Binary package “gtk2-engines-qtcurve” in ubuntu bionic

QtCurve widget style for applications based on GTK+ 2.x

 This package contains the QtCurve theme engine for GTK+ 2.x.
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 This package is most useful when installed together with kde-style-qtcurve.
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 QtCurve is a set of widget styles for Qt and GTK+ libraries. It provides a
 consistent look between KDE, GNOME and other applications based on these
 libraries, which is easy on the eyes and visually pleasing.