qt5-gtk-platformtheme 5.7.1+dfsg-2ubuntu4~1.17.04.1 (i386 binary) in ubuntu zesty

 Qt is a cross-platform C++ application framework. Qt's primary feature
 is its rich set of widgets that provide standard GUI functionality.
 .
 This package provides the GTK+ 3 platform theme, which makes Qt use
 native icon themes, fonts, and dialogs on GTK-based environments.