IssueTracker

Jetpack Compose version: 1.7.0

Jetpack Compose component(s) used: Transition

Android Studio Build: Koala

Could there be an "initial velocity" value that's passed for a Transition from an initial state?

An example:

• Let's say we want to Transition from "Open" to "Closed".
• We'd like this transition to also be run as part of some parent transition.
• This Transition will include a translation animation (e.g. from the center of the screen, to its resting place).
• We'd like to be able to optionally fling the element from its open state to its closed state.
• We'd like the initial velocity of the fling to be part of the translation transition animation.

Maybe there could be an argument that could be called to check if there's an intended initial velocity when beginning a transition from an initialState?

val childTransition = transition.createChildTransition { it /* value of isOpen: Boolean */ }
childTransition.animateValue(
  typeConverter = Dp.TypeConverter,
  initialVelocity = { initialStateIsOpen ->
    if (initialStateIsOpen) flingVelocity else null
  },
) { isOpen ->
  if (isOpen) centerOfScreen else restingOffset
}