Add errorBuilder

.github/workflows/analyze-and-test.yaml

@@ -10,7 +10,7 @@ jobs:
     name: Flutter analyze
     strategy:
       matrix:
-        flutter: ['beta']
+        flutter: ['stable', 'dev']
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v2
@@ -32,18 +32,4 @@ jobs:
           || (echo "##[error] found changed files after build. please run 'dart tool/prepare_submit.dart'" \
                    "and check in all changes" \
               && exit 1)
-        shell: bash
+        shell: bash
-  build_web_version:
-    name: Check that the web version compile
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: subosito/flutter-action@v1
-        with:
-          channel: 'beta'
-      - run: flutter config --enable-web
-      - run: flutter precache web
-      - run: flutter pub get
-        working-directory: example
-      - run: flutter build web
-        working-directory: example

.github/workflows/publish-on-pub.yaml

@@ -10,11 +10,12 @@ jobs:
       - uses: actions/checkout@v2
       - uses: subosito/flutter-action@v1
         with:
-          channel: 'beta'
+          channel: 'stable'
       - run: flutter pub get
       - run: flutter pub run tool/publish/comment_dependency_overrides.dart
       - run: flutter pub get
-      - run: flutter pub run tool/publish/check_version.dart ${GITHUB_REF}
+      - run: echo ::set-env name=RELEASE_VERSION::${GITHUB_REF}
+      - run: flutter pub run tool/publish/check_version.dart ${{ env.RELEASE_VERSION }}
       - name: Setup credentials
         run: |
           mkdir -p $FLUTTER_HOME/.pub-cache

CHANGELOG.md

@@ -1,16 +1,3 @@
-## [0.8.0]
-- Migrate to null safety
-- Fix some rendering bugs
-
-## [0.7.1]
-- Fix a crash for some lottie file with empty paths.
-
-## [0.7.0+1]
-- Fix Flutter Web compilation error
-
-## [0.7.0]
-- Performance improvement for complex animations.
-
 ## [0.6.0]
 - Runs the animation at the frame rate specified in the json file (ie. An animation encoded with a 20 FPS will only
   be paint 20 times per seconds even though the AnimationController will invalidate the widget 60 times per seconds).  

README.md

@@ -8,7 +8,7 @@ animations exported as json with [Bodymovin](https://github.com/airbnb/lottie-we
 
 This repository is a unofficial conversion of the [Lottie-android](https://github.com/airbnb/lottie-android) library in pure Dart. 
 
-It works on Android, iOS, macOS, linux, windows and web.
+It works on Android, iOS and macOS and web.
 
 ## Usage
 
@@ -64,7 +64,7 @@ class MyApp extends StatefulWidget {
 }
 
 class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
-  late final AnimationController _controller;
+  AnimationController _controller;
 
   @override
   void initState() {
@@ -137,7 +137,7 @@ class MyWidget extends StatefulWidget {
 }
 
 class _MyWidgetState extends State<MyWidget> {
-  late final Future<LottieComposition> _composition;
+  Future<LottieComposition> _composition;
 
   @override
   void initState() {
@@ -176,7 +176,7 @@ a specific position and size.
 class CustomDrawer extends StatelessWidget {
   final LottieComposition composition;
 
-  const CustomDrawer(this.composition, {Key? key}) : super(key: key);
+  const CustomDrawer(this.composition, {Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

README.template.md

@@ -8,7 +8,7 @@ animations exported as json with [Bodymovin](https://github.com/airbnb/lottie-we
 
 This repository is a unofficial conversion of the [Lottie-android](https://github.com/airbnb/lottie-android) library in pure Dart. 
 
-It works on Android, iOS, macOS, linux, windows and web.
+It works on Android, iOS and macOS and web.
 
 ## Usage
 

example/ios/Flutter/Debug.xcconfig

@@ -1,3 +1,2 @@
-#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"

example/ios/Flutter/Release.xcconfig

@@ -1,3 +1,2 @@
-#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"

example/lib/examples/alert_dialog.dart

@@ -23,7 +23,7 @@ class __PageState extends State<_Page> {
   void initState() {
     super.initState();
 
-    SchedulerBinding.instance!.addPostFrameCallback((_) => _showLoader());
+    SchedulerBinding.instance.addPostFrameCallback((_) => _showLoader());
   }
 
   void _showLoader() {

example/lib/examples/animate_no_repeat.dart

@@ -6,7 +6,7 @@ void main() async {
 }
 
 class App extends StatelessWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

example/lib/examples/animation_controller.dart

@@ -9,7 +9,7 @@ class MyApp extends StatefulWidget {
 }
 
 class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
-  late final AnimationController _controller;
+  AnimationController _controller;
 
   @override
   void initState() {

example/lib/examples/animation_full_control.dart

@@ -17,7 +17,7 @@ class MyApp extends StatefulWidget {
 }
 
 class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
-  late final AnimationController _controller;
+  AnimationController _controller;
 
   @override
   void initState() {
@@ -86,7 +86,7 @@ class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
               ],
             ),
             const SizedBox(height: 30),
-            ElevatedButton(
+            RaisedButton(
               child: Text('Loop between frames'),
               onPressed: () {
                 // Loop between 2 specifics frames
@@ -97,7 +97,7 @@ class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
                   min: start,
                   max: stop,
                   reverse: true,
-                  period: _controller.duration! * (stop - start),
+                  period: _controller.duration * (stop - start),
                 );
               },
             ),

example/lib/examples/custom_draw.dart

@@ -22,7 +22,7 @@ class MyWidget extends StatefulWidget {
 }
 
 class _MyWidgetState extends State<MyWidget> {
-  late final Future<LottieComposition> _composition;
+  Future<LottieComposition> _composition;
 
   @override
   void initState() {
@@ -57,7 +57,7 @@ class _MyWidgetState extends State<MyWidget> {
 class CustomDrawer extends StatelessWidget {
   final LottieComposition composition;
 
-  const CustomDrawer(this.composition, {Key? key}) : super(key: key);
+  const CustomDrawer(this.composition, {Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

example/lib/examples/custom_load.dart

@@ -23,7 +23,7 @@ class MyWidget extends StatefulWidget {
 }
 
 class _MyWidgetState extends State<MyWidget> {
-  late final Future<LottieComposition> _composition;
+  Future<LottieComposition> _composition;
 
