IllegalStateException: maximumVelocity should be a positive value

[SimonMarquis]

We are seeing a pretty substantial amount of errors in the latest version (0.9.0) that leads to this method:

https://github.com/saket/telephoto/blob/3e0c5573151e64908a024425bda9cd0be19f4d68/zoomable/src/commonMain/kotlin/me/saket/telephoto/zoomable/internal/transformable.kt#L152

And all the stacktraces look like this (with value 0.0):

Fatal Exception: java.lang.IllegalStateException
maximumVelocity should be a positive value. You specified=0.0
androidx.compose.ui.input.pointer.util.VelocityTracker1D.calculateVelocity (VelocityTracker.kt:283)
androidx.compose.ui.input.pointer.util.VelocityTracker.calculateVelocity-AH228Gc (VelocityTracker.kt:102)
me.saket.telephoto.zoomable.internal.TransformableNode$pointerInputNode$1$1$2.invokeSuspend (transformable.kt:152)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:33)
kotlinx.coroutines.DispatchedTaskKt.resume (DispatchedTask.kt:175)
kotlinx.coroutines.DispatchedTaskKt.dispatch (DispatchedTask.kt:164)

or this (with a tiny value, that looks like a 0 approximation in float):

Fatal Exception: java.lang.IllegalStateException
maximumVelocity should be a positive value. You specified=-1.3029473E-34
androidx.compose.ui.input.pointer.util.VelocityTracker1D.calculateVelocity (VelocityTracker.kt:283)
androidx.compose.ui.input.pointer.util.VelocityTracker.calculateVelocity-AH228Gc (VelocityTracker.kt:102)
me.saket.telephoto.zoomable.internal.TransformableNode$pointerInputNode$1$1$2.invokeSuspend (transformable.kt:152)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:33)
kotlinx.coroutines.DispatchedTaskKt.resume (DispatchedTask.kt:175)
kotlinx.coroutines.DispatchedTaskKt.dispatch (DispatchedTask.kt:164)

I'm not sure why it would throw here to be honest, since we always provide sane values Velocity(Int.MAX_VALUE.toFloat(), Int.MAX_VALUE.toFloat()). Could this be an issue with the devices packing floats incorrectly?

The device repartition is as follow:

• 70% Huawei
• 20% Samsung
• 6% Xiaomi
• 1% Hisense
• 3% Other (6)

[saket]

Just to confirm, were you not seeing any of these crashes on an older version of telephoto?

[saket]

Can you also share your version of Compose UI?

[SimonMarquis]

Oh you're right, we did have them on previous versions as well (Crashlytics groupped them differently):

androidx.compose.ui.input.pointer.util.VelocityTracker1D.calculateVelocity (VelocityTracker.kt:283)
androidx.compose.ui.input.pointer.util.VelocityTracker.calculateVelocity-AH228Gc (VelocityTracker.kt:102)
androidx.compose.ui.input.pointer.util.VelocityTracker.calculateVelocity-9UxMQ8M (VelocityTracker.kt:82)
me.saket.telephoto.zoomable.internal.TransformableKt.calculateVelocity-OGnQdUo (transformable.kt:267)
me.saket.telephoto.zoomable.internal.TransformableKt.access$calculateVelocity-OGnQdUo (transformable.kt:1)
me.saket.telephoto.zoomable.internal.TransformableNode$pointerInputNode$1$1$2.invokeSuspend (transformable.kt:156)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:33)
kotlinx.coroutines.DispatchedTaskKt.resume (DispatchedTask.kt:175)
kotlinx.coroutines.DispatchedTaskKt.dispatch (DispatchedTask.kt:164)

Our Compose UI version is currently at 1.6.4.

[saket]

I've replaced my manual calculation of maximum velocity with the framework one in https://github.com/saket/telephoto/commit/32309870a59a14d84be87b1a6cc39dc6be79b781. Let's see if this fixes the issue.

https://github.com/saket/telephoto/blob/71b96177f293dcb27b64a456894871534b31ea8b/zoomable/src/commonMain/kotlin/me/saket/telephoto/zoomable/internal/transformable.kt#L154-L156

I'm not certain, but https://github.com/saket/telephoto/pull/76 could also help.

I'll cut a release soon. In the meantime, the changes are available in 0.10.0-SNAPSHOT if your project is comfortable using snapshots.

[SimonMarquis]

Thanks for these updates. Unfortunately I won't be able to use such SNAPSHOT version in the main project for now 😖 I'll try to see if we can fork and test this patch.

[saket]

I just released https://github.com/saket/telephoto/releases/tag/0.10.0. Can you please give it a try?

[SimonMarquis]

Our app update will be rolled-out starting next monday 🚀

[saket]

@SimonMarquis were you able to verify if the frequency of crashes has decreased?

[SimonMarquis]

It seems like it did not change anything. New reports are coming up with this new version. To me, the only reason why there could be an error is if [maximumFlingVelocity](https://developer.android.com/reference/kotlin/androidx/compose/ui/platform/ViewConfiguration#maximumFlingVelocity()) coming from the ViewConfiguration is already negative:

https://github.com/saket/telephoto/blob/7f88d6308209b04ffc0a576a069e3b5562bed71a/zoomable/src/commonMain/kotlin/me/saket/telephoto/zoomable/internal/transformable.kt#L155

The packing/unpacking of 2 floats in a long seems fine.

Given the uncommon distribution of devices having this bug, this could be an OS bug. And from the docs, nothing really prevents it from being negative after all.

Do you think we could try clamping these values?

          val maximumVelocity = currentValueOf(LocalViewConfiguration)
              .maximumFlingVelocity
              .coerceAtLeast(0F)
              .let { Velocity(it, it) }

[saket]

Oof. Considering that Velocity(Int.MAX_VALUE.toFloat(), Int.MAX_VALUE.toFloat()) was also causing the same crash, I don't think the values provided by ViewConfiguration are invalid...

I'll file a bug report.

[saket]

@SimonMarquis can you share more data about these devices, including their API versions?

[SimonMarquis]

Devices:

• 57% Huawei
  • 6% Huawei P30 Lite
  • 6% Huawei P30
  • 5% P20 Lite
  • 40% Other (34)
• 26% Samsung
  • 10% Galaxy S8
  • 2% Galaxy A8(2018)
  • 2% Galaxy A5(2017)
  • 12% Other (19)
• 10% Xiaomi
  • 1% Redmi Note 9S
  • 1% Redmi Note 9 Pro
  • 1% Redmi Note 8 Pro
  • 6% Other (15)
• 2% Wiko - FIH Foxconn
  • 1% View5
  • 1% View5 Plus
• 5% Other (9)

OS:

• 57% Android 10
• 25% Android 9
• 18% Android 8

This OS distribution makes it look like a platform bug that has been fixed in Android 11.

[saket]

It very likely is! Interestingly, @jakewharton reminded me yesterday that we encountered a similar bug in Cash App a year ago. It's amazing that I've already run into it again.

I'll file a bug report on D8, and think of a way to suppress these in telephoto.

Is Android 8 your min sdk version?

[SimonMarquis]

We have minSdk set to 24 (Android 7)

[saket]

I've filed a bug report on D8: https://issuetracker.google.com/u/1/issues/338381315.

[saket]

@SimonMarquis will you be able to share your apk here? https://issuetracker.google.com/issues/338381315#comment2