Sources: release notes 3.16.0, breaking changes, CHANGELOG.md
The Material library has been updated to match the Material 3 Design spec. Changes include new components and component themes, updated component visuals, and much more. Many of these updates are seamless. You'll see the new version of an affected widget when recompiling your app against the 3.16 (or later) release. But some manual work is also required to complete the migration.
For some time now (years), Flutter has had two key event systems implemented. The new system reached parity with the old platform-specific raw key event system, and the raw system will be removed. To prepare for that, the Flutter APIs that use the old system are being modified, and for a select few of them we have decided to make breaking changes in the API in order to preserve the quality of the API.
The Material library has been updated to match the latest Material Design spec. Changes include new components, new component themes, and updated component visuals. As of this release, `ThemeData.useMaterial3` is set `true` by default.
Using `TabBar.tabAlignment` to customize the alignment of tabs in a `TabBar`.
Android 14 introduced nonlinear font scaling up to 200%. It may change how your app looks when the user changes the accessibility text scaling in system preferences.
The default text styles used for menus are updated to match the Material 3 specification.
When you add any external windows to your Flutter app, you need to include them in the Window's app lifecycle logic. To include the window, its `WndProc` function should invoke `FlutterEngine::ProcessExternalWindowMessage`.
Built executables for Flutter Windows apps are now located in architecture dependent folders.
In accordance with Flutter's Deprecation Policy, deprecated APIs that reached end of life after the 3.13 stable release have been removed.
In preparation for adopting the Android 14 nonlinear font scaling feature, all occurrences of `textScaleFactor` in the Flutter framework have been deprecated and replaced by `TextScaler`.
The global method `describeEnum` has been deprecated. Previous uses of `describeEnum(Enum.something)` should use `Enum.something.name` instead.
To support Android 14's Predictive Back feature, a set of ahead-of-time APIs have replaced just-in-time navigation APIs, like `WillPopScope` and `Navigator.willPop`.
`Paint.enableDithering` is now `true` by default (previously, `false`), and is _deprecated_ pending removal - Flutter no longer supports user-configurable dithering settings.