I am making custom widgets (plugins) for the Qt Designer, my problem is that I would
like to have them inactive when put into a layout, and “active” when in Preview mode.

What I mean by “active” or “inactive” in my case, is that my widgets need connections
to a database and I would not want to do this when designing the layout, however when
in Preview mode I would like to make it real and establish the connection.

I could not find the documentation about Preview mode.

Is there something I can use ?