Utility class using the plugin, flutter_local_notifications.dart.

schedule_notifications.dart

import 'dart:async' show Future;
import 'dart:math' show Random;
import 'dart:typed_data' show Int64List;
import 'dart:ui' show Color;

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
//
import 'package:flutter_local_notifications/flutter_local_notifications.dart';

/// Export those classes the user is likely to use and pass in.
export 'package:flutter_local_notifications/flutter_local_notifications.dart'
    show
        AndroidNotificationDetails,
        AndroidNotificationChannelAction,
        AndroidNotificationSound,
        AndroidBitmap,
        BigPictureStyleInformation,
        BigTextStyleInformation,
        Day,
        DefaultStyleInformation,
        DidReceiveLocalNotificationCallback,
        DrawableResourceAndroidBitmap,
        FilePathAndroidBitmap,
        GroupAlertBehavior,
        Importance,
        InitializationSettings,
        InboxStyleInformation,
        IOSNotificationDetails,
        IOSNotificationAttachment,
        MediaStyleInformation,
        NotificationAppLaunchDetails,
        NotificationDetails,
        NotificationVisibility,
        PendingNotificationRequest,
        Priority,
        RawResourceAndroidNotificationSound,
        RepeatInterval,
        SelectNotificationCallback,
        Time;

export 'dart:typed_data' show Int64List;

export 'package:flutter/material.dart' show Color;

class ScheduleNotifications with HandleError {
//
  ScheduleNotifications(
    this.channelId,
    this.channelName,
    this.channelDescription, {
    String appIcon,
    DateTime schedule,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    SelectNotificationCallback onSelectNotification,
    bool requestAlertPermission,
    bool requestSoundPermission,
    bool requestBadgePermission,
    bool defaultPresentAlert,
    bool defaultPresentSound,
    bool defaultPresentBadge,
    DidReceiveLocalNotificationCallback onDidReceiveLocalNotification,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) {
    if (appIcon == null || appIcon.trim().isEmpty) {
      // Assign the app's icon.
      _appIcon = '@mipmap/ic_launcher';
    } else {
      _appIcon = appIcon.trim();
    }
    // Take in parameter values into private variables.
    _schedule = schedule;
    _title = title ?? '';
    _body = body ?? '';
    _payload = payload;
    _androidAllowWhileIdle = androidAllowWhileIdle ?? false;
    _icon = icon;
    _importance = importance ?? Importance.Default;
    _priority = priority ?? Priority.Default;
    _styleInformation = styleInformation;
    _playSound = playSound ?? false;
    _sound = sound;
    _enableVibration = enableVibration ?? false;
    _vibrationPattern = vibrationPattern;
    _groupKey = groupKey;
    _setAsGroupSummary = setAsGroupSummary;
    _groupAlertBehavior = groupAlertBehavior ?? GroupAlertBehavior.All;
    _autoCancel = autoCancel ?? true;
    _ongoing = ongoing;
    _color = color;
    _largeIcon = largeIcon;
    _onlyAlertOnce = onlyAlertOnce;
    _showWhen = showWhen ?? true;
    _channelShowBadge = channelShowBadge ?? true;
    _showProgress = showProgress ?? false;
    _maxProgress = maxProgress ?? 0;
    _progress = progress ?? 0;
    _indeterminate = indeterminate ?? false;
    _channelAction =
        channelAction ?? AndroidNotificationChannelAction.CreateIfNotExists;
    _enableLights = enableLights ?? true;
    _ledColor = ledColor ?? const Color.fromARGB(255, 255, 0, 0);
    _ledOnMs = ledOnMs ?? 1000;
    _ledOffMs = ledOffMs ?? 500;
    _ticker = ticker;
    _visibility = visibility ?? NotificationVisibility.Private;
    _timeoutAfter = timeoutAfter;
    _category = category;
    _selectNotificationCallback = onSelectNotification;
    _requestAlertPermission = requestAlertPermission ?? true;
    _requestSoundPermission = requestSoundPermission ?? true;
    _requestBadgePermission = requestBadgePermission ?? true;
    _defaultPresentAlert = defaultPresentAlert ?? true;
    _defaultPresentSound = defaultPresentSound ?? true;
    _defaultPresentBadge = defaultPresentBadge ?? true;
    _onDidReceiveLocalNotification = onDidReceiveLocalNotification;
    _presentAlert = presentAlert ?? true;
    _presentSound = presentSound ?? true;
    _presentBadge = presentBadge ?? true;
    _soundFile = soundFile;
    _badgeNumber = badgeNumber;
    _attachments = attachments;
  }

