Roll engine 4f54a1d...2e97618 (#28899)

flutter/engine@f4951df19 (upstream/master) Minor cleanups to (flutter/engine#8043)
flutter/engine@effee2f80 remove extra statement (flutter/engine#8041)
flutter/engine@14e082fa0 (master) add lint script for Android with baseline (flutter/engine#8036)
flutter/engine@5fed42197 Roll src/third_party/skia 25bc174cf682..72542816cadb (14 commits) (flutter/engine#8040)
flutter/engine@e6a5201f0 Add missing values to semantics action enums (flutter/engine#8033)
flutter/engine@75d4db31d Roll src/third_party/skia fbc887df72ec..25bc174cf682 (7 commits) (flutter/engine#8039)
flutter/engine@c46226980 Roll src/third_party/skia 0a57971f0544..fbc887df72ec (1 commits) (flutter/engine#8037)
flutter/engine@ed628da00 Add missing kHasImplicitScrolling enum value (flutter/engine#8030)
flutter/engine@052774e1c Roll src/third_party/skia e3e80b7edfd1..0a57971f0544 (16 commits) (flutter/engine#8035)
flutter/engine@2cd9b41ba Select MPL instead of LGPL (flutter/engine#7991)
flutter/engine@629c0d836 Roll src/third_party/dart 7d8ffe0daf..571ea80e11 (3 commits)
flutter/engine@8f1fdcd19 Android Embedding PR 14: Almost done with FlutterFragment. (flutter/engine#8000)
flutter/engine@fb3e35d6a Android Embedding PR15: Add Viewport Metrics to FlutterView (flutter/engine#8029)
flutter/engine@36ca5740c (flutter/engine#8026)
flutter/engine@3d53e2026 Roll src/third_party/skia 5800f2e8a920..e3e80b7edfd1 (2 commits) (flutter/engine#8028)
flutter/engine@f3d4a7f71 Roll src/third_party/dart 7c70ab1817..7d8ffe0daf (77 commits)
flutter/engine@a2246c199 Start of linting Android embedding (flutter/engine#8023)
flutter/engine@48bf4803e [fuchsia] Fix snapshot file for Fuchsia roll (flutter/engine#8024)
2 files changed
tree: 1426e703187554a15c75d14d545e2ffc80366364
  1. .github/
  2. bin/
  3. dev/
  4. examples/
  5. packages/
  6. .cirrus.yml
  7. .gitattributes
  8. .gitignore
  9. analysis_options.yaml
  13. dartdoc_options.yaml
  14. flutter_console.bat

Flutter Flutter logo

Gitter Channel Build Status - Cirrus

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.


Main site:

For announcements about new releases and breaking changes, follow the mailing list.

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(() {

  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 Row(
      children: <Widget>[
          onPressed: increment,
          child: Text('Increment'),
        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<void> 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.

Learn more about what makes Flutter special in the technical overview.

More resources

Join us in our Gitter chat room or join our public mailing list,

How to contribute

To join the team working on Flutter, see our contributor guide.