Let's say I have several independent animations wh...

# compose

[rob42]

Let's say I have several independent animations where I want to use the same AnimationSpec for, e.g. tween(durationMillis = 100)
Let's also say they are animating different types, e.g. animateFloatAsState, animateColorAsState etc..

What's the best way to share a common animationSpec in this situation?
I can't just assign the same spec, because the AnimationSpec is generic, e.g. AnimationSpec<Float> .

[Zach Klippenstein (he/him) [MOD]]

i think you could just cast the generics? I don't think any of them actually have type-specific implementations

[Zach Klippenstein (he/him) [MOD]]

if you want to be less hacky, you could also just make your own factories:

fun <T> myAnimationSpec() = tween(durationMillis = 100)

[rob42]

Oh interesting, didn't realise they weren't type-specific. I assumed they were because they were generics!

A factory looks like it'll work well, although passing the animationSpec in to the composable as a parameter then presents a challenge (I can't think of an ergonomic way to do it without a non-fun interface)

[Zach Klippenstein (he/him) [MOD]]

if a function doesn't take a reified generic, then it can't change behavior based on the type because it has no idea at neither compile-time nor runtime what the concrete type is.

[tad]

It can certainly choose to crash at runtime, though :)

[tad]

Mostly via ClassCastException

[Zach Klippenstein (he/him) [MOD]]

Non-generic code can do bad casts too ¯\_(ツ)_/¯