  /// The icon representing the app implementing the notifications.
  String _appIcon;

  /// The channel's id.
  /// Required for Android 8.0+.
  final String channelId;

  /// The channel's name.
  /// Required for Android 8.0+.
  final String channelName;

  /// The channel's description.
  /// Required for Android 8.0+.
  final String channelDescription;

  DateTime _schedule;
  String _title;
  String _body;
  String _payload;
  bool _androidAllowWhileIdle;
  String _icon;
  Importance _importance;
  Priority _priority;
  StyleInformation _styleInformation;
  bool _playSound;
  AndroidNotificationSound _sound;
  bool _enableVibration;
  List<int> _vibrationPattern;
  String _groupKey;
  bool _setAsGroupSummary;
  GroupAlertBehavior _groupAlertBehavior;
  bool _autoCancel;
  bool _ongoing;
  Color _color;
  AndroidBitmap _largeIcon;
  bool _onlyAlertOnce;
  bool _showWhen;
  bool _channelShowBadge;
  bool _showProgress;
  int _maxProgress;
  int _progress;
  bool _indeterminate;
  AndroidNotificationChannelAction _channelAction;
  bool _enableLights;
  Color _ledColor;
  int _ledOnMs;
  int _ledOffMs;
  String _ticker;
  NotificationVisibility _visibility;
  int _timeoutAfter;
  String _category;
  SelectNotificationCallback _selectNotificationCallback;
  bool _requestAlertPermission;
  bool _requestSoundPermission;
  bool _requestBadgePermission;
  bool _defaultPresentAlert;
  bool _defaultPresentSound;
  bool _defaultPresentBadge;
  DidReceiveLocalNotificationCallback _onDidReceiveLocalNotification;
  bool _presentAlert;
  bool _presentSound;
  bool _presentBadge;
  String _soundFile;
  int _badgeNumber;
  List<IOSNotificationAttachment> _attachments;

  @mustCallSuper
  Future<bool> init({
    String appIcon,
    DateTime schedule,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    SelectNotificationCallback onSelectNotification,
    bool requestAlertPermission,
    bool requestSoundPermission,
    bool requestBadgePermission,
    bool defaultPresentAlert,
    bool defaultPresentSound,
    bool defaultPresentBadge,
    DidReceiveLocalNotificationCallback onDidReceiveLocalNotification,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) async {
    // No need to continue.
    if (_init) return _init;

    if (appIcon != null && appIcon.trim().isEmpty) appIcon = null;
    appIcon ??= _appIcon;
    // init parameters take over initial parameter values.
    if (schedule != null) _schedule = schedule;
    if (title != null) _title = title;
    if (body != null) _body = body;
    if (payload != null) _payload = payload;
    if (androidAllowWhileIdle != null)
      _androidAllowWhileIdle = androidAllowWhileIdle;
    if (icon != null) _icon = icon;
    if (importance != null) _importance = importance;
    if (priority != null) _priority = priority;
    if (styleInformation != null) _styleInformation = styleInformation;
    if (playSound != null) _playSound = playSound;
    if (sound != null) _sound = sound;
    if (enableVibration != null) _enableVibration = enableVibration;
    if (vibrationPattern != null) _vibrationPattern = vibrationPattern;
    if (groupKey != null) _groupKey = groupKey;
    if (setAsGroupSummary != null) _setAsGroupSummary = setAsGroupSummary;
    if (groupAlertBehavior != null) _groupAlertBehavior = groupAlertBehavior;
    if (autoCancel != null) _autoCancel = autoCancel;
    if (ongoing != null) _ongoing = ongoing;
    if (color != null) _color = color;
    if (largeIcon != null) _largeIcon = largeIcon;
    if (onlyAlertOnce != null) _onlyAlertOnce = onlyAlertOnce;
    if (showWhen != null) _showWhen = showWhen;
    if (channelShowBadge != null) _channelShowBadge = channelShowBadge;
    if (showProgress != null) _showProgress = showProgress;
    if (maxProgress != null) _maxProgress = maxProgress;
    if (progress != null) _progress = progress;
    if (indeterminate != null) _indeterminate = indeterminate;
    if (channelAction != null) _channelAction = channelAction;
    if (enableLights != null) _enableLights = enableLights;
    if (ledColor != null) _ledColor = ledColor;
    if (ledOnMs != null) _ledOnMs = ledOnMs;
    if (ledOffMs != null) _ledOffMs = ledOffMs;
    if (ticker != null) _ticker = ticker;
    if (visibility != null) _visibility = visibility;
    if (timeoutAfter != null) _timeoutAfter = timeoutAfter;
    if (category != null) _category = category;
    onSelectNotification ??= _selectNotificationCallback;
    requestAlertPermission ??= _requestAlertPermission;
    requestSoundPermission ??= _requestSoundPermission;
    requestBadgePermission ??= _requestBadgePermission;
    defaultPresentAlert ??= _defaultPresentAlert;
    defaultPresentSound ??= _defaultPresentSound;
    defaultPresentBadge ??= _defaultPresentBadge;
    onDidReceiveLocalNotification ??= _onDidReceiveLocalNotification;
    if (presentAlert != null) _presentAlert = presentAlert;
    if (presentSound != null) _presentSound = presentSound;
    if (presentBadge != null) _presentBadge = presentBadge;
    if (soundFile != null) _soundFile = soundFile;
    if (badgeNumber != null) _badgeNumber = badgeNumber;
    if (attachments != null) _attachments = attachments;

