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
  21 from common import sec2min
  22
  23 class Song(dict):
  24     """Song provides a dictionary-like wrapper around song metadata.
  25        Its instances _shouldn't_ be stored, use SongRef or PlaylistEntryRef for that.
  26        Access '?tag' to get always at least an empty string. """
  27
  28     def __init__(self, data):
  29         for tag in data:
  30             if isinstance(data[tag], list):
  31                 data[tag] = ','.join(data[tag])
  32
  33         dict.__init__(self, data)
  34
  35     def __eq__(self, other):
  36         if not isinstance(other, Song):
  37             return NotImplemented
  38         return self['file'] == other['file']
  39
  40     def __ne__(self, other):
  41         if not isinstance(other, Song):
  42             return NotImplemented
  43         return self['file'] != other['file']
  44
  45     def __getitem__(self, key):
  46         try:
  47             return dict.__getitem__(self, key)
  48         except KeyError:
  49             if key and key[0] == '?':
  50                 key = key[1:]
  51                 return self[key] if key in self else ''
  52             if key == 'tracknum':
  53                 try:
  54                     return int(self['track'])
  55                 except ValueError:
  56                     try:
  57                         return int(self['track'].split('/')[0])
  58                     except ValueError:
  59                         return 0
  60             elif key == 'length':
  61                 return sec2min(int(self['time']))
  62             elif key == 'id':
  63                 return '-1'
  64             elif key == 'title':
  65                 return self['file']
  66             elif key == 'albumartist':
  67                 return self['artist']
  68             elif key == 'songdir':
  69                 return os.path.dirname(self['file'])
  70
  71             raise KeyError
  72
  73     def __contains__(self, item):
  74         if dict.__contains__(self, item):
  75             return True
  76         try:
  77             self[item]
  78             return True
  79         except KeyError:
  80             return False
  81
  82     def __nonzero__(self):
  83         return bool(self['file'])
  84
  85     def expand_tags(self, str):
  86         """Expands tags in form $tag in str."""
  87         ret = str
  88         ret = ret.replace('$title', self['title'])    #to ensure that it is set to at least filename
  89         for tag in self.keys() + ['tracknum', 'length', 'id']:
  90             ret = ret.replace('$' + tag, unicode(self[tag]))
  91         ret = ret.replace('$songdir', os.path.dirname(self['file']))
  92         return ret
  93
  94 class SongRef:
  95     """SongRef stores only a reference to the song (uri) instead
  96        of full metadata to conserve memory. Song's tags can be accessed
  97        as in Song, but it requires a call to MPD for each tag. """
  98     path     = None
  99     mpclient = None
 100
 101     def __init__(self, mpclient, path):
 102         self.mpclient = mpclient
 103         self.path     = path
 104
 105     def __getitem__(self, key):
 106         return self.song()[key]
 107
 108     def __nonzero__(self):
 109         return bool(self.path)
 110
 111     def song(self):
 112         try:
 113             return Song(self.mpclient.find('file', self.path)[0])
 114         except IndexError:
 115             return Song({})
 116
 117 class PlaylistEntryRef:
 118     """This class stores a reference to a playlist entry instead of full
 119        metadata to conserve memory. Song's tags can be accessed
 120        as in Song, but it requires a call to MPD for each tag. """
 121     plid       = None
 122     mpclient = None
 123
 124     def __init__(self, mpclient, plid):
 125         self.mpclient = mpclient
 126         self.plid       = plid
 127
 128     def __getitem__(self, key):
 129         return self.plid if key == 'id' else self.song()[key]
 130
 131     def __nonzero__(self):
 132         return self.plid != '-1'
 133
 134     def song(self):
 135         try:
 136             return self.mpclient.playlistid(self.plid)
 137         except IndexError:
 138             return Song({})