ghost_app_bar

An invisible app bar scaffold for Flutter. The bar has no background — content scrolls behind it and dissolves into a soft gradient scrim that also covers the status bar, with no visible seam. A large title fades out as you scroll while a compact title fades into the bar (WhatsApp / iOS large-title style).

Works on all renderers: plain gradient paint, no ShaderMask.

Expanded	Collapsed	Dark

Features

• Transparent floating bar with leading and actions slots
• Gradient scrim covering the status bar — no seam between bar and content
• Large title that scrolls away and fades out
• Compact title that fades into the bar past a configurable offset
• Theme-aware: readable in light and dark mode with no colors passed
• Put any widget in the bar — subtitles, avatars, search fields, tabs
• Sliver-based content, or a plain children list via the convenience constructor
• Zero dependencies beyond Flutter itself

Usage

import 'package:ghost_app_bar/ghost_app_bar.dart';

Scaffold(
  body: GhostAppBarScaffold.children(
    title: 'Chats',
    leading: const CircleAvatar(radius: 18),
    actions: [
      IconButton(icon: const Icon(Icons.search), onPressed: () {}),
    ],
    children: [
      for (var i = 0; i < 40; i++) ListTile(title: Text('Item $i')),
    ],
  ),
)

Colors come from the ambient Theme, so this is readable in light and dark mode without passing any. Override scrimColor, largeTitleStyle, or compactTitleStyle when you want something specific.

Custom bar content

title is a shortcut. For anything else, pass widgets — they get the same fade and collapse behaviour for free:

GhostAppBarScaffold.children(
  // Expanded header: heading plus a subtitle.
  largeTitle: Column(
    crossAxisAlignment: CrossAxisAlignment.start,
    children: [
      Text('Library', style: Theme.of(context).textTheme.headlineMedium),
      Text('40 documents · 2 shared'),
    ],
  ),
  // What fades into the bar once collapsed.
  compactTitle: Row(
    children: [
      const Icon(Icons.folder_rounded, size: 20),
      const SizedBox(width: 8),
      const Text('Library'),
    ],
  ),
  leading: const BackButton(),
  actions: [IconButton(icon: const Icon(Icons.search), onPressed: () {})],
  children: [...],
)

Pass title alongside just one of them to override a single side — the other falls back to the text. For full control of the scroll content, use the default constructor with slivers.

Tuning

License

MIT