    //
    try {
      // Note: permissions aren't requested here just to demonstrate that can be done later using the `requestPermissions()` method
      // of the `IOSFlutterLocalNotificationsPlugin` class
      var initializationSettingsIOS = IOSInitializationSettings(
        requestAlertPermission: requestAlertPermission,
        requestBadgePermission: requestSoundPermission,
        requestSoundPermission: requestBadgePermission,
        defaultPresentAlert: defaultPresentAlert,
        defaultPresentSound: defaultPresentSound,
        defaultPresentBadge: defaultPresentBadge,
        onDidReceiveLocalNotification: onDidReceiveLocalNotification ??
            (int id, String title, String body, String payload) =>
                onSelectNotification(payload),
      );

      var initializationSettings = InitializationSettings(
          AndroidInitializationSettings(_appIcon), initializationSettingsIOS);

      _flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();

      _init = await _flutterLocalNotificationsPlugin.initialize(
          initializationSettings,
          onSelectNotification: onSelectNotification);
    } catch (ex) {
      getError(ex);
      _init = false;
    }
    return _init;
  }

  @mustCallSuper
  void dispose() {
    // Not really necessary but provides a dispose() function for the user.
    _flutterLocalNotificationsPlugin = null;
  }

  /// Returns the underlying platform-specific implementation of given type [T], which
  /// must be a concrete subclass of [FlutterLocalNotificationsPlatform](https://pub.dev/documentation/flutter_local_notifications_platform_interface/latest/flutter_local_notifications_platform_interface/FlutterLocalNotificationsPlatform-class.html).
  Future<bool> resolveIOSImplementation({
    bool alert = true,
    bool badge = true,
    bool sound = true,
  }) async {
    assert(_init, 'ScheduleNotifications: Failed to call init() first!');
    if (!_init) return false;
    var implementation;
    try {
      implementation = _flutterLocalNotificationsPlugin
          ?.resolvePlatformSpecificImplementation<
              IOSFlutterLocalNotificationsPlugin>();
    } catch (ex) {
      getError(ex);
    }
    var request = implementation != null;
    if (request) {
      request = await implementation.requestPermissions(
        alert: alert,
        badge: badge,
        sound: sound,
      );
    }
    return request;
  }

  // plugin
  FlutterLocalNotificationsPlugin _flutterLocalNotificationsPlugin;

  // Flag indicating it's initialized.
  bool _init = false;
  bool get initialized => _init;

  int show({
    int id,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) {
    //
    var notificationSpecifics = _notificationDetails(
      title,
      body,
      payload,
      androidAllowWhileIdle,
      icon,
      importance,
      priority,
      styleInformation,
      playSound,
      sound,
      enableVibration,
      vibrationPattern,
      groupKey,
      setAsGroupSummary,
      groupAlertBehavior,
      autoCancel,
      ongoing,
      color,
      largeIcon,
      onlyAlertOnce,
      showWhen,
      channelShowBadge,
      showProgress,
      maxProgress,
      progress,
      indeterminate,
      channelAction,
      enableLights,
      ledColor,
      ledOnMs,
      ledOffMs,
      ticker,
      visibility,
      timeoutAfter,
      category,
      presentAlert,
      presentSound,
      presentBadge,
      soundFile,
      badgeNumber,
      attachments,
    );

    if (notificationSpecifics == null) {
      id = -1;
    } else {
      //
      try {
        //
        if (id == null || id < 0) id = Random().nextInt(999);

