDefaultLineWidth(self, lineWidth):
        """Set the default line width.

        lineWidth -- an integer > 0.
        """
        assert isinstance(lineWidth, IntType)
        self.GetDefaultGroup().GetProperties().SetLineWidth(lineWidth)
        self.__SendNotification()
        
    def GetDefaultLineWidth(self):
        """Return the default line width."""
        return self.GetDefaultGroup().GetProperties().GetLineWidth()
        
    def AddGroup(self, item):
        """Add a new ClassGroup item to the classification.

        item -- this must be a valid ClassGroup object
        """

        assert isinstance(item, ClassGroup)

        if len(self.groups) > 0 and isinstance(item, ClassGroupDefault):
            self.groups[0] = item
        else:
            self.groups.append(item)

        self.__SendNotification()

    def GetGroup(self, value):
        """Return the associated group, or the default group.

           Groups are checked in the order the were added to the
           Classification.

           value -- the value to classify. If there is no mapping,
                    the field is None or value is None, 
                    return the default properties 
        """

        if self.GetField() is not None and value is not None:

            for i in range(1, len(self.groups)):
                group = self.groups[i]
                if group.Matches(value):
                    return group

        return self.GetDefaultGroup()

    def GetProperties(self, value):
        """Return the properties associated with the given value."""

        group = self.GetGroup(value)
        if isinstance(group, ClassGroupMap):
            return group.GetPropertiesFromValue(value)
        else:
            return group.GetProperties()

    def TreeInfo(self):
        items = []

        def build_color_item(text, color):
            if color is Color.Transparent:
                return ("%s: %s" % (text, _("None")), None)

            return ("%s: (%.3f, %.3f, %.3f)" % 
                    (text, color.red, color.green, color.blue),
                    color)

        def build_item(group, string):
            label = group.GetLabel()
            if label == "":
                label = string
            else:
                label += " (%s)" % string

            props = group.GetProperties()
            i = []
            v = props.GetLineColor()
            i.append(build_color_item(_("Line Color"), v))
            v = props.GetLineWidth()
            i.append(_("Line Width: %s") % v)
            v = props.GetFill()
            i.append(build_color_item(_("Fill"), v))
            return (label, i)

        for p in self:
            if isinstance(p, ClassGroupDefault):
                items.append(build_item(self.GetDefaultGroup(), _("'DEFAULT'")))
            elif isinstance(p, ClassGroupSingleton):
                items.append(build_item(p, str(p.GetValue())))
            elif isinstance(p, ClassGroupRange):
                items.append(build_item(p, "%s - %s" % 
                                           (p.GetMin(), p.GetMax())))

        return (_("Classification"), items)
 
class ClassIterator:
    """Allows the Groups in a Classifcation to be interated over.

    The items are returned in the following order:
        default data, singletons, ranges, maps
    """

    def __init__(self, data): #default, points, ranges, maps):
        """Constructor.

        default -- the default group
 
        points -- a list of singleton groups

        ranges -- a list of range groups
 
        maps -- a list of map groups
        """

        self.data = data #[default, points, ranges, maps]
        self.data_index = 0
        #self.data_iter = iter(self.data)
        #self.iter = None

    def __iter__(self):
        return self

    def next(self):
        """Return the next item."""

        if self.data_index >= len(self.data):
            raise StopIteration
        else:
            d = self.data[self.data_index]
            self.data_index += 1
            return d
        
#       if self.iter is None:
#           try:
#               self.data_item = self.data_iter.next()
#               self.iter = iter(self.data_item)
#           except TypeError:
#               return self.data_item

#       try:
#           return self.iter.next()
#       except StopIteration:
#           self.iter = None
#           return self.next()
      
class ClassGroupProperties:
    """Represents the properties of a single Classification Group.
  
