optionally listen for upower suspend/resume events to stop/start all receiver listeners

lib/hidapi/udev.py

@@ -120,13 +120,13 @@ def monitor_glib(callback, *device_filters):
 	c = _Context()
 
 	# already existing devices
-	for device in c.list_devices(subsystem='hidraw'):
-		# print (device, dict(device), dict(device.attributes))
-		for filter in device_filters:
-			d_info = _match('add', device, *filter)
-			if d_info:
-				GLib.idle_add(callback, 'add', d_info)
-				break
+	# for device in c.list_devices(subsystem='hidraw'):
+	# 	# print (device, dict(device), dict(device.attributes))
+	# 	for filter in device_filters:
+	# 		d_info = _match('add', device, *filter)
+	# 		if d_info:
+	# 			GLib.idle_add(callback, 'add', d_info)
+	# 			break
 
 	m = _Monitor.from_netlink(c)
 	m.filter_by(subsystem='hidraw')

lib/solaar/gtk.py

@@ -44,7 +44,9 @@ def _run(args):
 	ui.init()
 
 	import solaar.listener as listener
-	listener.start_scanner(ui.status_changed, ui.error_dialog)
+	listener.setup_scanner(ui.status_changed, ui.error_dialog)
+
+	listener.start_all()
 
 	# main UI event loop
 	ui.run_loop()

lib/solaar/listener.py

@@ -201,11 +201,11 @@ class ReceiverListener(_listener.EventsListener):
 _all_listeners = {}
 
 
-def start(device_info, status_changed_callback):
-	assert status_changed_callback
+def _start(device_info):
+	assert _status_callback
 	receiver = Receiver.open(device_info)
 	if receiver:
-		rl = ReceiverListener(receiver, status_changed_callback)
+		rl = ReceiverListener(receiver, _status_callback)
 		rl.start()
 		_all_listeners[device_info.path] = rl
 		return rl
@@ -213,12 +213,21 @@ def start(device_info, status_changed_callback):
 		_log.warn("failed to open %s", device_info)
 
 
+def start_all():
+	# just in case this it called twice in a row...
+	stop_all()
+
+	_log.info("starting receiver listening threads")
+	for device_info in _base.receivers():
+		_process_receiver_event('add', device_info)
+
+
 def stop_all():
 	listeners = list(_all_listeners.values())
 	_all_listeners.clear()
 
 	if listeners:
-		_log.info("stopping %s", listeners)
+		_log.info("stopping receiver listening threads %s", listeners)
 
 		for l in listeners:
 			l.stop()
@@ -230,10 +239,16 @@ def stop_all():
 			l.join()
 
 
+# stop/start all receiver threads on suspend/resume events, if possible
+from . import upower
+upower.watch(start_all, stop_all)
+
+
+from logitech.unifying_receiver import base as _base
 _status_callback = None
 _error_callback = None
 
-def start_scanner(status_changed_callback, error_callback):
+def setup_scanner(status_changed_callback, error_callback):
 	global _status_callback, _error_callback
 	if _status_callback:
 		raise Exception("scanner was already set-up")
@@ -241,7 +256,6 @@ def start_scanner(status_changed_callback, error_callback):
 	_status_callback = status_changed_callback
 	_error_callback = error_callback
 
-	from logitech.unifying_receiver import base as _base
 	_base.notify_on_receivers_glib(_process_receiver_event)
 
 
@@ -249,6 +263,7 @@ def start_scanner(status_changed_callback, error_callback):
 def _process_receiver_event(action, device_info):
 	assert action is not None
 	assert device_info is not None
+	assert _error_callback
 
 	_log.info("receiver event %s %s", action, device_info)
 
@@ -261,7 +276,7 @@ def _process_receiver_event(action, device_info):
 	if action == 'add':
 		# a new receiver device was detected
 		try:
-			start(device_info, _status_callback)
+			_start(device_info)
 		except OSError:
 			# permission error, ignore this path for now
 			_error_callback('permissions', device_info.path)

lib/solaar/upower.py

@@ -0,0 +1,64 @@
+#
+#
+#
+
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+from logging import getLogger
+_log = getLogger(__name__)
+del getLogger
+
+#
+# As suggested here: http://stackoverflow.com/a/13548984
+#
+
+
+_suspend_callback = None
+def _suspend():
+	if _suspend_callback:
+		_log.info("received suspend event from UPower")
+		_suspend_callback()
+
+
+_resume_callback = None
+def _resume():
+	if _resume_callback:
+		_log.info("received resume event from UPower")
+		_resume_callback()
+
+
+def watch(on_resume_callback, on_suspend_callback):
+	"""Register callback for suspend/resume events.
+	They are called only if the system DBus is running, and the UPower daemon is available."""
+	global _resume_callback, _suspend_callback
+	_suspend_callback = on_suspend_callback
+	_resume_callback = on_resume_callback
+
+
+try:
+	import dbus      # for dbus communication (obviously)
+
+	_UPOWER_BUS = 'org.freedesktop.UPower'
+	_UPOWER_INTERFACE = 'org.freedesktop.UPower'
+
+	# integration into the main GLib loop
+	from dbus.mainloop.glib import DBusGMainLoop
+	DBusGMainLoop(set_as_default=True)
+
+	bus = dbus.SystemBus()
+	assert bus
+
+	bus.add_signal_receiver(_suspend, signal_name='Sleeping',
+					dbus_interface=_UPOWER_INTERFACE, bus_name=_UPOWER_BUS)
+
+	bus.add_signal_receiver(_resume, signal_name='Resuming',
+					dbus_interface=_UPOWER_INTERFACE, bus_name=_UPOWER_BUS)
+
+	_log.info("connected to system dbus, watching for suspend/resume events")
+
+except:
+	# Either:
+	# - the dbus library is not available
+	# - the system dbus is not running
+	_log.warn("failed to register suspend/resume callbacks")
+	pass