   @override
   void initState() {

example/lib/examples/dynamic_properties.dart

@@ -8,7 +8,7 @@ void main() async {
 }
 
 class App extends StatefulWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   _AppState createState() => _AppState();
@@ -50,7 +50,7 @@ class _AppState extends State<App> with TickerProviderStateMixin {
               value: _useDelegates,
               onChanged: (newValue) {
                 setState(() {
-                  _useDelegates = newValue!;
+                  _useDelegates = newValue;
                 });
               },
             ),

example/lib/examples/dynamic_text.dart

@@ -7,14 +7,14 @@ void main() async {
 }
 
 class App extends StatefulWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   _AppState createState() => _AppState();
 }
 
 class _AppState extends State<App> with TickerProviderStateMixin {
-  late final TextEditingController _textController;
+  TextEditingController _textController;
 
   @override
   void initState() {

example/lib/examples/hide_after_complete.dart

@@ -6,14 +6,14 @@ void main() async {
 }
 
 class App extends StatefulWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   _AppState createState() => _AppState();
 }
 
 class _AppState extends State<App> with TickerProviderStateMixin {
-  late final AnimationController _animationController;
+  AnimationController _animationController;
   bool _showAnimation = true;
 
   @override

example/lib/examples/markers.dart

@@ -9,14 +9,14 @@ void main() async {
 }
 
 class App extends StatefulWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   _AppState createState() => _AppState();
 }
 
 class _AppState extends State<App> with TickerProviderStateMixin {
-  late final Future<LottieComposition> _composition;
+  Future<LottieComposition> _composition;
 
   @override
   void initState() {
@@ -35,9 +35,9 @@ class _AppState extends State<App> with TickerProviderStateMixin {
         body: FutureBuilder<LottieComposition>(
           future: _composition,
           builder: (context, snapshot) {
-            if (snapshot.hasError) return ErrorWidget(snapshot.error!);
+            if (snapshot.hasError) return ErrorWidget(snapshot.error);
             if (!snapshot.hasData) return CircularProgressIndicator();
-            return _LottieDetails(snapshot.data!);
+            return _LottieDetails(snapshot.data);
           },
         ),
       ),
@@ -48,7 +48,7 @@ class _AppState extends State<App> with TickerProviderStateMixin {
 class _LottieDetails extends StatefulWidget {
   final LottieComposition composition;
 
-  const _LottieDetails(this.composition, {Key? key}) : super(key: key);
+  const _LottieDetails(this.composition, {Key key}) : super(key: key);
 
   @override
   _LottieDetailsState createState() => _LottieDetailsState();
@@ -56,7 +56,7 @@ class _LottieDetails extends StatefulWidget {
 
 class _LottieDetailsState extends State<_LottieDetails>
     with TickerProviderStateMixin {
-  late final AnimationController _controller;
+  AnimationController _controller;
 
   @override
   void initState() {
@@ -87,15 +87,15 @@ class _LottieDetailsState extends State<_LottieDetails>
           title: Text('Composition duration'),
           trailing: Text(widget.composition.durationFrames.toStringAsFixed(1)),
         ),
-        ElevatedButton(
+        RaisedButton(
           child: Text('touchDownEnd - touchUpCancel'),
           onPressed: () => _playBetween('touchDownEnd', 'touchUpCancel'),
         ),
-        ElevatedButton(
+        RaisedButton(
           child: Text('touchDownStart - touchDownEnd'),
           onPressed: () => _playBetween('touchDownStart', 'touchDownEnd'),
         ),
-        ElevatedButton(
+        RaisedButton(
           child: Text('touchDownEnd - touchUpEnd'),
           onPressed: () => _playBetween('touchDownEnd', 'touchUpEnd'),
         ),
@@ -112,8 +112,8 @@ class _LottieDetailsState extends State<_LottieDetails>
   }
 
   void _playBetween(String marker1, String marker2) {
-    var start = widget.composition.getMarker(marker1)!.start;
+    var start = widget.composition.getMarker(marker1).start;
-    var end = widget.composition.getMarker(marker2)!.start;
+    var end = widget.composition.getMarker(marker2).start;
 
     _controller.value = start;
     _controller.animateTo(end,

example/lib/examples/repeat.dart

@@ -1,63 +0,0 @@
-import 'package:flutter/material.dart';
-import 'package:lottie/lottie.dart';
-
-void main() => runApp(MyApp());
-
-class MyApp extends StatefulWidget {
-  @override
-  _MyAppState createState() => _MyAppState();
-}
-
-class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
-  late final AnimationController _controller;
-  int _repeatIndex = 0;
-
-  @override
-  void initState() {
-    super.initState();
-
-    _controller = AnimationController(vsync: this)
-      ..addStatusListener((status) {
-        if (status == AnimationStatus.completed) {
-          setState(() {
-            _repeatIndex++;
-          });
-          if (_repeatIndex < 5) {
-            _controller.reset();
-            _controller.forward();
-          }
-        }
-      });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return MaterialApp(
-      home: Scaffold(
-        body: ListView(
-          children: [
-            Lottie.asset(
-              'assets/AndroidWave.json',
-              controller: _controller,
-              width: 150,
-              height: 150,
-              onLoaded: (composition) {
-                // Configure the AnimationController with the duration of the
-                // Lottie file and start the animation.
-                _controller.duration = composition.duration;
-                _controller.forward();
-              },
-            ),
-            Center(child: Text('Repeat: $_repeatIndex')),
-          ],
-        ),
-      ),
-    );
-  }
-
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
-  }
-}

example/lib/examples/run_once.dart

@@ -12,7 +12,7 @@ void main() async {
 }
 
 class App extends StatefulWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   _AppState createState() => _AppState();
@@ -20,7 +20,7 @@ class App extends StatefulWidget {
 
 class _AppState extends State<App> with TickerProviderStateMixin {
   int _index = 0;
-  late final AnimationController _animationController;
+  AnimationController _animationController;
 
