mnemo_cards/lib/widgets/shared_pref_button.dart

import 'dart:async';

import 'package:flutter/cupertino.dart';
import 'package:mnemo_cards/main.dart';
import 'package:mnemo_cards_common/mnemo_cards_common.dart';
import 'package:shared_preferences/shared_preferences.dart';

class SharedPrefButton<T> extends StatefulWidget {
  final Function(T)? onClick;
  final String spKey;
  final T Function(T? current)? setOnTap;
  final bool Function(T? current)? shouldRebuild;
  final Widget Function(T? value, ValueSetter<T> setValue)? builder;

  SharedPrefButton({
    this.builder,
    required this.spKey,
    this.setOnTap,
    this.onClick,
    this.shouldRebuild,
  });

  SharedPrefButton.builder({
    this.builder,
    required this.spKey,
    this.setOnTap,
    this.onClick,
    this.shouldRebuild,
  });

  @override
  State<StatefulWidget> createState() => _SharedPrefButtonState<T>();
}

class _SharedPrefButtonState<T> extends State<SharedPrefButton<T>> {
  SharedPreferences? _sp;
  T? value;

  StreamSubscription? _streamSubscription;

  @override
  void dispose() {
    _streamSubscription?.cancel();
    _streamSubscription = null;
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
    _sp = globalSharedPreferences;
    value = valueFromSp;
    _streamSubscription =
        Stream.periodic(const Duration(milliseconds: 500), (_) => valueFromSp)
            .distinct()
            .listen((v) {
      if (value != v) {
        value = v;
        if (mounted && widget.shouldRebuild?.call(value) != false) {
          setState(() {});
        }
      }
    });
  }

  T? get valueFromSp {
    if (T == bool) {
      return (_sp?.getBool(widget.spKey) ?? false).as<T?>();
    } else if (T == int) {
      return _sp?.getInt(widget.spKey).as<T?>();
    } else if (T == num || T == double) {
      return _sp?.getDouble(widget.spKey).as<T?>();
    } else if (T == String) {
      return _sp?.getString(widget.spKey).as<T?>();
    } else if (T == Iterable<String>) {
      return _sp?.getStringList(widget.spKey).as<T?>();
    }
    return null;
  }

  Future<void> setValue(T value) async {
    if (T == bool) {
      _sp?.setBool(widget.spKey, value as bool);
    } else if (T == int) {
      _sp?.setInt(widget.spKey, value as int);
    } else if (T == num || T == double) {
      _sp?.setDouble(widget.spKey, value as double);
    } else if (T == String) {
      _sp?.setString(widget.spKey, value as String);
    } else if (T == Iterable<String>) {
      _sp?.setStringList(widget.spKey, (value as Iterable<String>).toList());
    }
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      behavior: HitTestBehavior.opaque,
      onTap: widget.setOnTap != null
          ? () async {
              value = widget.setOnTap!.call(value);
              if (value != null) {
                _setValue(value!);
              }
            }
          : null,
      child: widget.builder?.call(value, _setValue),
    );
  }

  Future<void> _setValue(T value) async {
    await setValue(value!);
    if (widget.shouldRebuild?.call(value) != false) {
      setState(() {});
    }
  }
}