GlassLargeTitleController class

Coordinates the large-title + search-bar collapse animation between GlassLargeTitle and GlassAppBar.

Create one instance per screen, pass it to both widgets, and dispose it in your State.dispose(). The controller owns the ScrollController — callers attach it to their CustomScrollView via scrollController.

Two-phase iOS 26 collapse

Phase 1 — large title fades out over the first ~52pt of scroll. Driven by collapseProgress.

Phase 2 — search bar (when provided to GlassLargeTitle) collapses immediately after the title, over the next ~44pt. Driven by searchBarCollapseProgress.

class _MyScreenState extends State<MyScreen> {
  final _titleController = GlassLargeTitleController();

  @override
  void dispose() {
    _titleController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => GlassScaffold(
    appBar: GlassAppBar(
      title: Text('Chats'),
      largeTitleController: _titleController,
    ),
    body: CustomScrollView(
      controller: _titleController.scrollController,
      slivers: [
        GlassLargeTitle(
          text: 'Chats',
          controller: _titleController,
          searchBar: GlassSearchBar(placeholder: 'Search'),
        ),
        // ... content slivers
      ],
    ),
  );
}