refactor: Migrate to sound null safety

example/lib/attached_toast/attached_toast.dart

@@ -51,15 +51,15 @@ class _AttachedToastState extends State<AttachedToast> {
                     FlatButton.icon(
                       padding: EdgeInsets.all(5),
                       onPressed: (){
-                        BotToast.showSimpleNotification(title: "Let's go travel together.😘");
+                        BotToast.showSimpleNotification(title: "Tap favorite");
                       },
                       label: Text("favorite"),
                       icon: Icon(Icons.favorite,color: Colors.redAccent),
                     ),
                     FlatButton.icon(
                       padding: EdgeInsets.all(5),
                       onPressed: (){
-                        BotToast.showSimpleNotification(title: "Thank you for liking me.😝");
+                        BotToast.showSimpleNotification(title: "Tap bookmark");
                       },
                       label: Text("bookmark"),
                       icon: Icon(Icons.bookmark,color: Colors.redAccent),

example/lib/loading/custom_loading.dart

@@ -59,7 +59,7 @@ class __CustomLoadWidgetState extends State<_CustomLoadWidget>
                         }),
                     Padding(
                       padding: const EdgeInsets.symmetric(horizontal: 8.0),
-                      child: Text("me too"),
+                      child: Text("Tap loading toast"),
                     )
                   ],
                 ),
@@ -82,8 +82,11 @@ class __CustomLoadWidgetState extends State<_CustomLoadWidget>
                 onPressed: handleTap,
               ),
             ),
-            Text(
-              "i miss you",
+            Padding(
+              padding: const EdgeInsets.all(8.0),
+              child: Text(
+                "Loading",
+              ),
             )
           ],
         ),

example/lib/notification/notification.dart

@@ -38,8 +38,8 @@ class _NotificationState extends State<Notification> {
                             icon: Icon(Icons.favorite, color: Colors.redAccent),
                             onPressed: cancel,
                           )),
-                      title: (_) => Text('I love u'),
-                      subtitle: (_) => Text("let's be together"),
+                      title: (_) => Text('Notification title'),
+                      subtitle: (_) => Text("Notification subtitle"),
                       trailing: (cancel) => IconButton(
                             icon: Icon(Icons.cancel),
                             onPressed: cancel,

example/lib/notification/simple_notification.dart

@@ -20,8 +20,8 @@ class _SimpleNotificationState extends State<SimpleNotification> {
   @override
   void initState() {
     BotToast.showSimpleNotification(
-        title: "do you still love me ?",
-        subTitle: "yes!",
+        title: "Notification title",
+        subTitle: "Notification subtitle",
         enableSlideOff: enableSlideOff,
         hideCloseButton: hideCloseButton,
         onTap: () {
@@ -58,8 +58,8 @@ class _SimpleNotificationState extends State<SimpleNotification> {
               RaisedButton(
                 onPressed: () {
                   BotToast.showSimpleNotification(
-                      title: "do you still love me ?",
-                      subTitle: "yes!",
+                      title: "Notification title",
+                      subTitle: "Notification subtitle",
                       enableSlideOff: enableSlideOff,
                       hideCloseButton: hideCloseButton,
                       onlyOne: onlyOne,

example/lib/text/custom_text.dart

@@ -57,7 +57,7 @@ class _CustomTextState extends State<CustomText> {
                                 ),
                                 onPressed: () {
                                   BotToast.showSimpleNotification(
-                                      title: "Yes, I do!",
+                                      title: "Notification one",
                                       crossPage: crossPage,
                                       closeIcon: Icon(
                                         Icons.favorite,
@@ -68,7 +68,7 @@ class _CustomTextState extends State<CustomText> {
                             Padding(
                               padding:
                                   const EdgeInsets.symmetric(horizontal: 8),
-                              child: Text("propose marriage?"),
+                              child: Text("Text one"),
                             ),
                           ],
                         ),

example/lib/text/text.dart

@@ -40,9 +40,9 @@ class _TextSampleState extends State<TextSample> {
               RaisedButton(
                 onPressed: () {
                   BotToast.showText(
-                      text: (index++).isOdd
-                          ? "Always together☺"
-                          : "My mind is all about you.😘",
+                      text: (++index).isOdd
+                          ? "Text one"
+                          : "Text two",
                       duration: Duration(seconds: seconds),
                       onlyOne: onlyOne,
                       clickClose: clickClose,

lib/src/bot_toast_init.dart

@@ -6,17 +6,16 @@ import 'bot_toast_manager.dart';
 final GlobalKey<BotToastManagerState> _key = GlobalKey<BotToastManagerState>();
 
