Flutter Development Guide

Quick Reference

Widget Patterns

StateProvider

ConsumerWidget

NotifierProvider

Bloc

FutureProvider

AsyncNotifierProvider

StreamProvider

GoRouter

context.go/push

LayoutBuilder

ListView.builder

CustomScrollView

HookWidget

useState/useEffect

Form

TextFormField

Performance Patterns

const

ref.watch(provider.select(...))

RepaintBoundary

ListView.builder

compute()

cached_network_image

Core Principles

Widget Optimization

• Use

  const

  constructors wherever possible
• Extract static widgets to separate const classes
• Use

  Key

  for list items (ValueKey, ObjectKey)
• Prefer

  ConsumerWidget

  over

  StatefulWidget

  for state

State Management

• Riverpod for dependency injection and simple state
• Bloc/Cubit for event-driven workflows and complex logic
• Never mutate state directly (create new instances)
• Use

  select()

  to minimize rebuilds

Layout

• 8pt spacing increments (8, 16, 24, 32, 48)
• Responsive breakpoints: mobile (<650), tablet (650-1100), desktop (>1100)
• Support all screen sizes with flexible layouts
• Follow Material 3 / Cupertino design guidelines

Performance

• Profile with DevTools before optimizing
• Target <16ms frame time for 60fps
• Use

  RepaintBoundary

  for complex animations
• Offload heavy work with

  compute()

Checklist

Widget Best Practices

• const

  constructors on all static widgets
• Proper

  Key

  on list items

• ConsumerWidget

  for state-dependent widgets
• No widget building inside

  build()

  method
• Extract reusable widgets to separate files

State Management

• Immutable state objects

• select()

  for granular rebuilds
• Proper provider scoping
• Dispose controllers and subscriptions
• Handle loading/error states

Navigation

• GoRouter with typed routes
• Auth guards via redirect
• Deep linking support
• State preservation across routes

Performance

• Profile mode testing (

  flutter run --profile

  )
• <16ms frame rendering time
• No unnecessary rebuilds (DevTools check)
• Images cached and resized
• Heavy computation in isolates

Testing

• Widget tests for UI components
• Unit tests for business logic
• Integration tests for user flows
• Bloc tests with

  blocTest()

References