from what I can see the thumbnails in photonic and the main image don’t work like this?
Photonic works exactly as per the documentation of Splide. It syncs the two carousels.
As I said, anything that would mean the thumbnail bar is wider that the main container it all lives in breaks things.
Didn’t follow you – what breaks here? From what I can see, this too works fine. E.g. take a look at the slideshow example on the layouts page. Resize the browser so that the main content becomes narrower and the thumbnail strip has more photos that cannot be accommodated in the content width. The thumbnails stay at the bottom, and as you slide through the photos, the thumbnails adjust fine and vice versa.
Is there a way to make the thumbnail bar scrollable with a second set of controls as shown in native splide?
This is not planned, since it needs custom code to figure out how many thumbnails need to be advanced per click of the arrow. The default of 1 results in poor UX, because moving the thumbnails by 1 when you have several images doesn’t serve practical utility. The right approach would be to figure out how many thumbnails are present in the current viewport and then jump forward by that many, but this is easier said than done.
On a tangent, a slideshow/carousel is considered a fundamental “anti-pattern” particularly if you are using it for more than a handful of photos. I still offer the capability, but as a piece of general advice, if you have more than a handful of photos to show, a slideshow is not the right way to showcase your photos.
