filenames.py

   1 # Copyright (C) 2008, Vincent Povirk for CodeWeavers
   2 #
   3 # This library is free software; you can redistribute it and/or
   4 # modify it under the terms of the GNU Lesser General Public
   5 # License as published by the Free Software Foundation; either
   6 # version 2 of the License, or (at your option) any later version.
   7 #
   8 # This library is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 # Lesser General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU Lesser General Public
  14 # License along with this library; if not, write to the
  15 # Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16 # Boston, MA 02111-1307, USA.
  17
  18 # Sugar's metadata does not typically provide a file extension, and the
  19 #  filename tends to be unusable. Windows depends on extensions so we need
  20 #  a conversion of metadata -> usable filenames.
  21
  22 from sugar.activity import activity
  23 import os
  24
  25 settings = {}
  26 f = open(os.path.join(activity.get_bundle_path(), 'activity', 'wine.info'), 'U')
  27 for line in f.readlines():
  28     if '=' in line:
  29         key, value = line.rstrip('\n').split('=')
  30         settings[key] = value
  31 f.close()
  32
  33 def guess_extension(metadata):
  34     #try wine.info settings
  35     for key in settings:
  36         if key.startswith('.'):
  37             if metadata['mime_type'] in settings[key].split(';'):
  38                 return key
  39
  40     #then try python's standard library
  41     import mimetypes
  42     guess = mimetypes.guess_extension(metadata['mime_type'])
  43     if guess: return guess
  44
  45     #ok, maybe it's an application/x-extension- type?
  46     if metadata['mime_type'].startswith(['application/x-extension-']):
  47         return '.%s' % metadata['mime_type'][len('application/x-extension-'):]
  48
  49     #no? let's call it quits then
  50     return ''
  51
  52 def guess_filename(metadata):
  53     def sanitize_filename(string):
  54         for character in r'\/:*?"<>|':
  55             string = string.replace(character, '_')
  56         return string
  57
  58     try:
  59         # trivial case: someone told us what filename to use
  60         return sanitize_filename(metadata['suggested_filename'])
  61     except KeyError:
  62         ext = guess_extension(metadata)
  63         if ext:
  64             # if there is a word that ends with the extension, use it
  65             # this does the right thing for downloads in English, at least
  66             for word in metadata['title'].split():
  67                 if word.endswith(ext):
  68                     return sanitize_filename(word)
  69             # otherwise, just use the title and extension
  70             return '%s%s' % (sanitize_filename(metadata['title']), ext)
  71         else:
  72             return sanitize_filename(metadata['title'])
  73
  74 def create_dsobject_file(metadata, tmpdir=None):
  75     import tempfile
  76
  77     if tmpdir is None:
  78         tmpdir = tempfile.gettempdir()
  79
  80     filename = guess_filename(metadata)
  81
  82     try:
  83         path = os.path.join(tmpdir, filename)
  84         fd = os.open(path, os.O_RDWR|os.O_CREAT|os.O_EXCL, 0770)
  85     except OSError:
  86         fd, path = tempfile.mkstemp(suffix=filename, dir=tmpdir)
  87
  88     return fd, path
  89