add a function to pass through a stream of connection state information

Author: MoralCode

lib/models/ergometer.dart

@@ -12,6 +12,8 @@ import 'package:c2bluetooth/constants.dart' as Identifiers;
 import 'package:flutter_ble_lib_ios_15/flutter_ble_lib.dart';
 import 'package:rxdart/rxdart.dart';
 
+enum ErgometerConnectionState { connecting, connected, disconnected }
+
 class Ergometer {
   Peripheral _peripheral;
   Csafe? _csafeClient;
@@ -58,6 +60,25 @@ class Ergometer {
     });
   }
 
+  /// Expose a stream of events to enable monitoring the erg's connection state
+  /// This acts as a wrapper around the state provided by the internal bluetooth library to aid with swapping it out later.
+  Stream<ErgometerConnectionState> monitorConnectionState() {
+    return _peripheral.observeConnectionState().asyncMap((connectionState) {
+      switch (connectionState) {
+        case PeripheralConnectionState.connecting:
+          return ErgometerConnectionState.connecting;
+        case PeripheralConnectionState.connected:
+          return ErgometerConnectionState.connected;
+        case PeripheralConnectionState.disconnecting:
+          return ErgometerConnectionState.disconnected;
+        case PeripheralConnectionState.disconnected:
+          return ErgometerConnectionState.disconnected;
+        default:
+          return ErgometerConnectionState.disconnected;
+      }
+    });
+  }
+
   /// A read function for the PM over bluetooth.
   ///
   /// Intended for passing to the csafe_fitness library to allow it to read data from the erg