Crash with Android/Kotlin QR Scanner App and the latest version of Google ML Kit Scan Barcode

Question

I am trying to make an app which reads QR images and get the data from the image. I am using the latest version of the google machine learning kit for scan barcodes and followin

Answer 1

So if we look at the code:

1. Create InputImage from ImageProxy
2. scanner.process(image).addWhateverListener(etc etc) but not onComplete
3. imageProxy.close

Why would this not work? Step 2 is async so it takes say a fraction of time before it is executed but in the meantime, step 3 kicks in and clear the image - no image to detect. The solution is to use addOnCompleteListener to close the image:

    scanner.process(image)
        .addOnFailureListener { // Some code}
        .addOnSuccessListener { // Some more code}
        .addOnCompleteListener {
            // Close the image
            imageProxy.close()}

BTW this got me the first time too and we are thinking about adding better debug message than "Image is already close".