[SOLVED] QT Theming

greenjeans · 2025-10-08 20:34:19

Head_on_a_Stick wrote:

greenjeans wrote:
installed the qt6gtk2 package for trixie that HOAS made
That isn't needed for trixie and shouldn't be used.
Instead install the qt{5,6}-gtk-platformtheme packages, they work just fine for deadbang's trixie release.
https://packages.debian.org/trixie/qt5- … tformtheme
https://packages.debian.org/trixie/qt6- … tformtheme
EDIT: and the relevant environmental variable is still QT_QPA_PLATFORMTHEME=gtk2:
https://git.sr.ht/~head_on_a_stick/dead … 5_theme.sh

Already tried that, see post #68 above:

"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 gtk theme to colors themselves."

I tested all of them on both Trixie and Bookworm, and the packages you mentioned did not work to change colors. Perhaps something has changed since then, but I assure you the qt6gtk2 and qt5gtk2 worked wonderfully in testing.

Last edited by greenjeans (2025-10-08 20:59:29)

greenjeans · 2025-10-08 20:41:32

johnraff wrote:

greenjeans wrote:
...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 for Carbon we should have qt5gtk2 and qt6gtk2 available and installed, and set that environment variable. That advice still stands? If so, I should clone the code and rebuild the packages for our repo.

I think so. But it should be tested of course, I will try later in a live-session, but they worked great on Trixie when I tried them.

One thing though which I don't have Carbon running right now so I don't know, is does it have some qt5 and/or qt6 apps installed? I haven't put the qt6 version in my projects because no qt6 apps are installed, and installing the qt6gtk2 package requires some qt6 libraries to be installed. So I left it out but made the option available in a separate package.

The only qt5 app in my projects is VLC, so the libraries are already installed and it does a nice number on VLC.

And as I mentioned, the same export command works for both, so if a user does install qt6 apps then it's just a matter of installing the qt6gtk2 package and logging out/in or rebooting for it to take effect.

YMMV. I haven't tried this on Carbon.

Last edited by greenjeans (2025-10-08 21:08:49)

johnraff · 2025-10-09 03:50:26

Thanks to both @greenjeans and @Head_on_a_Stick

I'm not sure without researching, whether Carbon ships any qt6 apps, but I think we should have the necessary libraries in place by default, unless it's a question of many megabytes. I think having to search the forum for QT issues to discover they need to install qt6gtk2 is the sort of thing newer users don't enjoy.

As I said, unless it brings in a huge pile of dependencies. In that case, we would also have the option of including it in our "full" installs, but leaving it out of "lite" and "base".

Either way, at the moment qt6-gtk-platformtheme is not on our install list, so probably we should add it on a belt-and-braces principle?

Also I nearly missed this:

HoaS wrote:

the relevant environmental variable is still QT_QPA_PLATFORMTHEME=gtk2

greenjeans wrote:

they both work off the same export command in ~/.xsessionrc: export QT_QPA_PLATFORMTHEME=qt5gtk2

Which should we use?

greenjeans · 2025-10-09 15:12:13

johnraff wrote:

Thanks to both @greenjeans and @Head_on_a_Stick
Also I nearly missed this:
HoaS wrote:
the relevant environmental variable is still QT_QPA_PLATFORMTHEME=gtk2
greenjeans wrote:
they both work off the same export command in ~/.xsessionrc: export QT_QPA_PLATFORMTHEME=qt5gtk2
Which should we use?

With regard to the packages I recommended, the author of both has this to say on the code page for qt6gtk2:

"export QT_QPA_PLATFORMTHEME=gtk2

(qt5gtk2 for compatibility with Qt5Gtk2, qt6gtk2 is also a valid value)"

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

So you can see that package is pretty flexible, but for compatibility with the earlier qt5 package he says to use "Qt5Gtk2", so that is what I used in testing and can confirm it did work for both.

