Ubuntu

Binary package “qt5-gtk2-platformtheme” in ubuntu focal

  1. Focal (20.04)
  2. qt5-gtk2-platformtheme

Qt 5 extra widget styles - GTK+ 2 Platform theme

 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 contains the GTK+ 2 style and platform theme. Export
 QT_QPA_PLATFORMTHEME=gtk2 to enable it for all Qt applications.

Source package