Google LLC rolled out a big update today to its open-source Flutter user interface development framework today with version 2.5.

Flutter 2.5 had the second-highest stats in the history of any Flutter release, with 4,600 issues closed from 252 contributors with 216 reviewers.

The company also pushed out updates to Dart, a programming language created by Google to build mobile and web applications with C-syntax that is used in Flutter.

This update continues to improve the performance of Flutter from previous versions for animations and shaders so that users have the best experience possible when running apps. Especially in iOS, asynchronous events such as accessing network, filesystem, plugins and other events could interrupt animations.

Garbage collection improvements for reclaiming memory in the Flutter engine allow it to happen less often during animation cycles. Coupled with updates to Dart, low-memory situations can be avoided and animation glitches can be smoothed.

For example, during testing, 20-second animated GIFs went from needing over 400 garbage collection events to just four. Garbage collection consumes a great deal of computation and power and thus causes a lot of performance issues.

The framework included a number of fixes involving full-screen modes and their features. For example, apps can now listen for the usage of fullscreen changes in other modes, so that when the system UI comes back, developers can now write code to return to fullscreen mode appropriately or do something else. That way users aren’t left in the lurch.

The Flutter 2.5 release also continues to build Material You specification support, which is the updated version of Google’s Material Design language that will appear in Android 12 coming on all devices to be released this autumn. That includes updates to Floating Action Button sizes and theming and a new MaterialState.scrolledUnder state.

Flutter DevTools also got some attention by taking advantage of engine updates. According to Google, one set of these updates enables Flutter to associate trace events with specific frames, which will assist developers to determine why a frame might be going over budget. As a result, developers can more readily diagnose poor-quality shader compilation in the app.

This release of DevTools also comes with an update to the Widget Inspector that allows developers to evaluate objects, view properties, widget states and more. When a widget is selected it automatically populates a new Widget Inspector Console, where the widget properties can be explored.

Furthermore, the Widget Inspector has undergone what the team describes as a “facelift” by way of a partnership with Codemate Ltd., a creative tech agency in Finland.

Dart 2.14 improvements

Updates to Dart 2.14 include a number of improvements to formatting, pub support for ignoring files and new language features.

Amid the formatting improvements is an update to cascades, which is a programming feature that allows developers to execute a sequence of operations on the same object – for example, coloring a the letter “T” black, stroking its outside white and then rendering a shadow beneath it would be a cascade.

The updated pub command in Dart 2.14 will support a new .pubignore file, where developers can list the files that they don’t wish to upload to pub dev when publishing. That’s important for secrets like keys or password files or temp files that might need to stay local and mustn’t be uploaded to public repositories.

Image: Google