When I interact with views I often need to post an action or wait until the next layout pass, etc... If I need to expand a view with an animation I can do something like this

container.doOnLayout { 
    val originalHeight = it.height

    // expandedChild visibility was GONE
    expandedChild.isVisible = true

    view.doOnPredraw {
        val newHeight = it.height
        expandedChild.isVisible = false
    }
}
// Now I can animate the container height between originalHeight & newHeight

How Could I achieve a similar behaviour with compose?

Would

OnPositioned

or

OnChildPositioned

help? https://developer.android.com/reference/kotlin/androidx/ui/core/package-summary#OnChildPositioned(kotlin.Function1,%20kotlin.Function0)