base: make the register/listen call handling more literal

Calling listen on an unregistered device currently triggers a register on the
device. This can happen when the device has been registered but the
ManufacturerData has not yet been updated.

Disentangle this by only calling the right function based on what we're trying
to get. This also requires that the connected/disconnected signals are only
handled when we're actually trying to do something with them.

Fixes #79 (multiple patches required)

tuhi/base.py

@@ -20,7 +20,7 @@ from gi.repository import GObject, GLib
 
 from tuhi.dbusserver import TuhiDBusServer
 from tuhi.ble import BlueZDeviceManager
-from tuhi.wacom import WacomDevice
+from tuhi.wacom import WacomDevice, DeviceMode
 from tuhi.config import TuhiConfig
 
 logging.basicConfig(format='%(levelname)s: %(name)s: %(message)s',
@@ -62,9 +62,8 @@ class TuhiDevice(GObject.Object):
         self._battery_percent = 0
         self._last_battery_update_time = 0
         self._battery_timer_source = None
+        self._signals = {}
 
-        bluez_device.connect('connected', self._on_bluez_device_connected)
-        bluez_device.connect('disconnected', self._on_bluez_device_disconnected)
         self._bluez_device = bluez_device
 
         self._tuhi_dbus_device = None
@@ -126,11 +125,19 @@ class TuhiDevice(GObject.Object):
     def battery_state(self, value):
         self._battery_state = value
 
-    def connect_device(self):
+    def _connect_device(self, mode):
+        self._signals['connected'] = self._bluez_device.connect('connected', self._on_bluez_device_connected, mode)
+        self._signals['disconnected'] = self._bluez_device.connect('disconnected', self._on_bluez_device_disconnected)
         self._bluez_device.connect_device()
 
-    def _on_bluez_device_connected(self, bluez_device):
-        logger.debug(f'{bluez_device.address}: connected')
+    def register(self):
+        self._connect_device(DeviceMode.REGISTER)
+
+    def listen(self):
+        self._connect_device(DeviceMode.LISTEN)
+
+    def _on_bluez_device_connected(self, bluez_device, mode):
+        logger.debug(f'{bluez_device.address}: connected for {mode}')
         if self._wacom_device is None:
             self._wacom_device = WacomDevice(bluez_device, self.config)
             self._wacom_device.connect('drawing', self._on_drawing_received)
@@ -139,19 +146,30 @@ class TuhiDevice(GObject.Object):
             self._wacom_device.connect('notify::uuid', self._on_uuid_updated, bluez_device)
             self._wacom_device.connect('battery-status', self._on_battery_status, bluez_device)
 
-        if not self.registered:
+        if mode == DeviceMode.REGISTER:
             self._wacom_device.start_register()
         else:
             self._wacom_device.start_listen()
 
+        try:
+            bluez_device.disconnect(self._signals['connected'])
+            del self._signals['connected']
+        except KeyError:
+            pass
+
     def _on_bluez_device_disconnected(self, bluez_device):
         logger.debug(f'{bluez_device.address}: disconnected')
+        try:
+            bluez_device.disconnect(self._signals['disconnected'])
+            del self._signals['disconnected']
+        except KeyError:
+            pass
 
     def _on_register_requested(self, dbus_device):
         if self.registered:
             return
 
-        self.connect_device()
+        self.register()
 
     def _on_drawing_received(self, device, drawing):
         logger.debug('Drawing received')
@@ -303,7 +321,7 @@ class Tuhi(GObject.Object):
             d.registered = False
             logger.debug(f'{bluez_device.objpath}: call Register() on device')
         elif d.listening:
-            d.connect_device()
+            d.listen()
 
     def _on_listening_updated(self, tuhi_dbus_device, pspec):
         listen = self._search_stop_handler is not None