    These are used when rendering a layer."""

    def __init__(self, props = None):
        """Constructor.

        props -- a ClassGroupProperties object. The class is copied if
                 prop is not None. Otherwise, a default set of properties
                 is created such that: line color = Color.Black, line width = 1,
                 and fill color = Color.Transparent
        """

        self.stroke = None
        self.strokeWidth = 0
        self.fill = None

        if props is not None:
            self.SetProperties(props)
        else:
            self.SetLineColor(Color.Black)
            self.SetLineWidth(1)
            self.SetFill(Color.Transparent)

    def SetProperties(self, props):
        """Set this class's properties to those in class props."""

        assert isinstance(props, ClassGroupProperties)
        self.SetLineColor(props.GetLineColor())
        self.SetLineWidth(props.GetLineWidth())
        self.SetFill(props.GetFill())
        
    def GetLineColor(self):
        """Return the line color as a Color object."""
        return self.stroke

    def SetLineColor(self, color):
        """Set the line color.

        color -- the color of the line. This must be a Color object.
        """

        assert isinstance(color, Color)
        self.stroke = color

    def GetLineWidth(self):
        """Return the line width."""
        return self.strokeWidth

    def SetLineWidth(self, lineWidth):
        """Set the line width.

        lineWidth -- the new line width. This must be > 0.
        """
        assert isinstance(lineWidth, IntType)
        if (lineWidth < 1):
            raise ValueError(_("lineWidth < 1"))

        self.strokeWidth = lineWidth

    def GetFill(self):
        """Return the fill color as a Color object."""
        return self.fill
 
    def SetFill(self, fill):
        """Set the fill color.

        fill -- the color of the fill. This must be a Color object.
        """

        assert isinstance(fill, Color)
        self.fill = fill

    def __eq__(self, other):
        """Return true if 'props' has the same attributes as this class"""

        return isinstance(other, ClassGroupProperties)   \
            and self.stroke      == other.GetLineColor() \
            and self.strokeWidth == other.GetLineWidth() \
            and self.fill        == other.GetFill()

    def __ne__(self, other): 
        return not self.__eq__(other)

    def __copy__(self):
        return ClassGroupProperties(self)

    def __deepcopy__(self):
        return ClassGroupProperties(self)

class ClassGroup:
    """A base class for all Groups within a Classification"""

    def __init__(self, label = ""):
        """Constructor.

        label -- A string representing the Group's label
        """

        self.label = None

        self.SetLabel(label)

    def GetLabel(self):
        """Return the Group's label."""
        return self.label
 
    def SetLabel(self, label):
        """Set the Group's label.

        label -- a string representing the Group's label. This must
                 not be None.
        """
        assert isinstance(label, StringType)
        self.label = label

    def GetDisplayText(self):
        assert False, "GetDisplay must be overridden by subclass!"
        return ""

    def Matches(self, value):
        """Determines if this Group is associated with the given value.

        Returns False. This needs to be overridden by all subclasses.
        """
        assert False, "GetMatches must be overridden by subclass!"
        return False

    def GetProperties(self):
        """Return the properties associated with the given value.

        Returns None. This needs to be overridden by all subclasses.
        """
        assert False, "GetProperties must be overridden by subclass!"
        return None
 
    
class ClassGroupSingleton(ClassGroup):
    """A Group that is associated with a single value."""

    def __init__(self, value = 0, prop = None, label = ""):
        """Constructor.

        value -- the associated value.

        prop -- a ClassGroupProperites object. If prop is None a default
                 set of properties is created.

        label -- a label for this group.
        """
        ClassGroup.__init__(self, label)

        self.prop = None
        self.value = None

        self.SetValue(value)
        self.SetProperties(prop)

    def __copy__(self):
        return ClassGroupSingleton(self.GetValue(), 
                                   self.GetProperties(), 
                                   self.GetLabel())

    def __deepcopy__(self, memo):
        return ClassGroupSingleton(copy.copy(self.GetValue()), 
                                   copy.copy(self.GetProperties()), 
                                   copy.copy(self.GetLabel()))

    def GetValue(self):
        """Return the associated value."""
        return self.value

    def SetValue(self, value):
        """Associate this Group with the given value."""
        self.value = value

    def Matches(self, value):
        """Determine if the given value matches the associated Group value."""

