Hi all ! Sorry for this long example just in order to explain my main trouble : - I've drawn a check...

# compose

[loloof64]

Hi all ! Sorry for this long example just in order to explain my main trouble :
• I've drawn a checker board with some coins
• We can drag a coin to an empty cell
• If trying to drag a coin on another coin, then there should be a back animation.
Unfortunately, the back animation is not thrown and the coin goes back immediately

Checker coin animation

[loloof64]

I'm using android jetpack compose alpha11.

For the animation, I've tried to set the final state manually

goBackState.targetState = GoingBackStates.FINAL

(line 178)

[loloof64]

Also I'm forbidden to write this

goBackState.currentState = GoingBackStates.INITIAL

[loloof64]

Otherwise : is a transition object cheap or expensive ?

Because that way I could simply use a function to map each cell to a transition if it has a coin.

And my code could be cleaner and more readable.

[Doris Liu]

You can only change the targetState (i.e. not the currentState ) of a Transition/MutableTransitionState. If you need to change both the starting point and ending point of a transition, you could create a new MutableTransitionState like the second sample on this API: https://developer.android.com/reference/kotlin/androidx/compose/animation/core/package-summary#updatetransition_1 That would recreate the Transition animation with the new initial/target states specified in the new MutableTransitionState . Though that would mean that all the current values/velocities of the animation will be lost, and you may therefore see a visual jump.

[Doris Liu]

Creating a bunch of Transition s is not super expensive. I agree with you that each cell (in the snippet above) should have independent animation/transition states. I'd suggest having an Animatable<Offset> for each cell to animate their position as needed, independently.

[loloof64]

Thank you very much 🙂 So I'm going for the array of Transition 🙂

[loloof64]

Strange issue :

Looking at https://developer.android.com/reference/kotlin/androidx/compose/animation/core/Animatable, Animatable is a class that takes two parameters. But in my Android Studio Canary, I get an error saying that Animatable do not take parameter.

I am using compose 1.0.0-alpha11

[Doris Liu]

Animatable has a few overloaded factory methods. Also make sure you import the right one. There's also a Drawable class with the same name. 😅

[loloof64]

Thank you. I check my imports 🙂

[loloof64]

I did not read the documentation correctly: I'm just using

Animatable(Offset(0f, 0f), Offset.VectorConverter)

and that's fine.