Flutter

Flutter is Google’s open-source UI toolkit for building natively compiled applications for mobile, web, and desktop from a single codebase using the Dart language.

Core Concepts

Widgets

Everything in Flutter is a widget. Widgets describe what their view should look like given their current configuration and state.

StatelessWidget — immutable, rebuilt only when parent changes
StatefulWidget — mutable state, can trigger rebuilds via setState()


MaterialApp
└── Scaffold
    ├── AppBar
    └── body: Column
        ├── Text('Hello')
        └── ElevatedButton(...)

State Management

Approach	Best For
`setState`	Local, simple widget state
`Provider`	App-wide state, simple DI
`Riverpod`	Scalable, testable state (recommended)
`Bloc/Cubit`	Complex business logic separation

Project Structure (recommended)


lib/
├── main.dart
├── app.dart
├── features/
│   └── auth/
│       ├── data/
│       ├── domain/
│       └── presentation/
├── shared/
│   ├── widgets/
│   └── theme/
└── core/
    ├── router/
    └── services/

References

Flutter Team. Flutter Documentation. https://docs.flutter.dev
Dart Team. Dart Language Tour. https://dart.dev/language
Riverpod. Riverpod Documentation. https://riverpod.dev