GlassScaffold class

A one-stop-shop scaffold that replaces the manual assembly of GlassPage, Scaffold, GlassScrollEdgeEffect, and a Stack for proper z-ordering.

Why GlassScaffold?

When using glass surfaces (navigation bars, bottom bars, cards), the correct layout requires 4-5 nested widgets with manual padding calculations and scroll controller wiring. GlassScaffold handles all of this internally:

• Z-ordering: App bar and bottom bar always render above body content, preventing glass cards in the body from overlapping navigation buttons.
• Edge fading: Content fades smoothly as it approaches the bar areas, matching iOS 26's .scrollEdgeEffectStyle(.soft).
• Auto padding: Calculates safe-area-aware top/bottom padding so content starts below the app bar and above the bottom bar automatically.
• Background & glass layer: Wraps everything in GlassPage for the glass rendering context, background, and status bar styling.

Before (manual assembly)

GlassPage(
  background: Image.asset('assets/bg.jpg', fit: BoxFit.cover),
  settings: RecommendedGlassSettings.standard,
  statusBarStyle: GlassStatusBarStyle.light,
  child: Scaffold(
    extendBodyBehindAppBar: true,
    extendBody: true,
    appBar: GlassAppBar(
      title: Text('Messages'),
      scrollController: _ctrl,
      settings: RecommendedGlassSettings.surface,
    ),
    body: GlassScrollEdgeEffect(
      topFadeHeight: MediaQuery.paddingOf(context).top + 44 + 40,
      bottomFadeHeight: 60 + MediaQuery.paddingOf(context).bottom,
      child: CustomScrollView(
        controller: _ctrl,
        slivers: [
          SliverToBoxAdapter(
            child: SizedBox(
              height: MediaQuery.paddingOf(context).top + 44 + 16,
            ),
          ),
          // ... content
        ],
      ),
    ),
  ),
)

After (one widget)

GlassScaffold(
  background: Image.asset('assets/bg.jpg', fit: BoxFit.cover),
  settings: RecommendedGlassSettings.standard,
  statusBarStyle: GlassStatusBarStyle.light,
  appBar: GlassAppBar(
    title: Text('Messages'),
    scrollController: _ctrl,
    settings: RecommendedGlassSettings.surface,
  ),
  body: CustomScrollView(
    controller: _ctrl,
    slivers: [
      // No manual spacer needed — GlassScaffold handles it
      // ... content
    ],
  ),
)

How it works internally

GlassScaffold builds:

GlassPage(
  background: ...,
  child: CupertinoPageScaffold(
    child: Stack(
      children: [
        // 1. Body with edge fading (bottom of stack)
        // 2. Body overlays (between body and bars)
        // 3. App bar (top of stack — always above body)
        // 4. Bottom bar (top of stack — always above body)
      ],
    ),
  ),
)

The app bar and bottom bar are placed AFTER the body in the Stack's children list, guaranteeing they always paint on top regardless of BackdropFilter compositing from glass widgets in the body.