KDE Applications Use Oxygen Widget style eventhough Breeze is selected (Plasma 5)

[Anoop Panavalappil]

I have upgraded my Kubuntu to 15.04 Vivid from 14.10 and I use KDE. But I also have Gnome3 and Unity installed in my system.

After upgrade, I could find almost all applications are displayed with "Breeze" widget style (Kontact, Dolphin, KWalletManager, Kompare etc). But some KDE applications still shows the "Oxygen" widget style (System Settings, Kate, Gwenview, Quassel etc).

I selected "Breeze" for GUI style in Qt4 settings (qtconfig-qt4) and restarted still no use.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1434516/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Anoop Panavalappil (gnuanu)]

I could resolve the issue by uninstalling "appmenu-qt5" package. After uninstalling the package and rebooting, the styles are back to normal.

[Anoop Panavalappil (gnuanu)]

The issue is back again but in a whole new way. The Qt4 applications reverted back to Oxygen instead of Breeze style.

1. appmenu-qt5 is still not installed as it breaks the whole decorations and applications.
2. kde-style-breeze-qt4 package is installed in the system.
3. "Breeze" style is now missing from "Qt4 Config" (see attachment).

What am I really missing?

[Aleksandr Loktionov (loktionovam)]

I have this bug after upgrading Ubuntu to 15.04 Vivid. After debug with strace, i deleted ~/.config/Trolltech.conf, "Breeze" theme appeared in qtconfig-qt4 and now Qt4 application looks good. Maybe it help.

[Anoop Panavalappil (gnuanu)]

@Aleksandr Loktionov, That worked for me. Thanks a lot.

[imbezol (travis-c)]

Deleting Trolltech.conf seemed to work for me too but not immediately. I deleted it within KDE and then when I logged out the logout failed. I rebooted, logged back in.. and it wasn't fixed. I later logged out and back in again, and then found that my icons were working. Perhaps it takes a couple times for it to rebuild the config.

[Harald Sitter (apachelogger)]

If the package appmenu-qt5 is installed, Plasma is broken. This is due to appmenu-qt5 installing a /etc/profile.d/appmenu-qt5.sh which sets the QT_QPA_PLATFORMTHEME env variable. By having that loaded into the session the qpt plugin provided by plasma-integration won't be loaded.

[Dmitry Shachnev (mitya57)]

I am working on removing appmenu-qt5 from default installations: see bug 1612767 for that.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mohammad Anwar Shah (mohammadanwarshah)]

The possible workaround is unsetting `QT_QPA_PLATFORMTHEME` in ~/.profile file. A workaround is described in this askUbuntu answer written by me http://askubuntu.com/a/817066/61218

You put these in ~/.profile

## Fixing QT style override problem
if [ "x$XDG_SESSION_DESKTOP" == "xKDE" ]; then
    unset QT_STYLE_OVERRIDE
    unset QT_QPA_PLATFORMTHEME
fi

[Mohammad Anwar Shah (mohammadanwarshah)]

if "x$XDG_SESSION_DESKTOP" == "xKDE" doesn't work, use "xplasma" instead