Install libqxt-designer0 by entering the following commands in the terminal:
sudo apt update sudo apt install libqxt-designer0
Description:
LibQxt extensions to Qt Designer
LibQxt is an extension library for the Qt application framework. LibQxt provides a suite of cross-platform utility classes to add functionality not readily available in Qt. . Qt Designer is a tool for designing and building graphical user interfaces (GUIs) from Qt components. . This package enables usage of LibQxt widgets in Qt Designer.
Homepage: https://bitbucket.org/libqxt/libqxt/wiki/Home
Version: 0.6.2-3
Section: universe/libs