Fix android exit crash

src/states_screens/main_menu_screen.cpp

@@ -405,7 +405,11 @@ void MainMenuScreen::eventCallback(Widget* widget, const std::string& name,
     }
     else if (selection == "quit")
     {
+#ifdef ANDROID
+        ANativeActivity_finish(global_android_app->activity);
+#else
         StateManager::get()->popMenu();
+#endif
         return;
     }
     else if (selection == "about")
@@ -564,3 +568,15 @@ void MainMenuScreen::onDisabledItemClicked(const std::string& item)
     }
 #endif
 }   // onDisabledItemClicked
+
+// ----------------------------------------------------------------------------
+
+bool MainMenuScreen::onEscapePressed()
+{
+#ifdef ANDROID
+    ANativeActivity_finish(global_android_app->activity);
+    return false;
+#endif
+
+    return true;
+}   // onEscapePressed

src/states_screens/main_menu_screen.hpp

@@ -58,6 +58,10 @@ public:
 
     /** \brief implement callback from parent class GUIEngine::Screen */
     virtual void onDisabledItemClicked(const std::string& item) OVERRIDE;
+
+    /** \brief implement optional callback from parent
+     *  class GUIEngine::Screen */
+    virtual bool onEscapePressed() OVERRIDE;
 };
 
 #endif

src/states_screens/state_manager.cpp

@@ -252,13 +252,9 @@ void StateManager::onTopMostScreenChanged()
 
 void StateManager::onStackEmptied()
 {
-    #ifdef ANDROID
-    ANativeActivity_finish(global_android_app->activity);
-    #else
     GUIEngine::cleanUp();
     GUIEngine::deallocate();
     main_loop->abort();
-    #endif
 }   // onStackEmptied
 
 // ============================================================================