Camera Permission | QR Scanner

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.ImageView
import androidmads.library.qrgenearator.QRGContents
import androidmads.library.qrgenearator.QRGEncoder
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import com.google.zxing.WriterException

class MainActivity : AppCompatActivity() {
    var im: ImageView? = null
    var bGenerate: Button? = null
    var bScanner: Button? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        im = findViewById(R.id.imageView)
        bGenerate = findViewById(R.id.button)
        bScanner = findViewById(R.id.bScan)
        bScanner?.setOnClickListener {
             checkCameraPermission()
        }
        bGenerate?.setOnClickListener {
            generateQrCode("Поставь лайк если понравилось видео!!")
        }
    }

    private fun generateQrCode(text: String){
       val qrGenerator = QRGEncoder(text, null, QRGContents.Type.TEXT, 500)
       try {
         val bMap = qrGenerator.encodeAsBitmap()
         im?.setImageBitmap(bMap)
       } catch (e: WriterException){

       }
    }

    private fun checkCameraPermission(){
        if(ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
            != PackageManager.PERMISSION_GRANTED){

            ActivityCompat.requestPermissions(this,
                arrayOf(Manifest.permission.CAMERA), 12)

        } else {
            startActivity(Intent(this, ScannerActivity::class.java))
        }
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)

        if(requestCode == 12){
            if(grantResults[0] == PackageManager.PERMISSION_GRANTED){
                startActivity(Intent(this, ScannerActivity::class.java))
            }
        }
    }
}