Android emulator issue on Kotlin version of Vision-QuickStart

[michaelcarrano]

I have been playing around with these samples using an Emulator on API 29 (Pixel 2).

I noticed with the https://github.com/googlesamples/mlkit/tree/master/android/vision-quickstart

The Java version works fine without issues, however, the Kotlin version I run into issues.

On the Kotlin version, I am unable to move the emulator camera around and it does not seem to be detecting any objects. In the video below, you'll notice the message below the emulator keeps showing/dismissing non-stop.

Here's a video: https://youtu.be/jzaUEeOZT2Q

This is reproducible by myself and others on my team.

Let me know if there is any other information needed.

[michaelcarrano]

Had some free time this morning to look into this issue and I think I found it. I can open a PR if you'd like, otherwise the fix is pretty straight forward.

The issue lie within the bindPreviewUseCase() method on CameraXLivePreviewActivity.

Java - https://github.com/googlesamples/mlkit/blob/master/android/vision-quickstart/app/src/main/java/com/google/mlkit/vision/demo/CameraXLivePreviewActivity.java#L296-L310
Kotlin - https://github.com/googlesamples/mlkit/blob/master/android/vision-quickstart/app/src/main/java/com/google/mlkit/vision/demo/kotlin/CameraXLivePreviewActivity.kt#L266-L280

You'll notice the methods are not identical.

Main difference is that in the Kotlin version, we are binding the cameraProvider lifecycle before we set the previewUseCase surface.

Making this change locally, the emulator is behaving as expected in the Kotlin sample.

[sheepmaster]

Thanks for the report! Yes, please open a pull request with the fix if you already have one.

[michaelcarrano]

@sheepmaster done, submitted the PR.