Add a SyncState signal to the DBus interface

Propagated whenever we start talking to the device (and then again when we
stop). The purpose of this signal is merely that a UI can show e.g. a progress
bar while we're talking to the device to ensure the user something is
happening.

Fixes #138

README.md

@@ -378,6 +378,15 @@ org.freedesktop.tuhi1.Device
 
       These errnos indicate a bug in the daemon, and the client should
       display a message to that effect.
+
+  Signal: SyncState(i)
+      An enum to represent the current synchronization state of the device.
+      When on (1), Tuhi is currently trying to download data from the
+      device. When off (0), Tuhi is not currently connecting to the device.
+
+      This signal should be used for UI feedback.
+
+      This signal is only send when the device is **not** in Live mode.
 ```
 
 JSON File Format

tools/kete.py

@@ -285,6 +285,13 @@ class TuhiKeteDevice(_DBusObject):
             elif err < 0:
                 logger.error(f'{self}: an error occured: {os.strerror(-err)}')
             self.notify('listening')
+        elif signal == 'SyncState':
+            state = parameters[0]
+            if state:
+                logger.debug(f'{self}: Downloading from device')
+            else:
+                logger.debug(f'{self}: Download done')
+
 
     def _on_properties_changed(self, proxy, changed_props, invalidated_props):
         if changed_props is None:

tuhi/base.py

@@ -146,6 +146,10 @@ class TuhiDevice(GObject.Object):
     def battery_state(self, value):
         self._battery_state = value
 
+    @GObject.Property
+    def sync_state(self):
+        return self._sync_state
+
     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)
@@ -166,6 +170,7 @@ class TuhiDevice(GObject.Object):
             self._wacom_device.connect('button-press-required', self._on_button_press_required)
             self._wacom_device.connect('notify::uuid', self._on_uuid_updated, bluez_device)
             self._wacom_device.connect('battery-status', self._on_battery_status, bluez_device)
+            self._wacom_device.connect('notify::sync-state', self._on_sync_state)
 
         if mode == DeviceMode.REGISTER:
             self._wacom_device.start_register()
@@ -180,6 +185,10 @@ class TuhiDevice(GObject.Object):
         except KeyError:
             pass
 
+    def _on_sync_state(self, device, pspec):
+        self._sync_state = device.sync_state
+        self.notify('sync-state')
+
     def _on_bluez_device_disconnected(self, bluez_device):
         logger.debug(f'{bluez_device.address}: disconnected')
         try:

tuhi/dbusserver.py

@@ -106,6 +106,10 @@ INTROSPECTION_XML = '''
     <signal name='LiveStopped'>
        <arg name='status' type='i' />
     </signal>
+
+    <signal name='SyncState'>
+       <arg name='status' type='i' />
+    </signal>
   </interface>
 </node>
 '''
@@ -182,6 +186,7 @@ class TuhiDBusDevice(_TuhiDBus):
         device.connect('notify::battery-percent', self._on_battery_percent)
         device.connect('notify::battery-state', self._on_battery_state)
         device.connect('device-error', self._on_device_error)
+        device.connect('notify::sync-state', self._on_sync_state)
 
     @GObject.Property
     def listening(self):
@@ -330,6 +335,14 @@ class TuhiDBusDevice(_TuhiDBus):
             self._stop_listening(self.connection, self._listening_client[0],
                                  -exception.errno)
 
+    def _on_sync_state(self, device, pspec):
+        if self._listening_client is None:
+            return
+
+        dest = self._listening_client[0]
+        status = GLib.Variant.new_int32(device.sync_state)
+        self.signal('SyncState', status, dest=dest)
+
     def _start_listening(self, connection, sender):
         if self.listening:
             logger.debug(f'{self} - already listening')

tuhi/wacom.py

@@ -1115,6 +1115,7 @@ class WacomDevice(GObject.Object):
         self._is_running = False
         self._config = None
         self._wacom_protocol = None
+        self._sync_state = 0
 
         try:
             self._config = config.devices[device.address]
@@ -1168,6 +1169,14 @@ class WacomDevice(GObject.Object):
         assert self._wacom_protocol is not None
         return self._wacom_protocol.protocol
 
+    @GObject.Property
+    def sync_state(self):
+        return self._sync_state
+
+    @sync_state.setter
+    def sync_state(self, state):
+        self._sync_state = state
+
     def register_device(self):
         self._uuid = uuid.uuid4().hex[:12]
         logger.debug(f'{self._device.address}: registering device, assigned {self.uuid}')
@@ -1204,10 +1213,13 @@ class WacomDevice(GObject.Object):
                 self.register_device()
             else:
                 assert self._wacom_protocol is not None
+                self.sync_state = 1
                 self._wacom_protocol.retrieve_data()
+                self.sync_state = 0
         except WacomException as e:
             logger.error(f'**** Exception: {e} ****')
             exception = e
+            self.sync_state = 0
         finally:
             self._is_running = False
             self.emit('done', exception)