Qt apps not fully integrated with gtk

[-iak-]

Hello everybody,
I am using MX 23 with Xfce 4.20. Sadly some qt apps are not integrated with the system (i.e. Strawberry is, Okular is not).
I tried exporting the QT_PLATFORMTHEME=qt5ct, and apparently it's properly set:

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$ env | grep qt
QT_LOGGING_RULES=qt.qpa.xcb.warning=false
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.avif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:*~=00;90:*#=00;90:*.bak=00;90:*.old=00;90:*.orig=00;90:*.part=00;90:*.rej=00;90:*.swp=00;90:*.tmp=00;90:*.dpkg-dist=00;90:*.dpkg-old=00;90:*.ucf-dist=00;90:*.ucf-new=00;90:*.ucf-old=00;90:*.rpmnew=00;90:*.rpmorig=00;90:*.rpmsave=00;90:
QT_PLATFORMTHEME=qt5ct

Some system info:

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System:
  Kernel: 6.1.0-29-rt-amd64 [6.1.123-1] arch: x86_64 bits: 64 compiler: gcc v: 12.2.0
    parameters: BOOT_IMAGE=/boot/vmlinuz-6.1.0-29-rt-amd64 root=UUID=<filter> ro quiet splash
  Desktop: Xfce v: 4.20.0 tk: Gtk v: 3.24.38 info: xfce4-panel wm: xfwm v: 4.20.0 vt: 7
    dm: LightDM v: 1.32.0 Distro: MX-23.5_x64 Libretto Jan 12  2025 base: Debian GNU/Linux 12
    (bookworm)
Machine:
  Type: Laptop System: Dell product: Latitude 5490 v: N/A serial: <superuser required> Chassis:
    type: 10 serial: <superuser required>
  Mobo: Dell model: 0DH2HV v: A00 serial: <superuser required> UEFI: Dell v: 1.6.2
    date: 11/27/2018
Battery:
  ID-1: BAT0 charge: 30.2 Wh (100.0%) condition: 30.2/68.0 Wh (44.4%) volts: 8.5 min: 7.6
    model: BYD DELL KCM828A type: Li-poly serial: <filter> status: full
CPU:
  Info: model: Intel Core i5-8350U bits: 64 type: MT MCP arch: Coffee Lake gen: core 8 level: v3
    note: check built: 2017 process: Intel 14nm family: 6 model-id: 0x8E (142) stepping: 0xA (10)
    microcode: 0xF6
  Topology: cpus: 1x cores: 4 tpc: 2 threads: 8 smt: enabled cache: L1: 256 KiB
    desc: d-4x32 KiB; i-4x32 KiB L2: 1024 KiB desc: 4x256 KiB L3: 6 MiB desc: 1x6 MiB
  Speed (MHz): avg: 449 high: 798 min/max: 400/3600 scaling: driver: intel_pstate
    governor: powersave cores: 1: 400 2: 798 3: 400 4: 400 5: 400 6: 400 7: 400 8: 400
    bogomips: 30399
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
  Vulnerabilities:
  Type: gather_data_sampling mitigation: Microcode
  Type: itlb_multihit status: KVM: VMX disabled
  Type: l1tf mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable
  Type: mds mitigation: Clear CPU buffers; SMT vulnerable
  Type: meltdown mitigation: PTI
  Type: mmio_stale_data mitigation: Clear CPU buffers; SMT vulnerable
  Type: reg_file_data_sampling status: Not affected
  Type: retbleed mitigation: IBRS
  Type: spec_rstack_overflow status: Not affected
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer sanitization
  Type: spectre_v2 mitigation: IBRS; IBPB: conditional; STIBP: conditional; RSB filling;
    PBRSB-eIBRS: Not affected; BHI: Not affected
  Type: srbds mitigation: Microcode
  Type: tsx_async_abort mitigation: TSX disabled
Graphics:
  Device-1: Intel UHD Graphics 620 vendor: Dell driver: i915 v: kernel arch: Gen-9.5
    process: Intel 14nm built: 2016-20 ports: active: eDP-1 empty: DP-1,HDMI-A-1,HDMI-A-2
    bus-ID: 00:02.0 chip-ID: 8086:5917 class-ID: 0300
  Device-2: Realtek Integrated Webcam HD type: USB driver: uvcvideo bus-ID: 1-5:2
    chip-ID: 0bda:568c class-ID: 0e02 serial: <filter>
  Display: x11 server: X.Org v: 1.21.1.7 compositor: xfwm v: 4.20.0 driver: X:
    loaded: modesetting unloaded: fbdev,vesa dri: iris gpu: i915 display-ID: :0.0 screens: 1
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 508x285mm (20.00x11.22") s-diag: 582mm (22.93")
  Monitor-1: eDP-1 model: BOE Display 0x0810 built: 2018 res: 1920x1080 hz: 60 dpi: 158
    gamma: 1.2 size: 309x173mm (12.17x6.81") diag: 354mm (13.9") ratio: 16:9 modes: 1920x1080
  API: OpenGL v: 4.6 Mesa 22.3.6 renderer: Mesa Intel UHD Graphics 620 (KBL GT2)
    direct-render: Yes
