模块化导航配方 (Hilt)

此配方演示了如何使用 Navigation 3 和 Dagger/Hilt 进行依赖项注入，以构建多模块应用。目标是创建一个解耦架构，在该架构中，导航在单独的功能模块中定义和实现。

运作方式

应用分为多个模块：

  • app 模块 ：这是主应用模块。它提供 HiltDeepLinkActivity（一个演示常规 intent 和深层链接 intent 启动的入口点）、HiltModularActivity（用于托管 NavDisplay 并将深层链接 intent 委托给 Navigator.handleDeepLink(intent)）、起始目标绑定，并构建最终的 entryProvider。

  • common 模块 ：此模块包含核心导航逻辑，包括：

    • 一个 Navigator 类，用于管理返回堆栈、解析传入的深层链接 intent，并通过 handleDeepLink(intent) 构建合成返回堆栈。
    • 一个用于初始化返回堆栈的 startDestination: NavKey。
    • 一个 EntryProviderInstaller 类型，这是一个函数，功能模块使用该函数将其导航条目贡献给应用的 entryProvider。
    • BackStackMatcher<*, NavKey>，功能模块使用该函数将其深层链接匹配器与合成返回堆栈一起贡献。

  • 功能模块（例如 conversation、profile）：每个功能都分为两个子模块：

    • api 模块 ：定义功能的公共 API，包括其导航路线和深层链接 URI 模式。这样，其他模块便可以导航到此功能，而无需了解其实现细节。
    • impl 模块：提供功能的实现，包括其可组合项、将功能的路线映射到其可组合项的 EntryProviderInstaller，以及配置了 .withBackStack 以建立适当的分层返回堆栈（例如 [ConversationList, ConversationDetail(id)]）的 BackStackMatcher<*, NavKey>。两者均使用 Dagger/Hilt 多重绑定 (@IntoSet) 提供。

这种模块化方法可以清晰地分离关注点，使代码库更具可伸缩性和可维护性。每个功能都负责自己的导航逻辑，而 app 模块仅将这些部分组合在一起。

package com.example.nav3recipes.modular.hilt

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import androidx.navigation3.runtime.NavKey
import androidx.navigation3.runtime.deeplink.BackStackMatcher
import androidx.navigation3.runtime.deeplink.DeepLinkUri
import androidx.navigation3.runtime.deeplink.UriDeepLinkMatcher
import androidx.navigation3.runtime.deeplink.withBackStack
import dagger.Module
import dagger.Provides
import dagger.hilt.InstallIn
import dagger.hilt.android.components.ActivityRetainedComponent
import dagger.multibindings.IntoSet
import kotlinx.serialization.Serializable

// API
@Serializable
object Profile : NavKey

const val PROFILE_URI = "https://www.nav3recipes.com/profile"

// IMPLEMENTATION
@Module
@InstallIn(ActivityRetainedComponent::class)
object ProfileModule {

    @IntoSet
    @Provides
    fun provideEntryProviderInstaller() : EntryProviderInstaller = {
        entry<Profile>{
            ProfileScreen()
        }
    }

    @IntoSet
    @Provides
    fun provideDeepLinkMatcher(): BackStackMatcher<*, NavKey> =
        UriDeepLinkMatcher(
            uriPattern = DeepLinkUri(PROFILE_URI),
            serializer = Profile.serializer(),
        ).withBackStack { matchResult ->
            listOf(ConversationList, matchResult.key)
        }
}

@Composable
private fun ProfileScreen() {
    val profileColor = MaterialTheme.colorScheme.surfaceVariant
    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(profileColor)
            .padding(16.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center
    ) {
        Text(
            text = "Profile Screen",
            style = MaterialTheme.typography.headlineMedium,
            color = MaterialTheme.colorScheme.onSurface
        )
    }
}

package com.example.nav3recipes.modular.hilt

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Scaffold
import androidx.compose.ui.Modifier
import androidx.navigation3.runtime.entryProvider
import androidx.navigation3.ui.NavDisplay
import com.example.nav3recipes.ui.setEdgeToEdgeConfig
import dagger.hilt.android.AndroidEntryPoint
import javax.inject.Inject

@AndroidEntryPoint
class HiltModularActivity : ComponentActivity() {

    @Inject
    lateinit var navigator: Navigator

    @Inject
    lateinit var entryProviderScopes: Set<@JvmSuppressWildcards EntryProviderInstaller>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setEdgeToEdgeConfig()
        navigator.handleDeepLink(intent)
        setContent {
            Scaffold { paddingValues ->
                NavDisplay(
                    backStack = navigator.backStack,
                    modifier = Modifier.padding(paddingValues),
                    onBack = { navigator.goBack() },
                    entryProvider = entryProvider {
                        entryProviderScopes.forEach { builder -> this.builder() }
                    }
                )
            }
        }
    }
}

package com.example.nav3recipes.modular.hilt

import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.material3.Button
import androidx.compose.material3.ListItem
import androidx.compose.material3.ListItemDefaults
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.lifecycle.compose.dropUnlessResumed
import androidx.navigation3.runtime.NavKey
import androidx.navigation3.runtime.deeplink.BackStackMatcher
import androidx.navigation3.runtime.deeplink.DeepLinkUri
import androidx.navigation3.runtime.deeplink.UriDeepLinkMatcher
import androidx.navigation3.runtime.deeplink.withBackStack
import com.example.nav3recipes.ui.theme.colors
import dagger.Module
import dagger.Provides
import dagger.hilt.InstallIn
import dagger.hilt.android.components.ActivityRetainedComponent
import dagger.multibindings.IntoSet
import kotlinx.serialization.Serializable

