I don’t feel people who use keyboard nav are looking for videogame style transitions between posts… the whole point of using the keyboard efficiency, not meaningless (and slow) cosmetic animations.
I don’t want slow cosmetic changes, but something to make the transition less jarring on my eyes. I started using this feature recently and found the jumps to be disorienting especially if they were between long posts. I’d love to see a balance in the middle personally.
The component shows weird up and down moves if I hold on buttons. I have to click J and K buttons one by one for proper movement. Also that line on the left side of post should disappear after a few seconds and transtition between posts might be more slow, like floating.
First, I want to mention that this survived a Monday, which is awesome. This is the First time I was able to do my full catch up using keyboard, I do still sometimes reach to my mouse to cut-and-paste and quote and so on.
The basic mechanics of catching up are very close, to summarize here are all the bugs (+ a new one) that we want sorted.
I do feel this may become a core feature, cause with this component JK turned from unusable for Sam to indispensable to Sam, which is a big jump in my hierarchy of needs.
Bugs to fix:
Up navigation with K does not resume at end of post, instead goes to top of post. Repro is to make a giant post, a small post, hit k on giant post.
K does not work on post #1.
Debounce bug is severe, if I hold K or J down stuff queues and gets super weird. (when you want to reach first post and there are only a few, then holding K seems easiest)
Transition effect can be done smoother and with less CPU / JS. To be honest, I notice almost no issue on Firefox on my monster dev machine, but on my old laptop with Safari I notice this big time.
Once you get sorted can you enable the theme component on all themes on meta? Then @zogstrip and @eviltrout who also like using these keys cause Vim, can test it.
@dan fixed most of my list only open question is around making the nav a bit smoother, the downside of going native is that:
Safari does not support “smooth” built-in animation so we have to polyfill anyway
The “smooth” built-in nav is a lot slower than the 100ms transition we now have (about 400ms) so it would get in the way
Given (2) and that I am actually using this full-time now even on Safari and it is not getting in the way too much now that I am used to it. I think we are good for more extensive testing.
I enabled this on all themes on meta!
@zogstrip / @eviltrout can you try this for a few days and report back? Personally I think we should just ship this cause it works so much nicer than our previous implementation.
Not much but good things to say on this one for the time being - namely
I have to say that this was a huge painpoint with j/k keyboard shortcuts, and I think is a much better default. I do sometimes wish for a way to “go to next post”, when someone has a huge uninteresting walloftext and I just want to get to other responses, but it’s not as common as press j and --“hey I was reading that”.
I subscribe interest by way of emacs + evil ::ducks::
Must say i really hated having j jump to the next post when i was reading a really large post and just wanted to scroll down. (and i had to press k then scroll down with my mouse).
This! I never realized how often I was hitting J just to hit K so I could use the down arrow to scroll through the entire post. Seeing this first hand was amazing.
I used it all morning and it works much better than before. I did hit an edge case I didn’t love, where the post scrolled down just to show me the footer actions. I don’t think that part of the post should be included in the height calculations.
Otherwise I support putting this into core. I haven’t reviewed the code but functionally it works great.
This theme component has been deprecated and reimplemented in core.
)
This is the First time I was able to do my full catch up using keyboard, I do still sometimes reach to my mouse to cut-and-paste and quote and so on.
sorted can you enable the theme component on all themes on meta? Then 
only open question is around making the nav a bit smoother, the downside of going native is that:
definitely support that