   @override
   void initState() {

example/lib/examples/save_frames.dart

@@ -1,5 +1,3 @@
-//@dart=2.10
-
 import 'dart:io';
 import 'dart:ui';
 import 'package:flutter/material.dart';
@@ -28,7 +26,7 @@ class _MyAppState extends State<MyApp> {
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.stretch,
             children: [
-              ElevatedButton(
+              RaisedButton(
                 child: Text('Export all frames'),
                 onPressed: _export,
               ),

example/lib/main_app.dart

@@ -21,36 +21,32 @@ class App extends StatelessWidget {
         appBar: AppBar(
           title: Text('Lottie Flutter'),
         ),
-        body: Scrollbar(
+        body: GridView.builder(
-          child: GridView.builder(
+          itemCount: files.length,
-            itemCount: files.length,
+          gridDelegate:
-            gridDelegate:
+              SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 4),
-                SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 4),
+          itemBuilder: (context, index) {
-            itemBuilder: (context, index) {
+            var assetName = files[index];
-              var assetName = files[index];
+            return GestureDetector(
-              return GestureDetector(
+              child: _Item(
-                child: _Item(
+                child: Lottie.asset(
-                  child: Lottie.asset(
+                  assetName,
-                    assetName,
+                  frameBuilder: (context, child, composition) {
-                    frameBuilder: (context, child, composition) {
+                    return AnimatedOpacity(
-                      return AnimatedOpacity(
+                      child: child,
-                        child: child,
+                      opacity: composition == null ? 0 : 1,
-                        opacity: composition == null ? 0 : 1,
+                      duration: const Duration(seconds: 1),
-                        duration: const Duration(seconds: 1),
+                      curve: Curves.easeOut,
-                        curve: Curves.easeOut,
+                    );
-                      );
+                  },
-                    },
-                  ),
                 ),
-                onTap: () {
+              ),
-                  Navigator.push(
+              onTap: () {
-                      context,
+                Navigator.of(context).push(MaterialPageRoute<void>(
-                      MaterialPageRoute<void>(
+                    builder: (context) => Detail(assetName)));
-                          builder: (context) => Detail(assetName)));
+              },
-                },
+            );
-              );
+          },
-            },
-          ),
         ),
       ),
     );
@@ -60,7 +56,7 @@ class App extends StatelessWidget {
 class _Item extends StatelessWidget {
   final Widget child;
 
-  const _Item({Key? key, required this.child}) : super(key: key);
+  const _Item({Key key, this.child}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -85,18 +81,26 @@ class _Item extends StatelessWidget {
 class Detail extends StatefulWidget {
   final String assetName;
 
-  const Detail(this.assetName, {Key? key}) : super(key: key);
+  const Detail(this.assetName, {Key key}) : super(key: key);
 
   @override
   _DetailState createState() => _DetailState();
 }
 
 class _DetailState extends State<Detail> with TickerProviderStateMixin {
-  late final _controller = AnimationController(vsync: this);
+  AnimationController _controller;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _controller = AnimationController(vsync: this);
+  }
 
   @override
   void dispose() {
     _controller.dispose();
+
     super.dispose();
   }
 

example/lib/sizing_example.dart

@@ -13,7 +13,7 @@ void main() async {
 class App extends StatelessWidget {
   final LottieComposition composition;
 
-  const App({Key? key, required this.composition}) : super(key: key);
+  const App({Key key, this.composition}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -97,13 +97,13 @@ class App extends StatelessWidget {
 
 class _Lottie extends StatefulWidget {
   final LottieComposition composition;
-  final double? width;
+  final double width;
-  final double? height;
+  final double height;
-  final BoxFit? fit;
+  final BoxFit fit;
-  final AlignmentGeometry? alignment;
+  final AlignmentGeometry alignment;
 
   const _Lottie(this.composition,
-      {Key? key, this.width, this.height, this.fit, this.alignment})
+      {Key key, this.width, this.height, this.fit, this.alignment})
       : super(key: key);
 
   @override
@@ -111,7 +111,7 @@ class _Lottie extends StatefulWidget {
 }
 
 class __LottieState extends State<_Lottie> with TickerProviderStateMixin {
-  late AnimationController _controller;
+  AnimationController _controller;
 
   @override
   void initState() {

example/lib/tests/airbnb.dart

@@ -6,7 +6,7 @@ void main() async {
 }
 
 class App extends StatelessWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

example/lib/tests/we_accept.dart

@@ -6,7 +6,7 @@ void main() async {
 }
 
 class App extends StatelessWidget {
-  const App({Key? key}) : super(key: key);
+  const App({Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

example/macos/Flutter/Flutter-Debug.xcconfig

@@ -1,3 +1,2 @@
-#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "ephemeral/Flutter-Generated.xcconfig"

example/macos/Flutter/Flutter-Release.xcconfig

@@ -1,3 +1,2 @@
-#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "ephemeral/Flutter-Generated.xcconfig"

example/macos/Podfile.lock

@@ -1,28 +1,27 @@
 PODS:
-  - FlutterMacOS (1.22.4)
+  - FlutterMacOS (1.0.0)
   - path_provider (0.0.1)
   - path_provider_macos (0.0.1):
     - FlutterMacOS
 
 DEPENDENCIES:
+  - FlutterMacOS (from `Flutter/ephemeral/.symlinks/flutter/darwin-x64-profile`)
   - path_provider (from `Flutter/ephemeral/.symlinks/plugins/path_provider/macos`)
   - path_provider_macos (from `Flutter/ephemeral/.symlinks/plugins/path_provider_macos/macos`)
 
-SPEC REPOS:
-  trunk:
-    - FlutterMacOS
-
 EXTERNAL SOURCES:
+  FlutterMacOS:
+    :path: Flutter/ephemeral/.symlinks/flutter/darwin-x64-profile
   path_provider:
     :path: Flutter/ephemeral/.symlinks/plugins/path_provider/macos
   path_provider_macos:
     :path: Flutter/ephemeral/.symlinks/plugins/path_provider_macos/macos
 
 SPEC CHECKSUMS:
-  FlutterMacOS: ac210ef71944b3f04789076d70d4c72c7ec0c619
+  FlutterMacOS: 15bea8a44d2fa024068daa0140371c020b4b6ff9
   path_provider: e0848572d1d38b9a7dd099e79cf83f5b7e2cde9f
   path_provider_macos: a0a3fd666cb7cd0448e936fb4abad4052961002b
 
