Implement #15

PythonHome/Lib/idlelib/Delegator.py

@@ -0,0 +1,25 @@
+class Delegator:
+
+    # The cache is only used to be able to change delegates!
+
+    def __init__(self, delegate=None):
+        self.delegate = delegate
+        self.__cache = set()
+
+    def __getattr__(self, name):
+        attr = getattr(self.delegate, name) # May raise AttributeError
+        setattr(self, name, attr)
+        self.__cache.add(name)
+        return attr
+
+    def resetcache(self):
+        for key in self.__cache:
+            try:
+                delattr(self, key)
+            except AttributeError:
+                pass
+        self.__cache.clear()
+
+    def setdelegate(self, delegate):
+        self.resetcache()
+        self.delegate = delegate