MainActivity.kt

class MainActivity : AppCompatActivity() {

    val textview by lazy { findViewById<View>(R.id.textView) as TextView }
    val progressBar by lazy { findViewById<View>(R.id.progressbar) as ProgressBar }
    val buttonMusic by lazy { findViewById<View>(R.id.button_music) as Button }
    var progressPercentage = 0
    private var job: Job? = null
    val scope by lazy { CoroutineScope(Dispatchers.Main) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        Log.d("activity", "OnCreate")
        buttonMusic.setOnClickListener {
            startDownloading("Music", 200)
        }
    }

    private fun startDownloading(item: String, delay: Long) {
        job = scope.launch {
            textview.text = "Downloading..."
            delay(300)
            while (progressPercentage != 100) {
                delay(delay)
                progressPercentage++
                textview.text = "Percentage...$progressPercentage"
                progressBar.setProgress(progressPercentage)
                logCoroutineInfo("$item | perc $progressPercentage")
            }
            textview.text = "$item Downloaded ✅"
        }
    }
       fun logCoroutineInfo(msg: String) = println("Running on: [${Thread.currentThread().name}] | $msg")