I hope that my question has not been answered until now. Otherwise please give me a hint to the corresponding thread.
Q: If the main folder of an album contains no slides but only folders (with slides naturally!), a link to slideshow is confusing. Is there a way to suppress this link in slideless folders?
Edit: Sorry, this is an issue of Galleria, not of Turtle.
When I make a Galleria album with just folders at the top level, no individual images, I'm not seeing a link to the slideshow. On the other hand, if I include just one image at that top level, so that there's something "big" to show on the page, it does provide that slideshow option. So I suppose what you'd really like is to have the slideshow option turned off if there are fewer than two images at any given level. Does that sound right?
you are right, only if there is at least 1 image in the top level a link to a slideshow is present. The only solution I know is to modify the page-header.inc of Galleria where the number of images ist tested against >0. If changed to >1 or a greater number then you may set the desired amount of necessary slides.
I would prefer if there is a global setting to set the desired number in those skins offering a slideshow.
The developer of Galleria is no longer with jAlbum, so it's unlikely there will be any new versions. As you have discovered, you can simply edit line 68 of the page-header.inc file and change totalThumbnailCount > 0 to totalThumbnailCount > 1.
You could take it one step further and create a variable for that count in the user interface, and change page-header.inc to check against that variable.
Each skin is different, so there's no way for a jAlbum-wide setting to be used to control this.