(Same on both 42.3 and 15.0)
# zypper se -s qt | grep -i gtk
   | qtcurve-gtk2         | package | 1.8.19~git20150303-4.2  | x86_64 | OSS
i+ | trinity-gtk-qt-engine| package | 2:0.8-14.0.4_1.oss423   | x86_64 | TDE
i+ | trinity-gtk3-tqt-engine| package | 2:0.5-14.0.4_1.oss423 | x86_64 | TDE

TCC > GTK Styles & Fonts > GTK2 Styles:

	WARNING: The Gtk-Qt theme engine is not installed. This means you
	will not be able to use your TDE style in GTK2 applications.

Exactly what package is this warning referring to?
-- 
"Wisdom is supreme; therefore get wisdom. Whatever else you
get, get wisdom." Proverbs 4:7 (New Living Translation)

 Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata  ***  http://fm.no-ip.com/