From 2fd781974f6b7d37e0e3acadb27ad6b9f6b088a3 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Wed, 24 Jan 2018 21:23:09 +1000
Subject: [PATCH] dbus: pass the bus name lost signal up to tuhi

If we're losing the bus name (i.e. we can't get it on startup) there really
isn't much we can do other than fail miserably. But in passing signals around
we can't do exceptions, so we have to move the mainloop to Tuhi so we can
quit() it on error.

Fixes #25
---
 tuhi/base.py       | 11 +++++++++--
 tuhi/dbusserver.py |  5 ++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/tuhi/base.py b/tuhi/base.py
index 0af0e0c..c7239b3 100644
--- a/tuhi/base.py
+++ b/tuhi/base.py
@@ -203,6 +203,7 @@ class Tuhi(GObject.Object):
         GObject.Object.__init__(self)
         self.server = TuhiDBusServer()
         self.server.connect('bus-name-acquired', self._on_tuhi_bus_name_acquired)
+        self.server.connect('bus-name-lost', self._on_tuhi_bus_name_lost)
         self.server.connect('search-start-requested', self._on_start_search_requested)
         self.server.connect('search-stop-requested', self._on_stop_search_requested)
         self.bluez = BlueZDeviceManager()
@@ -216,10 +217,14 @@ class Tuhi(GObject.Object):
         self.devices = {}
 
         self._search_stop_handler = None
+        self.mainloop = GObject.MainLoop()
 
     def _on_tuhi_bus_name_acquired(self, dbus_server):
         self.bluez.connect_to_bluez()
 
+    def _on_tuhi_bus_name_lost(self, dbus_server):
+        self.mainloop.quit()
+
     def _on_start_search_requested(self, dbus_server, stop_handler):
         self._search_stop_handler = stop_handler
         self.bluez.start_discovery()
@@ -306,6 +311,9 @@ class Tuhi(GObject.Object):
         else:
             self.bluez.stop_discovery()
 
+    def run(self):
+        self.mainloop.run()
+
 
 def main(args=sys.argv):
     desc = "Daemon to extract the pen stroke data from Wacom SmartPad devices"
@@ -319,9 +327,8 @@ def main(args=sys.argv):
     if ns.verbose:
         logger.setLevel(logging.DEBUG)
 
-    Tuhi()
     try:
-        GObject.MainLoop().run()
+        Tuhi().run()
     except KeyboardInterrupt:
         pass
     finally:
diff --git a/tuhi/dbusserver.py b/tuhi/dbusserver.py
index 887b0db..ec47b9d 100755
--- a/tuhi/dbusserver.py
+++ b/tuhi/dbusserver.py
@@ -309,6 +309,8 @@ class TuhiDBusServer(_TuhiDBus):
     __gsignals__ = {
         "bus-name-acquired":
             (GObject.SIGNAL_RUN_FIRST, None, ()),
+        "bus-name-lost":
+            (GObject.SIGNAL_RUN_FIRST, None, ()),
 
         # Signal arguments:
         #    search_stop_handler(status)
@@ -361,7 +363,8 @@ class TuhiDBusServer(_TuhiDBus):
         self.emit('bus-name-acquired')
 
     def _bus_name_lost(self, connection, name):
-        pass
+        logger.error('Bus not available, is there another Tuhi process running?')
+        self.emit('bus-name-lost')
 
     def _method_cb(self, connection, sender, objpath, interface, methodname, args, invocation):
         if interface != self.interface: