wrapWithBackground function

Widget wrapWithBackground({ Border? border, required Color backgroundColor, Brightness? brightness, required Widget child, bool updateSystemUiOverlay = true, })

Returns child wrapped with background and a bottom border if background color is opaque. Otherwise, also blur with BackdropFilter.

When updateSystemUiOverlay is true, the nav bar will update the OS status bar's color theme based on the background color of the nav bar.

Implementation

Widget wrapWithBackground({
  Border? border,
  required Color backgroundColor,
  Brightness? brightness,
  required Widget child,
  bool updateSystemUiOverlay = true,
}) {
  Widget result = child;
  if (updateSystemUiOverlay) {
    final bool isDark = backgroundColor.computeLuminance() < 0.179;
    final Brightness newBrightness =
        brightness ?? (isDark ? Brightness.dark : Brightness.light);
    final SystemUiOverlayStyle overlayStyle;
    switch (newBrightness) {
      case Brightness.dark:
        overlayStyle = SystemUiOverlayStyle.light;
        break;
      case Brightness.light:
        overlayStyle = SystemUiOverlayStyle.dark;
        break;
    }
    // [SystemUiOverlayStyle.light] and [SystemUiOverlayStyle.dark] set some system
    // navigation bar properties,
    // Before https://github.com/flutter/flutter/pull/104827 those properties
    // had no effect, now they are used if there is no AnnotatedRegion on the
    // bottom of the screen.
    // For backward compatibility, create a `SystemUiOverlayStyle` without the
    // system navigation bar properties.
    result = AnnotatedRegion<SystemUiOverlayStyle>(
      value: SystemUiOverlayStyle(
        statusBarColor: overlayStyle.statusBarColor,
        statusBarBrightness: overlayStyle.statusBarBrightness,
        statusBarIconBrightness: overlayStyle.statusBarIconBrightness,
        systemStatusBarContrastEnforced:
            overlayStyle.systemStatusBarContrastEnforced,
      ),
      child: result,
    );
  }
  final DecoratedBox childWithBackground = DecoratedBox(
    decoration: BoxDecoration(
      border: border,
      color: backgroundColor,
    ),
    child: result,
  );

  if (backgroundColor.alpha == 0xFF) {
    return childWithBackground;
  }

  return ClipRect(
    child: BackdropFilter(
      filter: ImageFilter.blur(sigmaX: 10.0, sigmaY: 10.0),
      child: childWithBackground,
    ),
  );
}