buzz/mobile/lib/shared/widgets/frosted_scaffold.dart

import 'package:flutter/material.dart';

import 'directional_transition_scope.dart';
import 'frosted_app_bar.dart';

/// A convenience [Scaffold] that overlays a [FrostedAppBar] on top of its body.
///
/// The body is rendered full-bleed inside a [Stack] with the frosted app bar
/// floating above it. The body is responsible for adding its own top spacing
/// using [frostedAppBarHeight] so content starts below the bar.
class FrostedScaffold extends StatelessWidget {
  /// The frosted app bar displayed at the top of the screen.
  final FrostedAppBar appBar;

  /// The primary content of the scaffold. Must handle its own top spacing
  /// using [frostedAppBarHeight] — the scaffold does NOT add automatic padding.
  final Widget body;

  /// Optional floating action button, passed through to [Scaffold].
  final Widget? floatingActionButton;

  /// Whether the body should resize when the on-screen keyboard appears.
  final bool? resizeToAvoidBottomInset;

  /// Optional scaffold background, useful when a parent supplies a shared
  /// surface behind this page.
  final Color? backgroundColor;

  const FrostedScaffold({
    super.key,
    required this.appBar,
    required this.body,
    this.floatingActionButton,
    this.resizeToAvoidBottomInset,
    this.backgroundColor,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: backgroundColor,
      resizeToAvoidBottomInset: resizeToAvoidBottomInset,
      floatingActionButton: floatingActionButton,
      body: Stack(
        children: [
          DirectionalTransitionMotion(
            transformKey: const ValueKey(
              'frosted-scaffold-body-transition-transform',
            ),
            opacityKey: const ValueKey(
              'frosted-scaffold-body-transition-opacity',
            ),
            child: body,
          ),
          appBar,
        ],
      ),
    );
  }
}