What is new in Flutter 2

Neeraj Dana
Neeraj Dana

Web

As of today, Flutter’s web support has transitioned from beta to the stable channel. With this initial stable release, Flutter pushes reusability of code to another level with the support of the web platform. So now when you create a Flutter app in stable, web is just another device target for your app.

By leveraging the web platform’s many strengths, Flutter built a foundation for building rich interactive web applications. We primarily focused on performance and improvements to our rendering fidelity. In addition to our HTML renderer, we added a new CanvasKit-based renderer. We’ve also added web-specific features, such as a Link widget, to make sure your app running in the browser feels like a web app.

Find more details about this stable release in Flutter’s web support blog post.

Sound Null Safety

Sound null safety is a significant addition to the Dart language, which further strengthens the type system by distinguishing nullable types from non-nullable types. This enables developers to prevent null error crashes, a common reason for apps to crash. By incorporating null checks into the type system, these errors can be caught during development, thus preventing crashes in production. Sound null safety is fully supported in stable as of Flutter 2, which contains Dart 2.12.

The pub.dev package repository already has more than 1,000 null safe packages published, including hundreds of packages by the Dart, Flutter, Firebase, and Material teams. If you are a package author, review the migration guide and consider migrating today.

Desktop

In this release, we’re pleased to announce that Flutter’s desktop support is available in the stable channel under an early release flag. What this means is that we’re ready for you to give it a try as a deployment target for your Flutter apps: you can think of it as a “beta snapshot” that previews the final stable release coming later this year.

To bring Flutter desktop to this degree of quality, there have been improvements both big and small, starting with working to ensure that text editing operates like the native experience on each of the supported platforms, including foundational features like text selection pivot points and being able to stop propagation of a keyboard event once it’s been handled. On the mouse input side, dragging with a high precision pointing device now starts immediately instead of waiting for the lag needed when handling touch input. Also, a built-in context menu has been added to the TextField and TextFormField widgets for Material and Cupertino design languages. Finally, grab handles have been added to the ReorderableListView widget.

In addition, Flutter team has provided updated docs on what you need to do to begin preparing your desktop app for deployment to the appropriate OS-specific stores. Give them a try and please provide feedback if we’ve missed anything.

When it comes to trying the beta for Flutter desktop, you can access it by switching to the beta channel as expected as well as setting the config flags for the platforms you’re targeting according to the directions on flutter.dev. In addition, we’ve also made a snapshot of the beta bits available on the stable channel. If you use ‘flutter config’ to enable one of the desktop config settings (for example, enable-macos-desktop), then you can try out the beta functionality of the desktop support w/o having to go through the lengthy process of moving to the beta channel and pulling down all the latest beta of the Flutter SDK, building the tools, etc. This is great for giving it a try or using the desktop support as a simple “Flutter Emulator.”

However, if you choose to stay on the stable channel to access the desktop beta, you won’t get new features or bug fixes as quickly as switching to the beta or dev channels. So, if you’re actively targeting Windows, macOS, or Linux, we recommend switching to a channel that provides updates more quickly.

As we approach our first full production-quality release of Flutter desktop, we know Flutter team has more to do, including support for integration with native top-level menus, text editing that feels more like the experience of the individual platforms, and accessibility support, as well as general bug fixes and performance enhancements. If there are other things you think need doing before the desktop moves to production quality, please be sure to provide your feedback.

New widgets: Autocomplete and ScaffoldMessenger

This release of Flutter comes with two additional new widgets, AutocompleteCore and ScaffoldMessenger. AutocompleteCore represents the minimal functionality required to get auto-complete functionality into your Flutter app.

Autocomplete is an often-requested feature for Flutter, so this release starts to provide this functionality. You can use it today, but if you’re curious about the design for the complete feature, check out the autocomplete design document.

Likewise, the ScaffoldMessenger was created to deal with a number of SnackBar-related issues, including the ability to easily create a SnackBar in response to an AppBar action, creating SnackBars to persist between Scaffold transitions, and being able to show SnackBars at the completion of an asynchronous action, even if the user has navigated to a page with a different Scaffold.

Multiple Flutter instances with Add-to-App

We know from talking with many Flutter developers that a significant number of you don’t have the luxury of starting a brand new app but you can take advantage of Flutter by adding it to your existing iOS and Android apps. This feature, called Add-to-App, is an excellent way to reuse your Flutter code across both mobile platforms while still preserving your existing native code base. However, for those of you doing that, we’ve sometimes heard that it’s unclear how to go beyond integrating the first screen into Flutter. Interweaving Flutter and native screens makes navigation states difficult to maintain, and integrating multiple Flutters at the view level uses a lot of memory.

Flutter Fix

Whenever any framework matures and gathers users with larger and larger code bases, the tendency over time is to avoid making any changes to the framework API to avoid breaking an increasing number of lines of code. With over 500,000 Flutter developers across a growing number of platforms, Flutter 2 is quickly falling into this category. However, for us to continue to improve Flutter over time, we want to be able to make breaking changes to the API. The question becomes, how to continue to improve the Flutter API without breaking our developers?

Flutter DevTools

To make it clear that DevTools is a tool that should be used for debugging your Flutter apps, we’ve renamed it to be Flutter DevTools when it’s debugging a Flutter app. In addition, we’ve done a lot of work to bring it to production quality worthy of Flutter 2.

One new feature that helps you zero in on your issues even before you’ve launched DevTools is the ability for Android Studio, IntelliJ, or Visual Studio Code to notice when there’s a common exception and offer to bring it up in DevTools to help you debug it. For example, the following shows an overflow exception has been thrown in your app, which brings up an option in Visual Studio Code to debug the issue in DevTools.

Visual Studio Code Extension

The Flutter extension for Visual Studio Code has improved for Flutter 2 as well, starting with a number of testing enhancements, including the ability to re-run just failed tests.

After two years in development, the LSP (Language Server Protocol) support for Dart is rolling out now as the default way to get to the Dart analyzer for integration into Visual Studio Code for the Flutter extension. The LSP support enables a number of improvements for Flutter development, including the ability to apply all fixes of a certain kind in the current Dart file and to cause code completion to generate complete function calls, including parenthesis and required arguments.

DartPad updated to support Flutter 2

This list of tooling updates would not be complete without a mention of DartPad, which has been updated to support Flutter 2.

Now you can try the new null safe version of Flutter without leaving the comfort of your favorite browser.

Ecosystem updates

The Flutter development experience includes more than the framework and the tools; it also includes the wide range of packages and plugins available for Flutter apps. In the time since the last Flutter stable release, much has happened in that space as well. For example, between the camera and the video_player plugins, nearly 30 PRs have been merged to greatly increase the quality of both. If you’ve had trouble using either of these in the past, you should have another look; we think you’ll find them much more robust.

Also, if you’re a Firebase user, we are pleased to announce that the most popular plugins have been brought to production quality, including null safety support, and a full set of reference documentation and common usage tutorials for Android, iOS, web, and macOS. These plugins include the following:

  • Core
  • Authentication
  • Cloud Firestore
  • Cloud Functions
  • Cloud Messaging
  • Cloud Storage
  • Crashlytics

Credit And Orignal Post :  https://medium.com/flutter/whats-new-in-flutter-2-0-fe8e95ecc65#:~:text=Sound null safety is a,types from non-nullable types.&text=Sound null safety is fully,the Dart 2.12 blog post.

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