Scansioni codici QR in Kotlin Android

Nel 2013 avevo fatto qualche esperimento con la lettura dei codici a barre tramite la libreria ZXing.

Ad oggi le funzioni di scansioni dei codici sono incluse nelle librerie di Google Play ma le trovo complicate mentre la libreria ZXing (https://github.com/zxing/zxing) e' in maintenance mode. Ho trovato una alternativa a questo link    https://github.com/yuriy-budiyev/code-scanner

build.gradle(app)

implementation 'com.budiyev.android:code-scanner:2.1.0'

Layout

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<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <FrameLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.budiyev.android.codescanner.CodeScannerView
            android:id="@+id/scanner_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:autoFocusButtonColor="@android:color/white"
            app:autoFocusButtonVisible="true"
            app:flashButtonColor="@android:color/white"
            app:flashButtonVisible="true"
            app:frameColor="@android:color/white"
            app:frameCornersSize="50dp"
            app:frameCornersRadius="0dp"
            app:frameAspectRatioWidth="1"
            app:frameAspectRatioHeight="1"
            app:frameSize="0.75"
            app:frameThickness="2dp"
            app:maskColor="#77000000"/>
    </FrameLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

=====================================================

codice

=====================================================

    val scannerView = findViewById<CodeScannerView>(R.id.scanner_view)

    codeScanner = CodeScanner(this, scannerView)

    // Parameters (default values)
    codeScanner.camera = CodeScanner.CAMERA_BACK // or CAMERA_FRONT or specific camera id
    codeScanner.formats = CodeScanner.ALL_FORMATS // list of type BarcodeFormat,
    // ex. listOf(BarcodeFormat.QR_CODE)
    codeScanner.autoFocusMode = AutoFocusMode.SAFE // or CONTINUOUS
    codeScanner.scanMode = ScanMode.SINGLE // or CONTINUOUS or PREVIEW
    codeScanner.isAutoFocusEnabled = true // Whether to enable auto focus or not
    codeScanner.isFlashEnabled = false // Whether to enable flash or not

    // Callbacks
    codeScanner.decodeCallback = DecodeCallback {
        runOnUiThread {
            Toast.makeText(this, "Scan result: ${it.text}", Toast.LENGTH_LONG).show()
        }
    }
    codeScanner.errorCallback = ErrorCallback { // or ErrorCallback.SUPPRESS
        runOnUiThread {
            Toast.makeText(this, "Camera initialization error: ${it.message}",
                Toast.LENGTH_LONG).show()
        }
    }

    scannerView.setOnClickListener {
        codeScanner.startPreview()
    }
}

override fun onResume() {
    super.onResume()
    codeScanner.startPreview()
}

override fun onPause() {
    codeScanner.releaseResources()
    super.onPause()
}