Hi, I won't mention any specific version in the warning, just "a future Qt release." That way we can continue the discussion of which version changes the default after this. I hope to have both the patches to add the warnings up today, since this is the urgent part.
Deprecate and replace existing functions/properties: I don’t like that the new names will be longer. Wouldn’t it be nice to eventually get back to what we already have, except with the default format being plain text? If we warn about auto-detection for a while (every time it actually happens), and then just change the behavior in some future release before the next LTS, maybe we don’t need to rename anything. I think it can mostly be solved without replacing any functions, just changing the default. The static functions in QMessageBox are a bit more tricky, since they don't have any way to override the text format. So we can't really add a warning there since there will be no way to silence it without adding new API. I think accepting that these default to rich text is one option, same as for QToolTip. You could still get into traps if you show an error dialog with something like a filename which includes HTML tags for instance, but at some point, maybe it is the user's responsibility to familiarize themselves with the documented behavior. An alternative is to add overloads that accept a text format in Qt 6.13 and then start warning that we will change the default in the next one. Either way, I think QLabel/Text/Label are the most important ones to fix first, so I will focus on those. -- Eskil Abrahamsen Blomfeldt Principal Manager, Graphics Engines The Qt Company Sandakerveien 116 0484 Oslo, Norway [email protected] http://qt.io Confidential ________________________________ From: Development <[email protected]> on behalf of Shawn Rutledge via Development <[email protected]> Sent: Thursday, November 5, 2026 9:54 AM To: List for announcements regarding Qt releases and development via Announce via Development <[email protected]> Subject: Re: [Development] Changing the default of AutoText to PlainText On Nov 2, 2026, at 16:00, Eskil Abrahamsen Blomfeldt via Development <[email protected]> wrote: * Add run-time warning to Qt 6.12.x which triggers whenever AutoText gets resolved to RichText/StyledText. This detects intentional use and alerts developers that they need to update their code before the next minor release. Work in progress for Qt Widgets here: https://codereview.qt-project.org/c/qt/qtbase/+/784816 * Add compile-time warnings using qmllint and clazy to detect uses where AutoText is used with either rich text or undeterminable (possibly user-provided) text. * Blog about it and try to spread the word as much as possible * Change the default from AutoText to PlainText in Qt 6.13. Possibly with an environment variable to manually select the old behavior. * For the static functions in QMessageBox, it does not make sense to warn, since there would be no way for users to fix the warning in the Qt 6.12 timespan. But in Qt 6.13, we can deprecate the existing functions and replace them with ones that also accept a text format. * In Qt Widgets, add convenience constructors that take a text format as well as a string in classes such as QLabel. * For cases like QToolTip, it has always been rich text enabled and there is no way in the API to make it plain text-only. I would consider tooltips with user-provided content rare enough that we can just document this, as done in the patch linked above. I worry whether 6.13 is too soon to change behavior. But I want to eventually get rid of the AutoText implementation, because it’s not possible to be completely correct: to be reasonable, we only try to detect an HTML tag within some prefix of the whole text; and we cannot detect markdown. Plain text is also HTML (the whole thing is one paragraph) and is also markdown (double-newlines are significant). So we should do what we can to encourage specifying text format whenever it’s not plain text and whenever it comes from user input: we need the warning ASAP. But we might also expect someone to write a bug about the default changing. Maybe that’s also ok, we just mark it invalid: I’m not sure how big a deal that would be for anyone. Warning over a somewhat longer period (until 6.14?) might soften the blow. Deprecate and replace existing functions/properties: I don’t like that the new names will be longer. Wouldn’t it be nice to eventually get back to what we already have, except with the default format being plain text? If we warn about auto-detection for a while (every time it actually happens), and then just change the behavior in some future release before the next LTS, maybe we don’t need to rename anything.
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