A wrapper widget to enable tapping to switch off or on an experimental mode setting

experimental_switcher.dart

import 'package:flutter/material.dart';
import 'package:japanese_reading/settings_page/services/experimental_mode.dart';

class ExperimentalModeSwitcher extends StatefulWidget {
  final Widget child;
  final ExperimentalMode experimentalMode;

  const ExperimentalModeSwitcher({Key key, @required this.child, @required this.experimentalMode}) : super(key: key);

  @override
  _ExperimentalModeSwitcherState createState() => _ExperimentalModeSwitcherState();
}

class _ExperimentalModeSwitcherState extends State<ExperimentalModeSwitcher> {
  static final int tapsRequired = 5;
  int _taps = 0;

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: _tapped,
      child: widget.child
    );
  }

  void _tapped() {
    _taps += 1;
    if (_taps >= tapsRequired) {
      _taps = 0;
      _toggleMode();
    } else {
      showToast("${tapsRequired - _taps} taps left", Duration(milliseconds: 100));
    }
  }

  void _toggleMode() {
    var mode = this.widget.experimentalMode.isExperimentalMode;
    mode = !mode;

    String message = mode ? 'Experimental mode on, please restart' : 'Experimental mode off, please restart';
    showToast(message, Duration(seconds: 2));

    this.widget.experimentalMode.setExperimentalMode(mode);
  }

  void showToast(String message, Duration duration) {
    ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
            content: Text(message),
            duration: duration,
            margin: EdgeInsets.symmetric(vertical: 64.0, horizontal: 16.0),
            behavior: SnackBarBehavior.floating,
        )
    );
  }
}