feat: Migrated null-safety

example/ios/Flutter/flutter_export_environment.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+# This is a generated file; do not edit or check into version control.
+export "FLUTTER_ROOT=c:\src\flutter"
+export "FLUTTER_APPLICATION_PATH=C:\Users\Marcelo\Documents\sbsistemas\t\t\flutter_skeleton\example"
+export "COCOAPODS_PARALLEL_CODE_SIGN=true"
+export "FLUTTER_TARGET=lib\main.dart"
+export "FLUTTER_BUILD_DIR=build"
+export "SYMROOT=${SOURCE_ROOT}/../build\ios"
+export "FLUTTER_BUILD_NAME=1.0.0"
+export "FLUTTER_BUILD_NUMBER=1"
+export "DART_OBFUSCATION=false"
+export "TRACK_WIDGET_CREATION=false"
+export "TREE_SHAKE_ICONS=false"
+export "PACKAGE_CONFIG=.packages"

lib/src/skeleton_style.dart

@@ -8,9 +8,9 @@ class SkeletonStyle {
   final bool isCircleAvatar;
   final int barCount;
   final BorderRadius borderRadius;
-  final EdgeInsetsGeometry padding;
-  final List<Color> colors;
-  final Color backgroundColor;
+  final EdgeInsetsGeometry? padding;
+  final List<Color>? colors;
+  final Color? backgroundColor;
   final SkeletonTheme theme;
 
   SkeletonStyle({

lib/src/widget/card_list_skeleton.dart

@@ -8,7 +8,7 @@ class CardListSkeleton extends StatelessWidget {
   final int length;
 
   CardListSkeleton({
-    Key key,
+    Key? key,
     this.style: const SkeletonStyle.origin(),
     this.length: 10,
   }) : super(key: key);

lib/src/widget/card_skeleton.dart

@@ -7,7 +7,7 @@ class CardSkeleton extends StatelessWidget {
   final SkeletonStyle style;
 
   CardSkeleton({
-    Key key,
+    Key? key,
     this.style: const SkeletonStyle.origin(),
   }) : super(key: key);
 

lib/src/widget/list_skeleton.dart

@@ -8,7 +8,7 @@ class ListSkeleton extends StatelessWidget {
   final int length;
 
   ListSkeleton({
-    Key key,
+    Key? key,
     this.style: const SkeletonStyle.origin(),
     this.length: 10,
   }) : super(key: key);

lib/src/widget/list_tile_skeleton.dart

@@ -11,7 +11,7 @@ class ListTileSkeleton extends StatefulWidget {
   final SkeletonStyle style;
 
   ListTileSkeleton({
-    Key key,
+    Key? key,
     this.style: const SkeletonStyle.origin(),
   }) : super(key: key);
 
@@ -21,7 +21,7 @@ class ListTileSkeleton extends StatefulWidget {
 
 class _ListTileSkeletonState extends State<ListTileSkeleton>
     with SingleTickerProviderStateMixin {
-  _SkeletonAnimation _skeletonAnimation;
+  _SkeletonAnimation? _skeletonAnimation;
 
   @override
   void initState() {
@@ -34,12 +34,12 @@ class _ListTileSkeletonState extends State<ListTileSkeleton>
   @override
   void dispose() {
     if (widget.style.isAnimation) {
-      _skeletonAnimation.dispose();
+      _skeletonAnimation!.dispose();
     }
     super.dispose();
   }
 
-  Color get _backgroundColor {
+  Color? get _backgroundColor {
     if (widget.style.backgroundColor != null) {
       return widget.style.backgroundColor;
     }
@@ -49,16 +49,16 @@ class _ListTileSkeletonState extends State<ListTileSkeleton>
     return lightBackgroundColor;
   }
 
-  EdgeInsetsGeometry get _padding {
+  EdgeInsetsGeometry? get _padding {
     if (widget.style.padding != null) {
       return widget.style.padding;
     }
     return EdgeInsets.all(16.0);
   }
 
   _SkeletonDecoration _createSkeletonDecoration(bool isCircle) {
-    List<Color> colors = [];
-    if (widget.style.colors != null && widget.style.colors.length > 0) {
+    List<Color>? colors = [];
+    if (widget.style.colors != null && widget.style.colors!.length > 0) {
       colors = widget.style.colors;
     } else {
       colors =
@@ -69,15 +69,15 @@ class _ListTileSkeletonState extends State<ListTileSkeleton>
       animation: _skeletonAnimation,
       isCircle: isCircle,
       isAnimation: widget.style.isAnimation,
-      colors: colors,
+      colors: colors!,
     );
   }
 
   @override
   Widget build(BuildContext context) {
     return widget.style.isAnimation
         ? AnimatedBuilder(
-            animation: _skeletonAnimation.animation,
+            animation: _skeletonAnimation!.animation,
             builder: (context, child) {
               return _renderContainer();
             },
@@ -162,7 +162,7 @@ class _ListTileSkeletonState extends State<ListTileSkeleton>
       return Offstage();
     }
 
-    List<double> widths = [width * 0.7, width * 0.8, width * 0.5];
+    List<double?> widths = [width * 0.7, width * 0.8, width * 0.5];
     List<Widget> children = [];
     children.add(SizedBox(height: 20.0));
     for (int i = 0; i < count; i++) {

lib/src/widget/skeleton_animation.dart

@@ -1,8 +1,8 @@
 part of 'list_tile_skeleton.dart';
 
 class _SkeletonAnimation {
-  AnimationController _controller;
-  Animation<double> animation;
+  late AnimationController _controller;
+  late Animation<double> animation;
 
   _SkeletonAnimation(TickerProvider provider) {
     _controller =

lib/src/widget/skeleton_decoration.dart

@@ -2,9 +2,9 @@ part of 'list_tile_skeleton.dart';
 
 class _SkeletonDecoration extends BoxDecoration {
   _SkeletonDecoration({
-    @required List<Color> colors,
+    required List<Color> colors,
     isAnimation: true,
-    _SkeletonAnimation animation,
+    _SkeletonAnimation? animation,
     isCircle: false,
   }) : super(
             shape: isCircle ? BoxShape.circle : BoxShape.rectangle,
@@ -15,7 +15,7 @@ class _SkeletonDecoration extends BoxDecoration {
                     end: Alignment.centerRight,
                     colors: colors,
                     stops: [
-                      animation.animation.value - 1,
+                      animation!.animation.value - 1,
                       animation.animation.value,
                       animation.animation.value + 1
                     ],

pubspec.yaml

@@ -9,5 +9,5 @@ dependencies:
     sdk: flutter
 
 environment:
-  sdk: ">=1.19.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
   flutter: ">=0.4.1 <2.0.0"