[SOLVED] QT Theming

greenjeans · 2025-04-19 16:23:32

Head_on_a_Stick wrote:

Just tried to build a trixie version of deadbang, it failed with this message:
Package qt5-gtk2-platformtheme is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'qt5-gtk2-platformtheme' has no installation candidate
And sure enough: https://tracker.debian.org/pkg/qtstyleplugins-src
I've replaced it with qt{5,6}-gtk-platformtheme, but that only works for GTK3 applications.
What is left that uses GTK2? I'll have to investigate...

Weird, there is no trixie version listed, but there is an updated version in sid, go figure...

But I expect before it's done with, a lot of stuff in sid will make it to trixie before the final freeze. I just reported a bug the other day in Caja (the Mate file manager) in the trixie version, nasty bug at that. Reported it about 6:00 one night, and the very next day the dev pushed an updated version into sid and closed the bug, and now some of it's depends have also been pushed into sid.

It will have to get pushed to trixie eventually, no way current version will work right. So I will be patient, lol it's Murphy's law that I chose to do my testing for trixie with a Mate desktop and now i'm on hold, arrgh.

Maybe try your deadbang build with the newer version?

Really appreciate your work with this stuff, it's important for good consistent theming.

https://packages.debian.org/sid/qt5-gtk2-platformtheme

EDIT: ia64 and riscv, unofficial ports....arrgh

Last edited by greenjeans (2025-04-19 16:32:37)

greenjeans · 2025-04-19 17:32:13

Another note for the database: The author of the qt6gtk2 package had closed down his github and archived the package, that's what led to finding a copy on the Suse build service and subsequently HOAS re-packaged it, but just found the guy on opencode.net, looks like he just moved his stuff there and is still working on it with some new commits just a month ago:

https://www.opencode.net/trialuser/qt6gtk2

Head_on_a_Stick · 2025-04-19 21:41:16

greenjeans wrote:

there is no trixie version listed, but there is an updated version in sid

The sid version is just for the ia64 & risv64 (unofficial) ports and the update just adds a patch for building against Qt v5.15 and some packaging changes; the package is built from the same git commit as for bookworm. EDIT: missed your edit...

I think it may be the case that the qt{5,6}-gtk-platformtheme packages are intended to replace the GTK2 configuration with GTK3. I will test and report back. I might even open a new thread if I'm feeling conscientious

Last edited by Head_on_a_Stick (2025-04-19 21:42:02)

johnraff · 2025-07-11 06:37:41

Anyway, qt5-style-plugins is definitely gone.
I'm sorry but I've lost touch with what's happening here.
Can someone clue me in on what we ought to be putting in the carbon package lists, and any environment variables we should be setting?

greenjeans · 2025-07-11 13:26:48

johnraff wrote:

Anyway, qt5-style-plugins is definitely gone.
I'm sorry but I've lost touch with what's happening here.
Can someone clue me in on what we ought to be putting in the carbon package lists, and any environment variables we should be setting?

The package you want that automatically applys theme colors for qt5 is qt5-gtk2-platformtheme, it's in Bookworm and in Sid, but I don't see it in Trixie: https://packages.debian.org/sid/qt5-gtk2-platformtheme

And for qt6 use the package HOAS and Micko re-packaged qt6gtk2.

~/.xsessionrc : export QT_QPA_PLATFORMTHEME=gtk2 <that command works for both packages. But some qt6 programs might be persnickety.

Last edited by greenjeans (2025-07-11 13:32:51)

johnraff · 2025-07-12 04:28:11

^Many thanks!

I do see there is a package qt5-gtk-platformtheme (not gtk2) for Trixie however.
https://packages.debian.org/trixie/qt5- … tformtheme

Are you sure that's not the one we want?

greenjeans · 2025-07-13 14:13:00

^^ It's in Bookworm too and I tried it at one point and it didn't seem to do anything. The difference between the two is that the package you mentioned only has one file (other than docs) an .so file that goes in /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so

While the gtk2 package, has two:
/usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk2.so
/usr/lib/x86_64-linux-gnu/qt5/plugins/styles/libqgtk2style.so

And the qt6gtk2 package also has two similar files. And those two packages do work, and off the same export command. Seems it's style.so that's needed to do the work, not sure what the deal is with qt5-gtk-platformtheme, looks like it's missing a style.so.

I'm finished up with a lot of my own projects for now, i'll test on a clean mini iso that doesn't have it, I also need to run an updated vanilla Devuan excalibur (trixie) iso for testing so once I get that knocked out I'll test on a fresh trixie-based iso too, and i'll report back.

greenjeans · 2025-07-13 16:55:59

Okay, tons of testing and searching, currently all on bookworm, not trixie yet.

The qt5-gtk-platformtheme doesn't do anything you'd notice because it's not a style plugin, it only has an effect on settings for icons, fonts, file chooser etc. It will not apply your gtk3 theme to colors themselves.

The qt5-gtk2-platformtheme will do the above PLUS apply colors from your gtk2 theme, because it is a style plugin, thus the additional style.so that gets installed.

The qt6gtk2 that HOAS and Micko have worked on, is also a style plugin and will change colors etc., again using gtk2 theme.

Those two packages work automatically with the same export command: export QT_QPA_PLATFORMTHEME=gtk2

There is a trixie package for qt6gtk2. There is not one for the qt5-gtk2-platformtheme, and the package in sid is not for amd64, just riscv and arm.

Recommendation: Maybe try to re-use the bookworm version of qt5-gtk2-platformtheme, it probably still works, will test later. Or possibly re-build/package it for trixie. I'm not sure there's any more upstream development for it unless some folks are doing it on their own.

There seems to be a concerted effort in several areas in Linux, to disable people's ability to apply their own themes to various apps, the CSD mentality is creeping in...

greenjeans · 2025-07-13 17:51:17

Hold on, possible alternative, the original author of qt6gtk2 is also making another package qt5gtk2, which i'm assuming works like the qt6 package does, and could replace qt5-gtk2-platformtheme.

And they both can use the same export command and so will work together.

https://www.opencode.net/trialuser/qt5gtk2

Last edited by greenjeans (2025-07-13 17:57:49)

johnraff · 2025-07-14 01:24:14

^Thanks for all that work!

greenjeans wrote:

Hold on...another package qt5gtk2...

...with bated breath.

---
qtstyleplugins-src has been removed from Debian, taking qt5-gtk2-platformtheme with it:
https://bugs.debian.org/cgi-bin/bugrepo … ug=1102992
https://bugs.debian.org/cgi-bin/bugrepo … bug=967720

Simon McVittie wrote:

GTK 2 was superseded by GTK 3 in 2011 (see
<https://bugs.debian.org/947713>). It no longer receives any significant
upstream maintenance, and in particular does not get feature development
for new features like UI scaling on high-pixel-density displays (HiDPI)
and native Wayland support. GTK 3 is in maintenance mode and GTK 4 is
approaching release, so it seems like a good time to be thinking about
minimizing the amount of GTK 2 in the archive.
GTK 2 is used by some important productivity applications like GIMP, and
has also historically been a popular UI toolkit for proprietary software
that we can't change, so perhaps removing GTK 2 from Debian will never be
feasible. However, it has reached the point where a dependency on it is
a bug - not a release-critical bug, and not a bug that can necessarily
be fixed quickly, but a piece of technical debt that maintainers should
be aware of.

greenjeans wrote:

There seems to be a concerted effort in several areas in Linux, to disable people's ability to apply their own themes to various apps, the CSD mentality is creeping in...

sigh...

hhh · 2025-07-14 01:34:19

greenjeans wrote:

There seems to be a concerted effort in several areas in Linux, to disable people's ability to apply their own themes to various apps, the CSD mentality is creeping in...

It's not Client Side Decorations (though that was an offshoot of it and you said mentality, so I get what you mean) and it's not several areas, it's all GTK and it (limiting customization) has been the mantra of gnome-shell since, what, the second release, and what you're talking about specifically is libadwaita apps.

Wikipedia wrote:

The most common criticism of GTK is the lack of backward-compatibility in major updates, most notably in the application programming interface (API) and theming. The result is that application developers or theme developers have to rewrite parts of their code to make it work with a newer version of GTK.

And developers were all "Challenge accepted!", and here we are.

Last edited by hhh (2025-07-14 01:44:05)

greenjeans · 2025-07-14 22:48:11

Results of a LOT of testing today:
All tests used VLC for qt5 and Cutemaze for qt6 as the test subjects.

1st test: Bookworm based system. Used the authors instructions to do a local make/install. Changed the export command to:
export QT_QPA_PLATFORMTHEME=qt5gtk2, logout/login and test: Great success! works just like the qt5-gtk2-platformtheme package!

Then I installed the qt6gtk2 .deb HOAS packaged and tested: More great success! And no need to change the export command, the above command works for both!

Test 2: Trixie-based system. I first had to install all the dev packages (which may be different than the bookworm versions), then I followed the same procedure, it complied and installed fine, but no effect when I tested it on VLC.

Then I installed the other package HOAS made for qt6gtk2 that he compiled for trixie, I seem to remember him saying he had to make some changes. In any case I installed it and it worked great.

So for trixie, likely somebody with more skill than I currently have will need to take a look at the qt5gtk2 source code and possibly make some mods for it to work like the qt6gtk2 package. But seems like it can be done, and if so will work great going forward as both packages are currently maintained even if they aren't in Debian.