 PODFILE CHECKSUM: d8ba9b3e9e93c62c74a660b46c6fcb09f03991a7
 
-COCOAPODS: 1.10.1
+COCOAPODS: 1.9.1

example/macos/Runner.xcodeproj/project.pbxproj

@@ -26,6 +26,10 @@
 		33CC10F32044A3C60003C045 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 33CC10F22044A3C60003C045 /* Assets.xcassets */; };
 		33CC10F62044A3C60003C045 /* MainMenu.xib in Resources */ = {isa = PBXBuildFile; fileRef = 33CC10F42044A3C60003C045 /* MainMenu.xib */; };
 		33CC11132044BFA00003C045 /* MainFlutterWindow.swift in Sources */ = {isa = PBXBuildFile; fileRef = 33CC11122044BFA00003C045 /* MainFlutterWindow.swift */; };
+		33D1A10422148B71006C7A3E /* FlutterMacOS.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 33D1A10322148B71006C7A3E /* FlutterMacOS.framework */; };
+		33D1A10522148B93006C7A3E /* FlutterMacOS.framework in Bundle Framework */ = {isa = PBXBuildFile; fileRef = 33D1A10322148B71006C7A3E /* FlutterMacOS.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		D73912F022F37F9E000D13A0 /* App.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D73912EF22F37F9E000D13A0 /* App.framework */; };
+		D73912F222F3801D000D13A0 /* App.framework in Bundle Framework */ = {isa = PBXBuildFile; fileRef = D73912EF22F37F9E000D13A0 /* App.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		F03CC91740A974D36C2A6384 /* Pods_Runner.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 0BC6FF5FCD90624533CC60DB /* Pods_Runner.framework */; };
 /* End PBXBuildFile section */
 
@@ -46,6 +50,8 @@
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
+				D73912F222F3801D000D13A0 /* App.framework in Bundle Framework */,
+				33D1A10522148B93006C7A3E /* FlutterMacOS.framework in Bundle Framework */,
 			);
 			name = "Bundle Framework";
 			runOnlyForDeploymentPostprocessing = 0;
@@ -67,12 +73,14 @@
 		33CEB47222A05771004F2AC0 /* Flutter-Debug.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = "Flutter-Debug.xcconfig"; sourceTree = "<group>"; };
 		33CEB47422A05771004F2AC0 /* Flutter-Release.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = "Flutter-Release.xcconfig"; sourceTree = "<group>"; };
 		33CEB47722A0578A004F2AC0 /* Flutter-Generated.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; name = "Flutter-Generated.xcconfig"; path = "ephemeral/Flutter-Generated.xcconfig"; sourceTree = "<group>"; };
+		33D1A10322148B71006C7A3E /* FlutterMacOS.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = FlutterMacOS.framework; path = Flutter/ephemeral/FlutterMacOS.framework; sourceTree = SOURCE_ROOT; };
 		33E51913231747F40026EE4D /* DebugProfile.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = DebugProfile.entitlements; sourceTree = "<group>"; };
 		33E51914231749380026EE4D /* Release.entitlements */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.entitlements; path = Release.entitlements; sourceTree = "<group>"; };
 		33E5194F232828860026EE4D /* AppInfo.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = AppInfo.xcconfig; sourceTree = "<group>"; };
 		5B4C0E87024EC2686CA05E23 /* Pods-Runner.profile.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Runner.profile.xcconfig"; path = "Target Support Files/Pods-Runner/Pods-Runner.profile.xcconfig"; sourceTree = "<group>"; };
 		7AFA3C8E1D35360C0083082E /* Release.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Release.xcconfig; sourceTree = "<group>"; };
 		9740EEB21CF90195004384FC /* Debug.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = Debug.xcconfig; sourceTree = "<group>"; };
+		D73912EF22F37F9E000D13A0 /* App.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = App.framework; path = Flutter/ephemeral/App.framework; sourceTree = SOURCE_ROOT; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -80,6 +88,8 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				D73912F022F37F9E000D13A0 /* App.framework in Frameworks */,
+				33D1A10422148B71006C7A3E /* FlutterMacOS.framework in Frameworks */,
 				F03CC91740A974D36C2A6384 /* Pods_Runner.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -135,6 +145,8 @@
 				33CEB47222A05771004F2AC0 /* Flutter-Debug.xcconfig */,
 				33CEB47422A05771004F2AC0 /* Flutter-Release.xcconfig */,
 				33CEB47722A0578A004F2AC0 /* Flutter-Generated.xcconfig */,
+				D73912EF22F37F9E000D13A0 /* App.framework */,
+				33D1A10322148B71006C7A3E /* FlutterMacOS.framework */,
 			);
 			path = Flutter;
 			sourceTree = "<group>";
@@ -269,7 +281,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "echo \"$PRODUCT_NAME.app\" > \"$PROJECT_DIR\"/Flutter/ephemeral/.app_filename && \"$FLUTTER_ROOT\"/packages/flutter_tools/bin/macos_assemble.sh embed\n";
+			shellScript = "echo \"$PRODUCT_NAME.app\" > \"$PROJECT_DIR\"/Flutter/ephemeral/.app_filename\n";
 		};
 		33CC111E2044C6BF0003C045 /* ShellScript */ = {
 			isa = PBXShellScriptBuildPhase;
@@ -318,10 +330,10 @@
 			buildActionMask = 2147483647;
 			files = (
 			);
-			inputPaths = (
+			inputFileListPaths = (
 			);
 			name = "[CP] Embed Pods Frameworks";
-			outputPaths = (
+			outputFileListPaths = (
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;