        _flutterLocalNotificationsPlugin.show(
          id,
          title,
          body,
          notificationSpecifics,
          payload: payload,
        );
      } catch (ex) {
        id = -1;
        getError(ex);
      }
    }
    return id;
  }

  int schedule(
    DateTime schedule, {
    int id,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) {
    // Too late!
    if (schedule == null || DateTime.now().isAfter(schedule)) return -1;

    var notificationSpecifics = _notificationDetails(
      title,
      body,
      payload,
      androidAllowWhileIdle,
      icon,
      importance,
      priority,
      styleInformation,
      playSound,
      sound,
      enableVibration,
      vibrationPattern,
      groupKey,
      setAsGroupSummary,
      groupAlertBehavior,
      autoCancel,
      ongoing,
      color,
      largeIcon,
      onlyAlertOnce,
      showWhen,
      channelShowBadge,
      showProgress,
      maxProgress,
      progress,
      indeterminate,
      channelAction,
      enableLights,
      ledColor,
      ledOnMs,
      ledOffMs,
      ticker,
      visibility,
      timeoutAfter,
      category,
      presentAlert,
      presentSound,
      presentBadge,
      soundFile,
      badgeNumber,
      attachments,
    );

    if (notificationSpecifics == null) {
      id = -1;
    } else {
      //
      if (id == null || id < 0) id = Random().nextInt(999);

      try {
        //
        _flutterLocalNotificationsPlugin.schedule(
          id,
          title,
          body,
          schedule,
          notificationSpecifics,
          payload: payload,
          androidAllowWhileIdle: androidAllowWhileIdle,
        );
      } catch (ex) {
        id = -1;
        getError(ex);
      }
    }
    return id;
  }

  int periodicallyShow(
    RepeatInterval repeatInterval, {
    int id,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) {
    //
    var notificationSpecifics = _notificationDetails(
      title,
      body,
      payload,
      androidAllowWhileIdle,
      icon,
      importance,
      priority,
      styleInformation,
      playSound,
      sound,
      enableVibration,
      vibrationPattern,
      groupKey,
      setAsGroupSummary,
      groupAlertBehavior,
      autoCancel,
      ongoing,
      color,
      largeIcon,
      onlyAlertOnce,
      showWhen,
      channelShowBadge,
      showProgress,
      maxProgress,
      progress,
      indeterminate,
      channelAction,
      enableLights,
      ledColor,
      ledOnMs,
      ledOffMs,
      ticker,
      visibility,
      timeoutAfter,
      category,
      presentAlert,
      presentSound,
      presentBadge,
      soundFile,
      badgeNumber,
      attachments,
    );

    if (notificationSpecifics == null) {
      id = -1;
    } else {
      //
      try {
        //
        if (id == null || id < 0) id = Random().nextInt(999);

        _flutterLocalNotificationsPlugin.periodicallyShow(
          id,
          title,
          body,
          repeatInterval,
          notificationSpecifics,
          payload: payload,
        );
      } catch (ex) {
        id = -1;
        getError(ex);
      }
    }
    return id;
  }

  int showDailyAtTime(
    Time notificationTime, {
    int id,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) {
    //
    var notificationSpecifics = _notificationDetails(
      title,
      body,
      payload,
      androidAllowWhileIdle,
      icon,
      importance,
      priority,
      styleInformation,
      playSound,
      sound,
      enableVibration,
      vibrationPattern,
      groupKey,
      setAsGroupSummary,
      groupAlertBehavior,
      autoCancel,
      ongoing,
      color,
      largeIcon,
      onlyAlertOnce,
      showWhen,
      channelShowBadge,
      showProgress,
      maxProgress,
      progress,
      indeterminate,
      channelAction,
      enableLights,
      ledColor,
      ledOnMs,
      ledOffMs,
      ticker,
      visibility,
      timeoutAfter,
      category,
      presentAlert,
      presentSound,
      presentBadge,
      soundFile,
      badgeNumber,
      attachments,
    );

    if (notificationSpecifics == null) {
      id = -1;
    } else {
      //
      try {
        //
        if (id == null || id < 0) id = Random().nextInt(999);

