we are facing a crash in lazy column which is excl...

# compose

[karandeep singh]

we are facing a crash in lazy column which is exclusively happening on one plus and oppo devices which is happening due to some fling behaviour,
there seems to be a google issue too for the same.. anyone found a workaround for it?

Fatal Exception: java.lang.ArrayIndexOutOfBoundsException: length=101; index=-12
    at androidx.compose.animation.AndroidFlingSpline.flingPosition(SplineBasedDecay.kt:96)
    at androidx.compose.animation.FlingCalculator$FlingInfo.position(FlingCalculator.java:120)
    at androidx.compose.animation.SplineBasedFloatDecayAnimationSpec.getValueFromNanos(SplineBasedFloatDecayAnimationSpec.kt:51)
    at androidx.compose.animation.core.VectorizedFloatDecaySpec.getValueFromNanos(VectorizedFloatDecaySpec.java:144)
    at androidx.compose.animation.core.DecayAnimation.getValueFromNanos(Animation.kt:401)

[karandeep singh]

Screenshot 2024-01-05 at 8.33.59 PM.png

[Doris Liu]

If you have a reliable repro, that'll be helpful for our investigation.

If you could reproduce the crash at all, even if not reliably, I'd recommend trying out the suggestion in comment #5 of the google issue to help confirm the potential cause.

[karandeep singh]

LaunchedEffect(key1 = Unit, block = {
    var lastFrameTime = 0L
    withFrameNanos { frameTimeNanos ->
        if (frameTimeNanos < lastFrameTime) {
            Timber.tag("compose_debug").v("last_frame_time: $lastFrameTime : current_frame_time: $frameTimeNanos : decreasing frame time")
        }

        lastFrameTime = frameTimeNanos
    }
})

something like this would work @Doris Liu?

[Doris Liu]

We'll need a while-loop around withFrameNanos so that we can inspect consecutive frame callbacks during the animation. With that said, you might also want to time bound the while loop so that frame callbacks are only requested as needed (i.e. during the fling animation).

[karandeep singh]

thank you. got it. but do we get any callback for fling? should we log this in when scroll is in progress? 🤔

[Doris Liu]

should we log this in when scroll is in progress?

Logging based on isScrollInProgress might be the easier way to do it. The LaunchedEffect could key on it so the job gets canceled when scrolling finishes, like:

LaunchedEffect(state.isScrollInProgress) {
   if (state.isScrollInProgress) { // while-loop goes here }
}