 BotToastManagerState get botToastManager {
-  assert(_key?.currentState != null);
-  return _key.currentState;
+  assert(_key.currentState != null);
+  return _key.currentState!;
 }
 
 class BotToastWidgetsBindingObserver with WidgetsBindingObserver {
-  BotToastWidgetsBindingObserver._() {
-    _listener = <PopTestFunc>[];
-    WidgetsBinding.instance.addObserver(this);
+  BotToastWidgetsBindingObserver._() : _listener = <PopTestFunc>[] {
+    WidgetsBinding.instance!.addObserver(this);
   }
 
-  List<PopTestFunc> _listener;
+  final List<PopTestFunc> _listener;
 
   static final BotToastWidgetsBindingObserver _singleton =
       BotToastWidgetsBindingObserver._();
@@ -49,7 +48,7 @@ TransitionBuilder BotToastInit() {
 
   //ignore: unnecessary_statements
   BotToastWidgetsBindingObserver._singleton;
-  return (_, Widget child) {
-    return BotToastManager(key: _key, child: child);
+  return (_, Widget? child) {
+    return BotToastManager(key: _key, child: child!);
   };
 }

lib/src/bot_toast_manager.dart

@@ -3,16 +3,16 @@ import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
 void safeRun(void Function() callback) {
-  SchedulerBinding.instance.addPostFrameCallback((_) {
+  SchedulerBinding.instance!.addPostFrameCallback((_) {
     callback();
   });
-  SchedulerBinding.instance.ensureVisualUpdate();
+  SchedulerBinding.instance!.ensureVisualUpdate();
 }
 
 class BotToastManager extends StatefulWidget {
   final Widget child;
 
-  const BotToastManager({Key key, this.child}) : super(key: key);
+  const BotToastManager({Key? key, required this.child}) : super(key: key);
 
   @override
   BotToastManagerState createState() => BotToastManagerState();
@@ -23,7 +23,8 @@ class _IndexWidget extends StatelessWidget {
 
   final int index;
 
-  const _IndexWidget({Key key, this.child, this.index}) : super(key: key);
+  const _IndexWidget({Key? key, required this.child, required this.index})
+      : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -62,7 +63,7 @@ class BotToastManagerState extends State<BotToastManager> {
           _map[groupKey]?.remove(key);
         },
       );
-      _map[groupKey][key] = _IndexWidget(
+      _map[groupKey]![key] = _IndexWidget(
         key: uniqueKey,
         index: ++_nextAddIndex,
         child: widget,
@@ -90,14 +91,12 @@ class BotToastManagerState extends State<BotToastManager> {
         return;
       }
 
-      _map[groupKey].removeWhere((key, _) => !_pending.contains(key));
+      _map[groupKey]!.removeWhere((key, _) => !_pending.contains(key));
       _update();
 
-      if (_map[groupKey].isNotEmpty) {
-        _map[groupKey].forEach((key, value) {
-          return remove(groupKey, key);
-        });
-      }
+      _map[groupKey]!.forEach((key, value) {
+        return remove(groupKey, key);
+      });
     });
   }
 

lib/src/keyboard_safe_area.dart

@@ -6,7 +6,7 @@ class KeyboardSafeArea extends StatelessWidget {
 
   final bool enable;
 
-  const KeyboardSafeArea({Key key, this.child, this.enable}) : super(key: key);
+  const KeyboardSafeArea({Key? key,required this.child,required this.enable}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

lib/src/keyboard_visibility.dart

@@ -5,9 +5,9 @@ class KeyboardVisibility extends StatefulWidget {
   final Widget child;
 
   const KeyboardVisibility(
-      {@required this.onKeyboardVisibilityChanged,
-      @required this.child,
-      Key key})
+      {required this.onKeyboardVisibilityChanged,
+      required this.child,
+      Key? key})
       : super(key: key);
 
   @override
@@ -18,7 +18,7 @@ class _KeyboardVisibilityState extends State<KeyboardVisibility>
     with WidgetsBindingObserver {
   @override
   void initState() {
-    WidgetsBinding.instance.addObserver(this);
+    WidgetsBinding.instance!.addObserver(this);
     super.initState();
   }
 
@@ -34,7 +34,7 @@ class _KeyboardVisibilityState extends State<KeyboardVisibility>
 
   @override
   void dispose() {
-    WidgetsBinding.instance.removeObserver(this);
+    WidgetsBinding.instance!.removeObserver(this);
     super.dispose();
   }