Audio:
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Dell driver: snd_hda_intel v: kernel
    alternate: snd_soc_skl,snd_sof_pci_intel_skl bus-ID: 00:1f.3 chip-ID: 8086:9d71 class-ID: 0403
  API: ALSA v: k6.1.0-29-rt-amd64 status: kernel-api tools: alsamixer,amixer
  Server-1: JACK v: 1.9.21 status: off tools: jack_control,qjackctl
  Server-2: PipeWire v: 1.0.0 status: active with: 1: pipewire-pulse status: active
    2: wireplumber status: active 3: pipewire-alsa type: plugin 4: pw-jack type: plugin
    tools: pactl,pw-cat,pw-cli,wpctl
Network:
  Device-1: Intel Ethernet I219-LM vendor: Dell driver: e1000e v: kernel port: N/A bus-ID: 00:1f.6
    chip-ID: 8086:15d7 class-ID: 0200
  IF: eth0 state: down mac: <filter>
  Device-2: Intel Wireless 8265 / 8275 driver: iwlwifi v: kernel pcie: gen: 1 speed: 2.5 GT/s
    lanes: 1 bus-ID: 02:00.0 chip-ID: 8086:24fd class-ID: 0280
  IF: wlan0 state: up mac: <filter>
  IF-ID-1: wwan0 state: down mac: <filter>
RAID:
  Hardware-1: Intel 82801 Mobile SATA Controller [RAID mode] driver: ahci v: 3.0 port: f060
    bus-ID: 00:17.0 chip-ID: 8086:282a rev: N/A class-ID: 0104
Drives:
  Local Storage: total: 119.24 GiB used: 21.39 GiB (17.9%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/sda maj-min: 8:0 vendor: SK Hynix model: SC311 SATA 128GB size: 119.24 GiB
    block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s type: SSD serial: <filter> rev: 0P10
    scheme: GPT
Partition:
  ID-1: / raw-size: 29.3 GiB size: 28.67 GiB (97.86%) used: 12.43 GiB (43.4%) fs: ext4
    dev: /dev/sda2 maj-min: 8:2
  ID-2: /boot/efi raw-size: 100 MiB size: 96 MiB (96.00%) used: 30.8 MiB (32.1%) fs: vfat
    dev: /dev/sda1 maj-min: 8:1
  ID-3: /home raw-size: 14.65 GiB size: 14.32 GiB (97.76%) used: 4.44 GiB (31.0%) fs: ext4
    dev: /dev/sda3 maj-min: 8:3
Swap:
  Kernel: swappiness: 15 (default 60) cache-pressure: 100 (default)
  ID-1: swap-1 type: partition size: 1.95 GiB used: 0 KiB (0.0%) priority: -2 dev: /dev/sda4
    maj-min: 8:4
Sensors:
  System Temperatures: cpu: 38.0 C pch: 36.0 C mobo: 31.0 C
  Fan Speeds (RPM): cpu: 0
Repos:
  Packages: pm: dpkg pkgs: 2918 libs: 1665 tools: apt,apt-get,aptitude,nala,synaptic pm: rpm
    pkgs: 0 pm: flatpak pkgs: 0
  No active apt repos in: /etc/apt/sources.list
  Active apt repos in: /etc/apt/sources.list.d/debian-stable-updates.list
    1: deb [url]http://deb.debian.org/debian[/url] bookworm-updates main contrib non-free non-free-firmware
  Active apt repos in: /etc/apt/sources.list.d/debian.list
    1: deb [url]http://deb.debian.org/debian[/url] bookworm main contrib non-free non-free-firmware
    2: deb [url]http://security.debian.org/debian-security[/url] bookworm-security main contrib non-free non-free-firmware
  Active apt repos in: /etc/apt/sources.list.d/mx.list
    1: deb [url]http://ftp.halifax.rwth-aachen.de/mxlinux/packages/mx/repo/[/url] bookworm main non-free
    2: deb [url]http://ftp.halifax.rwth-aachen.de/mxlinux/packages/mx/testrepo/[/url] bookworm test
  Active apt repos in: /etc/apt/sources.list.d/vivaldi.list
    1: deb [arch=amd64] [url]https://repo.vivaldi.com/stable/deb/[/url] stable main
Info:
  Processes: 326 Uptime: 15m wakeups: 18980 Memory: 7.62 GiB used: 2.53 GiB (33.2%) Init: SysVinit
  v: 3.06 runlevel: 5 default: graphical tool: systemctl Compilers: gcc: 12.2.0 alt: 12
  Client: shell wrapper v: 5.2.15-release inxi: 3.3.26
Boot Mode: UEFI

What else can I try?
Thank you in advance for your replies.

[dolphin_oracle]

by default we set Qt to follow gtk2 themes. all of our included themes have both gtk3 and gtk2 components.

if you set to qt5ct, you must have the qt5ct plugin installed. and set it up to use some theme arrangement via qt5ct settings utility. None of that is installed by default.

strawberry does work to pick up basic theme elements on our default install. icons might be its own though. Can't say about okular. being a KDE app rather than a straight Qt app, it may well have weirdness.

