Are there any known issues with compose on Android...

# compose

[Zoltan Demant]

Are there any known issues with compose on Android 12? Ive received a few super-strange reports where ui actions have ~1 second delay; e.g. typing text in an input field has a 1 second delay between letters, etc. In all other cases, all of this happens instantaneously.

[Casey Brooks]

Are you launching any coroutines in your composable's rememberCoroutineScope()? That scope by default runs on Dispatchers.Main.immediate, so any long-running work on it would block UI rendering and event dispatching, and it should be moved to another dispatcher

[Zoltan Demant]

I do use it as the overall scope so that operations stop whenever the compose-scope is cancelled, but I make sure that all background work runs on Dispatchers.Default/IO (and I just verified thats the case).

[Rick Regan]

I have performance issues with Crossfade on Android 12, though that doesn't sound like it's related to your problem: https://issuetracker.google.com/u/1/issues/207107680

[Zoltan Demant]

@Rick Regan Thank you, its hard to tell if its the same underlying issue - but your screen recordings look exactly like what Im seeing, and I do use Crossfade a lot. Is this local to Crossfade only, or does a similar thing happen with AnimatedContent for you as well?

[Rick Regan]

I don't use `AnimatedContent`; in fact, Crossfade is the only animation I (explicitly) use.

[Zoltan Demant]

@Rick Regan Got it. I just got a response about the delay being fixed after having switched to AnimatedContent, so thats a good sign! Thank you so much for bringing this to my attention. Im still seeing some lag on Android 12, but I think thats internal components using the broken animations, likely the same thing that Crossfade uses.

[Rick Regan]

Can you share more detail on the "delay being fixed after having switched to AnimatedContent?

[Zoltan Demant]

Delay/Lag 🙂 Same thing that you showed in your screen-recordings.

[Rick Regan]

Oh...I thought you meant you had a side channel with someone else 🙂

[Rick Regan]

(@Doris Liu I wanted to make you aware of the issue cited above. Thank you.)

[Zoltan Demant]

Oh snap, the response I was referring to is from a user of my app - I cant recreate these issues locally, so thankfully there are people out there who are happy to help :)

[Rick Regan]

I never really looked into`AnimatedContent` so it's interesting to learn that it's a "drop-in replacement" for Crossfade. (Although the doc page I am looking at calls it "experimental".) I will try it out.

[Zoltan Demant]

Ridiculously simplified probably, but I think of Crossfade like an AnimatedContent that just uses fadeIn and fadeOut.

[Rick Regan]

Funny, AnimatedContent made the example in my issue much slower (both API 31 and 30). Although, I'm not 100% sure I'm comparing them correctly (for Crossfade I used animationSpec = tween(10) and for AnimatedContent I used

transitionSpec = {
  fadeIn(animationSpec = tween(5)) with
      fadeOut(animationSpec = tween(5))
},

(the low tween times was just to factor that out of the issue.)

[Zoltan Demant]

Do you see the same behavior if you use something like a Text? Ive noticed that buttons do something when animating their enabled/disabled state, Im curious if something in there is related to this as well.

[Rick Regan]

Still slow with `Text`s instead of `Button`s (both Crossfade and AnimatedContent, with AnimatedContent still slower).

[Zoltan Demant]

Hopefully well find the answers soon enough! Have you tried running this on a real device too?

[Rick Regan]

The Crossfade version I had, yes, and I saw it there too.

[Doris Liu]

@Rick Regan Do you see any difference in performance between 30 & 31 when using AnimatedContent with

slideIntoContainer(AnimatedContentScope.SlideDirection.Left) with slideOutOfContainer(AnimatedContentScope.SlideDirection.Left)

instead of fade? That might help narrow down the issue here.

[Rick Regan]

I posted an update (with videos) to the issue (31 is much slower).