##
## image.py
## Login : <uli@pu.smp.net>
## Started on  Mon Apr 25 12:32:42 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
##
"""
Components for handling image files.
"""
from StringIO import StringIO
from hurry.file import HurryFile
from hurry.file.interfaces import IFileRetrieval
from zope.component import queryUtility
from zope.interface import implements
from waeup.sirp.image.interfaces import IWAeUPImageFile

class WAeUPImageFile(HurryFile):
    """A file prepared for storing image files.

    This file type is built upon :class:`hurry.file.HurryFile`.
    """
    implements(IWAeUPImageFile)

    def _get_file(self):
        """Get the real file.

        We have to override this method from
        :class:`hurry.file.HurryFile` base because we need a more
        careful utility lookup.
        """
        storage = queryUtility(IFileRetrieval)
        if storage is None:
            # can happen on startup, see https://trac.waeup.org/ticket/32
            return StringIO(self.data)
        return storage.getFile(self.data)

    file = property(_get_file)