[-iak-]

by default we set Qt to follow gtk2 themes. all of our included themes have both gtk3 and gtk2 components.

if you set to qt5ct, you must have the qt5ct plugin installed. and set it up to use some theme arrangement via qt5ct settings utility. None of that is installed by default.

strawberry does work to pick up basic theme elements on our default install. icons might be its own though. Can't say about okular. being a KDE app rather than a straight Qt app, it may well have weirdness.

Thank you for your reply. Talking about qt5ct, I forgot to mention that I already had it installed and that it shows a warning message saying that the QT_QPA_PLATFORMTHEME variable is set to gtk2 instead of qt5ct. Apparently, env says it's also set properly, instead.

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$ env
SHELL=/bin/bash
SESSION_MANAGER=local/dell:@/tmp/.ICE-unix/3427,unix/dell:/tmp/.ICE-unix/3427
WINDOWID=119537671
QT_ACCESSIBILITY=1
COLORTERM=truecolor
XDG_CONFIG_DIRS=/etc/xdg
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
XDG_MENU_PREFIX=xfce-
QT_LOGGING_RULES=qt.qpa.xcb.warning=false
SSH_AUTH_SOCK=/tmp/ssh-MARK2EgoxoM4/agent.3427
XDG_CONFIG_HOME=/home/rawyak/.config
DESKTOP_SESSION=xfce
SSH_AGENT_PID=3522
GTK_MODULES=canberra-gtk-module:gail:atk-bridge
XDG_SEAT=seat0
PWD=/home/rawyak
LOGNAME=rawyak
XDG_SESSION_DESKTOP=xfce
QT_QPA_PLATFORMTHEME=qt5ct
XDG_SESSION_TYPE=x11
XAUTHORITY=/home/rawyak/.Xauthority
XDG_GREETER_DATA_DIR=/var/lib/lightdm/data/rawyak
GDM_LANG=it_IT.UTF-8
HOME=/home/rawyak
LANG=it_IT.UTF-8
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.avif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:*~=00;90:*#=00;90:*.bak=00;90:*.old=00;90:*.orig=00;90:*.part=00;90:*.rej=00;90:*.swp=00;90:*.tmp=00;90:*.dpkg-dist=00;90:*.dpkg-old=00;90:*.ucf-dist=00;90:*.ucf-new=00;90:*.ucf-old=00;90:*.rpmnew=00;90:*.rpmorig=00;90:*.rpmsave=00;90:
XDG_CURRENT_DESKTOP=XFCE
VTE_VERSION=7006
QT_PLATFORMTHEME=qt5ct
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_CACHE_HOME=/home/rawyak/.cache
XDG_SESSION_CLASS=user
TERM=xterm-256color
USER=rawyak
DISPLAY=:0.0
SHLVL=1
XDG_VTNR=7
XDG_SESSION_ID=1
PAPERSIZE=a4
XDG_RUNTIME_DIR=/run/user/1000
QT_PLATFORM_PLUGIN=gtk2
XDG_DATA_DIRS=/usr/share/xfce4:/home/rawyak/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/sbin:/usr/sbin
GDMSESSION=xfce
DBUS_SESSION_BUS_ADDRESS=unix:path=/tmp/dbus-LO8ixa9j78,guid=dd30b03a199e9414f634f5dc67c04b99
QT_SCALE_FACTOR=1
_=/usr/bin/env

[dolphin_oracle]

Code: Select all

QT_PLATFORM_PLUGIN=gtk2

try also changing that one.

[AVLinux]

@dolphin_oracle

Do you know what the difference is between the platformtheme and qt5ct methods vs. the qt6gtk2 and qt5gtk2 plugins that are in MX Repos? In my experience the qt6gtk2 Plugin is working well for qt6 apps but it's unclear to me if the the QT5 ones does much since the platform theme stuff works well

[dolphin_oracle]

they are different plugins, although the qt6gtk2 plugin works harmoniously with the qt5 style builtins.

[-iak-]

Code: Select all

QT_PLATFORM_PLUGIN=gtk2

try also changing that one.

I tried. If I logout and then back in it's gone, and if I try to launch qt5ct or Okular in the same session, it still doesn't make any change.

Does anyone have any clue on where qt5ct is going to look for the QT_QPA_PLATFORMTHEME variable?

[dolphin_oracle]

Code: Select all

QT_PLATFORM_PLUGIN=gtk2

try also changing that one.

I tried. If I logout and then back in it's gone, and if I try to launch qt5ct or Okular in the same session, it still doesn't make any change.

Does anyone have any clue on where qt5ct is going to look for the QT_QPA_PLATFORMTHEME variable?

its an environement variable, in ram.

if you are running Xfce, the variables are set by /etc/X11/Xsession.d/56xfce4-qtconfig.

you can set up an override in "$HOME/.config/MX-Linux/qt_plugin.conf" by setting the plugin variable there. so "qt5ct" in that file, log out, login.

[dontknowlinux]

just a stupid question:
why that 2 variables are not there by default?

[dolphin_oracle]

just a stupid question:
why that 2 variables are not there by default?

The variables are set not just the way the op needs them set.