gramps/src/gen/lib/attrbase.py

#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2000-2006  Donald N. Allingham
# Copyright (C) 2010       Michiel D. Nauta
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

# $Id$

"""
AttributeBase class for GRAMPS.
"""

#-------------------------------------------------------------------------
#
# GRAMPS modules
#
#-------------------------------------------------------------------------
from gen.lib.attribute import Attribute
from gen.lib.const import IDENTICAL, EQUAL

#-------------------------------------------------------------------------
#
# AttributeBase class
#
#-------------------------------------------------------------------------
class AttributeBase(object):
    """
    Base class for attribute-aware objects.
    """

    def __init__(self, source=None):
        """
        Initialize a AttributeBase. 
        
        If the source is not None, then object is initialized from values of 
        the source object.

        :param source: Object used to initialize the new object
        :type source: AttributeBase
        """
        if source:
            self.attribute_list = [Attribute(attribute)
                                    for attribute in source.attribute_list]
        else:
            self.attribute_list = []

    def serialize(self):
        """
        Convert the object to a serialized tuple of data.
        """
        return [attr.serialize() for attr in self.attribute_list]

    def unserialize(self, data):
        """
        Convert a serialized tuple of data to an object.
        """
        self.attribute_list = [Attribute().unserialize(item) for item in data]

    def add_attribute(self, attribute):
        """
        Add the :class:`~gen.lib.attribute.Attribute` instance to the object's list of attributes.

        :param attribute: :class:`~gen.lib.attribute.Attribute` instance to add.
        :type attribute: :class:`~gen.lib.attribute.Attribute`
        """
        assert not isinstance(attribute, unicode)
        self.attribute_list.append(attribute)

    def remove_attribute(self, attribute):
        """
        Remove the specified :class:`~gen.lib.attribute.Attribute` instance from the attribute list.
        
        If the instance does not exist in the list, the operation has
        no effect.

        :param attribute: :class:`~gen.lib.attribute.Attribute` instance to remove from the list
        :type attribute: :class:`~gen.lib.attribute.Attribute`

        :returns: True if the attribute was removed, False if it was not
            in the list.
        :rtype: bool
        """
        if attribute in self.attribute_list:
            self.attribute_list.remove(attribute)
            return True
        else:
            return False

    def get_attribute_list(self):
        """
        Return the list of :class:`~gen.lib.attribute.Attribute` instances associated with the object.
        
        :returns: Returns the list of :class:`~gen.lib.attribute.Attribute` instances.
        :rtype: list
        """
        return self.attribute_list

    def set_attribute_list(self, attribute_list):
        """
        Assign the passed list to the Person's list of :class:`~gen.lib.attribute.Attribute` instances.

        :param attribute_list: List of :class:`~gen.lib.attribute.Attribute` instances to ba associated
            with the Person
        :type attribute_list: list
        """
        self.attribute_list = attribute_list

    def _merge_attribute_list(self, acquisition):
        """
        Merge the list of attributes from acquisition with our own.

        :param acquisition: the attribute list of this object will be merged
            with the current attribute list.
        :rtype acquisition: AttributeBase
        """
        attr_list = self.attribute_list[:]
        for addendum in acquisition.get_attribute_list():
            for attr in attr_list:
                equi = attr.is_equivalent(addendum)
                if equi == IDENTICAL:
                    break
                elif equi == EQUAL:
                    attr.merge(addendum)
                    break
            else:
                self.attribute_list.append(addendum)