example/pubspec.lock

@@ -7,70 +7,77 @@ packages:
       name: archive
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.0"
+    version: "2.0.13"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.6.0"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0"
+    version: "2.4.2"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0"
+    version: "2.0.0"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.0.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.1.3"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.0.1"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0"
+    version: "1.14.13"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.1"
   crypto:
     dependency: transitive
     description:
       name: crypto
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.0"
+    version: "2.1.5"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.1.0"
-  ffi:
-    dependency: transitive
-    description:
-      name: ffi
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.1.3"
   file:
     dependency: transitive
     description:
@@ -89,7 +96,7 @@ packages:
       name: flutter_colorpicker
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.4.0-nullsafety.0"
+    version: "0.3.4"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -101,7 +108,7 @@ packages:
       name: golden_toolkit
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.0-nullsafety.0"
+    version: "0.6.0"
   http:
     dependency: "direct main"
     description:
@@ -129,42 +136,42 @@ packages:
       name: logging
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.0"
+    version: "0.11.4"
   lottie:
     dependency: "direct main"
     description:
       path: ".."
       relative: true
     source: path
-    version: "0.8.0-nullsafety.4"
+    version: "0.6.0"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10"
+    version: "0.12.8"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.1.8"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0"
+    version: "1.7.0"
   path_provider:
     dependency: "direct main"
     description:
       name: path_provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.27"
+    version: "1.6.14"
   path_provider_linux:
     dependency: transitive
     description:
@@ -178,28 +185,21 @@ packages:
       name: path_provider_macos
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.4+8"
+    version: "0.0.4+3"
   path_provider_platform_interface:
     dependency: transitive
     description:
       name: path_provider_platform_interface
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "1.0.3"
-  path_provider_windows:
-    dependency: transitive
-    description:
-      name: path_provider_windows
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.0.4+3"
   pedantic:
     dependency: transitive
     description:
       name: pedantic
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.2"
+    version: "1.9.0"
   platform:
     dependency: transitive
     description:
@@ -213,7 +213,7 @@ packages:
       name: plugin_platform_interface
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.3"
+    version: "1.0.2"
   process:
     dependency: transitive
     description:
@@ -232,70 +232,63 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0"
+    version: "1.7.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0"
+    version: "1.9.5"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0"
+    version: "2.0.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.0.5"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.1.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19"
+    version: "0.2.17"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.2.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0"
+    version: "2.0.8"
-  win32:
-    dependency: transitive
-    description:
-      name: win32
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.7.4"
   xdg_directories:
     dependency: transitive
     description:
       name: xdg_directories
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.2"
+    version: "0.1.0"
 sdks:
-  dart: ">=2.12.0-29.10.beta <3.0.0"
+  dart: ">=2.9.0-14.0.dev <3.0.0"
-  flutter: ">=1.24.0-10.2.pre"
+  flutter: ">=1.12.13+hotfix.5 <2.0.0"

example/pubspec.yaml

@@ -1,23 +1,23 @@
 name: lottie_example
 description: A sample app for the Lottie player
-publish_to: none
+version: 0.0.1
 
 environment:
-  sdk: ">=2.12.0-0 <3.0.0"
+  sdk: ">=2.7.0 <3.0.0"
 
 dependencies:
   flutter:
     sdk: flutter
-  flutter_colorpicker: ^0.4.0-nullsafety.0
-  http:
   lottie:
     path: ../
+  flutter_colorpicker:
   path_provider:
+  http:
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  golden_toolkit: ^0.9.0-nullsafety.0
+  golden_toolkit:
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec
@@ -31,7 +31,6 @@ flutter:
     - assets/lottiefiles/
     - assets/Mobilo/
     - assets/Tests/
-    - assets/Tests/images/
     - assets/Logo/
     - assets/Images/
     - assets/Images/WeAccept/

example/test/dynamic_image_test.dart

@@ -1,74 +0,0 @@
-import 'dart:async';
-import 'dart:io';
-import 'dart:ui' as ui;
-import 'package:flutter/widgets.dart';
-import 'package:flutter_test/flutter_test.dart';
-import 'package:lottie/lottie.dart';
-import 'utils.dart';
-
-void main() {
-  testWidgets('Can specify ImageProvider with zip file ', (tester) async {
-    var size = Size(500, 400);
-    tester.binding.window.physicalSizeTestValue = size;
-    tester.binding.window.devicePixelRatioTestValue = 1.0;
-
-    var callCount = 0;
-    LottieImageProviderFactory imageProviderFactory = (image) {
-      ++callCount;
-      return FileImage(File('assets/Images/WeAccept/img_0.png'));
-    };
-
-    var composition = (await tester.runAsync(() => FileLottie(
-            File('assets/spinning_carrousel.zip'),
-            imageProviderFactory: imageProviderFactory)
-        .load()))!;
-
-    await tester.pumpWidget(FilmStrip(composition, size: size));
-
-    expect(callCount, 2);
-    await expectLater(find.byType(FilmStrip),
-        matchesGoldenFile('goldens/dynamic_image/zip_with_provider.png'));
-  });
-
-  testWidgets('Can specify image delegate', (tester) async {
-    var size = Size(500, 400);
-    tester.binding.window.physicalSizeTestValue = size;
-    tester.binding.window.devicePixelRatioTestValue = 1.0;
-
-    var image = await tester.runAsync(
-        () => loadImage(FileImage(File('assets/Images/WeAccept/img_0.png'))));
-
-    var composition = (await tester.runAsync(
-        () => FileLottie(File('assets/spinning_carrousel.zip')).load()))!;
-
-    var delegates = LottieDelegates(image: (composition, asset) {
-      return image;
-    });
-    await tester.pumpWidget(FilmStrip(
-      composition,
-      size: size,
-      delegates: delegates,
-    ));
-
-    await expectLater(find.byType(FilmStrip),
-        matchesGoldenFile('goldens/dynamic_image/delegate.png'));
-  });
-}
-
-Future<ui.Image?> loadImage(ImageProvider provider) {
-  var completer = Completer<ui.Image?>();
-  var imageStream = provider.resolve(ImageConfiguration.empty);
-  late ImageStreamListener listener;
-  listener = ImageStreamListener((image, synchronousLoaded) {
-    imageStream.removeListener(listener);
-
-    completer.complete(image.image);
-  }, onError: (dynamic e, __) {
-    imageStream.removeListener(listener);
-
-    completer.complete();
-  });
-  imageStream.addListener(listener);
-
-  return completer.future;
-}

example/test/dynamic_properties_test.dart

@@ -7,7 +7,7 @@ import 'package:lottie/lottie.dart';
 import 'utils.dart';
 