Last edited by greenjeans (2025-07-14 22:48:53)

johnraff · 2025-07-15 00:17:29

^Many thanks for that!

Anyway, it doesn't look as if we can expect much help from Debian with gtk2 support going forward, while OTOH the need for gtk2 doesn't seem likely to go away soon. So let's see if we can get qt6gtk2 and qt5gtk2 working for us...

greenjeans wrote:

Bookworm based system. Used the authors instructions to do a local make/install.

You're talking about qt5gtk2 here, right? Could you post again the link to the original source code? Also HOAS's qt6gtk2? Thanks.

If we want to provide these on BL (and if we can get qt5gtk2 to work) we want to have copies of the source repositories here, and to be able to build our .deb files from that source.

We'll need to try and pin down what changes HOAS made to qt6gtk2, to try to apply them to qt5gtk2. It's a pity he no longer seems to be around, or we could just ask him.

greenjeans · 2025-07-15 00:32:16

johnraff wrote:

greenjeans wrote:
Bookworm based system. Used the authors instructions to do a local make/install.
You're talking about qt5gtk2 here, right? Could you post again the link to the original source code? Also HOAS's qt6gtk2? Thanks.

Yep, qt5gtk2. Links:

Author of both packages: https://www.opencode.net/trialuser
Source for qt5gtk2: https://www.opencode.net/trialuser/qt5gtk2
Source for qt6gtk2: https://www.opencode.net/trialuser/qt6gtk2
HOAS at Opensuse, qt6gtk2 packages: https://software.opensuse.org//download … ge=qt6gtk2

I think Micko already has copies of the qt6gtk2 packages in his repo as well. Possibly Micko knows how to re-write it.

Maybe we can use the bat-signal, or rather the cat-signal to call for HOAS, lol, very handy guy to have around, wish I was a little further along in my education so I could do it, but i'm working towards that day.

Last edited by greenjeans (2025-07-15 00:55:36)

johnraff · 2025-07-15 01:32:39

Thanks!

greenjeans · 2025-07-18 20:17:00

Found .debs of the qt5gtk2 package, the same user on the opensuse build service that we got the .deb for the qt6gtk2 from (unit193) built some a while back, for Debian 12 (bookworm), testing (trixie) and unstable (sid). They were built almost 2 years ago, so the version for that package is 1.0 while the latest version of the source is 1.1. But at least I can test the qt5 package and see if it works.

There is also another user who made a .deb for bookworm about 8 months ago possibly using a little newer source.

Links:
https://build.opensuse.org/repositories … 93/qt5gtk2
https://build.opensuse.org/repositories … 18/qt5gtk2

May be able to just re-build using newer source? I downloaded unit193's packages for both bookworm and testing, will boot up my trixie build here in a bit and test.

greenjeans · 2025-07-18 21:14:49

Success! I booted up a trixie-based live-session (Devuan 6 Excalibur, Mate environment, sysvinit) and installed the qt5gtk2 package for Debian testing from unit193's repo on the opensuse build service. Works fine, also installed the qt6gtk2 package for trixie that HOAS made and confirmed they both work off the same export command in ~/.xsessionrc: export QT_QPA_PLATFORMTHEME=qt5gtk2.

So that package even being almost 2 years old, works for trixie as it is. Might be better to try and re-package with the updated source, but at least it's a working verification of the package.

So cool man, going through all those apps that formerly have that stark-white qt look in the header and menu bars, and seeing it all change to my lovely gtk theme!

#61 2025-04-19 16:23:32

Re: [SOLVED] QT Theming

#62 2025-04-19 17:32:13

Re: [SOLVED] QT Theming

#63 2025-04-19 21:41:16

Re: [SOLVED] QT Theming

#64 2025-07-11 06:37:41

Re: [SOLVED] QT Theming

#65 2025-07-11 13:26:48

Re: [SOLVED] QT Theming

#66 2025-07-12 04:28:11

Re: [SOLVED] QT Theming

#67 2025-07-13 14:13:00

Re: [SOLVED] QT Theming

#68 2025-07-13 16:55:59

Re: [SOLVED] QT Theming

#69 2025-07-13 17:51:17

Re: [SOLVED] QT Theming

#70 2025-07-14 01:24:14

Re: [SOLVED] QT Theming

#71 2025-07-14 01:34:19

Re: [SOLVED] QT Theming

#72 2025-07-14 22:48:11

Re: [SOLVED] QT Theming

#73 2025-07-15 00:17:29

Re: [SOLVED] QT Theming

#74 2025-07-15 00:32:16

Re: [SOLVED] QT Theming

#75 2025-07-15 01:32:39

Re: [SOLVED] QT Theming

#76 2025-07-18 20:17:00

Re: [SOLVED] QT Theming

#77 2025-07-18 21:14:49

Re: [SOLVED] QT Theming

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