I did some stuff with strace, and I'm certain that it gets the theme information from lxsession.

On Sun, Nov 10, 2013 at 1:24 AM, Jerome Leclanche <adys.wh@gmail.com> wrote:
Likely related to which .gtkrc file is being used. I think some DEs
force-load specific gtkrc files which might be what you want.
J. Leclanche

On Sun, Nov 10, 2013 at 6:22 AM, Mark Deneen <mdeneen+lxde@gmail.com> wrote:
> I've built everything have have it running now.  Most things look good, but
> I still use a handful of GTK apps and, for the life of me, I can't get them
> to use the proper theme.  If I just start up openbox without a full desktop
> environment, things are great and the theme can be set.  This leads me to
> believe that it's something that possibly lxsession is doing.
> Any ideas?
> On Wed, Oct 30, 2013 at 9:46 AM, Jerome Leclanche <adys.wh@gmail.com> wrote:
>> Hi lists
>> LXQt is now compilable and available for testing. Archlinux users will
>> find packages in the AUR and are able to install the *full* suite
>> with:
>> yaourt -S libqtxdg-git liblxqt-git liblxqt-mount-git libsysstat-git
>> lxsession-git pcmanfm-qt-git lxqt-common-git lxqt-panel-git
>> lxinput-qt-git lxqt-about-git lxqt-config-git lxqt-globalkeys-git
>> lxqt-notificationd-git lxqt-openssh-askpass-git lxqt-policykit-git
>> lxqt-power-git lxqt-runner-git
>> Most of these modules are optional (the first few are not).
>> For a display manager, SDDM is recommended:
>>   yaourt -S sddm-git
>>   sudo systemctl enable sddm.service
>> You very well may have to start the window manager manually. Packaging
>> issues should be reported directly to me. Bugs can be reported on
>> github (https://github.com/LXDE), or in this email thread.
>> Ubuntu (and possibly Debian) packages are coming soon. Contact Julien
>> Lavergne for those.
>> We need people to test and more than ever improve these. There are
>> some killer issues currently with the panel, pcmanfm-qt, keybindings
>> and session management. This is not suitable for production AT ALL
>> yet, but I'm really hoping if a few devs join us in fixing those
>> issues we can get back to where Razor currently is very soon.
>> J. Leclanche
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