connection_watcher.py

   1 # This should eventually land in telepathy-python, so has the same license:
   2 # Copyright (C) 2008 Collabora Ltd. <http://www.collabora.co.uk/>
   3 #
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU Lesser General Public License as published
   6 # by the Free Software Foundation; either version 2.1 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program 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 Lesser General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Lesser General Public License
  15 # along with this program; if not, write to the Free Software
  16 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17
  18 # FIXME: this sould go upstream, in telepathy-python
  19
  20 import logging
  21
  22 import dbus
  23 import dbus.mainloop.glib
  24 import gobject
  25
  26 from telepathy.client import Connection
  27 from telepathy.interfaces import CONN_INTERFACE
  28 from telepathy.constants import CONNECTION_STATUS_CONNECTED, \
  29                                 CONNECTION_STATUS_DISCONNECTED
  30
  31 class ConnectionWatcher(gobject.GObject):
  32     __gsignals__ = {
  33         'connection-added': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
  34                         ([gobject.TYPE_PYOBJECT])),
  35         'connection-removed': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
  36                         ([gobject.TYPE_PYOBJECT]))
  37     }
  38
  39     def __init__(self, bus=None):
  40         gobject.GObject.__init__(self)
  41
  42         if bus is None:
  43             self.bus = dbus.Bus()
  44         else:
  45             self.bus = bus
  46
  47         # D-Bus path -> Connection
  48         self._connections = {}
  49
  50         self.bus.add_signal_receiver(self._status_changed_cb,
  51             dbus_interface=CONN_INTERFACE, signal_name='StatusChanged',
  52             path_keyword='path')
  53
  54         for conn in Connection.get_connections(bus):
  55             conn.call_when_ready(self._conn_ready_cb)
  56
  57     def _status_changed_cb(self, *args, **kwargs):
  58         path = kwargs['path']
  59         if not path.startswith('/org/freedesktop/Telepathy/Connection/'):
  60             return
  61
  62         status, reason_ = args
  63         service_name = path.replace('/', '.')[1:]
  64
  65         if status == CONNECTION_STATUS_CONNECTED:
  66             self._add_connection(service_name, path)
  67         elif status == CONNECTION_STATUS_DISCONNECTED:
  68             self._remove_connection(service_name, path)
  69
  70     def _conn_ready_cb(self, conn):
  71         if conn.object_path in self._connections:
  72             return
  73
  74         self._connections[conn.object_path] = conn
  75         self.emit('connection-added', conn)
  76
  77     def _add_connection(self, service_name, path):
  78         if path in self._connections:
  79             return
  80
  81         try:
  82             Connection(service_name, path, ready_handler=self._conn_ready_cb)
  83         except dbus.exceptions.DBusException:
  84             logging.debug('%s is propably already gone.', service_name)
  85
  86     def _remove_connection(self, service_name, path):
  87         conn = self._connections.pop(path, None)
  88         if conn is None:
  89             return
  90
  91         self.emit('connection-removed', conn)
  92
  93     def get_connections(self):
  94         return self._connections.values()
  95
  96 if __name__ == '__main__':
  97     dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
  98
  99     def connection_added_cb(conn_watcher, conn):
 100         print "new connection", conn.service_name
 101
 102     def connection_removed_cb(conn_watcher, conn):
 103         print "removed connection", conn.service_name
 104
 105     watcher = ConnectionWatcher()
 106     watcher.connect('connection-added', connection_added_cb)
 107     watcher.connect('connection-removed', connection_removed_cb)
 108
 109     loop = gobject.MainLoop()
 110     loop.run()