Migrate Interests nested NavHost to safe args

Change-Id: I4f3c310be693ecbcbc8b99c4e573d7fc6e9a2f74

app/build.gradle.kts

@@ -25,6 +25,10 @@ plugins {
     id("com.google.android.gms.oss-licenses-plugin")
     alias(libs.plugins.baselineprofile)
     alias(libs.plugins.roborazzi)
+    // Serialization is used for type-safe navigation.
+    // TODO: Use the plugin ID from the version catalog when
+    //  https://github.com/gradle/gradle/issues/15383# is resolved
+    id("org.jetbrains.kotlin.plugin.serialization")
 }
 
 android {
@@ -103,6 +107,7 @@ dependencies {
     implementation(libs.androidx.window.core)
     implementation(libs.kotlinx.coroutines.guava)
     implementation(libs.coil.kt)
+    implementation(libs.kotlinx.serialization.json)
 
     ksp(libs.hilt.compiler)
 

app/src/main/kotlin/com/google/samples/apps/nowinandroid/ui/interests2pane/InterestsListDetailScreen.kt

@@ -38,11 +38,13 @@ import com.google.samples.apps.nowinandroid.feature.interests.InterestsRoute
 import com.google.samples.apps.nowinandroid.feature.interests.navigation.INTERESTS_ROUTE
 import com.google.samples.apps.nowinandroid.feature.interests.navigation.TOPIC_ID_ARG
 import com.google.samples.apps.nowinandroid.feature.topic.TopicDetailPlaceholder
-import com.google.samples.apps.nowinandroid.feature.topic.navigation.TOPIC_ROUTE
 import com.google.samples.apps.nowinandroid.feature.topic.navigation.navigateToTopic
 import com.google.samples.apps.nowinandroid.feature.topic.navigation.topicScreen
+import kotlinx.serialization.Serializable
 
-private const val DETAIL_PANE_NAVHOST_ROUTE = "detail_pane_route"
+
+@Serializable object TopicPlaceholderDestination
+@Serializable object DetailPaneNavHostDestination
 
 fun NavGraphBuilder.interestsListDetailScreen() {
     composable(
@@ -86,7 +88,7 @@ internal fun InterestsListDetailScreen(
     fun onTopicClickShowDetailPane(topicId: String) {
         onTopicClick(topicId)
         nestedNavController.navigateToTopic(topicId) {
-            popUpTo(DETAIL_PANE_NAVHOST_ROUTE)
+            popUpTo<DetailPaneNavHostDestination>()
         }
         listDetailNavigator.navigateTo(ListDetailPaneScaffoldRole.Detail)
     }
@@ -103,15 +105,15 @@ internal fun InterestsListDetailScreen(
         detailPane = {
             NavHost(
                 navController = nestedNavController,
-                startDestination = TOPIC_ROUTE,
+                startDestination = TopicPlaceholderDestination::class,
-                route = DETAIL_PANE_NAVHOST_ROUTE,
+                route = DetailPaneNavHostDestination::class
             ){
                 topicScreen(
                     showBackButton = !listDetailNavigator.isListPaneVisible(),
                     onBackClick = listDetailNavigator::navigateBack,
                     onTopicClick = ::onTopicClickShowDetailPane,
                 )
-                composable(route = TOPIC_ROUTE) {
+                composable<TopicPlaceholderDestination> {
                     TopicDetailPlaceholder()
                 }
             }

feature/topic/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/topic/TopicScreen.kt

@@ -71,7 +71,7 @@ import com.google.samples.apps.nowinandroid.core.ui.userNewsResourceCardItems
 import com.google.samples.apps.nowinandroid.feature.topic.R.string
 
 @Composable
-internal fun TopicRoute(
+internal fun TopicScreen(
     showBackButton: Boolean,
     onBackClick: () -> Unit,
     onTopicClick: (String) -> Unit,

feature/topic/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/topic/navigation/TopicNavigation.kt

@@ -21,7 +21,7 @@ import androidx.navigation.NavController
 import androidx.navigation.NavGraphBuilder
 import androidx.navigation.NavOptionsBuilder
 import androidx.navigation.compose.composable
-import com.google.samples.apps.nowinandroid.feature.topic.TopicRoute
+import com.google.samples.apps.nowinandroid.feature.topic.TopicScreen
 import kotlinx.serialization.Serializable
 
 // TODO: Remove
@@ -29,11 +29,10 @@ import kotlinx.serialization.Serializable
 internal const val TOPIC_ID_ARG = "topicId"
 const val TOPIC_ROUTE = "topic_route"
 
-@Serializable
+@Serializable data class TopicDestination(val id: String)
-data class TopicDestination(val id: String)
 
 fun NavController.navigateToTopic(topicId: String, navOptions: NavOptionsBuilder.() -> Unit = {}) {
-    navigate(TopicDestination(topicId)) {
+    navigate(route = TopicDestination(topicId)) {
         navOptions()
     }
 }
@@ -44,7 +43,7 @@ fun NavGraphBuilder.topicScreen(
     onTopicClick: (String) -> Unit,
 ) {
     composable<TopicDestination> {
-        TopicRoute(
+        TopicScreen(
             showBackButton = showBackButton,
             onBackClick = onBackClick,
             onTopicClick = onTopicClick,