Flutter Gallery

Flutter Gallery is a resource to help developers evaluate and use Flutter. It is a collection of Material Design & Cupertino widgets, behaviors, and vignettes implemented with Flutter. We often get asked how one can see Flutter in action, and this gallery demonstrates what Flutter provides and how it behaves in the wild.

Features

• Showcase for material, cupertino, and other widgets
• Adaptive layout for mobile and desktop
• State restoration support
• Settings to text scaling, text direction, locale, theme, and more...
• Demo for animations
• Foldable support and demo for dual_screen
• Deferred loading
• CI/CD
• ...and much more!

Supported Platforms

Flutter Gallery has been built to support multiple platforms. These include:

• Android (Google Play Store, .apk)
• iOS (locally)
• web (gallery.flutter.dev)
• macOS (.zip)
• Linux (.tar.gz)
• Windows (.zip)

Running

One can run the gallery locally for any of these platforms. For desktop platforms, please see the Flutter docs for the latest requirements.

cd gallery/
flutter pub get
flutter run

Troubleshooting

Flutter master channel

The Flutter Gallery targets Flutter's master channel. As such, it can take advantage of new SDK features that haven't landed in the stable channel.

If you'd like to run the Flutter Gallery, you may have to switch to the master channel first:

flutter channel master
flutter upgrade

When you're done, use this command to return to the safety of the stable channel:

flutter channel stable
flutter upgrade

Development

Generating localizations

If this is the first time building the Flutter Gallery, the localized code will not be present in the project directory. However, after running the application for the first time, a synthetic package will be generated containing the app's localizations through importing package:flutter_gen/gen_l10n/.

flutter pub get
flutter pub run grinder l10n

See separate README for more details.

Generating highlighted code segments

flutter pub get
flutter pub run grinder update-code-segments

See separate README for more details.

Including a new splash animation

1. Convert your animation to a .gif file. Ideally, use a background color of 0xFF030303 to ensure the animation blends into the background of the app.

2. Add your new .gif file to the assets directory under assets/splash_effects. Ensure the name follows the format splash_effect_$num.gif. The number should be the next number after the current largest number in the repository.

3. Update the map _effectDurations in splash.dart to include the number of the new .gif as well as its estimated duration. The duration is used to determine how long to display the splash animation at launch.

Releasing

for flutter-hackers members

The process is largely automated and easy to set in motion.

First things first, bump the pubspec.yaml version number. This can be in a PR making a change or a separate PR. Use semantic versioning to determine which part to increment. The version number after the + should also be incremented. For example 1.2.3+010203 with a patch should become 1.2.4+010204.

Then, use the following workflows. It is strongly recommended to use the staging/beta environments when available, before deploying to production.

• Deploy to Play Store: Uses Fastlane to create a beta (freely available on the Play Store), promote an existing beta to production, or publish straight to production (Play Store).

  Note Once an .aab is released with a particular version number, it can't be replaced. The version number must be incremented again.

• Deploy to web: Deploys a web build to the Firebase-hosted staging or production site.
• Draft GitHub release: Drafts a GitHub release, including automatically generated release notes and packaged builds for Android, macOS, Linux, and Windows.

  Note The release draft is private until published. Upon being published, the specified version tag will be created.

For posterity, information about doing these things locally is available at go/flutter-gallery-manual-deployment.

Tests

The gallery has its own set of unit, golden, and integration tests.

In addition, Flutter itself uses the gallery in tests. To enable breaking changes, the gallery version is pinned in two places:

• flutter analyze: https://github.com/flutter/tests/blob/master/registry/flutter_gallery.test
• DeviceLab tests: https://github.com/flutter/flutter/blob/master/dev/devicelab/lib/versions/gallery.dart