[Python-checkins] bpo-32857: Raise error when tkinter after_cancel() is called with None. (GH-5701)
Miss Islington (bot)
webhook-mailer at python.org
Sun Mar 4 07:00:36 EST 2018
https://github.com/python/cpython/commit/a5303dd9c263b337f02dda0038f2f5a10208140c
commit: a5303dd9c263b337f02dda0038f2f5a10208140c
branch: 3.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2018-03-04T04:00:33-08:00
summary:
bpo-32857: Raise error when tkinter after_cancel() is called with None. (GH-5701)
(cherry picked from commit 74382a3f175ac285cc924a73fd758e8dc3cc41bb)
Co-authored-by: Cheryl Sabella <cheryl.sabella at gmail.com>
files:
A Misc/NEWS.d/next/Library/2018-02-16-14-37-14.bpo-32857.-XljAx.rst
M Lib/tkinter/__init__.py
M Lib/tkinter/test/test_tkinter/test_misc.py
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py
index deea791831ed..53bad3fa95ae 100644
--- a/Lib/tkinter/__init__.py
+++ b/Lib/tkinter/__init__.py
@@ -739,6 +739,7 @@ def after(self, ms, func=None, *args):
if not func:
# I'd rather use time.sleep(ms*0.001)
self.tk.call('after', ms)
+ return None
else:
def callit():
try:
@@ -762,11 +763,13 @@ def after_cancel(self, id):
"""Cancel scheduling of function identified with ID.
Identifier returned by after or after_idle must be
- given as first parameter."""
+ given as first parameter.
+ """
+ if not id:
+ raise ValueError('id must be a valid identifier returned from '
+ 'after or after_idle')
try:
data = self.tk.call('after', 'info', id)
- # In Tk 8.3, splitlist returns: (script, type)
- # In Tk 8.4, splitlist may return (script, type) or (script,)
script = self.tk.splitlist(data)[0]
self.deletecommand(script)
except TclError:
diff --git a/Lib/tkinter/test/test_tkinter/test_misc.py b/Lib/tkinter/test/test_tkinter/test_misc.py
index 9dc1e37547fc..1d1a3c29f6bc 100644
--- a/Lib/tkinter/test/test_tkinter/test_misc.py
+++ b/Lib/tkinter/test/test_tkinter/test_misc.py
@@ -48,6 +48,114 @@ def test_tk_setPalette(self):
'^must specify a background color$',
root.tk_setPalette, highlightColor='blue')
+ def test_after(self):
+ root = self.root
+
+ def callback(start=0, step=1):
+ nonlocal count
+ count = start + step
+
+ # Without function, sleeps for ms.
+ self.assertIsNone(root.after(1))
+
+ # Set up with callback with no args.
+ count = 0
+ timer1 = root.after(0, callback)
+ self.assertIn(timer1, root.tk.call('after', 'info'))
+ (script, _) = root.tk.splitlist(root.tk.call('after', 'info', timer1))
+ root.update() # Process all pending events.
+ self.assertEqual(count, 1)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call(script)
+
+ # Set up with callback with args.
+ count = 0
+ timer1 = root.after(0, callback, 42, 11)
+ root.update() # Process all pending events.
+ self.assertEqual(count, 53)
+
+ # Cancel before called.
+ timer1 = root.after(1000, callback)
+ self.assertIn(timer1, root.tk.call('after', 'info'))
+ (script, _) = root.tk.splitlist(root.tk.call('after', 'info', timer1))
+ root.after_cancel(timer1) # Cancel this event.
+ self.assertEqual(count, 53)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call(script)
+
+ def test_after_idle(self):
+ root = self.root
+
+ def callback(start=0, step=1):
+ nonlocal count
+ count = start + step
+
+ # Set up with callback with no args.
+ count = 0
+ idle1 = root.after_idle(callback)
+ self.assertIn(idle1, root.tk.call('after', 'info'))
+ (script, _) = root.tk.splitlist(root.tk.call('after', 'info', idle1))
+ root.update_idletasks() # Process all pending events.
+ self.assertEqual(count, 1)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call(script)
+
+ # Set up with callback with args.
+ count = 0
+ idle1 = root.after_idle(callback, 42, 11)
+ root.update_idletasks() # Process all pending events.
+ self.assertEqual(count, 53)
+
+ # Cancel before called.
+ idle1 = root.after_idle(callback)
+ self.assertIn(idle1, root.tk.call('after', 'info'))
+ (script, _) = root.tk.splitlist(root.tk.call('after', 'info', idle1))
+ root.after_cancel(idle1) # Cancel this event.
+ self.assertEqual(count, 53)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call(script)
+
+ def test_after_cancel(self):
+ root = self.root
+
+ def callback():
+ nonlocal count
+ count += 1
+
+ timer1 = root.after(5000, callback)
+ idle1 = root.after_idle(callback)
+
+ # No value for id raises a ValueError.
+ with self.assertRaises(ValueError):
+ root.after_cancel(None)
+
+ # Cancel timer event.
+ count = 0
+ (script, _) = root.tk.splitlist(root.tk.call('after', 'info', timer1))
+ root.tk.call(script)
+ self.assertEqual(count, 1)
+ root.after_cancel(timer1)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call(script)
+ self.assertEqual(count, 1)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call('after', 'info', timer1)
+
+ # Cancel same event - nothing happens.
+ root.after_cancel(timer1)
+
+ # Cancel idle event.
+ count = 0
+ (script, _) = root.tk.splitlist(root.tk.call('after', 'info', idle1))
+ root.tk.call(script)
+ self.assertEqual(count, 1)
+ root.after_cancel(idle1)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call(script)
+ self.assertEqual(count, 1)
+ with self.assertRaises(tkinter.TclError):
+ root.tk.call('after', 'info', idle1)
+
tests_gui = (MiscTest, )
diff --git a/Misc/NEWS.d/next/Library/2018-02-16-14-37-14.bpo-32857.-XljAx.rst b/Misc/NEWS.d/next/Library/2018-02-16-14-37-14.bpo-32857.-XljAx.rst
new file mode 100644
index 000000000000..4ebbde4d1946
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-02-16-14-37-14.bpo-32857.-XljAx.rst
@@ -0,0 +1 @@
+In :mod:`tkinter`, ``after_cancel(None)`` now raises a :exc:`ValueError` instead of canceling the first scheduled function. Patch by Cheryl Sabella.
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