Add a method to unregister advertisement (#50)

Co-authored-by: Markus Proeller <markus.proeller@lytentec.com>

Author: Coimbra1984

bluez_peripheral/advert.py

@@ -104,6 +104,10 @@ def __init__(
         self._duration = duration
         self.releaseCallback = releaseCallback
 
+        self._exportBus: Optional[MessageBus] = None
+        self._exportPath: Optional[str] = None
+        self._adapter: Optional[Adapter] = None
+
         super().__init__(self._INTERFACE)
 
     async def register(
@@ -135,10 +139,25 @@ async def register(
         if adapter is None:
             adapter = await Adapter.get_first(bus)
 
+        self._adapter = adapter
+
         # Get the LEAdvertisingManager1 interface for the target adapter.
         interface = adapter._proxy.get_interface(self._MANAGER_INTERFACE)
         await interface.call_register_advertisement(path, {})
 
+    async def unregister(self):
+        """
+        Unregister this advertisement from bluez to stop advertising.
+        """
+        if not self._exportBus or not self._adapter or not self._exportPath:
+            return
+
+        interface = self._adapter._proxy.get_interface(self._MANAGER_INTERFACE)
+
+        await interface.call_unregister_advertisement(self._exportPath)
+
+        self.Release()
+
     @classmethod
     async def GetSupportedIncludes(cls, adapter: Adapter) -> AdvertisingIncludes:
         interface = adapter._proxy.get_interface(cls._MANAGER_INTERFACE)
@@ -154,6 +173,10 @@ async def GetSupportedIncludes(cls, adapter: Adapter) -> AdvertisingIncludes:
     def Release(self):  # type: ignore
         self._exportBus.unexport(self._exportPath, self._INTERFACE)
 
+        self._exportBus = None
+        self._adapter = None
+        self._exportPath = None
+
         if self.releaseCallback is not None:
             self.releaseCallback()