 void main() {
-  late LottieComposition composition;
+  LottieComposition composition;
 
   setUpAll(() async {
     composition = await LottieComposition.fromBytes(
@@ -15,7 +15,7 @@ void main() {
   });
 
   void testGolden(String description, ValueDelegate delegate,
-      {double? progress}) async {
+      {double progress}) async {
     var screenshotName = description
         .toLowerCase()
         .replaceAll(RegExp('[^a-z0-9 ]'), '')
@@ -288,8 +288,8 @@ void main() {
     testGolden(
         'Opacity interpolation ($progress)',
         ValueDelegate.transformOpacity(['Shape Layer 1', 'Rectangle'],
-            callback: (frameInfo) => lerpDouble(10, 100,
+            callback: (frameInfo) => lerpDouble(
-                    Curves.linear.transform(frameInfo.overallProgress))!
+                    10, 100, Curves.linear.transform(frameInfo.overallProgress))
                 .round()),
         progress: progress);
   }

example/test/flutter_test_config.dart

@@ -1,7 +1,7 @@
 import 'dart:async';
 import 'package:golden_toolkit/golden_toolkit.dart';
 
-Future<void> testExecutable(FutureOr<void> Function() testMain) async {
+Future<void> main(FutureOr<void> Function() testMain) async {
   await loadAppFonts();
   return testMain();
 }

example/test/golden_test.dart

@@ -16,8 +16,7 @@ void main() {
       var size = Size(500, 400);
       tester.binding.window.physicalSizeTestValue = size;
       tester.binding.window.devicePixelRatioTestValue = 1.0;
-      var composition =
+      var composition = await tester.runAsync(() => FileLottie(asset).load());
-          (await tester.runAsync(() => FileLottie(asset).load()))!;
 
       await tester.pumpWidget(FilmStrip(composition, size: size));
 

example/test/utils.dart

@@ -3,11 +3,11 @@ import 'package:lottie/lottie.dart';
 
 class FilmStrip extends StatelessWidget {
   final LottieComposition composition;
-  final LottieDelegates? delegates;
+  final LottieDelegates delegates;
   final Size size;
 
   const FilmStrip(this.composition,
-      {Key? key, required this.size, this.delegates})
+      {Key key, @required this.size, this.delegates})
       : super(key: key);
 
   @override

lib/lottie.dart

@@ -9,7 +9,6 @@ export 'src/model/marker.dart' show Marker;
 export 'src/options.dart' show LottieOptions;
 export 'src/providers/asset_provider.dart' show AssetLottie;
 export 'src/providers/file_provider.dart' show FileLottie;
-export 'src/providers/load_image.dart' show LottieImageProviderFactory;
 export 'src/providers/lottie_provider.dart' show LottieProvider;
 export 'src/providers/memory_provider.dart' show MemoryLottie;
 export 'src/providers/network_provider.dart' show NetworkLottie;

lib/src/animation/content/base_stroke_content.dart

@@ -34,20 +34,21 @@ abstract class BaseStrokeContent
   final List<double> _dashPatternValues;
   final Paint paint = Paint()..style = PaintingStyle.stroke;
 
-  final BaseKeyframeAnimation<Object, double> _widthAnimation;
+  final BaseKeyframeAnimation<dynamic, double> _widthAnimation;
-  final BaseKeyframeAnimation<Object, int> _opacityAnimation;
+  final BaseKeyframeAnimation<dynamic, int> _opacityAnimation;
-  final List<BaseKeyframeAnimation<Object, double>> _dashPatternAnimations;
+  final List<BaseKeyframeAnimation<dynamic, double>> _dashPatternAnimations;
-  final BaseKeyframeAnimation<Object, double>? _dashPatternOffsetAnimation;
+  final BaseKeyframeAnimation<dynamic,
-  BaseKeyframeAnimation<ColorFilter, ColorFilter?>? _colorFilterAnimation;
+      double> /*?*/ _dashPatternOffsetAnimation;
+  BaseKeyframeAnimation<ColorFilter, ColorFilter> /*?*/ _colorFilterAnimation;
 
   BaseStrokeContent(this.lottieDrawable, this.layer,
-      {required StrokeCap cap,
+      {StrokeCap cap,
-      required StrokeJoin join,
+      StrokeJoin join,
-      required double miterLimit,
+      double miterLimit,
-      required AnimatableIntegerValue opacity,
+      AnimatableIntegerValue opacity,
-      required AnimatableDoubleValue width,
+      AnimatableDoubleValue width,
-      required List<AnimatableDoubleValue> dashPattern,
+      List<AnimatableDoubleValue> dashPattern,
-      AnimatableDoubleValue? dashOffset})
+      AnimatableDoubleValue dashOffset})
       : _widthAnimation = width.createAnimation(),
         _opacityAnimation = opacity.createAnimation(),
         _dashPatternOffsetAnimation = dashOffset?.createAnimation(),
@@ -75,7 +76,7 @@ abstract class BaseStrokeContent
       _dashPatternAnimations[i].addUpdateListener(onUpdateListener);
     }
     if (_dashPatternOffsetAnimation != null) {
-      _dashPatternOffsetAnimation!.addUpdateListener(onUpdateListener);
+      _dashPatternOffsetAnimation.addUpdateListener(onUpdateListener);
     }
   }
 
@@ -85,7 +86,7 @@ abstract class BaseStrokeContent
 
   @override
   void setContents(List<Content> contentsBefore, List<Content> contentsAfter) {
-    TrimPathContent? trimPathContentBefore;
+    TrimPathContent trimPathContentBefore;
     for (var i = contentsBefore.length - 1; i >= 0; i--) {
       var content = contentsBefore[i];
       if (content is TrimPathContent &&
@@ -97,7 +98,7 @@ abstract class BaseStrokeContent
       trimPathContentBefore.addListener(onUpdateListener);
     }
 
-    _PathGroup? currentPathGroup;
+    _PathGroup currentPathGroup;
     for (var i = contentsAfter.length - 1; i >= 0; i--) {
       var content = contentsAfter[i];
       if (content is TrimPathContent &&
@@ -118,8 +119,7 @@ abstract class BaseStrokeContent
   }
 