        """Returns True if the value matches, False otherwise."""

        return self.value == value

    def GetProperties(self):
        """Return the Properties associated with this Group."""

        return self.prop

    def SetProperties(self, prop):
        """Set the properties associated with this Group.

        prop -- a ClassGroupProperties object. if prop is None, 
                a default set of properties is created.
        """

        if prop is None: prop = ClassGroupProperties()
        assert isinstance(prop, ClassGroupProperties)
        self.prop = prop

    def GetDisplayText(self):
        label = self.GetLabel()

        if label != "": return label

        return str(self.GetValue())

    def __eq__(self, other):
        return isinstance(other, ClassGroupSingleton) \
            and self.GetProperties() == other.GetProperties() \
            and self.GetValue() == other.GetValue()

    def __ne__(self, other):
        return not self.__eq__(other)

class ClassGroupDefault(ClassGroup):
    """The default Group. When values do not match any other
       Group within a Classification, the properties from this
       class are used."""

    def __init__(self, prop = None, label = ""):
        """Constructor.

        prop -- a ClassGroupProperites object. If prop is None a default
                 set of properties is created.

        label -- a label for this group.
        """

        ClassGroup.__init__(self, label)
        self.SetProperties(prop)

    def __copy__(self):
        return ClassGroupDefault(self.GetProperties(), self.GetLabel())

    def __deepcopy__(self, memo):
        return ClassGroupDefault(copy.copy(self.GetProperties()), 
                                 copy.copy(self.GetLabel()))

    def Matches(self, value):
        return True

    def GetProperties(self):
        """Return the Properties associated with this Group."""
        return self.prop

    def SetProperties(self, prop):
        """Set the properties associated with this Group.

        prop -- a ClassGroupProperties object. if prop is None, 
                a default set of properties is created.
        """

        if prop is None: prop = ClassGroupProperties()
        assert isinstance(prop, ClassGroupProperties)
        self.prop = prop

    def GetDisplayText(self):
        label = self.GetLabel()

        if label != "": return label

        return "DEFAULT"

    def __eq__(self, other):
        return isinstance(other, ClassGroupDefault) \
            and self.GetProperties() == other.GetProperties()

    def __ne__(self, other):
        return not self.__eq__(other)

class ClassGroupRange(ClassGroup):
    """A Group that represents a range of values that map to the same
       set of properties."""

    def __init__(self, min = 0, max = 1, prop = None, label = ""):
        """Constructor.

        The minumum value must be strictly less than the maximum.

        min -- the minimum range value

        max -- the maximum range value

        prop -- a ClassGroupProperites object. If prop is None a default
                 set of properties is created.

        label -- a label for this group.
        """

        ClassGroup.__init__(self, label)

        self.min = self.max = 0
        self.prop = None

        self.SetRange(min, max)
        self.SetProperties(prop)

    def __copy__(self):
        return ClassGroupRange(self.GetMin(), 
                               self.GetMax(), 
                               self.GetProperties(), 
                               self.GetLabel())

    def __deepcopy__(self, memo):
        return ClassGroupRange(copy.copy(self.GetMin()), 
                               copy.copy(self.GetMax()), 
                               copy.copy(self.GetProperties()), 
                               copy.copy(self.GetLabel()))

    def GetMin(self):
        """Return the range's minimum value."""
        return self.min

    def SetMin(self, min):
        """Set the range's minimum value.
     
        min -- the new minimum. Note that this must be less than the current
               maximum value. Use SetRange() to change both min and max values.
        """
     
        self.SetRange(min, self.max)

    def GetMax(self):
        """Return the range's maximum value."""
        return self.max

    def SetMax(self, max):
        """Set the range's maximum value.
     
        max -- the new maximum. Note that this must be greater than the current
               minimum value. Use SetRange() to change both min and max values.
        """
        self.SetRange(self.min, max)

    def SetRange(self, min, max):
        """Set a new range.

        Note that min must be strictly less than max.

        min -- the new minimum value
        min -- the new maximum value
        """

        if min >= max:
            raise ValueError(_("ClassGroupRange: %i(min) >= %i(max)!") %
                             (min, max))
        self.min = min
        self.max = max

    def GetRange(self):
        """Return the range as a tuple (min, max)"""
        return (self.min, self.max)

    def Matches(self, value):
        """Determine if the given value lies with the current range.

