Update SerialConnectionFactory.kt

Author: consuelita

Transmission/src/main/java/org/operatorfoundation/transmission/SerialConnectionFactory.kt

@@ -231,6 +231,19 @@ class SerialConnectionFactory(context: Context)
         _connectionState.value = ConnectionState.Disconnected
     }
 
+    /**
+     * Closes the current connection and resets state to Disconnected.
+     * Does not cancel the connection scope, so reconnection remains possible.
+     * Call this when a USB device detach event is received.
+     */
+    fun onDeviceDetached() {
+        val currentState = _connectionState.value
+        if (currentState is ConnectionState.Connected) {
+            currentState.connection.close()
+        }
+        _connectionState.value = ConnectionState.Disconnected
+    }
+
     /**
     * Creates the actual SerialConnection instance from a permitted USB device.
     *