        _flutterLocalNotificationsPlugin.showDailyAtTime(
          id,
          title,
          body,
          notificationTime,
          notificationSpecifics,
          payload: payload,
        );
      } catch (ex) {
        id = -1;
        getError(ex);
      }
    }
    return id;
  }

  int showWeeklyAtDayAndTime(
    Day day,
    Time notificationTime, {
    int id,
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  }) {
    //
    var notificationSpecifics = _notificationDetails(
      title,
      body,
      payload,
      androidAllowWhileIdle,
      icon,
      importance,
      priority,
      styleInformation,
      playSound,
      sound,
      enableVibration,
      vibrationPattern,
      groupKey,
      setAsGroupSummary,
      groupAlertBehavior,
      autoCancel,
      ongoing,
      color,
      largeIcon,
      onlyAlertOnce,
      showWhen,
      channelShowBadge,
      showProgress,
      maxProgress,
      progress,
      indeterminate,
      channelAction,
      enableLights,
      ledColor,
      ledOnMs,
      ledOffMs,
      ticker,
      visibility,
      timeoutAfter,
      category,
      presentAlert,
      presentSound,
      presentBadge,
      soundFile,
      badgeNumber,
      attachments,
    );

    if (notificationSpecifics == null) {
      id = -1;
    } else {
      //
      try {
        //
        if (id == null || id < 0) id = Random().nextInt(999);

        _flutterLocalNotificationsPlugin.showWeeklyAtDayAndTime(
          id,
          title,
          body,
          day,
          notificationTime,
          notificationSpecifics,
          payload: payload,
        );
      } catch (ex) {
        id = -1;
        getError(ex);
      }
    }
    return id;
  }

  NotificationDetails _notificationDetails(
    String title,
    String body,
    String payload,
    bool androidAllowWhileIdle,
    String icon,
    Importance importance,
    Priority priority,
    StyleInformation styleInformation,
    bool playSound,
    AndroidNotificationSound sound,
    bool enableVibration,
    List<int> vibrationPattern,
    String groupKey,
    bool setAsGroupSummary,
    GroupAlertBehavior groupAlertBehavior,
    bool autoCancel,
    bool ongoing,
    Color color,
    AndroidBitmap largeIcon,
    bool onlyAlertOnce,
    bool showWhen,
    bool channelShowBadge,
    bool showProgress,
    int maxProgress,
    int progress,
    bool indeterminate,
    AndroidNotificationChannelAction channelAction,
    bool enableLights,
    Color ledColor,
    int ledOnMs,
    int ledOffMs,
    String ticker,
    NotificationVisibility visibility,
    int timeoutAfter,
    String category,
    bool presentAlert,
    bool presentSound,
    bool presentBadge,
    String soundFile,
    int badgeNumber,
    List<IOSNotificationAttachment> attachments,
  ) {
    //
    NotificationDetails notificationSpecifics;

    // Failed to initialized.
    if (!_init) {
      if (hasError) {
        assert(false, errorMsg);
      } else {
        assert(false, 'ScheduleNotifications: Failed to call init() first!');
      }
      return notificationSpecifics;
    }

    title ??= _title;
    body ??= _body;
    payload ??= _payload;
    androidAllowWhileIdle ??= _androidAllowWhileIdle;
    icon ??= _icon;
    importance ??= _importance;
    priority ??= _priority;
    styleInformation ??= _styleInformation;
    playSound ??= _playSound;
    sound ??= _sound;
    enableVibration ??= _enableVibration;
    vibrationPattern ??= _vibrationPattern;
    groupKey ??= _groupKey;
    setAsGroupSummary ??= _setAsGroupSummary;
    groupAlertBehavior ??= _groupAlertBehavior;
    autoCancel ??= _autoCancel;
    ongoing ??= _ongoing;
    color ??= _color;
    largeIcon ??= _largeIcon;
    onlyAlertOnce ??= _onlyAlertOnce;
    showWhen ??= _showWhen;
    channelShowBadge ??= _channelShowBadge;
    showProgress ??= _showProgress;
    maxProgress ??= _maxProgress;
    progress ??= _progress;
    indeterminate ??= _indeterminate;
    channelAction ??= _channelAction;
    enableLights ??= _enableLights;
    ledColor ??= _ledColor;
    ledOnMs ??= _ledOnMs;
    ledOffMs ??= _ledOffMs;
    ticker ??= _ticker;
    visibility ??= _visibility;
    timeoutAfter ??= _timeoutAfter;
    category ??= _category;
    presentAlert ??= _presentAlert;
    presentSound ??= _presentSound;
    presentBadge ??= _presentBadge;
    soundFile ??= _soundFile;
    badgeNumber ??= _badgeNumber;
    attachments ??= _attachments;

