Thuta Learning
Flutter
IntermediateMobile Developmentbeginner

Lazy Lists, Grids & Slivers

FlutterLesson 11

What you'll walk away with

  • Explain the widget, state, and lifecycle behavior of Lazy Lists, Grids & Slivers
  • Test responsive, failure, and interaction cases
  • Write accessible, testable, and performant Flutter

Treat Lazy Lists, Grids & Slivers as a contract for constraints, size, position, rebuild scope, semantics, and platform adaptation—not merely widget syntax. Prefer focused widgets, const constructors, lazy builders, and responsive constraints.

Build a Complete Mental Model

Treat Lazy Lists, Grids & Slivers as a contract for constraints, size, position, rebuild scope, semantics, and platform adaptation—not merely widget syntax. Prefer focused widgets, const constructors, lazy builders, and responsive constraints.

Apply It in Production Flutter

Run and test an original Lazy Lists, Grids & Slivers example with small and large screens, text scaling, empty/loading/error states, rapid interaction, navigation restoration, and disposal cases. Use flutter analyze, widget tests, and profile mode where relevant.

After This Lesson

dart
ListView.builder(
  itemCount: 1000,
  itemBuilder: (context, index) => ListTile(
    key: ValueKey(index),
    title: Text('Item ${index + 1}'),
  ),
)
You should see
Only visible list rows are built lazily

Try It Yourself

Run and test an original Lazy Lists, Grids & Slivers example with small and large screens, text scaling, empty/loading/error states, rapid interaction, navigation restoration, and disposal cases. Use flutter analyze, widget tests, and profile mode where relevant.

Lifecycle and Performance Warning

Assuming one screen's sample output proves every rebuild, overflow, accessibility, async, and lifecycle path.

Flutter documentationFlutter

Easy traps

  • Assuming one screen's sample output proves every rebuild, overflow, accessibility, async, and lifecycle path.
  • Doing expensive work in build(), leaking controllers or subscriptions, or calling setState over an unnecessarily large subtree.

Hands-on Exercise

Run and test an original Lazy Lists, Grids & Slivers example with small and large screens, text scaling, empty/loading/error states, rapid interaction, navigation restoration, and disposal cases. Use flutter analyze, widget tests, and profile mode where relevant.

You'll know it worked when: Only visible list rows are built lazily

Lazy Lists, Grids & Slivers | Thuta Learning