Is it possible to pause the slideshow somehow, and also, to go back to the previous image? I have tried the arrow and pause buttons so far, but it had no effect.
The usual buttons/commands work for going to the next/previous image. They hotkeys are Space and Backspace by default, but you can change them. Same as when not in a slideshow.
S toggles slideshow mode by default*. It's also in the View menu and the right-click context menu of the viewer, and can be changed if you want. You can also add a toolbar button for it if that's preferred.
(* At least in English. Check in the View menu and it should tell you the key.)
some text/icon on the viewer status bar indicating slideshow is active/paused/etc. is a good idea.
Slideshows are usually fullscreen so you can't see the status bar.
You can tell you're in a slideshow as the image keeps changing.
Both, Space and Backspace are working here, though it would be a nice feature, if the slideshow was paused when going back, until the next keystroke. The "s" hotkey is actually "h" in the german version, and pausing the slideshow is possible in combination with the Context Menu key (Context ... h to toggle the state), that works fine. Thanks!
You can edit the Previous and Next buttons and/or hotkeys so they turn off the slideshow:
Show VIEWERCMD=prev @if:Show VIEWERCMD=slideshow Show VIEWERCMD=slideshow
Show VIEWERCMD=next @if:Show VIEWERCMD=slideshow Show VIEWERCMD=slideshow
That's cool. Thanks, Leo.