Historical map overlay with MapBox in Flutter

home_page.dart

Widget _openPopupMenu() => PopupMenuButton<int>(
        onSelected: (value) {
          setState(() {
            value == 1 ? isPresentTime = true : isPresentTime = false; // shorter form: isPresent = value == 1;
          });
        },
        itemBuilder: (context) => [
          ...
        ],
        icon: Container(
          ...
          ),
          ...
        ),
      );