Add Wear navigation 3 snippets

wear/build.gradle.kts

@@ -4,6 +4,7 @@ plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.compose.compiler)
     alias(libs.plugins.roborazzi)
+    alias(libs.plugins.kotlin.serialization)
 }
 
 kotlin {
@@ -139,4 +140,10 @@ dependencies {
     debugImplementation(libs.androidx.compose.ui.tooling.preview)
     debugImplementation(libs.androidx.compose.ui.test.manifest)
 
+    // Navigation 3
+    implementation("androidx.wear.compose:compose-navigation3:1.6.0")
+    implementation(libs.androidx.navigation3.runtime)
+    implementation(libs.androidx.navigation3.ui)
+    implementation(libs.androidx.lifecycle.viewmodel.navigation3)
+    implementation(libs.kotlinx.serialization.json)
 }

wear/src/main/java/com/example/wear/snippets/navigation3/Navigation.kt

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2026 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.wear.snippets.navigation3
+
+import androidx.compose.runtime.Composable
+import androidx.lifecycle.viewmodel.compose.viewModel
+import androidx.navigation3.runtime.NavKey
+import androidx.navigation3.runtime.entryProvider
+import androidx.navigation3.runtime.rememberNavBackStack
+import androidx.navigation3.runtime.rememberSaveableStateHolderNavEntryDecorator
+import androidx.navigation3.ui.NavDisplay
+import androidx.wear.compose.material3.ScreenScaffold
+import androidx.wear.compose.material3.Text
+import androidx.wear.compose.navigation3.rememberSwipeDismissableSceneStrategy
+import kotlinx.serialization.Serializable
+import androidx.lifecycle.viewmodel.navigation3.rememberViewModelStoreNavEntryDecorator
+
+// [START android_wear_navigation3_destinations]
+@Serializable
+sealed interface Screen : NavKey {
+    @Serializable
+    data object Home : Screen
+
+    @Serializable
+    data class Details(val itemId: String) : Screen
+}
+// [END android_wear_navigation3_destinations]
+
+@Composable
+fun WearApp() {
+    // [START android_wear_navigation3_setup]
+    // 1. Create the persistent back stack starting at the Home screen
+    val backStack = rememberNavBackStack(Screen.Home)
+
+    // 2. Initialize the Wear OS swipe-to-dismiss strategy
+    val strategy = rememberSwipeDismissableSceneStrategy<NavKey>()
+
+    // 3. Render the NavDisplay
+    NavDisplay(
+        backStack = backStack,
+        sceneStrategies = listOf(strategy),
+        entryProvider = entryProvider {
+            // 4. Map keys to Composables
+            entry<Screen.Home> {
+                HomeScreen(
+                    onNavigateToDetails = { id -> backStack.add(Screen.Details(id)) }
+                )
+            }
+            entry<Screen.Details> { key ->
+                DetailsScreen(
+                    itemId = key.itemId,
+                    onBack = { backStack.removeLast() }
+                )
+            }
+        }
+    )
+    // [END android_wear_navigation3_setup]
+}
+
+// [START_EXCLUDE]
+@Composable
+fun HomeScreen(onNavigateToDetails: (String) -> Unit) {
+    ScreenScaffold {
+        Text("Home Screen")
+    }
+}
+
+@Composable
+fun DetailsScreen(itemId: String, onBack: () -> Unit) {
+    ScreenScaffold {
+        Text("Details Screen for item $itemId")
+    }
+}
+
+class HomeViewModel : androidx.lifecycle.ViewModel()
+// [END_EXCLUDE]
+
+@Composable
+fun WearAppWithViewModel() {
+    val backStack = rememberNavBackStack(Screen.Home)
+    val strategy = rememberSwipeDismissableSceneStrategy<NavKey>()
+
+    // [START android_wear_navigation3_viewmodel]
+    NavDisplay(
+        backStack = backStack,
+        sceneStrategies = listOf(strategy),
+        entryDecorators = listOf(
+            rememberSaveableStateHolderNavEntryDecorator(),
+            rememberViewModelStoreNavEntryDecorator()
+        ),
+        entryProvider = entryProvider {
+            entry<Screen.Home> {
+                // Any viewModel() requested here will be scoped to this NavEntry
+                val viewModel: HomeViewModel = viewModel()
+                // [START_EXCLUDE silent]
+                HomeScreen(onNavigateToDetails = {})
+                // [END_EXCLUDE]
+            }
+        }
+    )
+    // [END android_wear_navigation3_viewmodel]
+}