뒤로가기 버튼 더블클릭

BackPressCloseHandler.java

public class BackPressCloseHandler {
    
    private long backKeyPressedTime = 0;
    private Toast toast;
    private Activity activity;
    public BackPressCloseHandler(Activity context) {
        this.activity = context;
    }

    
    public void onBackPressed() {
        if (System.currentTimeMillis() > backKeyPressedTime + 1000) {
            backKeyPressedTime = System.currentTimeMillis();
            showGuide();
            return;
        }

        if (System.currentTimeMillis() <= backKeyPressedTime + 1000) {
            activity.finish();
            toast.cancel();
        }
    }
    
    private void showGuide() {
        toast = Toast.makeText(activity, "\'뒤로\'버튼을 한번 더 누르시면 종료됩니다.",
                Toast.LENGTH_SHORT);
        toast.show();
    }
}

---

MainActivity.kt

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    ...(생략)
    backPressCloseHandler = BackPressCloseHandler(this)
}

override fun onBackPressed() {
    backPressCloseHandler?.onBackPressed()
}