Simple QR Code

QR Code Implementation

class MainActivity : BaseActivity() {

    override val layoutId: Int?
        get() = R.layout.activity_main
 
    override fun viewCreated() { 
        bScan.setOnClickListener {
            startActivityForResult<QRCodeActivity>(REQUEST_CODE_QR) // Kotlin Anko Intent Library
        } 
    }
    
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)

        if (resultCode == Activity.RESULT_OK) {
            if (requestCode == REQUEST_CODE_QR) {
                data?.getStringExtra("qr")?.let {
                    Log.d("QR Code Received", it) 
                }
            }
        }
    }
}

QR Code Receiver

class QRCodeActivity : BaseActivity(), QRCodeReaderView.OnQRCodeReadListener {

    override val layoutId: Int?
        get() = R.layout.activity_qrcode

    override fun viewCreated() {
        qrCode.setOnQRCodeReadListener(this)

        setSupportActionBar(toolbar)
        supportActionBar?.setDisplayHomeAsUpEnabled(true)
        supportActionBar?.setDisplayShowHomeEnabled(true)
    }

    override fun onResume() {
        super.onResume()
        qrCode.startCamera()
    }

    override fun onPause() {
        super.onPause()
        qrCode.stopCamera()
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            android.R.id.home -> {
                finish()
                return true
            }
        }
        return super.onOptionsItemSelected(item)
    }

    override fun onQRCodeRead(text: String?, points: Array<out PointF>?) {
        qrCode.stopCamera()

        val intent = Intent()
        intent.putExtra("qr", text)
        setResult(Activity.RESULT_OK, intent)

        finish()
    }