gramps/gramps/gen/dbstate.py
2014-08-08 19:39:45 -07:00

124 lines
3.8 KiB
Python

#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2000-2006 Donald N. Allingham
# Copyright (C) 2011 Tim G L Lyons
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
"""
Provide the database state class
"""
from .db import DbBsddbRead
from .proxy.proxybase import ProxyDbBase
from .utils.callback import Callback
from .config import config
class DbState(Callback):
"""
Provide a class to encapsulate the state of the database.
"""
__signals__ = {
'database-changed' : ((DbBsddbRead, ProxyDbBase), ),
'no-database' : None,
}
def __init__(self):
"""
Initalize the state with an empty (and useless) DbBsddbRead. This is
just a place holder until a real DB is assigned.
"""
Callback.__init__(self)
self.db = DbBsddbRead()
self.open = False
self.stack = []
def change_database(self, database):
"""
Closes the existing db, and opens a new one.
Retained for backward compatibility.
"""
self.emit('no-database', ())
self.db.close()
self.change_database_noclose(database)
def change_database_noclose(self, database):
"""
Change the current database. and resets the configuration prefixes.
"""
self.db = database
self.db.set_prefixes(
config.get('preferences.iprefix'),
config.get('preferences.oprefix'),
config.get('preferences.fprefix'),
config.get('preferences.sprefix'),
config.get('preferences.cprefix'),
config.get('preferences.pprefix'),
config.get('preferences.eprefix'),
config.get('preferences.rprefix'),
config.get('preferences.nprefix') )
self.open = True
self.signal_change()
def signal_change(self):
"""
Emits the database-changed signal with the new database
"""
self.emit('database-changed', (self.db, ))
def no_database(self):
"""
Closes the database without a new database
"""
self.emit('no-database', ())
self.db.close()
self.db = DbBsddbRead()
self.db.db_is_open = False
self.open = False
self.emit('database-changed', (self.db, ))
def get_database(self):
"""
Get a reference to the current database.
"""
return self.db
def apply_proxy(self, proxy, *args, **kwargs):
"""
Add a proxy to the current database. Use pop_proxy() to
revert to previous db.
>>> dbstate.apply_proxy(gen.proxy.LivingProxyDb, 1)
>>> dbstate.apply_proxy(gen.proxy.PrivateProxyDb)
"""
self.stack.append(self.db)
self.db = proxy(self.db, *args, **kwargs)
self.emit('database-changed', (self.db, ))
def pop_proxy(self):
"""
Remove the previously applied proxy.
>>> dbstate.apply_proxy(gen.proxy.LivingProxyDb, 1)
>>> dbstate.pop_proxy()
>>> dbstate.apply_proxy(gen.proxy.PrivateProxyDb)
>>> dbstate.pop_proxy()
"""
self.db = self.stack.pop()
self.emit('database-changed', (self.db, ))