Independent Stacks per Tab

DeclarativeTabsScaffold keeps each tab's page list independent while preserving declarative updates.

Next: Back Handling Back to Overlays

Tab-local page lists

Manage Map<TabId, List<PageEntry>> for predictable tab navigation state.

Per-screen overlays

Use TabPageKey = (TabId, pageKey) to scope overlay state for each tab screen.

Consistent back order

Overlay -> pop tab stack -> first tab -> onBackAtRoot.

Tabs Scaffold Pattern

Prepare root pages per tab and route all tab events through state updates.

Tab Overlay Map

DeclarativeTabsScaffold

const tabHome = TabId('home');
const tabSettings = TabId('settings');

final pagesByTab = <TabId, List<PageEntry>>{
  tabHome: [const PageEntry(key: 'home', name: '/home')],
  tabSettings: [const PageEntry(key: 'settings', name: '/settings')],
};

return DeclarativeTabsScaffold(
  items: items,
  currentTab: currentTab,
  onSelectTab: _selectTab,
  pagesByTab: pagesByTab,
  setPagesForTab: _setPagesForTab,
  buildPage: _buildTabPage,
);

Constraint

For each tab, pagesByTab[tab] must stay non-empty because the root page is required for stable navigation behavior.

Resolver

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