git.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 gobject
  13 import gtk
  14 import hildon
  15
  16 log = logging.getLogger(__name__)
  17
  18 class _Worker(threading.Thread):
  19     def __init__(self, generator, owner):
  20         threading.Thread.__init__(self)
  21         self.setDaemon(True)
  22         self.generator = generator
  23         self.owner = owner
  24
  25     def _post(self, item):
  26         def idle_fetch(owner, item):
  27             postoffice.notify("fetch", owner, item)
  28         gobject.idle_add(idle_fetch, self.owner, item)
  29
  30     def _post_ok(self):
  31         def idle_fetch_ok(owner):
  32             postoffice.notify("fetch-ok", owner)
  33         gobject.idle_add(idle_fetch_ok, self.owner)
  34
  35     def _post_fail(self, e):
  36         def idle_fetch_fail(owner, e):
  37             postoffice.notify("fetch-fail", owner, e)
  38         gobject.idle_add(idle_fetch_fail, self.owner, e)
  39
  40     def run(self):
  41         try:
  42             for item in self.generator():
  43                 self._post(item)
  44             self._post_ok()
  45         except jamaendo.JamendoAPIException, e:
  46             log.exception("Failed to fetch, id %s" % (self.owner))
  47             self._post_fail(e)
  48
  49 class Fetcher(object):
  50     def __init__(self, generator, owner, on_item = None, on_ok = None, on_fail = None):
  51         self.generator = generator
  52         self.owner = owner
  53         self.worker = None
  54
  55         self.on_item = on_item
  56         self.on_ok = on_ok
  57         self.on_fail = on_fail
  58
  59     def _on_item_cb(self, i, x):
  60         self.on_item(i, x)
  61
  62     def _on_ok_cb(self, i):
  63         self.on_ok(i)
  64         if isinstance(self.owner, gtk.Window):
  65             hildon.hildon_gtk_window_set_progress_indicator(self.owner, 0)
  66
  67     def _on_fail_cb(self, i, e):
  68         self.on_fail(i, e)
  69         if isinstance(self.owner, gtk.Window):
  70             hildon.hildon_gtk_window_set_progress_indicator(self.owner, 0)
  71
  72     def start(self):
  73         postoffice.connect('fetch', self, self._on_item_cb)
  74         postoffice.connect('fetch-ok', self, self._on_ok_cb)
  75         postoffice.connect('fetch-fail', self, self._on_fail_cb)
  76         if isinstance(self.owner, gtk.Window):
  77             hildon.hildon_gtk_window_set_progress_indicator(self.owner, 1)
  78         self.worker = _Worker(self.generator, self.owner)
  79         self.worker.start()
  80
  81     def stop(self):
  82         postoffice.disconnect(['fetch', 'fetch-ok', 'fetch-fail'], self)