vcs.maemo.org Git - jamaendo/blob - jamaui/fetcher.py

   1 # Background fetcher:
   2 # Takes a generator and a notification identifier as parameter,
   3 # starts a thread, and post a notification whenever data arrives.
   4 # Posts a completion notification when done.
   5 # Terminates if generator fails or encounters an error.
   6
   7 import threading
   8 from postoffice import postoffice
   9 import jamaendo
  10 import logging
  11
  12 import gtk
  13 import hildon
  14
  15 log = logging.getLogger(__name__)
  16
  17 class _Worker(threading.Thread):
  18     def __init__(self, generator, owner):
  19         threading.Thread.__init__(self)
  20         self.setDaemon(True)
  21         self.generator = generator
  22         self.owner = owner
  23
  24     def _post(self, item):
  25         postoffice.notify("fetch", self.owner, item)
  26
  27     def _post_ok(self):
  28         postoffice.notify("fetch-ok", self.owner)
  29
  30     def _post_fail(self, e):
  31         postoffice.notify("fetch-fail", self.owner, e)
  32
  33     def run(self):
  34         try:
  35             for item in self.generator():
  36                 self._post(item)
  37             self._post_ok()
  38         except jamaendo.JamendoAPIException, e:
  39             log.exception("Failed to fetch, id %s" % (self.owner))
  40             self._post_fail(e)
  41
  42 class Fetcher(object):
  43     def __init__(self, generator, owner, on_item = None, on_ok = None, on_fail = None):
  44         self.generator = generator
  45         self.owner = owner
  46         self.worker = None
  47
  48         self.on_item = on_item
  49         self.on_ok = on_ok
  50         self.on_fail = on_fail
  51
  52     def _on_item_cb(self, i, x):
  53         self.on_item(i, x)
  54
  55     def _on_ok_cb(self, i):
  56         self.on_ok(i)
  57         if isinstance(self.owner, gtk.Window):
  58             hildon.hildon_gtk_window_set_progress_indicator(self.owner, 0)
  59
  60     def _on_fail_cb(self, i, e):
  61         self.on_fail(i, e)
  62         if isinstance(self.owner, gtk.Window):
  63             hildon.hildon_gtk_window_set_progress_indicator(self.owner, 0)
  64
  65     def start(self):
  66         postoffice.connect('fetch', self, self._on_item_cb)
  67         postoffice.connect('fetch-ok', self, self._on_ok_cb)
  68         postoffice.connect('fetch-fail', self, self._on_fail_cb)
  69         if isinstance(self.owner, gtk.Window):
  70             hildon.hildon_gtk_window_set_progress_indicator(self.owner, 1)
  71         self.worker = _Worker(self.generator, self.owner)
  72         self.worker.start()
  73
  74     def stop(self):
  75         postoffice.disconnect(['fetch', 'fetch-ok', 'fetch-fail'], self)