Add after_info to tkinter

csabella · csabella · commit f3598e1c658d · 2018-03-04T08:40:07.000-05:00
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py
@@ -759,6 +759,7 @@ def after_idle(self, func, *args):
         Return an identifier to cancel the scheduling with
         after_cancel."""
         return self.after('idle', func, *args)
+
     def after_cancel(self, id):
         """Cancel scheduling of function identified with ID.
 
@@ -775,6 +776,24 @@ def after_cancel(self, id):
         except TclError:
             pass
         self.tk.call('after', 'cancel', id)
+
+    def after_info(self, id=None):
+        """Return information about existing event handlers.
+
+        With no argument, return a list of the identifiers for all existing
+        event handlers created by the after command for this interpreter.
+        If id is supplied, it specifies an existing handler; id must have been
+        the return value from some previous call to after or after_idle and it
+        must not have triggered yet or been canceled. If the id doesn't exist,
+        a TclError is raised.  Othewise, the return value is a tuple
+        containing (script, type) where type is either 'idle' or 'timer' to
+        indicate what kind of event handler it is.
+        """
+        if id is None:
+            return self.tk.call('after', 'info')
+        else:
+            return self.tk.call('after', 'info', id)
+
     def bell(self, displayof=0):
         """Ring a display's bell."""
         self.tk.call(('bell',) + self._displayof(displayof))
diff --git a/Lib/tkinter/test/test_tkinter/test_misc.py b/Lib/tkinter/test/test_tkinter/test_misc.py
@@ -156,6 +156,40 @@ def callback():
         with self.assertRaises(tkinter.TclError):
             root.tk.call('after', 'info', idle1)
 
+    def test_after_info(self):
+        root = self.root
+        # Add timer.
+        timer = root.after(1, lambda: 'break')
+
+        # With no parameter, it returns a tuple of the event handler ids.
+        self.assertEqual(root.after_info(), (timer, ))
+        # Process event to remove it.
+        root.update()
+
+        timer1 = root.after(5000, lambda: 'break')
+        timer2 = root.after(5000, lambda: 'break')
+        idle1 = root.after_idle(lambda: 'break')
+        # Only contains new events and not 'timer'.
+        self.assertEqual(root.after_info(), (idle1, timer2, timer1))
+
+        # With a paramter returns a tuple of (script, type).
+        timer1_info = root.after_info(timer1)
+        self.assertIn('lambda', timer1_info[0])
+        self.assertEqual(timer1_info[1], 'timer')
+        idle1_info = root.after_info(idle1)
+        self.assertIn('lambda', idle1_info[0])
+        self.assertEqual(idle1_info[1], 'idle')
+
+        root.after_cancel(timer1)
+        with self.assertRaises(tkinter.TclError):
+            root.after_info(timer1)
+        root.after_cancel(timer2)
+        with self.assertRaises(tkinter.TclError):
+            root.after_info(timer2)
+        root.after_cancel(idle1)
+        with self.assertRaises(tkinter.TclError):
+            root.after_info(idle1)
+
 
 tests_gui = (MiscTest, )
 
diff --git a/Misc/NEWS.d/next/Library/2018-02-13-10-02-54.bpo-32839.McbVz3.rst b/Misc/NEWS.d/next/Library/2018-02-13-10-02-54.bpo-32839.McbVz3.rst
@@ -0,0 +1 @@
+Add after_info to tkinter.
