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
  27     def __init__(self, data):
  28         # decode all strings to unicode
  29         for tag in data:
  30             if isinstance(data[tag], str):
  31                 data[tag] = data[tag].decode('utf-8')
  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 == 'tracknum':
  50                 try:
  51                     return int(self['track'])
  52                 except ValueError:
  53                     try:
  54                         return int(self['track'].split('/')[0])
  55                     except ValueError:
  56                         return 0
  57             elif key == 'length':
  58                 return sec2min(int(self['time']))
  59             elif key == 'id':
  60                 return '-1'
  61             elif key == 'title':
  62                 return self['file']
  63             return ''
  64
  65     def __nonzero__(self):
  66         return bool(self['file'])
  67
  68     def expand_tags(self, str):
  69         """Expands tags in form $tag in str."""
  70         ret = str
  71         ret = ret.replace('$title', self['title'])    #to ensure that it is set to at least filename
  72         for tag in self.keys() + ['tracknum', 'length', 'id']:
  73             ret = ret.replace('$' + tag, unicode(self[tag]))
  74         ret = ret.replace('$songdir', os.path.dirname(self['file']))
  75         return ret
  76
  77
  78 class SongRef:
  79     """SongRef stores only a reference to the song (uri) instead
  80        of full metadata to conserve memory. Song's tags can be accessed
  81        as in Song, but it requires a call to MPD for each tag. """
  82     path     = None
  83     mpclient = None
  84
  85     def __init__(self, mpclient, path):
  86         self.mpclient = mpclient
  87         self.path     = path
  88
  89     def __getitem__(self, key):
  90         return self.song()[key]
  91
  92     def __nonzero__(self):
  93         return bool(self.path)
  94
  95     def song(self):
  96         try:
  97             return Song(self.mpclient.find('file', self.path)[0])
  98         except IndexError:
  99             return Song({})
 100
 101 class PlaylistEntryRef:
 102     """This class stores a reference to a playlist entry instead of full
 103        metadata to conserve memory. Song's tags can be accessed
 104        as in Song, but it requires a call to MPD for each tag. """
 105     id       = None
 106     mpclient = None
 107
 108     def __init__(self, mpclient, id):
 109         self.mpclient = mpclient
 110         self.id       = id
 111
 112     def __getitem__(self, key):
 113         return self.song()[key]
 114
 115     def __nonzero__(self):
 116         return self.id != '-1'
 117
 118     def song(self):
 119         try:
 120             return Song(self.mpclient.playlistid(id)[0])
 121         except IndexError:
 122             return Song({})