nephilim/song.py

   1 #
   2 #    Copyright (C) 2009 Anton Khirnov <wyskas@gmail.com>
   3 #
   4 #    Nephilim is free software: you can redistribute it and/or modify
   5 #    it under the terms of the GNU General Public License as published by
   6 #    the Free Software Foundation, either version 3 of the License, or
   7 #    (at your option) any later version.
   8 #
   9 #    Nephilim is distributed in the hope that it will be useful,
  10 #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 #    GNU General Public License for more details.
  13 #
  14 #    You should have received a copy of the GNU General Public License
  15 #    along with Nephilim.  If not, see <http://www.gnu.org/licenses/>.
  16 #
  17
  18 from PyQt4 import QtCore
  19 import os
  20 from   string import Template
  21
  22 from common import sec2min
  23
  24 class Song(dict):
  25     """
  26     Song provides a dictionary-like wrapper around song metadata.
  27     Its instances are generated by MPClient, don't instantiate it
  28     directly.
  29     Its instances _shouldn't_ be stored, use SongRef or PlaylistEntryRef for that.
  30     Access '?tag' to get always at least an empty string.
  31     """
  32
  33     #### PUBLIC ####
  34     def __init__(self, data = {}):
  35         dict.__init__(self)
  36         for key in data:
  37             dict.__setitem__(self, key.lower(), data[key])
  38         if not 'file' in self:
  39             self['file'] = ''
  40     def __eq__(self, other):
  41         if not isinstance(other, Song):
  42             return NotImplemented
  43         return self['file'] == other['file']
  44     def __ne__(self, other):
  45         if not isinstance(other, Song):
  46             return NotImplemented
  47         return self['file'] != other['file']
  48     def __getitem__(self, key):
  49         key = key.lower()
  50         try:
  51             return dict.__getitem__(self, key)
  52         except KeyError:
  53             if key and key[0] == '?':
  54                 key = key[1:]
  55                 return self[key] if key in self else ''
  56             if key == 'tracknum':
  57                 try:
  58                     return int(self['track'])
  59                 except ValueError:
  60                     try:
  61                         return int(self['track'].split('/')[0])
  62                     except ValueError:
  63                         return 0
  64             elif key == 'length':
  65                 return sec2min(int(self['time']))
  66             elif key == 'id':
  67                 return '-1'
  68             elif key == 'title':
  69                 return self['file']
  70             elif key == 'albumartist':
  71                 return self['artist']
  72             elif key == 'songdir':
  73                 return os.path.dirname(self['file'])
  74
  75             raise KeyError
  76     def __contains__(self, item):
  77         if dict.__contains__(self, item.lower()):
  78             return True
  79         try:
  80             self[item]
  81             return True
  82         except KeyError:
  83             return False
  84     def __nonzero__(self):
  85         return bool(self['file'])
  86
  87     def expand_tags(self, s):
  88         """Expands tags in form ${tag} in string s."""
  89         ret = Template(s)
  90         ret = ret.safe_substitute(self)
  91         return ret
  92
  93 class SongRef:
  94     """SongRef stores only a reference to the song (uri) instead
  95        of full metadata to conserve memory. Song's tags can be accessed
  96        as in Song, but it requires a call to MPD for each tag. """
  97     path     = None
  98     mpclient = None
  99
 100     def __init__(self, mpclient, path):
 101         self.mpclient = mpclient
 102         self.path     = path
 103
 104     def __getitem__(self, key):
 105         return self.song()[key]
 106
 107     def __nonzero__(self):
 108         return bool(self.path)
 109
 110     def song(self):
 111         return list(self.mpclient.find_sync('file', self.path))[0]
 112
 113 class PlaylistEntryRef:
 114     """This class stores a reference to a playlist entry instead of full
 115        metadata to conserve memory. Song's tags can be accessed
 116        as in Song, but it requires a call to MPD for each tag. """
 117     plid     = None
 118     mpclient = None
 119
 120     def __init__(self, mpclient, plid):
 121         self.mpclient = mpclient
 122         self.plid       = plid
 123
 124     def __getitem__(self, key):
 125         return self.plid if key == 'id' else self.song()[key]
 126
 127     def __nonzero__(self):
 128         return self.plid != '-1'
 129
 130     def song(self):
 131         return self.mpclient.get_plist_song(self.plid)