        The following check is used: min <= value < max.
        """

        return self.min <= value < self.max

    def GetProperties(self):
        """Return the Properties associated with this Group."""
        return self.prop

    def SetProperties(self, prop):
        """Set the properties associated with this Group.

        prop -- a ClassGroupProperties object. if prop is None, 
                a default set of properties is created.
        """
        if prop is None: prop = ClassGroupProperties()
        assert isinstance(prop, ClassGroupProperties)
        self.prop = prop

    def GetDisplayText(self):
        label = self.GetLabel()

        if label != "": return label

        return _("%s - %s") % (self.GetMin(), self.GetMax())

    def __eq__(self, other):
        return isinstance(other, ClassGroupRange) \
            and self.GetProperties() == other.GetProperties() \
            and self.GetRange() == other.GetRange()

    def __ne__(self, other):
        return not self.__eq__(other)

class ClassGroupMap(ClassGroup):
    """Currently, this class is not used."""

    FUNC_ID = "id"

    def __init__(self, map_type = FUNC_ID, func = None, prop = None, label=""):
        ClassGroup.__init__(self, label)

        self.map_type = map_type
        self.func = func

        if self.func is None:
            self.func = func_id

    def Map(self, value):
        return self.func(value)

    def GetProperties(self):
        return None

    def GetPropertiesFromValue(self, value):
        pass

    def GetDisplayText(self):
        return "Map: " + self.map_type

    #
    # built-in mappings
    #
    def func_id(value):
        return value

1	# Copyright (c) 2001, 2003 by Intevation GmbH
2	# Authors:
3	# Jonathan Coles <[email protected]>
4	#
5	# This program is free software under the GPL (>=v2)
6	# Read the file COPYING coming with Thuban for details.
7
8	__version__ = "$Revision$"
9
10	"""
11	A Classification provides a mapping from an input value
12	to data. This mapping can be specified in two ways.
13	First, specific values can be associated with data.
14	Second, ranges can be associated with data such that if
15	an input value falls with a range that data is returned.
16	If no mapping can be found then default data will
17	be returned. Input values must be hashable objects
18
19	See the description of GetGroup() for more information
20	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 _
34	from Thuban.Model.color import Color
35
36	import Thuban.Model.layer
37
38	# constants
39	RANGE_MIN = 0
40	RANGE_MAX = 1
41	RANGE_DATA = 2
42
43	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):
50	"""Initialize a classification.
51
52	layer -- the Layer object who owns this classification
53
54	field -- the name of the data table field that
55	is to be used to classify layer properties
56	"""
57
58	self.layer = None
59	self.field = None
60	self.fieldType = None
61	self.groups = []
62
63	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.
80
81	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
110
111	self.__SendNotification()
112
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	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	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 SetLayer(self, layer):
136	"""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	# prevent infinite recursion when calling SetClassification()
143	if self.__setLayerLock: return
144
145	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	def SetDefaultGroup(self, group):
175	"""Set the group to be used when a value can't be classified.
176
177	group -- group that the value maps to.
178	"""
179
180	assert isinstance(group, ClassGroupDefault)
181	self.AddGroup(group)
182
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.Transparent:
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.Transparent
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.Transparent)
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	def __deepcopy__(self):
454	return ClassGroupProperties(self)
455
456	class ClassGroup:
457	"""A base class for all Groups within a Classification"""
458
459	def __init__(self, label = ""):
460	"""Constructor.
461
462	label -- A string representing the Group's label
