Hi,

I'm not a KDE user but gwenview is the only slideshow program which do what I want : do a slideshow with photos AND videos from a directory
But I also need the loop function (to repeat the slideshow from the begining when all photos/videos are showed).
On the documentation, it's look like this option is there, but I can't find it on my gwenview instance (maybe because I don't have all kde-libs installed ?)
Here a screenshoot : http://img.spheerys.fr/images/2015/07/18/gwenview.jpg

How can I set this option globally, or manually ?

next time is it useful to include information about your gwenview version, os, kde version etc

maybe this feature is not supported yet in your gwenview version, try to upgrade it.
mine is gwenview 16 and you can do this via control in top right corner