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 FindGroup() for more information 
on the mapping algorithm.
"""
  
import copy, operator, types

from Thuban import _

from messages import \
    LAYER_PROJECTION_CHANGED, \
    LAYER_LEGEND_CHANGED, \
    LAYER_VISIBILITY_CHANGED

from Thuban.Model.color import Color, Transparent, Black
from Thuban.Model.range import Range

import Thuban.Model.layer

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.SetDefaultGroup(ClassGroupDefault())

        self.SetFieldInfo(field, None)

        self._set_layer(layer)

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

    def __deepcopy__(self, memo):
        clazz = Classification()

        # note: the only thing that isn't copied is the layer reference
        clazz.field = self.field
        clazz.fieldType = self.fieldType
        clazz.__groups[0] = copy.deepcopy(self.__groups[0])

        for i in range(1, len(self.__groups)):
            clazz.__groups.append(copy.deepcopy(self.__groups[i]))

        return clazz

    def __SendNotification(self):
        """Notify the layer that this class has changed."""
        if self.layer is not None:
            self.layer.ClassChanged()
    
    def GetField(self):
        """Return the name of the field."""
        return self.field

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

    def SetFieldInfo(self, name, type):
        """Set the classified field name to 'name' and it's field
        type to 'type'
 
        If this classification has an owning layer a ValueError 
        exception will be thrown either the field or field type 
        mismatch the information in the layer's table.

        If the field info is successful set and the class has
        an owning layer, the layer will be informed that the
        classification has changed.
        """

        if name == "":
            name = None

        if self.layer is None:
            self.field = name
            self.fieldType = type
        elif name is None:
            self.field = None
            self.fieldType = None
        else:
            #
            # verify that the field exists in the layer and that
            # the type is correct.
            #
            fieldType = self.layer.GetFieldType(name)
            if fieldType is None:
                raise ValueError("'%s' was not found in the layer's table."
                                 % self.field)
            elif type is not None and fieldType != type:
                raise ValueError("type doesn't match layer's field type for %s"
                                 % self.field)

            self.field = name
            self.fieldType = fieldType

        self.__SendNotification()

    def _set_layer(self, layer):
        """Internal: 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.

        If the layer is successful set, the layer will be informed 
        that the classification has changed.
        """

        if layer is None:
            self.layer = None
        else:
            old_layer = self.layer
            self.layer = layer

            try:
                # this sync's the fieldType
                # and sends a notification to the layer
                self.SetFieldInfo(self.GetField(), None)
            except ValueError:
                self.layer = old_layer
                raise ValueError

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

    #
    # 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.
        """
        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.
        """
        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, types.IntType)
        self.GetDefaultGroup().GetProperties().SetLineWidth(lineWidth)
        self.__SendNotification()
        
    def GetDefaultLineWidth(self):
        """Return the default line width."""
        return self.GetDefaultGroup().GetProperties().GetLineWidth()
        

    #
    # The methods that manipulate self.__groups have to be kept in
    # sync. We store the default group in index 0 to make it
    # convienent to iterate over the classification's groups, but
    # from the user's perspective the first (non-default) group is
    # at index 0 and the DefaultGroup is a special entity.
    #

    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)
        if len(self.__groups) > 0:
            self.__groups[0] = group
        else:
            self.__groups.append(group)

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

    def AppendGroup(self, item):
        """Append a new ClassGroup item to the classification.

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

        self.InsertGroup(self.GetNumGroups(), item)

    def InsertGroup(self, index, group):
        
        assert isinstance(group, ClassGroup)

        self.__groups.insert(index + 1, group)

        self.__SendNotification()

    def RemoveGroup(self, index):
        return self.__groups.pop(index + 1)

    def ReplaceGroup(self, index, group):
        assert isinstance(group, ClassGroup)

        self.__groups[index + 1] = group

        self.__SendNotification()

    def GetGroup(self, index):
        return self.__groups[index + 1]

    def GetNumGroups(self):
        """Return the number of non-default groups in the classification."""
        return len(self.__groups) - 1


    def FindGroup(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.
       
        Use this function rather than Classification.FindGroup().GetProperties()
        since the returned group may be a ClassGroupMap which doesn't support
        a call to GetProperties(). 
        """

        group = self.FindGroup(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 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:
            items.append(build_item(p, p.GetDisplayText()))

#           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 = Black, line width = 1,
                 and fill color = Transparent
        """

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

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

        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, types.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.
        """

        self.__fill = fill

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

        #
        # using 'is' over '==' results in a huge performance gain
        # in the renderer
        #
        return isinstance(other, ClassGroupProperties)   \
            and (self.__stroke is other.__stroke or      \
                 self.__stroke == other.__stroke)        \
            and (self.__fill is other.__fill or          \
                 self.__fill == other.__fill)            \
            and self.__strokeWidth == other.__strokeWidth

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

    def __copy__(self):
        return ClassGroupProperties(self)

    def __deepcopy__(self):
        return ClassGroupProperties(self)

    def __repr__(self):
        return repr((self.__stroke, self.__strokeWidth, self.__fill))

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

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

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

        if group is not None:
            self.SetLabel(copy.copy(group.GetLabel()))
            self.SetProperties(copy.copy(group.GetProperties()))
            self.SetVisible(group.IsVisible())
        else:
            self.SetLabel(label)
            self.SetProperties(props)
            self.SetVisible(True)

    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, types.StringTypes)
        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."""

        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 IsVisible(self):
        return self.visible

    def SetVisible(self, visible):
        self.visible = visible

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

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

    def __repr__(self):
        return repr(self.label) + ", " + repr(self.GetProperties())
    
class ClassGroupSingleton(ClassGroup):
    """A Group that is associated with a single value."""

    def __init__(self, value = 0, props = None, label = "", group = None):
        """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, props, group)

        self.SetValue(value)

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

    def __deepcopy__(self, memo):
        return ClassGroupSingleton(self.GetValue(), group = self)

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

        if label != "": return label

        return str(self.GetValue())

    def __eq__(self, other):
        return ClassGroup.__eq__(self, other) \
            and isinstance(other, ClassGroupSingleton) \
            and self.__value == other.__value

    def __repr__(self): 
        return "(" + repr(self.__value) + ", " + ClassGroup.__repr__(self) + ")"

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, props = None, label = "", group = None):
        """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, props, group)

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

    def __deepcopy__(self, memo):
        return ClassGroupDefault(label = self.GetLabel(), group = self)

    def Matches(self, value):
        return True

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

        if label != "": return label

        return _("DEFAULT")

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

    def __repr__(self): 
        return "(" + ClassGroup.__repr__(self) + ")"

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, props = None, label = "", group=None):
        """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, props, group)

        #self.__min = self.__max = 0
        #self.__range = Range("[" + repr(float(min)) + ";" + 
                                   #repr(float(max)) + "[")
        self.SetRange(min, max)

    def __copy__(self):
        return ClassGroupRange(min = self.__range,
                               max = None, 
                               props = self.GetProperties(), 
                               label = self.GetLabel())

    def __deepcopy__(self, memo):
        return ClassGroupRange(min = copy.copy(self.__range), 
                               max = copy.copy(self.GetMax()), 
                               group = self)

    def GetMin(self):
        """Return the range's minimum value."""
        return self.__range.GetRange()[1]

    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.__range.GetRange()[2])

    def GetMax(self):
        """Return the range's maximum value."""
        return self.__range.GetRange()[2]

    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.__range.GetRange()[1], max)

    def SetRange(self, min, max = None):
        """Set a new range.

        Note that min must be strictly less than max.

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

        if isinstance(min, Range):
            self.__range = min
        else:
            if max is None:
                raise ValueError()

            self.__range = Range(("[", min, max, "["))

    def GetRange(self):
        """Return the range as a string"""
        #return (self.__min, self.__max)
        return self.__range.string(self.__range.GetRange())

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

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

        return operator.contains(self.__range, value)
        #return self.__min <= value < self.__max

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

        if label != "": return label

        #return _("%s - %s") % (self.GetMin(), self.GetMax())
        #return repr(self.__range)
        return self.__range.string(self.__range.GetRange())

    def __eq__(self, other):
        return ClassGroup.__eq__(self, other) \
            and isinstance(other, ClassGroupRange) \
            and self.__range == other.__range
            #and self.__min == other.__min \
            #and self.__max == other.__max

    def __repr__(self): 
        return "(" + str(self.__range) + ClassGroup.__repr__(self) + ")"
        #return "(" + repr(self.__min) + ", " + repr(self.__max) + ", " + \
               #ClassGroup.__repr__(self) + ")"

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

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