code release

xlib/python/EventListener.py

@@ -0,0 +1,24 @@
+from collections import Iterable
+
+
+class EventListener:
+    __slots__ = ['_funcs']
+    def __init__(self):
+        self._funcs = []
+
+    def has_listeners(self):
+        return len(self._funcs) != 0
+
+    def add(self, func_or_list):
+        if isinstance(func_or_list, Iterable):
+            func_or_list = tuple(func_or_list)
+        else:
+            func_or_list = (func_or_list,)
+
+        for func in func_or_list:
+            if func not in self._funcs:
+                self._funcs.append(func)
+
+    def call(self, *args, **kwargs):
+        for func in self._funcs:
+            func(*args, **kwargs)