Learn JETPACK-COMPOSE with Real Code Examples

Jetpack Compose allows developers to define UI components in Kotlin code using a declarative syntax.

It replaces XML-based layouts, enabling more concise and reactive UI creation.

Compose emphasizes unidirectional data flow, state management, and integration with modern Android architecture components.

Composable functions for UI elements

State management with remember, mutableStateOf, and StateFlow

Layouts like Column, Row, Box, LazyColumn

Material and custom design system support

Animation APIs for smooth UI transitions

Composable: basic building block for UI

State: holds UI data that can change

Layouts: Column, Row, Box, LazyColumn, LazyRow

Modifiers: styling and positioning elements

Material components: Buttons, TextField, Scaffold, Snackbar

MainActivity.kt - entry point of the app

ui/ - folder for composable UI components

theme/ - color, typography, and shape theming

viewmodel/ - state management and business logic

data/ - repository or data source integration

Define Composable functions for UI

Use state variables to manage dynamic data

Compose layouts using Column, Row, Box, Lazy lists

Apply Modifiers for padding, alignment, styling

Preview UI and deploy to device/emulator

Beginner: basic layouts and text/buttons

Intermediate: forms and navigation

Advanced: complex state management with ViewModel

Expert: animations, gestures, and performance optimization

Community: integrating Compose with existing XML apps

Android-native focus vs cross-platform frameworks like Flutter/Titanium

Declarative UI vs XML layouts

Tightly integrated with Kotlin and Jetpack

Better state management vs traditional XML + LiveData

Best for modern, reactive Android apps

2019 – Jetpack Compose announced at Google I/O

2020 – Compose alpha versions released

2021 – Compose 1.0 stable release

2022 – Compose 1.1 with material3 support

2025 – Compose 2.0 with performance and tooling enhancements

Composable: reusable UI function

State: holds UI data

Modifier: styling and layout

LazyColumn/LazyRow: scrollable lists

Material: design system components