
* Roll Dart to 4cf2d3990bac1f1df2f524899e1560a3683f3133 Included CLs: 4cf2d3990b [VM runtime] Store Smi instance type in type test cache when using the interpreter. a6b1a99f4c Make mixins abstract by default ab305f2f26 Recover from duplicated declarations 4e32a356e0 Ignore synthetic elements created by the parser fc04f56430 [infra] Remove deleted Dart 1 builders (app/precomp) from the test matrix 8477dc2131 Update status after 570fd5a7884 1652850381 Compute static types during impact computation b4341f02db Remove unneeded method rti need 570fd5a788 Error on re-export, export and import of libraries with same name. 4b312b2b8c Support multiple superclasses in the mixin `on` clause. 8debb4e9db [fuchsia] Add zx_vmo_replace_as_executable calls d34337aa2d Ignore noSuchMethod() for the purpose of searching concrete member implementations. b6284b41e3 Revert "[VM] Dart_Initialize no longer crashes after Dart_Cleanup" 94481adbd4 [vm] Only include debugger/profiler slots in RawCode in product mode. 519ee905f9 [VM] Dart_Initialize no longer crashes after Dart_Cleanup 53497549ab [vm] Specialize 'new List()' on kernel AST afd4cc9d1a [vm/tfa] Infer concrete class of int literals in TFA a4d48f49e7 [vm/tfa] Infer concrete class of string literals in TFA 9106228a55 [vm, dwarf] Set default_is_stmt to true for compatability with dsymutil. 6ce0dc0006 dartfix stub implementation e4eb2437b8 Look into superclassConstraints while searching for a member in interfaces. 95d37b0921 Revert "Implement inheritance/override checks from the spec." 355c73d4ee [VM] Remove support for option --no-preview-dart-2 95b8a19a20 Mixin declarations don't have supertype, fix isMoreSpecificThan(). e9586a5d14 [vm] Update workaround for Android Kernel bug (b089d4f). ef7d144bc7 Add regression test for issue 34392. 56f6c52d58 large_class_declaration_test is slow now. 0ac3b8fff9 [fuchsia] Add missing vm:entry-point annotation 19e844ed5b [dart/fuzzing] Use current directory as SDK top (by default) 58e44c1400 Don't use ClassElementImpl for now in override checking. 62d154f6a3 [vm/bytecode] Record null-initialized fields in bytecode 70cc34df21 Custom format errors and exceptions to show traces 95831136b4 Fix NPE when accessing superclass 836a1d7a88 Implement inheritance/override checks from the spec. d07039782a Remove redundant resolution dba8b37d38 [vm] Benchmark for reading kernel bytecode * Move one revision later. Rationale: Relatively harmless change, but at least has builds (force builds on the older revision will take a while again).
Flutter 
Build beautiful native apps in record time
Flutter is Google’s mobile app SDK for crafting high-quality native interfaces on iOS and Android in record time. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
Documentation
- Main site: flutter.io
- Install
- Get started
- Contribute
Fast development
Flutter's hot reload helps you quickly and easily experiment, build UIs, add features, and fix bugs. Experience sub-second reload times, without losing state, on emulators, simulators, and hardware for iOS and Android.

Expressive and flexible UI
Quickly ship features with a focus on native end-user experiences. Layered architecture allows full customization, which results in incredibly fast rendering and expressive and flexible designs.
Delight your users with Flutter's built-in beautiful Material Design and Cupertino (iOS-flavor) widgets, rich motion APIs, smooth natural scrolling, and platform awareness.
Browse the widget catalog.
Modern, reactive framework
Easily compose your UI with Flutter's modern functional-reactive framework and rich set of platform, layout, and foundation widgets. Solve your tough UI challenges with powerful and flexible APIs for 2D, animation, gestures, effects, and more.
class CounterState extends State<Counter> {
int counter = 0;
void increment() {
// Tells the Flutter framework that state has changed,
// so the framework can run build() and update the display.
setState(() {
counter++;
});
}
Widget build(BuildContext context) {
// This method is rerun every time setState is called.
// The Flutter framework has been optimized to make rerunning
// build methods fast, so that you can just rebuild anything that
// needs updating rather than having to individually change
// instances of widgets.
return new Row(
children: <Widget>[
new RaisedButton(
onPressed: increment,
child: new Text('Increment'),
),
new Text('Count: $counter'),
],
);
}
}
Browse the widget catalog and learn more about the functional-reactive framework.
Access native features and SDKs
Make your app come to life with platform APIs, 3rd party SDKs, and native code. Flutter lets you reuse your existing Java/Kotlin and ObjC/Swift code, and access native features and SDKs on Android and iOS.
Accessing platform features is easy. Here is a snippet from our interop example:
Future<Null> getBatteryLevel() async {
var batteryLevel = 'unknown';
try {
int result = await methodChannel.invokeMethod('getBatteryLevel');
batteryLevel = 'Battery level: $result%';
} on PlatformException {
batteryLevel = 'Failed to get battery level.';
}
setState(() {
_batteryLevel = batteryLevel;
});
}
Learn how to use packages, or write platform channels, to access native code, APIs, and SDKs.
Unified app development
Flutter has the tools and libraries to help you easily bring your ideas to life on iOS and Android. If you don't have any mobile development experience, Flutter is an easy and fast way to build beautiful mobile apps. If you are an experienced iOS or Android developer, you can use Flutter for your views and leverage much of your existing Java/Kotlin/ObjC/Swift investment.
Build
- Beautiful app UIs
- Rich 2D GPU-accelerated APIs
- Reactive framework
- Animation/motion APIs
- Material Design and iOS widgets
- Fluid coding experience
- Sub-second, stateful hot reload
- IntelliJ: refactor, code completion, etc
- Dart language and core libs
- Package manager
- Full-featured apps
- Interop with mobile OS APIs & SDKs
- Gradle/Java/Kotlin
- Cocoapods/ObjC/Swift
Optimize
- Test
- Unit testing
- Integration testing
- On-device testing
- Debug
- IDE debugger
- Web-based debugger
- async/await aware
- Expression evaluator
- Profile
- Timeline
- CPU and memory
- In-app perf charts
Deploy
- Compile
- Native ARM code
- Dead code elimination
- Distribution
- App Store
- Play Store
Learn more about what makes Flutter special in the technical overview.
Join us in our Gitter chat room or join our public mailing list, flutter-dev@googlegroups.com.