Index: leahi_dialin/utils/base.py
===================================================================
diff -u -r18c90a1b2b6c7339bdd192a2d2fac32f2b8a35df -rc5bfcf84ed942ca5841bf9de155aa0f495b4d28d
--- leahi_dialin/utils/base.py	(.../base.py)	(revision 18c90a1b2b6c7339bdd192a2d2fac32f2b8a35df)
+++ leahi_dialin/utils/base.py	(.../base.py)	(revision c5bfcf84ed942ca5841bf9de155aa0f495b4d28d)
@@ -315,3 +315,16 @@
     def stop(self):
         self._timer.cancel()
         self.is_running = False
+
+
+class InternalEvent:
+    def __init__(self):
+        self._listeners = []
+
+    def add_listener(self, func):
+        self._listeners.append(func)
+        return func
+    
+    def trigger(self, *args, **kwargs):
+        for func in self._listeners:
+            func(*args, **kwargs)