    // Play the sound if supplied a sound.
    if (playSound == null && sound != null) playSound = true;

    // If to vibrate then do so.
    if (enableVibration &&
        (vibrationPattern == null || vibrationPattern.isEmpty)) {
      vibrationPattern = Int64List(4);
      vibrationPattern[0] = 0;
      vibrationPattern[1] = 1000;
      vibrationPattern[2] = 5000;
      vibrationPattern[3] = 2000;
    }

    AndroidNotificationDetails androidSettings;
    IOSNotificationDetails iOSSettings;

    try {
      androidSettings = AndroidNotificationDetails(
        channelId,
        channelName,
        channelDescription,
        icon: icon,
        importance: importance,
        priority: priority,
        styleInformation: styleInformation,
        playSound: playSound,
        sound: sound,
        enableVibration: enableVibration,
        vibrationPattern: vibrationPattern,
        groupKey: groupKey,
        setAsGroupSummary: setAsGroupSummary,
        groupAlertBehavior: groupAlertBehavior,
        autoCancel: autoCancel,
        ongoing: ongoing,
        color: color,
        largeIcon: largeIcon,
        onlyAlertOnce: onlyAlertOnce,
        showWhen: showWhen,
        channelShowBadge: channelShowBadge,
        showProgress: showProgress,
        maxProgress: maxProgress,
        progress: progress,
        indeterminate: indeterminate,
        channelAction: channelAction,
        enableLights: enableLights,
        ledColor: ledColor,
        ledOnMs: ledOnMs,
        ledOffMs: ledOffMs,
        ticker: ticker,
        visibility: visibility,
        timeoutAfter: timeoutAfter,
        category: category,
      );
    } catch (ex) {
      getError(ex);
      return notificationSpecifics;
    }

    try {
      iOSSettings = IOSNotificationDetails(
        presentAlert: presentAlert,
        presentSound: presentSound,
        presentBadge: presentBadge,
        sound: soundFile,
        badgeNumber: badgeNumber,
        attachments: attachments,
      );

      notificationSpecifics = NotificationDetails(androidSettings, iOSSettings);
    } catch (ex) {
      notificationSpecifics = null;
      getError(ex);
    }
    return notificationSpecifics;
  }

  /// Cancel a specific notification.
  Future<void> cancel(int id) async {
    if (id == null || id < 0) return;
    await _flutterLocalNotificationsPlugin.cancel(id);
    return;
  }

  /// Cancel all Notifications.
  Future<void> cancelAll() => _flutterLocalNotificationsPlugin.cancelAll();

  /// Returns info on if a notification created from this plugin had been used to launch the application.
  Future<NotificationAppLaunchDetails> getNotificationAppLaunchDetails() =>
      _flutterLocalNotificationsPlugin.getNotificationAppLaunchDetails();

  /// Returns a list of notifications pending to be delivered/shown.
  Future<List<PendingNotificationRequest>> pendingNotificationRequests() =>
      _flutterLocalNotificationsPlugin.pendingNotificationRequests();
}

mixin HandleError {
  /// Return the 'last' error if any.
  Exception getError([dynamic error]) {
    var ex = _error;
    if (error == null) {
      _error = null;
    } else {
      if (error is! Exception) {
        _error = Exception(error.toString());
      } else {
        _error = error;
      }
      ex ??= _error;
    }
    return ex;
  }

  /// Simply display the error.
  String get errorMsg => _error == null ? '' : _error.toString();

  /// Determine if app is 'in error.'
  bool get inError => _error != null;
  bool get hasError => _error != null;
  Exception _error;
}