Status of "default Qt5" Gear components

[Luigi Toscano]

Hi,

I've analyzed the status of the deliverables part of Gear which are still
tracked as Qt5 applications from the i18n point of view.

In light of the recent discussion about finding a shutdown date for the Qt5 CI
on invent.kde.org, I've already done a a similar investigation for the
independently released repositories. My hope here was to find some
applications that are basically ready for being Qt6 only.

So here are the results for Gear, grouped by types:


# Ready for Qt6-only
They supports Qt5 and Qt6, and they are compiled using Qt6 by some distributions.

- kalzium
- step


# Ready for Qt6-only, maybe with dependencies

There are 3 subcategories: libraries, thumbnailers and KIO workers.
They supports Qt5 and Qt6, and they are compiled using Qt6 by some distributions.

## Libraries
The complicated part is to see whether the Qt5 flavors is still needed.

- libkdcraw: Qt5 required at least by krita
- libkexiv2
- libkcddb
- signon-kwallet-extension

## Thumbnailers
Probably not enough users left to keep the Qt5 version around:

- kdegraphics-thumbnailers
- ffmpegthumbs
- kdesdk-thumbnailers

## KIO Workers
Same arguments as for the thumbnailers.

- kio-admin
- kio-zeroconf


# Almost ready for Qt6-only

- minuet
It supports both Qt5 and Qt6, but the Qt6 version doesn't seem to work as
expected in my quick testing (I didn't manage to progress in any of the
questions), maybe a QML porting issue?


# Work in progress

- artikulate: https://invent.kde.org/education/artikulate/-/merge_requests/15
- kamoso: https://invent.kde.org/multimedia/kamoso/-/tree/work/chonky/kf6-port
- kig: several MRs https://invent.kde.org/education/kig/-/merge_requests
- kqtquickcharts: apparently no port, but only used by ktouch, which has WIP
- ktouch: https://invent.kde.org/education/ktouch/-/merge_requests/35
- rocs: requires porting away from QScript first:
   * https://invent.kde.org/education/rocs/-/merge_requests/53


# Not started

- cervisia: I think I've seen someone's offer to take a look
   * https://mail.kde.org/pipermail/kde-core-devel/2024-December/092382.html
- umbrello: which just recently removed the Qt4 leftovers



# Proposal

Switch kalzium, step, the thumbnailers and the KIO workers to Qt6 only for
Gear 25.04 (and even minuet if anyone is able to figure it out what doesn't
work, or whether I just didn't understand how it is supposed to work).
Evaluate which libraries are still needed and switch them too.

This would leave a few components left (between 8 and 12) as "primarily Qt5",
which could get more attention for a (hopefully) final port in 25.08.

Thoughts?

Ciao
-- 
Luigi