#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2007-2008  Brian G. Matherly
# Copyright (C) 2008       Gary Burton
#
# 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
#
# $Id$

"""
The base option class for all other option classes.
"""

#-------------------------------------------------------------------------
#
# gramps modules
#
#-------------------------------------------------------------------------
from ...utils.callback import Callback

#-------------------------------------------------------------------------
#
# Option class
#
#-------------------------------------------------------------------------
class Option(Callback):
    """
    This class serves as a base class for all options. All Options must 
    minimally provide the services provided by this class. Options are allowed 
    to add additional functionality.
    """
    
    __signals__ = { 'value-changed' : None,
                    'avail-changed' : None}
    
    def __init__(self, label, value):
        """
        @param label: A friendly label to be applied to this option.
            Example: "Exclude living people"
        @type label: string
        @param value: An initial value for this option.
            Example: True
        @type value: The type will depend on the type of option.
        @return: nothing
        """
        Callback.__init__(self)
        self.__value = value
        self.__label = label
        self.__help_str = ""
        self.__available = True
        
    def get_label(self):
        """
        Get the friendly label for this option.
        
        @return: string
        """
        return self.__label
    
    def set_label(self, label):
        """
        Set the friendly label for this option.
        
        @param label: A friendly label to be applied to this option.
            Example: "Exclude living people"
        @type label: string
        @return: nothing
        """
        self.__label = label
        
    def get_value(self):
        """
        Get the value of this option.
        
        @return: The option value.
        """
        return self.__value
    
    def set_value(self, value):
        """
        Set the value of this option.
        
        @param value: A value for this option.
            Example: True
        @type value: The type will depend on the type of option.
        @return: nothing
        """
        self.__value = value
        self.emit('value-changed')
        
    def get_help(self):
        """
        Get the help information for this option.
        
        @return: A string that provides additional help beyond the label.
        """
        return self.__help_str
        
    def set_help(self, help_text):
        """
        Set the help information for this option.
        
        @param help: A string that provides additional help beyond the label.
            Example: "Whether to include or exclude people who are calculated 
            to be alive at the time of the generation of this report"
        @type value: string
        @return: nothing
        """
        self.__help_str = help_text
        
    def set_available(self, avail):
        """
        Set the availability of this option.
        
        @param avail: An indicator of whether this option is currently 
        available. True indicates that the option is available. False indicates
        that the option is not available.
        @type avail: Bool
        @return: nothing
        """
        if avail != self.__available:
            self.__available = avail
            self.emit('avail-changed')
        
    def get_available(self):
        """
        Get the availability of this option.
        
        @return: A Bool indicating the availablity of this option. 
        True indicates that the option is available. 
        False indicates that the option is not available.
        """
        return self.__available
