https://github.com/python/cpython/commit/88e5d8a7b74e391c8ded63d3f5e9d67bf8cc2559
commit: 88e5d8a7b74e391c8ded63d3f5e9d67bf8cc2559
branch: main
author: Serhiy Storchaka <[email protected]>
committer: serhiy-storchaka <[email protected]>
date: 2026-06-20T17:11:21+03:00
summary:
gh-151675: Add tkinter Text.sync() and Text.pendingsync() (GH-151677)
Wrap the Tk text widget "sync" and "pendingsync" subcommands, which
control and report the synchronization of the displayed view with the
underlying text when line heights have not yet been computed.
files:
A Misc/NEWS.d/next/Library/2026-06-19-12-00-01.gh-issue-151675.acLD7L.rst
M Doc/library/tkinter.rst
M Doc/whatsnew/3.16.rst
M Lib/test/test_tkinter/test_text.py
M Lib/tkinter/__init__.py
diff --git a/Doc/library/tkinter.rst b/Doc/library/tkinter.rst
index 3d8983c57a12bf0..222a4d0128bd8d5 100644
--- a/Doc/library/tkinter.rst
+++ b/Doc/library/tkinter.rst
@@ -5608,6 +5608,29 @@ Widget classes
.. versionadded:: 3.3
+ .. method:: sync(command=None)
+
+ Control the synchronization of the displayed view with the underlying
+ text, which may lag behind when line heights have not yet been computed
+ (for example, for lines that have never been displayed).
+ If *command* is omitted, bring the line metrics up to date immediately by
+ forcing computation of any outdated line heights, and return once they
+ are current.
+ Otherwise schedule *command* to be called, with no arguments, exactly
+ once as soon as all line heights are up to date; if there are no pending
+ calculations, it is called immediately.
+
+ .. versionadded:: next
+
+ .. method:: pendingsync()
+
+ Return ``True`` if the line height calculations are not up to date, and
+ ``False`` otherwise.
+ The ``<<WidgetViewSync>>`` virtual event fires whenever this state
+ changes, with the *detail* field set to the new value.
+
+ .. versionadded:: next
+
.. method:: yview_pickplace(*what)
Adjust the view so that the location given by *what* is visible.
diff --git a/Doc/whatsnew/3.16.rst b/Doc/whatsnew/3.16.rst
index 2b6f396bdf16dd9..aa7b9b2223ec5ec 100644
--- a/Doc/whatsnew/3.16.rst
+++ b/Doc/whatsnew/3.16.rst
@@ -152,6 +152,11 @@ tkinter
is possible.
(Contributed by Serhiy Storchaka in :gh:`151674`.)
+* Added new :class:`!tkinter.Text` methods :meth:`~tkinter.Text.sync` and
+ :meth:`~tkinter.Text.pendingsync` which control and report the
+ synchronization of the displayed view with the underlying text.
+ (Contributed by Serhiy Storchaka in :gh:`151675`.)
+
xml
---
diff --git a/Lib/test/test_tkinter/test_text.py
b/Lib/test/test_tkinter/test_text.py
index 4f02502b7d216a1..905c194af3ac474 100644
--- a/Lib/test/test_tkinter/test_text.py
+++ b/Lib/test/test_tkinter/test_text.py
@@ -26,6 +26,18 @@ def test_debug(self):
text.debug(olddebug)
self.assertEqual(text.debug(), olddebug)
+ def test_sync(self):
+ text = self.text
+ # sync() returns None and brings line metrics up to date.
+ self.assertIsNone(text.sync())
+ self.assertIs(text.pendingsync(), False)
+
+ # sync(command) schedules a one-shot callback.
+ events = []
+ text.sync(command=lambda: events.append('synced'))
+ text.update()
+ self.assertEqual(events, ['synced'])
+
def test_index(self):
text = self.text
text.insert('1.0', 'Lorem ipsum\ndolor sit amet')
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py
index 559fe87ed46193b..8bdf7cc1e2d96b8 100644
--- a/Lib/tkinter/__init__.py
+++ b/Lib/tkinter/__init__.py
@@ -4110,6 +4110,44 @@ def peer_names(self): # new in Tk 8.5
the widget itself)."""
return self.tk.splitlist(self.tk.call(self._w, 'peer', 'names'))
+ def pendingsync(self): # new in Tk 8.5
+ """Return whether the line heights calculations are not up-to-date.
+
+ Return True if the line heights calculations are not up-to-date,
+ and False otherwise.
+ """
+ return self.tk.getboolean(self.tk.call(self._w, 'pendingsync'))
+
+ def sync(self, command=None): # new in Tk 8.5
+ """Control the synchronization of the view of the text widget.
+
+ If command is not specified, immediately bring the line metrics
+ up-to-date by forcing computation of any outdated line heights.
+ The command returns immediately if there is no such outdated line.
+
+ If command is specified, schedule it to be executed (by the event
+ loop) exactly once as soon as all line heights are up-to-date.
+ If there are no pending line metrics calculations, command is
+ executed immediately.
+ """
+ if command is None:
+ self.tk.call(self._w, 'sync')
+ else:
+ def callit():
+ try:
+ command()
+ finally:
+ try:
+ self.deletecommand(name)
+ except TclError:
+ pass
+ try:
+ callit.__name__ = command.__name__
+ except AttributeError:
+ callit.__name__ = type(command).__name__
+ name = self._register(callit)
+ self.tk.call(self._w, 'sync', '-command', name)
+
def replace(self, index1, index2, chars, *args): # new in Tk 8.5
"""Replaces the range of characters between index1 and index2 with
the given characters and tags specified by args.
diff --git
a/Misc/NEWS.d/next/Library/2026-06-19-12-00-01.gh-issue-151675.acLD7L.rst
b/Misc/NEWS.d/next/Library/2026-06-19-12-00-01.gh-issue-151675.acLD7L.rst
new file mode 100644
index 000000000000000..92bd69de6bdc0ec
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-06-19-12-00-01.gh-issue-151675.acLD7L.rst
@@ -0,0 +1,3 @@
+Add the :meth:`~tkinter.Text.sync` and :meth:`~tkinter.Text.pendingsync`
+methods of :class:`!tkinter.Text`, wrapping the Tk ``sync`` and
+``pendingsync`` subcommands.
_______________________________________________
Python-checkins mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://mail.python.org/mailman3//lists/python-checkins.python.org
Member address: [email protected]
