Demo of transparent AnnotatedRegion

This repo was originally used to test issue: flutter/flutter#135657

But later modified to demonstrate usage of AnnotatedRegion to use transparent system navigation bar on Android.

Note that for this to work you must also set SystemUiMode.edgeToEdge so:

  // If opacity is specified, we need to enable SystemUiMode.edgeToEdge to
  // be able to see content scrolling behind the transparent bar. Only do
  // this when using opacity or transparent system navigation bar.
  await SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);

In this example that is done in the main.dart file.

After that setting the transparent system navigation bar style is typically enough to do in the screen(s) that can chnage the theme mode between light and dark mode.

There you can do something like:

  @override
  Widget build(BuildContext context) {
    final bool isLight = Theme.of(context).brightness == Brightness.light;
    return AnnotatedRegion<SystemUiOverlayStyle>(
      value: SystemUiOverlayStyle(
        systemNavigationBarContrastEnforced: false,
        systemNavigationBarColor: Colors.transparent,
        systemNavigationBarDividerColor: Colors.transparent,
        systemNavigationBarIconBrightness:
            isLight ? Brightness.dark : Brightness.light,
      ),
      child: Scaffold(...),
    );

In this demo it is done in file settings_view.dart.

The bottom navigation bar on the home screen does not do anything, it is only there to show what it looks like when one is present. The theme settings and details page show the look when a navigator is not present.

The system nav also changes correctly in this demo when the ThemeMode.system is used and light/dark mode is toggled via Android system settings.

Getting Started

This project is a starting point for a Flutter application that follows the simple app state management tutorial.

For help getting started with Flutter development, view the online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

Assets

The assets directory houses images, fonts, and any other files you want to include with your application.

The assets/images directory contains resolution-aware images.

Localization

This project generates localized messages based on arb files found in the lib/src/localization directory.

To support additional languages, please visit the tutorial on Internationalizing Flutter apps