Index: leahi_dialin/utils/base.py
===================================================================
diff -u -r2138d06d100fdcf23f2e9069f35ee2fdee62008f -r894abd4d8e62d20ba65ca78e443ffb5ea00c07ea
--- leahi_dialin/utils/base.py	(.../base.py)	(revision 2138d06d100fdcf23f2e9069f35ee2fdee62008f)
+++ leahi_dialin/utils/base.py	(.../base.py)	(revision 894abd4d8e62d20ba65ca78e443ffb5ea00c07ea)
@@ -321,3 +321,16 @@
     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)