1 Click -> Go back / / Can't go back --> close

Question

Is there a nice way to fix this Problem?

In my Webview I can go back if click on the backbutton. I need a way to go back if I click once, and if I can't go back (startdisplay/startside) it should say "Click once more to Exit the app" with a toast. Is this possible?

public class MainActivity extends AppCompatActivity {

private ImageButton Ilias_link;
private ImageButton Lsf_link;
private WebView mWebView;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    Ilias_link = (ImageButton) findViewById(R.id.ilias_link);
    mWebView = new WebView(this);
    Ilias_link.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            mWebView.getSettings().setJavaScriptEnabled(true);
            mWebView.loadUrl("https://elearns02.fh-biberach.de/ilias3/login.php?target=&soap_pw=&ext_uid=&cookies=nocookies&client_id=HSBC&lang=de");
            mWebView.setWebViewClient(new WebViewClient());
            setContentView(mWebView);

        }
    });

    Lsf_link = (ImageButton) findViewById(R.id.lsf_link);
    mWebView = new WebView(this);
    Lsf_link.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            mWebView.getSettings().setJavaScriptEnabled(true);
            mWebView.loadUrl("https://lsf.fh-biberach.de/qisserver/rds?state=user&type=0");
            mWebView.setWebViewClient(new WebViewClient());
            setContentView(mWebView);
        }
    });
}



@Override
    public void onBackPressed() {
        if (mWebView.canGoBack()) {
            mWebView.goBack();
        } else {
            super.onBackPressed();
        }
}

}

Answer 1

Hello I suggest you a different method based on time. Because after user see toast message that warning about exit, she/he shouldn't want to exit app.

boolean doubleBack = false;
@Override
public void onBackPressed() {
    if (mWebView.canGoBack()) {
        mWebView.goBack();
        return ;
    }

    if (doubleBack) {
        super.onBackPressed();
        return;
    }

    doubleBack = true;
    Toast.makeText(this, "Click once more to Exit the app", Toast.LENGTH_SHORT).show();

    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            doubleBack = false;                       
        }
    }, 2000);
}