Bug: showing flashbar at Position.top changes the systemNavigationBarColor to black

[tmaihoff]

Here is the minimal reproducible example.

So when you first set the systemNavigationBarColor like so:

    SystemChrome.setSystemUIOverlayStyle(
      const SystemUiOverlayStyle(
        statusBarColor: Colors.transparent,
        systemNavigationBarColor: Colors.green,
        systemNavigationBarContrastEnforced: false,
      ),
    );
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual, overlays: [
      SystemUiOverlay.bottom,
    ]);

and then call context.showFlash with FlashPosition.top, the green system navigation bar changes from green back to black.

This is clearly unwanted as the systemNavigationBarColor is normally set once and supposed to keep its value.

I have tracked down the issue to the following part in the flash code:

    // flash.dart:583
    if (widget.position == FlashPosition.top) {
      final brightness = ThemeData.estimateBrightnessForColor(backgroundColor);
      child = AnnotatedRegion<SystemUiOverlayStyle>(
        value: brightness == Brightness.dark ? SystemUiOverlayStyle.light : SystemUiOverlayStyle.dark,
        child: child,
      );
    }

I deleted this if statement which makes it work. However, I don't know if that has any implications that I'm not aware of. For me it fixes the issue.

I have opened a PR and looking forward to your comments about if this statement is necessary or can safely be removed.

[Ludo978]

As a workaround, you can set the surfaceTintColor property to white in the FlashBar widget.