##
## objecthistory.py
## Login : <uli@pu.smp.net>
## Started on  Fri Jun 10 16:06:02 2011 Uli Fouquet
## $Id$
## 
## Copyright (C) 2011 Uli Fouquet
## 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
##
import grok
from persistent.list import PersistentList
from zope.annotation.interfaces import IAnnotations
from waeup.sirp.interfaces import IObjectHistory, IWAeUPObject

class ObjectHistory(grok.Adapter):
    """A history for objects.
    """
    grok.context(IWAeUPObject)
    grok.provides(IObjectHistory)

    history_key = 'waeup.history'

    def __init__(self, context):
        from zope.security.proxy import removeSecurityProxy
        self.context = removeSecurityProxy(context)
        self._annotations = IAnnotations(self.context)

    def _getMessages(self):
        return self._annotations.get(self.history_key, PersistentList())

    @property
    def messages(self):
        return self._getMessages()

    def addMessage(self, msg):
        msgs = self._getMessages()
        msgs.append(msg)
        self._annotations[self.history_key] = msgs
        return