dating-card-transition-handler.kt

class CardsTransitionHandler<T>(
    private val transitionSpec: TransitionSpec<Cards.State, Float> = { 
        spring(stiffness = Spring.StiffnessVeryLow) 
    }
) : ModifierTransitionHandler<T, Cards.State>() {
 
    private fun Cards.State.toProps() =
        when (this) {
            is Queued -> queued
            is Bottom -> bottom
            is Top -> top
            is VoteLike -> voteLike
            is VotePass -> votePass
    }
    
    override fun createModifier(
        modifier: Modifier,
        transition: Transition<Cards.State>,
        descriptor: TransitionDescriptor<T, Cards.State>
    ): Modifier = modifier.composed {
    
        val rotation = transition.animateFloat(
            transitionSpec = transitionSpec,
            targetValueByState = { it.toProps().rotation })
    
        val scale = transition.animateFloat(
            transitionSpec = transitionSpec,
            targetValueByState = { it.toProps().scale })
    
        val dpOffsetX = transition.animateFloat(
            transitionSpec = transitionSpec,
            targetValueByState = { it.toProps().offsetX.value })
    
        val zIndex = transition.animateFloat(
            transitionSpec = transitionSpec,
            targetValueByState = { it.toProps().zIndex })
    
        return@composed this
            .offset {
                IntOffset(x = (this.density * (dpOffsetX.value)).roundToInt(), y = 0)
            }
            .zIndex(zIndex.value)
            .graphicsLayer(
                rotationZ = rotation.value
            )
            .scale(scale.value)
    }
}