SlackBuildsOrg/development/Xdialog

Xdialog is designed to be a drop in replacement for the "dialog" or
"cdialog" programs. It converts any terminal based program into a
program with an X-windows interface. The dialogs are easier to see and
use while adding even more functionalities (e.g. with the treeview, the
file selector, the edit box, the range box, the help button/box).
Because Xdialog uses GTK+, it will also match your desktop theme.

If you wish to have NLS support, pass 'NLS=enable' to the SlackBuild.
Xdialog is a GTK"1" program but may optionally be compiled against GTK2.
The developer recommends against this but you may enable it (as I do)
with 'GTK2=enable'.