https://github.com/python/cpython/commit/73a43960c7be50e136c5482404980175cb9... commit: 73a43960c7be50e136c5482404980175cb99f611 branch: 3.6 author: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> committer: GitHub <noreply@github.com> date: 2018-03-04T03:42:41-08:00 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@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.