   @override
-  void draw(Canvas canvas, Size size, Matrix4 parentMatrix,
+  void draw(Canvas canvas, Size size, Matrix4 parentMatrix, {int parentAlpha}) {
-      {required int parentAlpha}) {
     L.beginSection('StrokeContent#draw');
     if (parentMatrix.hasZeroScaleAxis) {
       L.endSection('StrokeContent#draw');
@@ -136,7 +136,7 @@ abstract class BaseStrokeContent
     }
 
     if (_colorFilterAnimation != null) {
-      paint.colorFilter = _colorFilterAnimation!.value;
+      paint.colorFilter = _colorFilterAnimation.value;
     }
 
     for (var i = 0; i < _pathGroups.length; i++) {
@@ -175,17 +175,18 @@ abstract class BaseStrokeContent
     var pathMetrics = _path.computeMetrics().toList();
     var totalLength = pathMetrics.fold<double>(0.0, (a, b) => a + b.length);
 
-    var trimPath = pathGroup.trimPath!;
+    var offsetLength = totalLength * pathGroup.trimPath.offset.value / 360.0;
-    var offsetLength = totalLength * trimPath.offset.value / 360.0;
+    var startLength =
-    var startLength = totalLength * trimPath.start.value / 100.0 + offsetLength;
+        totalLength * pathGroup.trimPath.start.value / 100.0 + offsetLength;
-    var endLength = totalLength * trimPath.end.value / 100.0 + offsetLength;
+    var endLength =
+        totalLength * pathGroup.trimPath.end.value / 100.0 + offsetLength;
 
     var currentLength = 0.0;
     for (var j = pathGroup.paths.length - 1; j >= 0; j--) {
       _trimPathPath
           .set(pathGroup.paths[j].getPath().transform(parentMatrix.storage));
       var pathMetrics = _trimPathPath.computeMetrics().toList();
-      var length = pathMetrics.isNotEmpty ? pathMetrics.first.length : 0;
+      var length = pathMetrics.first.length;
       if (endLength > totalLength &&
           endLength - totalLength < currentLength + length &&
           currentLength < endLength - totalLength) {
@@ -228,7 +229,7 @@ abstract class BaseStrokeContent
   }
 
   @override
-  Rect getBounds(Matrix4 parentMatrix, {required bool applyParents}) {
+  Rect getBounds(Matrix4 parentMatrix, {bool applyParents}) {
     L.beginSection('StrokeContent#getBounds');
     _path.reset();
     for (var i = 0; i < _pathGroups.length; i++) {
@@ -241,9 +242,11 @@ abstract class BaseStrokeContent
     var bounds = _path.getBounds();
 
     var width = _widthAnimation.value;
-    bounds = bounds.inflate(width / 2.0);
+    bounds = Rect.fromLTWH(bounds.left - width / 2.0, bounds.top - width / 2.0,
+        bounds.right + width / 2.0, bounds.bottom + width / 2.0);
     // Add padding to account for rounding errors.
-    bounds = bounds.inflate(1);
+    bounds = Rect.fromLTWH(
+        bounds.left - 1, bounds.top - 1, bounds.right + 1, bounds.bottom + 1);
     L.endSection('StrokeContent#getBounds');
     return bounds;
   }
@@ -276,7 +279,7 @@ abstract class BaseStrokeContent
 
     var offset = _dashPatternOffsetAnimation == null
         ? 0.0
-        : _dashPatternOffsetAnimation!.value * scale;
+        : _dashPatternOffsetAnimation.value * scale;
     var newPath = dashPath(path, intervals: _dashPatternValues, phase: offset);
     L.endSection('StrokeContent#applyDashPattern');
 
@@ -292,7 +295,7 @@ abstract class BaseStrokeContent
 
   @override
   @mustCallSuper
-  void addValueCallback<T>(T property, LottieValueCallback<T>? callback) {
+  void addValueCallback<T>(T property, LottieValueCallback<T> /*?*/ callback) {
     if (property == LottieProperty.opacity) {
       _opacityAnimation.setValueCallback(callback as LottieValueCallback<int>);
     } else if (property == LottieProperty.strokeWidth) {
@@ -306,9 +309,9 @@ abstract class BaseStrokeContent
         _colorFilterAnimation = null;
       } else {
         _colorFilterAnimation =
-            ValueCallbackKeyframeAnimation<ColorFilter, ColorFilter?>(
+            ValueCallbackKeyframeAnimation<ColorFilter, ColorFilter>(
-                callback as LottieValueCallback<ColorFilter>, null);
+                callback as LottieValueCallback<ColorFilter>);
-        _colorFilterAnimation!.addUpdateListener(onUpdateListener);
+        _colorFilterAnimation.addUpdateListener(onUpdateListener);
         layer.addAnimation(_colorFilterAnimation);
       }
     }
@@ -318,7 +321,7 @@ abstract class BaseStrokeContent
 /// Data class to help drawing trim paths individually.
 class _PathGroup {
   final List<PathContent> paths = <PathContent>[];
-  final TrimPathContent? trimPath;
+  final TrimPathContent /*?*/ trimPath;
 
   _PathGroup(this.trimPath);
 }

lib/src/animation/content/content.dart

@@ -1,5 +1,5 @@
 abstract class Content {
-  String? get name;
+  String get name;
 
   void setContents(List<Content> contentsBefore, List<Content> contentsAfter);
 }

lib/src/animation/content/content_group.dart

@@ -1,4 +1,5 @@
 import 'dart:ui';
+import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
 import '../../lottie_drawable.dart';
 import '../../model/animatable/animatable_transform.dart';
@@ -31,7 +32,8 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
     return contents;
   }
 
-  static AnimatableTransform? findTransform(List<ContentModel> contentModels) {
+  static AnimatableTransform /*?*/ findTransform(
+      List<ContentModel> contentModels) {
     for (var i = 0; i < contentModels.length; i++) {
       var contentModel = contentModels[i];
       if (contentModel is AnimatableTransform) {
@@ -45,12 +47,12 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
   final Path _path = PathFactory.create();
 