// API
object ConversationList : NavKey

@Serializable
data class ConversationDetail(val id: Int) : NavKey {
    val color: Color
        get() = colors[id % colors.size]
}

const val CONVERSATION_URI = "https://www.nav3recipes.com/conversation"

// IMPL
@Module
@InstallIn(ActivityRetainedComponent::class)
object ConversationModule {

    @IntoSet
    @Provides
    fun provideEntryProviderInstaller(navigator: Navigator): EntryProviderInstaller =
        {
            entry<ConversationList> {
                ConversationListScreen(
                    onConversationClicked = { conversationDetail ->
                        navigator.goTo(conversationDetail)
                    }
                )
            }
            entry<ConversationDetail> { key ->
                ConversationDetailScreen(key) {
                    navigator.goTo(Profile)
                }
            }
        }

    @IntoSet
    @Provides
    fun provideDeepLinkMatcher(): BackStackMatcher<*, NavKey> =
        UriDeepLinkMatcher(
            uriPattern = DeepLinkUri("$CONVERSATION_URI/{id}"),
            serializer = ConversationDetail.serializer(),
        ).withBackStack { matchResult ->
            listOf(ConversationList, matchResult.key)
        }
}

@Composable
private fun ConversationListScreen(
    onConversationClicked: (ConversationDetail) -> Unit
) {
    LazyColumn(
        modifier = Modifier.fillMaxSize(),
    ) {
        items(10) { index ->
            val conversationId = index + 1
            val conversationDetail = ConversationDetail(conversationId)
            val backgroundColor = conversationDetail.color
            ListItem(
                modifier = Modifier
                    .fillMaxWidth()
                    .clickable(onClick = dropUnlessResumed {
                        onConversationClicked(conversationDetail)
                    }),
                headlineContent = {
                    Text(
                        text = "Conversation $conversationId",
                        style = MaterialTheme.typography.headlineSmall,
                        color = MaterialTheme.colorScheme.onSurface
                    )
                },
                colors = ListItemDefaults.colors(
                    containerColor = backgroundColor // Set container color directly
                )
            )
        }
    }
}

@Composable
private fun ConversationDetailScreen(
    conversationDetail: ConversationDetail,
    onProfileClicked: () -> Unit
) {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(conversationDetail.color)
            .padding(16.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center
    ) {
        Text(
            text = "Conversation Detail Screen: ${conversationDetail.id}",
            style = MaterialTheme.typography.headlineMedium,
            color = MaterialTheme.colorScheme.onSurface
        )
        Spacer(modifier = Modifier.height(16.dp))
        Button(onClick = dropUnlessResumed(block = onProfileClicked)) {
            Text("View Profile")
        }
    }
}

package com.example.nav3recipes.modular.hilt

import android.content.Intent
import androidx.compose.runtime.mutableStateListOf
import androidx.compose.runtime.snapshots.SnapshotStateList
import androidx.navigation3.runtime.EntryProviderScope
import androidx.navigation3.runtime.NavKey
import androidx.navigation3.runtime.deeplink.BackStackMatcher
import androidx.navigation3.runtime.deeplink.DeepLinkRequest
import androidx.navigation3.runtime.deeplink.invoke
import dagger.hilt.android.scopes.ActivityRetainedScoped
import javax.inject.Inject

typealias EntryProviderInstaller = EntryProviderScope<NavKey>.() -> Unit

@ActivityRetainedScoped
class Navigator @Inject constructor(
    startDestination: NavKey,
    private val deepLinkMatchers: Set<@JvmSuppressWildcards BackStackMatcher<*, NavKey>>,
) {
    val backStack: SnapshotStateList<NavKey> = mutableStateListOf(startDestination)

    fun goTo(destination: NavKey) {
        backStack.add(destination)
    }

    fun handleDeepLink(intent: Intent) {
        if (intent.data == null && intent.extras == null) return

        val request = DeepLinkRequest(intent)
        val matchResult = deepLinkMatchers.firstNotNullOfOrNull { matcher ->
            matcher.match(request)
        } ?: return

        backStack.clear()
        backStack.addAll(matchResult.backStack)
    }

    fun goBack() {
        backStack.removeLastOrNull()
    }
}
 
package com.example.nav3recipes.modular.hilt

import androidx.navigation3.runtime.NavKey
import dagger.Module
import dagger.Provides
import dagger.hilt.InstallIn
import dagger.hilt.android.components.ActivityRetainedComponent

@Module
@InstallIn(ActivityRetainedComponent::class)
object AppModule {

    @Provides
    fun provideStartDestination(): NavKey = ConversationList
}