#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2000-2006  Donald N. Allingham
#
# 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
#

# $Id$

"""
DateBase class for GRAMPS.
"""

#-------------------------------------------------------------------------
#
# GRAMPS modules
#
#-------------------------------------------------------------------------
from gen.lib.date import Date

#-------------------------------------------------------------------------
#
# Base classes
#
#-------------------------------------------------------------------------
class DateBase(object):
    """
    Base class for storing date information.
    """

    def __init__(self, source=None):
        """
        Create a new DateBase, copying from source if not None.
        
        :param source: Object used to initialize the new object
        :type source: DateBase
        """
        if source:
            self.date = Date(source.date)
        else:
            self.date = Date()

    def serialize(self, no_text_date=False):
        """
        Convert the object to a serialized tuple of data.
        """
        if self.date is None or (self.date.is_empty() and not self.date.text):
            date = None
        else:
            date = self.date.serialize(no_text_date)
        return date

    def unserialize(self, data):
        """
        Convert a serialized tuple of data to an object.
        """
        self.date = Date()
        if data is not None:
            self.date.unserialize(data)

    def get_date_object(self):
        """
        Return the :class:`~gen.lib.date.Date` object associated with the DateBase.

        :returns: Returns a DateBase :class:`~gen.lib.date.Date` instance.
        :rtype: :class:`~gen.lib.date.Date`
        """
        if not self.date:
            self.date = Date()
        return self.date

    def set_date_object(self, date):
        """
        Set the :class:`~gen.lib.date.Date` object associated with the DateBase.

        :param date: :class:`~gen.lib.date.Date` instance to be assigned to the DateBase
        :type date: :class:`~gen.lib.date.Date`
        """
        self.date = date