   @override
-  final String? name;
+  final String name;
   final bool _hidden;
   final List<Content> _contents;
   final LottieDrawable _lottieDrawable;
-  List<PathContent>? _pathContents;
+  List<PathContent> /*?*/ _pathContents;
-  TransformKeyframeAnimation? _transformAnimation;
+  TransformKeyframeAnimation /*?*/ _transformAnimation;
 
   ContentGroup(final LottieDrawable lottieDrawable, BaseLayer layer,
       ShapeGroup shapeGroup)
@@ -63,11 +65,11 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
             findTransform(shapeGroup.items));
 
   ContentGroup.copy(this._lottieDrawable, BaseLayer layer, this.name,
-      this._hidden, this._contents, AnimatableTransform? transform) {
+      this._hidden, this._contents, AnimatableTransform /*?*/ transform) {
     if (transform != null) {
-      _transformAnimation = transform.createAnimation()
+      _transformAnimation = transform.createAnimation();
-        ..addAnimationsToLayer(layer)
+      _transformAnimation.addAnimationsToLayer(layer);
-        ..addListener(onValueChanged);
+      _transformAnimation.addListener(onValueChanged);
     }
 
     var greedyContents = <GreedyContent>[];
@@ -102,20 +104,20 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
 
   List<PathContent> getPathList() {
     if (_pathContents == null) {
-      var pathContents = _pathContents = <PathContent>[];
+      _pathContents = <PathContent>[];
       for (var i = 0; i < _contents.length; i++) {
         var content = _contents[i];
         if (content is PathContent) {
-          pathContents.add(content);
+          _pathContents.add(content);
         }
       }
     }
-    return _pathContents!;
+    return _pathContents;
   }
 
   Matrix4 getTransformationMatrix() {
     if (_transformAnimation != null) {
-      return _transformAnimation!.getMatrix();
+      return _transformAnimation.getMatrix();
     }
     _matrix.reset();
     return _matrix;
@@ -126,7 +128,7 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
     // TODO: cache this somehow.
     _matrix.reset();
     if (_transformAnimation != null) {
-      _matrix.set(_transformAnimation!.getMatrix());
+      _matrix.set(_transformAnimation.getMatrix());
     }
     _path.reset();
     if (_hidden) {
@@ -143,17 +145,17 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
 
   @override
   void draw(Canvas canvas, Size size, Matrix4 parentMatrix,
-      {required int parentAlpha}) {
+      {@required int parentAlpha}) {
     if (_hidden) {
       return;
     }
     _matrix.set(parentMatrix);
     int layerAlpha;
     if (_transformAnimation != null) {
-      _matrix.preConcat(_transformAnimation!.getMatrix());
+      _matrix.preConcat(_transformAnimation.getMatrix());
-      var opacity = _transformAnimation?.opacity == null
+      var opacity = _transformAnimation.opacity == null
           ? 100
-          : _transformAnimation!.opacity!.value;
+          : _transformAnimation.opacity.value;
       layerAlpha = ((opacity / 100.0 * parentAlpha / 255.0) * 255).round();
     } else {
       layerAlpha = parentAlpha;
@@ -197,10 +199,10 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
   }
 
   @override
-  Rect getBounds(Matrix4 parentMatrix, {required bool applyParents}) {
+  Rect getBounds(Matrix4 parentMatrix, {bool applyParents}) {
     _matrix.set(parentMatrix);
     if (_transformAnimation != null) {
-      _matrix.preConcat(_transformAnimation!.getMatrix());
+      _matrix.preConcat(_transformAnimation.getMatrix());
     }
     var bounds = Rect.zero;
     for (var i = _contents.length - 1; i >= 0; i--) {
@@ -221,8 +223,8 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
       return;
     }
 
-    if ('__container' != name && name != null) {
+    if ('__container' != name) {
-      currentPartialKeyPath = currentPartialKeyPath.addKey(name!);
+      currentPartialKeyPath = currentPartialKeyPath.addKey(name);
 
       if (keyPath.fullyResolvesTo(name, depth)) {
         accumulator.add(currentPartialKeyPath.resolve(this));
@@ -243,9 +245,9 @@ class ContentGroup implements DrawingContent, PathContent, KeyPathElement {
   }
 
   @override
-  void addValueCallback<T>(T property, LottieValueCallback<T>? callback) {
+  void addValueCallback<T>(T property, LottieValueCallback<T> /*?*/ callback) {
     if (_transformAnimation != null) {
-      _transformAnimation!.applyValueCallback(property, callback);
+      _transformAnimation.applyValueCallback(property, callback);
     }
   }
 }

lib/src/animation/content/drawing_content.dart

@@ -1,9 +1,10 @@
 import 'dart:ui';
+import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
 import 'content.dart';
 
 abstract class DrawingContent extends Content {
   void draw(Canvas canvas, Size canvasSize, Matrix4 parentMatrix,
-      {required int parentAlpha});
+      {@required int parentAlpha});
-  Rect getBounds(Matrix4 parentMatrix, {required bool applyParents});
+  Rect getBounds(Matrix4 parentMatrix, {@required bool applyParents});
 }

lib/src/animation/content/ellipse_content.dart

@@ -22,10 +22,10 @@ class EllipseContent implements PathContent, KeyPathElementContent {
   final Path _path = PathFactory.create();
 
   @override
-  final String? name;
+  final String name;
   final LottieDrawable lottieDrawable;
-  final BaseKeyframeAnimation<Object, Offset> _sizeAnimation;
+  final BaseKeyframeAnimation<dynamic, Offset> _sizeAnimation;
-  final BaseKeyframeAnimation<Object, Offset> _positionAnimation;
+  final BaseKeyframeAnimation<dynamic, Offset> _positionAnimation;
   final CircleShape _circleShape;
 
   final CompoundTrimPathContent _trimPaths = CompoundTrimPathContent();
@@ -115,7 +115,7 @@ class EllipseContent implements PathContent, KeyPathElementContent {
   }
 
   @override
-  void addValueCallback<T>(T property, LottieValueCallback<T>? callback) {
+  void addValueCallback<T>(T property, LottieValueCallback<T> /*?*/ callback) {
     if (property == LottieProperty.ellipseSize) {
       _sizeAnimation.setValueCallback(callback as LottieValueCallback<Offset>);
     } else if (property == LottieProperty.position) {