Transitioning a Jetpack Compose application from Material Design 2 (M2) to Material Design 3 (M3) involves updating dependencies, modifying theming, and adapting to changes in component APIs. M3 introduces an updated visual language, dynamic color capabilities, and new component specifications, which necessitate careful migrasion.

Key API Changes and Component Equivalents

The shift to Material 3 brings significant changes to the Compose Material library. Developers should be aware of components that have been removed, replaced, or renamed. Understanding these changes is crucial for a smooth migration process.

Removed Components (No Direct M3 Equivalent)

Some M2 components do not have a direct M3 counterpart, requiring developers to use alternative patterns or more fundamental composables.

Renamed Components (M3 Equivalents)

Many components have been renamed to align with M3's terminology or to better reflect their functionality within the new design system.

Currently Unavailable APIs

As of certain Compose Material3 versions, some functionalities might still be under development or pending integration. For example:

• androidx.compose.material.swipeable: Functionality for swipeable containers may not have a direct, fully integrated M3 counterpart yet.

Migration Steps

The migration from M2 to M3 can be performed incrementally, module by module, or screen by screen, depending on the application's architecture and complexity. Here's a general workflow:

1. Add M3 Dependencies: Include the Material 3 library in your project while retaining M2 for a gradual transition.
2. Implement M3 Theming: Introduce M3-specific theme composables alongside your existing M2 themes.
3. Migrate Components Incrementally: Update individual modules, screens, or composables to use their M3 counterparts.
4. Remove M2 Theming: Once all components are migrated, remove the M2 theme.
5. Remove M2 Dependencies: Finally, eliminate the Material 2 library dependency from your project.

It's important to note that other Material-related dependencies, such as Compose Material Icons (androidx.compose.material:material-icons-*) and Compose Material Ripple (androidx.compose.material:material-ripple), are generally compatible and can be used with both M2 and M3 packages without requiring specific version changes during the migration.

Updating Dependencies

The first step is to include the Material 3 library. This typically involves modifying your build.gradle file:

// Retain M2 dependency initially for gradual migration
implementation "androidx.compose.material:material:1.x.x"

// Add M3 dependency
implementation "androidx.compose.material3:material3:1.x.x"

// After full migration, the M2 dependency should be removed:
// remove "androidx.compose.material:material:1.x.x"

Revising Color Schemes and Theming

Material 3 introduces a more extensive color system, encluding dynamic color capabilities. You'll switch from M2's Colors to M3's ColorScheme, generated using lightColorScheme and darkColorScheme from androidx.compose.material3.

import androidx.compose.material3.darkColorScheme
import androidx.compose.material3.lightColorScheme
import androidx.compose.runtime.Composable
import androidx.compose.ui.graphics.Color

// Define your M3 light color scheme
private val AppLightColors = lightColorScheme(
    primary = Color(0xFF673AB7), // Example: Deep Purple
    onPrimary = Color.White,
    secondary = Color(0xFF9C27B0), // Example: Purple Accent
    onSecondary = Color.White,
    tertiary = Color(0xFFE91E63), // Example: Pink Accent
    onTertiary = Color.White,
    background = Color(0xFFF0F0F0),
    onBackground = Color.Black,
    surface = Color.White,
    onSurface = Color.Black,
    error = Color(0xFFB00020),
    onError = Color.White,
    // ... define other M3 light color parameters
)

// Define your M3 dark color scheme
private val AppDarkColors = darkColorScheme(
    primary = Color(0xFFBB86FC), // Example: Purple A200
    onPrimary = Color.Black,
    secondary = Color(0xFF03DAC5), // Example: Teal A200
    onSecondary = Color.Black,
    tertiary = Color(0xFF00C853), // Example: Green A400
    onTertiary = Color.Black,
    background = Color(0xFF121212),
    onBackground = Color.White,
    surface = Color(0xFF1E1E1E),
    onSurface = Color.White,
    error = Color(0xFFCF6679),
    onError = Color.Black,
    // ... define other M3 dark color parameters
)

@Composable
fun getApplicationColorScheme(isDarkTheme: Boolean) =
    if (isDarkTheme) AppDarkColors else AppLightColors

Your main application theme composable will then use the M3 MaterialTheme, passing the appropriate color scheme.

Adapting Navigation Components

Changes to navigation components are notable. For instance, the Scaffold composable in M3 no longer directly manages drawer-related parameters like drawerShape or drawerContent. Instead, you should integrate dedicated drawer composables like ModalNavigationDrawer alongside Scaffold:

import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.ModalDrawerSheet
import androidx.compose.material3.ModalNavigationDrawer
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.material3.rememberDrawerState
import androidx.compose.runtime.Composable
import androidx.compose.runtime.rememberCoroutineScope
import kotlinx.coroutines.launch

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AppLayoutContent() {
    val navDrawerState = rememberDrawerState(initialValue = androidx.compose.material3.DrawerValue.Closed)
    val coroutineScope = rememberCoroutineScope()

    ModalNavigationDrawer(
        drawerState = navDrawerState,
        drawerContent = {
            ModalDrawerSheet {
                Text("Drawer content goes here")
                // Add NavigationDrawerItem or custom items
            }
        },
        gesturesEnabled = navDrawerState.isOpen
    ) {
        Scaffold(
            topBar = { /* Your M3 TopAppBar */ },
            bottomBar = { /* Your M3 NavigationBar */ }
        ) { paddingValues ->
            // Main content of your screen
            Text("Main content", modifier = androidx.compose.ui.Modifier.padding(paddingValues))
            // Example of opening the drawer programmatically
            // Button(onClick = { coroutineScope.launch { navDrawerState.open() } }) { Text("Open Drawer") }
        }
    }
}

Similarly, for bottom navigation, replace androidx.compose.material.BottomNavigation and BottomNavigationItem with androidx.compose.material3.NavigationBar and NavigationBarItem respectively, applying the new M3 design specifications.