Make customCameraController internal

[maciek-s]

Hello, it would be great to have access to the customCameraController field inside CameraController. I need access to the AVCaptureVideoPreviewLayer for my implementation.
Thanks for your great work!”

[Kashif-E]

@maciek-s could you share your usecase? maybe we could find a better way to handle it

[maciek-s]

I think I was a bit rushed (I’m an Android developer with limited experience in iOS), but I found that I can extract it from AVCaptureConnection…

[maciek-s]

Unfortunately previewLayer is always null... I would like to map scanned barcode corners/bound to camera preview position

override fun captureOutput(
    output: AVCaptureOutput,
    didOutputMetadataObjects: List<*>,
    fromConnection: AVCaptureConnection
) {
    for (metadata in didOutputMetadataObjects) {
        if (metadata is AVMetadataMachineReadableCodeObject) {
            metadata.stringValue?.let { code ->
                fromConnection.videoPreviewLayer?.let { previewLayer ->
                }
                onResult(
                    CardBarcode(
                        code = code,
                        type = metadata.getCardCodeType()
                    )
                )
            }
        }
    }
}

[Kashif-E]

you should use the plugin api to build your own plugin

[maciek-s]

I know, this is the full code based on your qr_scanner_plugin. I’m not limiting the type to QR codes and also returning a custom result. However, videoPreviewLayer is always null. I would like to map the detected code points to the camera preview points.

actual fun startScanning(
    controller: CameraController,
    private val onResult: (CardBarcode) -> Unit
) {
    val analyzer = BarcodeAnalyzer(onQrScanner = onQrScanner)

    controller.setMetadataObjectsDelegate(analyzer)
    controller.updateMetadataObjectTypes(
        listOf(
            AVMetadataObjectTypeQRCode!!,
            AVMetadataObjectTypeEAN13Code!!,
            AVMetadataObjectTypeEAN8Code!!,
            AVMetadataObjectTypeCode128Code!!,
            AVMetadataObjectTypePDF417Code!!
        )
    )
    controller.startSession()
}


private class BarcodeAnalyzer(private val onResult: (CardBarcode) -> Unit) : NSObject(),
    AVCaptureMetadataOutputObjectsDelegateProtocol {

    override fun captureOutput(
        output: AVCaptureOutput,
        didOutputMetadataObjects: List<*>,
        fromConnection: AVCaptureConnection
    ) {
        for (metadata in didOutputMetadataObjects) {
            if (metadata is AVMetadataMachineReadableCodeObject) {
                fromConnection.videoPreviewLayer?.let { previewLayer ->
                }
                metadata.stringValue?.let { code ->
                    onResult(
                        CardBarcode(
                            code = code,
                            type = metadata.getCardCodeType()
                        )
                    )
                }
            }
        }
    }
}

[Kashif-E]

are you working on a fork? could you share project link?

[maciek-s]

This is not a fork, and I can’t share the project link as it is private. However, I manually calculated the necessary information based on the corner points from metadata.corners and my scanner area fraction points. I just need to map it based on the device orientation, which on my device is always AVCaptureVideoOrientationLandscapeRight. When I rotate, the preview becomes incorrect, as I reported here.

[Kashif-E]

ill look into it will fix this in the next release

[Kashif-E]

@maciek-s i have added a function to get the preview layer and support for barcodes in qr scanner plugin let me know if that works for you or you need something else

[Kashif-E]

check the latest master

[maciek-s]

Hi, thanks for the function to access the preview layer—it works!