463	"""
464
465	self.label = None
466
467	self.SetLabel(label)
468
469	def GetLabel(self):
470	"""Return the Group's label."""
471	return self.label
472
473	def SetLabel(self, label):
474	"""Set the Group's label.
475
476	label -- a string representing the Group's label. This must
477	not be None.
478	"""
479	assert isinstance(label, StringType)
480	self.label = label
481
482	def GetDisplayText(self):
483	assert False, "GetDisplay must be overridden by subclass!"
484	return ""
485
486	def Matches(self, value):
487	"""Determines if this Group is associated with the given value.
488
489	Returns False. This needs to be overridden by all subclasses.
490	"""
491	assert False, "GetMatches must be overridden by subclass!"
492	return False
493
494	def GetProperties(self):
495	"""Return the properties associated with the given value.
496
497	Returns None. This needs to be overridden by all subclasses.
498	"""
499	assert False, "GetProperties must be overridden by subclass!"
500	return None
501
502
503	class ClassGroupSingleton(ClassGroup):
504	"""A Group that is associated with a single value."""
505
506	def __init__(self, value = 0, prop = None, label = ""):
507	"""Constructor.
508
509	value -- the associated value.
510
511	prop -- a ClassGroupProperites object. If prop is None a default
512	set of properties is created.
513
514	label -- a label for this group.
515	"""
516	ClassGroup.__init__(self, label)
517
518	self.prop = None
519	self.value = None
520
521	self.SetValue(value)
522	self.SetProperties(prop)
523
524	def __copy__(self):
525	return ClassGroupSingleton(self.GetValue(),
526	self.GetProperties(),
527	self.GetLabel())
528
529	def __deepcopy__(self, memo):
530	return ClassGroupSingleton(copy.copy(self.GetValue()),
531	copy.copy(self.GetProperties()),
532	copy.copy(self.GetLabel()))
533
534	def GetValue(self):
535	"""Return the associated value."""
536	return self.value
537
538	def SetValue(self, value):
539	"""Associate this Group with the given value."""
540	self.value = value
541
542	def Matches(self, value):
543	"""Determine if the given value matches the associated Group value."""
544
545	"""Returns True if the value matches, False otherwise."""
546
547	return self.value == value
548
549	def GetProperties(self):
550	"""Return the Properties associated with this Group."""
551
552	return self.prop
553
554	def SetProperties(self, prop):
555	"""Set the properties associated with this Group.
556
557	prop -- a ClassGroupProperties object. if prop is None,
558	a default set of properties is created.
559	"""
560
561	if prop is None: prop = ClassGroupProperties()
562	assert isinstance(prop, ClassGroupProperties)
563	self.prop = prop
564
565	def GetDisplayText(self):
566	label = self.GetLabel()
567
568	if label != "": return label
569
570	return str(self.GetValue())
571
572	def __eq__(self, other):
573	return isinstance(other, ClassGroupSingleton) \
574	and self.GetProperties() == other.GetProperties() \
575	and self.GetValue() == other.GetValue()
576
577	def __ne__(self, other):
578	return not self.__eq__(other)
579
580	class ClassGroupDefault(ClassGroup):
581	"""The default Group. When values do not match any other
582	Group within a Classification, the properties from this
583	class are used."""
584
585	def __init__(self, prop = None, label = ""):
586	"""Constructor.
587
588	prop -- a ClassGroupProperites object. If prop is None a default
589	set of properties is created.
590
591	label -- a label for this group.
592	"""
593
594	ClassGroup.__init__(self, label)
595	self.SetProperties(prop)
596
597	def __copy__(self):
598	return ClassGroupDefault(self.GetProperties(), self.GetLabel())
599
600	def __deepcopy__(self, memo):
601	return ClassGroupDefault(copy.copy(self.GetProperties()),
602	copy.copy(self.GetLabel()))
603
604	def Matches(self, value):
605	return True
606
607	def GetProperties(self):
608	"""Return the Properties associated with this Group."""
609	return self.prop
610
611	def SetProperties(self, prop):
612	"""Set the properties associated with this Group.
613
614	prop -- a ClassGroupProperties object. if prop is None,
615	a default set of properties is created.
616	"""
617
618	if prop is None: prop = ClassGroupProperties()
619	assert isinstance(prop, ClassGroupProperties)
