Confirm closing the app on back pressed ONLY in MainAcitity?

Question

I want the user to confirm closing my app. I use the following code for that in my MainActivity:

@Override
public void onBackPressed() {
    if (this.lastBackPressTime < System.currentTimeMillis() - 4000) {
        toast = Toast.makeText(this, "Press back again to close this app", Toast.LENGTH_LONG);
        toast.setGravity(Gravity.CENTER, 0, 0);
        toast.show();
        this.lastBackPressTime = System.currentTimeMillis();
    } else {
        if (toast != null) {
            toast.cancel();
        }
        super.onBackPressed();
    }
}

In other classes I use this:

@Override public void onBackPressed() {
    if (!mWebView.onBackPressed()) { return; }
    // ...
    super.onBackPressed(); }

Now I get the confirm event in EVERY class, but I only want it in my MainActivity. How can I do that?

Note: I have to extent my MainActivity in other classes. That should be the main problem to solve, but I still dont know how exactly?

Answer 1

@Vala, If your adding fragments to the Activty, then you can make use BackSackEntryCount of FragmentManager like below.

  int backStackCount = getSupportFragmentManager().getBackStackEntryCount();
                if (backStackCount == 1) {
                    Toast.makeText(this, "Press back again to close this app", Toast.LENGTH_LONG).show();
                }

if backstackcount is one, it means, on pressing the back button again, remaining frgament will be popped from back stack and app will be quit.