Add confirm dialog to logout when pressing back would lead to the LoginActivity

app/src/main/java/com/testapp/NavDrawerActivity.java

@@ -155,10 +155,24 @@ public class NavDrawerActivity extends AppCompatActivity implements NavigationVi
         DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
         if (drawer.isDrawerOpen(GravityCompat.START)) {
             drawer.closeDrawer(GravityCompat.START);
+        } else {
+            if(AppUtils.isLoggedIn()) {
+                new AlertDialog.Builder(this)
+                        .setTitle("Logout")
+                        .setMessage("Are you sure you want to log out?")
+                        .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                                NavDrawerActivity.super.onBackPressed();
+                            }
+                        })
+                        .setNegativeButton(R.string.no, null)
+                        .show();
             } else {
                 super.onBackPressed();
             }
         }
+    }
 
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {