#   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 3 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, see <http://www.gnu.org/licenses/>.

from base import Base

class Lockable(Base):
    """Component that stores the data of a lock"""

    def __init__(self):
        """Constructor"""
        Base.__init__(self, closed=bool, locked=bool)

class LockedError(Exception):

    def __str__(self):
        return "Is locked"

class OpenError(Exception):

    def __str__(self):
        return "Is open"

def lock(lock):
    if not lock.closed:
        raise OpenError
    lock.locked = True    

def unlock(lock):
    lock.locked = False

def open(lock):
    if lock.locked:
        raise LockedError
    lock.closed = False

def close(lock):
    lock.closed = True