620	self.prop = prop
621
622	def GetDisplayText(self):
623	label = self.GetLabel()
624
625	if label != "": return label
626
627	return "DEFAULT"
628
629	def __eq__(self, other):
630	return isinstance(other, ClassGroupDefault) \
631	and self.GetProperties() == other.GetProperties()
632
633	def __ne__(self, other):
634	return not self.__eq__(other)
635
636	class ClassGroupRange(ClassGroup):
637	"""A Group that represents a range of values that map to the same
638	set of properties."""
639
640	def __init__(self, min = 0, max = 1, prop = None, label = ""):
641	"""Constructor.
642
643	The minumum value must be strictly less than the maximum.
644
645	min -- the minimum range value
646
647	max -- the maximum range value
648
649	prop -- a ClassGroupProperites object. If prop is None a default
650	set of properties is created.
651
652	label -- a label for this group.
653	"""
654
655	ClassGroup.__init__(self, label)
656
657	self.min = self.max = 0
658	self.prop = None
659
660	self.SetRange(min, max)
661	self.SetProperties(prop)
662
663	def __copy__(self):
664	return ClassGroupRange(self.GetMin(),
665	self.GetMax(),
666	self.GetProperties(),
667	self.GetLabel())
668
669	def __deepcopy__(self, memo):
670	return ClassGroupRange(copy.copy(self.GetMin()),
671	copy.copy(self.GetMax()),
672	copy.copy(self.GetProperties()),
673	copy.copy(self.GetLabel()))
674
675	def GetMin(self):
676	"""Return the range's minimum value."""
677	return self.min
678
679	def SetMin(self, min):
680	"""Set the range's minimum value.
681
682	min -- the new minimum. Note that this must be less than the current
683	maximum value. Use SetRange() to change both min and max values.
684	"""
685
686	self.SetRange(min, self.max)
687
688	def GetMax(self):
689	"""Return the range's maximum value."""
690	return self.max
691
692	def SetMax(self, max):
693	"""Set the range's maximum value.
694
695	max -- the new maximum. Note that this must be greater than the current
696	minimum value. Use SetRange() to change both min and max values.
697	"""
698	self.SetRange(self.min, max)
699
700	def SetRange(self, min, max):
701	"""Set a new range.
702
703	Note that min must be strictly less than max.
704
705	min -- the new minimum value
706	min -- the new maximum value
707	"""
708
709	if min >= max:
710	raise ValueError(_("ClassGroupRange: %i(min) >= %i(max)!") %
711	(min, max))
712	self.min = min
713	self.max = max
714
715	def GetRange(self):
716	"""Return the range as a tuple (min, max)"""
717	return (self.min, self.max)
718
719	def Matches(self, value):
720	"""Determine if the given value lies with the current range.
721
722	The following check is used: min <= value < max.
723	"""
724
725	return self.min <= value < self.max
726
727	def GetProperties(self):
728	"""Return the Properties associated with this Group."""
729	return self.prop
730
731	def SetProperties(self, prop):
732	"""Set the properties associated with this Group.
733
734	prop -- a ClassGroupProperties object. if prop is None,
735	a default set of properties is created.
736	"""
737	if prop is None: prop = ClassGroupProperties()
738	assert isinstance(prop, ClassGroupProperties)
739	self.prop = prop
740
741	def GetDisplayText(self):
742	label = self.GetLabel()
743
744	if label != "": return label
745
746	return _("%s - %s") % (self.GetMin(), self.GetMax())
747
748	def __eq__(self, other):
749	return isinstance(other, ClassGroupRange) \
750	and self.GetProperties() == other.GetProperties() \
751	and self.GetRange() == other.GetRange()
752
753	def __ne__(self, other):
754	return not self.__eq__(other)
755
756	class ClassGroupMap(ClassGroup):
757	"""Currently, this class is not used."""
758
759	FUNC_ID = "id"
760
761	def __init__(self, map_type = FUNC_ID, func = None, prop = None, label=""):
762	ClassGroup.__init__(self, label)
763
764	self.map_type = map_type
765	self.func = func
766
767	if self.func is None:
768	self.func = func_id
769
770	def Map(self, value):
771	return self.func(value)
772
773	def GetProperties(self):
774	return None
775
776	def GetPropertiesFromValue(self, value):
777	pass
778
779	def GetDisplayText(self):
780	return "Map: " + self.map_type
781
782	#
783	# built-in mappings
784	#
785	def func_id(value):
786	return value
787
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