diff --git a/Lib/tkinter/test/test_ttk/test_extensions.py b/Lib/tkinter/test/test_ttk/test_extensions.py index e6b3eccf7afb8a..4da3845e01301e 100644 --- a/Lib/tkinter/test/test_ttk/test_extensions.py +++ b/Lib/tkinter/test/test_ttk/test_extensions.py @@ -301,6 +301,19 @@ def test_unique_radiobuttons(self): optmenu.destroy() optmenu2.destroy() + def test_trace_variable(self): + # prior to bpo45160, tracing a variable would cause the callback to be made twice + success = [] + items = ('a', 'b', 'c') + textvar = tkinter.StringVar(self.root) + def cb_test(*args): + self.assertEqual(textvar.get(), items[1]) + success.append(True) + optmenu = ttk.OptionMenu(self.root, textvar, "a", *items) + textvar.trace("w", cb_test) + optmenu['menu'].invoke(1) + self.assertEqual(success, [True]) + class DefaultRootTest(AbstractDefaultRootTest, unittest.TestCase): diff --git a/Lib/tkinter/ttk.py b/Lib/tkinter/ttk.py index b854235a626793..acdd565ec48a92 100644 --- a/Lib/tkinter/ttk.py +++ b/Lib/tkinter/ttk.py @@ -1643,7 +1643,10 @@ def set_menu(self, default=None, *values): menu.delete(0, 'end') for val in values: menu.add_radiobutton(label=val, - command=tkinter._setit(self._variable, val, self._callback), + command=( + None if self._callback is None + else lambda val=val: self._callback(val) + ), variable=self._variable) if default: diff --git a/Misc/NEWS.d/next/Library/2021-09-11-14-47-05.bpo-45160.VzMXbW.rst b/Misc/NEWS.d/next/Library/2021-09-11-14-47-05.bpo-45160.VzMXbW.rst new file mode 100644 index 00000000000000..9d11ed0e55d24c --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-09-11-14-47-05.bpo-45160.VzMXbW.rst @@ -0,0 +1 @@ +When tracing a tkinter variable used by a ttk OptionMenu, callbacks are no longer made twice. \ No newline at end of file