I don't remember though what the total was for size of QT libraries installed to use the QT6 package, what's a lot to me may be no big deal for y'all, I seem to remember about 80 mb worth or so.

johnraff · 2025-10-11 01:39:42

greenjeans wrote:

johnraff wrote:
Thanks to both @greenjeans and @Head_on_a_Stick
Also I nearly missed this:
HoaS wrote:
the relevant environmental variable is still QT_QPA_PLATFORMTHEME=gtk2
greenjeans wrote:
they both work off the same export command in ~/.xsessionrc: export QT_QPA_PLATFORMTHEME=qt5gtk2
Which should we use?
With regard to the packages I recommended, the author of both has this to say on the code page for qt6gtk2:
"export QT_QPA_PLATFORMTHEME=gtk2
(qt5gtk2 for compatibility with Qt5Gtk2, qt6gtk2 is also a valid value)"
https://www.opencode.net/trialuser/qt6gtk2
So you can see that package is pretty flexible, but for compatibility with the earlier qt5 package he says to use "Qt5Gtk2", so that is what I used in testing and can confirm it did work for both.

Hmm... So I guess we can use 'qt5gtk2' and wait to see if we get any user complaints?
It's not a core central config for our GTK-based setup.

I don't remember though what the total was for size of QT libraries installed to use the QT6 package, what's a lot to me may be no big deal for y'all, I seem to remember about 80 mb worth or so.

That's a lot to me too. Depends on whether some of those libraries are already pulled in by our "full" package list, or whether they'd be only to support qt6gtk2. If the latter, then I'm not sure it should go in by default...

greenjeans · 2025-10-11 02:28:02

johnraff wrote:

greenjeans wrote:
johnraff wrote:
Thanks to both @greenjeans and @Head_on_a_Stick
Also I nearly missed this:

Which should we use?
With regard to the packages I recommended, the author of both has this to say on the code page for qt6gtk2:
"export QT_QPA_PLATFORMTHEME=gtk2
(qt5gtk2 for compatibility with Qt5Gtk2, qt6gtk2 is also a valid value)"
https://www.opencode.net/trialuser/qt6gtk2
So you can see that package is pretty flexible, but for compatibility with the earlier qt5 package he says to use "Qt5Gtk2", so that is what I used in testing and can confirm it did work for both.
Hmm... So I guess we can use 'qt5gtk2' and wait to see if we get any user complaints?
It's not a core central config for our GTK-based setup.
I don't remember though what the total was for size of QT libraries installed to use the QT6 package, what's a lot to me may be no big deal for y'all, I seem to remember about 80 mb worth or so.
That's a lot to me too. Depends on whether some of those libraries are already pulled in by our "full" package list, or whether they'd be only to support qt6gtk2. If the latter, then I'm not sure it should go in by default...

Yeah i'm conflicted as well...I want to keep stuff lean and mean, and I balked at adding all that just for programs that might never get installed, there's so many toolkits now to try and support, gtk 2,3 4, qt 5, 6 etc. All creating more bloat.

But on the other hand, in my projects I add a whole lot of firmware to ensure things work for most hardware, and in my max projects where I add printer support I include tons of printer drivers...and all that's extra weight too...wondering now philosophy-of-use if I should just add those libraries at least in max versions to ensure theme-compliance and a consistent user-experience.

ETA: Love to get triple-h's thoughts on this.

Last edited by greenjeans (2025-10-11 02:33:25)

#81 2025-10-08 20:34:19

Re: [SOLVED] QT Theming

#82 2025-10-08 20:41:32

Re: [SOLVED] QT Theming

#83 2025-10-09 03:50:26

Re: [SOLVED] QT Theming

#84 2025-10-09 15:12:13

Re: [SOLVED] QT Theming

#85 2025-10-11 01:39:42

Re: [SOLVED] QT Theming

#86 2025-10-11 02:28:02

Re: [SOLVED] QT Theming

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