Add a new QtInstanceLevelBar class that is
the weld::LevelBar implementation using a native
Qt widget. The widget used is a QProgressBar.
This is used e.g. in password dialogs where
the level bar is used as an indicator for the
password strength, e.g. in Writer:
"File" -> "Properties" -> "Security", press
"Protect..." button.
(But this is not using native Qt widgets yet,
more needs to be implemented first.)
Change-Id: I4400b8d1a03e8978bc96152166dec87f8134f48f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175805
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins