Manage onBackPressed in single activity android app

Question

I have a single activity app and I want to manage app exit by pressing twice back button. Now I don't know how and where to manage onBack. Would you please help on this?

Answer 1

Can do something like this

override fun onBackPressed() {

    if (i == 0){
        i++
        return
    }
    else {
        i = 0
        super.onBackPressed()
    }
}

Answer 2

Add this to your Activity

 private var doublePressToExit = false
override fun onBackPressed() {
    if (doublePressToExit) {
        super.onBackPressed()
        return
    }
    this.doublePressToExit = true
    Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show()

    Handler().postDelayed(Runnable { doublePressToExit = false }, 2000)  // to reset doublePressToExit to false after 2 sec
}