stack_wallet/lib/widgets/desktop/desktop_app_bar.dart

import 'package:flutter/material.dart';
import 'package:stackwallet/widgets/conditional_parent.dart';

const double kDesktopAppBarHeight = 96.0;
const double kDesktopAppBarHeightCompact = 82.0;

class DesktopAppBar extends StatelessWidget {
  const DesktopAppBar({
    Key? key,
    this.leading,
    this.center,
    this.overlayCenter,
    this.trailing,
    this.background = Colors.transparent,
    required this.isCompactHeight,
    this.useSpacers = true,
  }) : super(key: key);

  final Widget? leading;
  final Widget? center;
  final Widget? overlayCenter;
  final Widget? trailing;
  final Color background;
  final bool isCompactHeight;
  final bool useSpacers;

  @override
  Widget build(BuildContext context) {
    final List<Widget> items = [];
    if (leading != null) {
      items.add(leading!);
    }

    if (useSpacers) {
      items.add(const Spacer());
    }

    if (center != null) {
      items.add(center!);
      if (useSpacers) {
        items.add(const Spacer());
      }
    }

    if (trailing != null) {
      items.add(trailing!);
    }

    return ConditionalParent(
      condition: overlayCenter != null,
      builder: (child) => Stack(
        children: [
          child,
          Positioned.fill(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [overlayCenter!],
            ),
          ),
        ],
      ),
      child: Container(
        decoration: BoxDecoration(
          color: background,
        ),
        height: isCompactHeight
            ? kDesktopAppBarHeightCompact
            : kDesktopAppBarHeight,
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: items,
        ),
      ),
    );
  }
}