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