Widget get whichToShow {
    switch (which) {
      case 12: return Column(children: listToTest);
      case 13: return ListView(children: listToTest);
    }
    return Container();
  }

  List<Widget> get listToTest => [
    const FlutterLogo(size: 25),
    Container(color: Colors.red),
    Container(
      width: 50,
      color: Colors.green,
      child: const FlutterLogo(size: 25),
    ),
    Container(
      height: 50,
      color: Colors.blue,
      child: const FlutterLogo(size: 25),
    ),
    Container(
      alignment: Alignment.bottomRight,
      height: 50,
      color: Colors.yellow,
      child: const FlutterLogo(size: 25),
    ),
    const Align(
      alignment: Alignment.bottomRight,
      child: FlutterLogo(size: 25),
    ),
    LayoutBuilder(builder: (context, constraints) {
      return Text('$constraints', style: const TextStyle(color: Colors.white));
      // BoxConstraints(0.0<=w<=300.0, 0.0<=h<=Infinity) in Column
      // BoxConstraints(w=300.0, 0.0<=h<=Infinity) in ListView
    }),
  ];