calculus-use-case-calculus-screen.dart

class _CalculusScreenState extends State<CalculusScreen> {
  CalculatorUseCase useCase = CalculatorUseCase();

  void onMemorise() {
    setState(() {
      useCase.memorise();
    });
  }

  void onResetMemory() {
    setState(() {
      useCase.resetMemory();
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      ...
      // providing use case to the children elements
      MemoryInfo(memory: useCase.memory),
      CalculatorInput(useCase: useCase),
      MemoryManagement(onMemorise: onMemorise, onResetMemory: onResetMemory),
    );
  }
}