[BUG] Detection stops working when toggling flash

[Hulcsa]

Describe the bug
The barcode detection stops working when i toggle the flash via setCameraFlashMode(). This is what i see in the error logs:

2022-10-15 12:20:57.008 23489-23489/hu.egis.greta E/BarcodeImageProcessor: Barcode processing error
    com.google.mlkit.common.MlKitException: This detector is already closed!
        at com.google.mlkit.vision.common.internal.MobileVisionBase.processBase(com.google.mlkit:vision-common@@16.3.0:3)
        at com.google.mlkit.vision.barcode.internal.BarcodeScannerImpl.process(com.google.android.gms:play-services-mlkit-barcode-scanning@@16.1.5:1)
        at uk.co.brightec.kbarcode.processor.BarcodeImageProcessor.detectInImage$kbarcode_release(BarcodeImageProcessor.kt:1)
        at uk.co.brightec.kbarcode.processor.base.ImageProcessorBase.startDetection$kbarcode_release(ImageProcessorBase.kt:30)
        at uk.co.brightec.kbarcode.processor.base.ImageProcessorBase$startDetection$1.invokeSuspend(Unknown Source:12)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loopOnce(Looper.java:226)
        at android.os.Looper.loop(Looper.java:313)
        at android.app.ActivityThread.main(ActivityThread.java:8669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)

I went through your code and i saw that the updateCameraFeature closes the BarcodeScanner, and it is not recreated. I saw that if i call setBarcodeFormats() then it will trigger a createScanner() so the barcode detection continues, but with this solution sometimes i get a crash:

2022-10-15 12:32:53.847 3210-26680/? E/DropBoxUtil: [AppErrors] null InputStream [CONTEXT service_id=254 ]
    java.io.IOException: null InputStream
        at bupm.c(:com.google.android.gms@223915045@22.39.15 (190408-480654083):23)
        at buno.apply(:com.google.android.gms@223915045@22.39.15 (190408-480654083):5)
        at jxy.apply(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at jym.apply(:com.google.android.gms@223915045@22.39.15 (190408-480654083):5)
        at clsc.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at ctwm.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at cztz.d(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at czub.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):9)
        at czvl.execute(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at cztx.q(:com.google.android.gms@223915045@22.39.15 (190408-480654083):1)
        at cztx.gn(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at czub.g(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at clro.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at ctwk.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at czvr.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at czxt.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at czwu.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):3)
        at czxv.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at czvt.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):7)
        at czvl.execute(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at czvt.execute(:com.google.android.gms@223915045@22.39.15 (190408-480654083):9)
        at cztx.q(:com.google.android.gms@223915045@22.39.15 (190408-480654083):1)
        at cztx.gn(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at czvv.c(:com.google.android.gms@223915045@22.39.15 (190408-480654083):5)
        at clrt.h(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at clsd.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at ctwm.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at cztz.d(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at czub.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):9)
        at czvl.execute(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at cztx.q(:com.google.android.gms@223915045@22.39.15 (190408-480654083):1)
        at cztx.gn(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at czub.g(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at clsa.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at ctwk.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at czvr.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at czxt.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at czwu.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):3)
        at czxv.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at czvt.run(:com.google.android.gms@223915045@22.39.15 (190408-480654083):7)
        at czvl.execute(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at czvt.execute(:com.google.android.gms@223915045@22.39.15 (190408-480654083):9)
        at cztx.q(:com.google.android.gms@223915045@22.39.15 (190408-480654083):1)
        at cztx.gn(:com.google.android.gms@223915045@22.39.15 (190408-480654083):4)
        at czvv.c(:com.google.android.gms@223915045@22.39.15 (190408-480654083):5)
        at clsi.c(:com.google.android.gms@223915045@22.39.15 (190408-480654083):5)
        at clsi.b(:com.google.android.gms@223915045@22.39.15 (190408-480654083):2)
        at com.google.android.gms.stats.service.DropBoxEntryAddedChimeraService.a(:com.google.android.gms@223915045@22.39.15 (190408-480654083):32)
2022-10-15 12:32:53.847 3210-26680/? E/DropBoxUtil:     at com.google.android.gms.framework.tracing.wrapper.TracingIntentService.onHandleIntent(:com.google.android.gms@223915045@22.39.15 (190408-480654083):1)
        at gjl.handleMessage(:com.google.android.gms@223915045@22.39.15 (190408-480654083):0)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loopOnce(Looper.java:226)
        at android.os.Looper.loop(Looper.java:313)
        at android.os.HandlerThread.run(HandlerThread.java:67)

[iTruff]

Hi @Hulcsa I was able to solve this issue in my project, still not tested in production but seems like working.

Add these two methods in BarcodeView.kt

    fun turnFlashOn() {
        barcodeScanner.turnFlashOn()
    }

    fun turnFlashOff() {
        barcodeScanner.turnFlashOff()
    }

Add these two methods in BarcodeScanner.kt

    fun turnFlashOn() {
        cameraSource.turnFlashOn()
    }

    fun turnFlashOff() {
        cameraSource.turnFlashOff()
    }

Add these two methods in Camera2Source.kt

    fun turnFlashOn() {
        currentSession?.stopRepeating()

        val captureRequest = cameraDevice
            ?.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW)
            ?.apply { currentSurfaces?.forEach { addTarget(it) } } ?: return

        captureRequest.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_TORCH)
        currentSession?.setRepeatingRequest(captureRequest.build(), null, null)
    }

    fun turnFlashOff() {
        currentSession?.stopRepeating()

        val captureRequest = cameraDevice
            ?.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW)
            ?.apply { currentSurfaces?.forEach { addTarget(it) } } ?: return

        captureRequest.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_OFF)
        currentSession?.setRepeatingRequest(captureRequest.build(), null, null)
    }

[Hulcsa]

Thanks, it seems to be working! It would be nice if the original lib would implement this.

[alistairsykes]

Thanks for issue and for the community support in providing a solution.

FYI: This library is no longer maintained. Closing and marking wontfix.