src/gpodder/services.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # gPodder - A media aggregator and podcast client
   4 # Copyright (c) 2005-2009 Thomas Perl and the gPodder Team
   5 #
   6 # gPodder is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # gPodder is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 #
  19
  20
  21 #
  22 #  services.py -- Core Services for gPodder
  23 #  Thomas Perl <thp@perli.net>   2007-08-24
  24 #
  25 #
  26
  27 import gpodder
  28 from gpodder.liblogger import log
  29
  30 from gpodder import util
  31 from gpodder import download
  32
  33 import threading
  34 import time
  35 import urllib2
  36 import os
  37
  38 _ = gpodder.gettext
  39
  40 class ObservableService(object):
  41     def __init__(self, signal_names=[]):
  42         self.observers = {}
  43         for signal in signal_names:
  44             self.observers[signal] = []
  45
  46     def register(self, signal_name, observer):
  47         if signal_name in self.observers:
  48             if not observer in self.observers[signal_name]:
  49                 self.observers[signal_name].append(observer)
  50             else:
  51                 log('Observer already added to signal "%s".', signal_name, sender=self)
  52         else:
  53             log('Signal "%s" is not available for registration.', signal_name, sender=self)
  54
  55     def unregister(self, signal_name, observer):
  56         if signal_name in self.observers:
  57             if observer in self.observers[signal_name]:
  58                 self.observers[signal_name].remove(observer)
  59             else:
  60                 log('Observer could not be removed from signal "%s".', signal_name, sender=self)
  61         else:
  62             log('Signal "%s" is not available for un-registration.', signal_name, sender=self)
  63
  64     def notify(self, signal_name, *args):
  65         if signal_name in self.observers:
  66             for observer in self.observers[signal_name]:
  67                 util.idle_add(observer, *args)
  68         else:
  69             log('Signal "%s" is not available for notification.', signal_name, sender=self)
  70
  71
  72 class DependencyManager(object):
  73     def __init__(self):
  74         self.dependencies = []
  75
  76     def depend_on(self, feature_name, description, modules, tools):
  77         self.dependencies.append([feature_name, description, modules, tools])
  78
  79     def modules_available(self, modules):
  80         """
  81         Receives a list of modules and checks if each
  82         of them is available. Returns a tuple with the
  83         first item being a boolean variable that is True
  84         when all required modules are available and False
  85         otherwise. The second item is a dictionary that
  86         lists every module as key with the available as
  87         boolean value.
  88         """
  89         result = {}
  90         all_available = True
  91         for module in modules:
  92             try:
  93                 __import__(module)
  94                 result[module] = True
  95             except:
  96                 result[module] = False
  97                 all_available = False
  98
  99         return (all_available, result)
 100
 101     def tools_available(self, tools):
 102         """
 103         See modules_available.
 104         """
 105         result = {}
 106         all_available = True
 107         for tool in tools:
 108             if util.find_command(tool):
 109                 result[tool] = True
 110             else:
 111                 result[tool] = False
 112                 all_available = False
 113
 114         return (all_available, result)
 115
 116
 117 dependency_manager = DependencyManager()
 118
 119
 120 # Register non-module-specific dependencies here
 121 dependency_manager.depend_on(_('Bluetooth file transfer'), _('Send podcast episodes to Bluetooth devices. Needs Python Bluez bindings.'), ['bluetooth'], ['bluetooth-sendto'])
 122 dependency_manager.depend_on(_('HTML episode shownotes'), _('Display episode shownotes in HTML format using GTKHTML2.'), ['gtkhtml2'], [])
 123