Simplify migration recipe

app/src/androidTest/java/com/example/nav3recipes/MigrationActivityNavigationTest.kt → app/src/androidTest/java/com/example/nav3recipes/AtomicMigrationTest.kt

@@ -8,24 +8,19 @@ import androidx.compose.ui.test.junit4.createAndroidComposeRule
 import androidx.compose.ui.test.onNodeWithText
 import androidx.compose.ui.test.performClick
 import androidx.test.espresso.Espresso
-import com.example.nav3recipes.migration.start.StartMigrationActivity
-import com.example.nav3recipes.migration.step2.Step2MigrationActivity
-import com.example.nav3recipes.migration.step3.Step3MigrationActivity
-import com.example.nav3recipes.migration.step4.Step4MigrationActivity
-import com.example.nav3recipes.migration.step5.Step5MigrationActivity
-import com.example.nav3recipes.migration.step6.Step6MigrationActivity
-import com.example.nav3recipes.migration.step7.Step7MigrationActivity
+import com.example.nav3recipes.migration.atomic.begin.BeginAtomicMigrationActivity
+import com.example.nav3recipes.migration.atomic.end.EndAtomicMigrationActivity
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.junit.runners.Parameterized
 import org.junit.runners.Parameterized.Parameters
 
 /**
- * Instrumented navigation tests for each of the migration steps.
+ * Instrumented navigation tests for the start and end states of the atomic migration guide.
  */
 @RunWith(Parameterized::class)
-class MigrationActivityNavigationTest(activityClass: Class<out ComponentActivity>) {
+class AtomicMigrationTest(activityClass: Class<out ComponentActivity>) {
 
     @get:Rule(order = 0)
     val composeTestRule = createAndroidComposeRule(activityClass)
@@ -35,13 +30,8 @@ class MigrationActivityNavigationTest(activityClass: Class<out ComponentActivity
         @Parameters(name = "{0}")
         fun data(): Collection<Array<Any>> {
             return listOf(
-                arrayOf(StartMigrationActivity::class.java),
-                arrayOf(Step2MigrationActivity::class.java),
-                arrayOf(Step3MigrationActivity::class.java),
-                arrayOf(Step4MigrationActivity::class.java),
-                arrayOf(Step5MigrationActivity::class.java),
-                arrayOf(Step6MigrationActivity::class.java),
-                arrayOf(Step7MigrationActivity::class.java)
+                arrayOf(BeginAtomicMigrationActivity::class.java),
+                arrayOf(EndAtomicMigrationActivity::class.java)
             )
         }
     }

app/src/main/AndroidManifest.xml

@@ -114,31 +114,11 @@
             android:label="@string/app_name"
             android:theme="@style/Theme.Nav3Recipes"/>
         <activity
-            android:name=".migration.start.StartMigrationActivity"
+            android:name=".migration.atomic.begin.BeginAtomicMigrationActivity"
             android:exported="true"
             android:theme="@style/Theme.Nav3Recipes"/>
         <activity
-            android:name=".migration.step2.Step2MigrationActivity"
-            android:exported="true"
-            android:theme="@style/Theme.Nav3Recipes"/>
-        <activity
-            android:name=".migration.step3.Step3MigrationActivity"
-            android:exported="true"
-            android:theme="@style/Theme.Nav3Recipes"/>
-        <activity
-            android:name=".migration.step4.Step4MigrationActivity"
-            android:exported="true"
-            android:theme="@style/Theme.Nav3Recipes"/>
-        <activity
-            android:name=".migration.step5.Step5MigrationActivity"
-            android:exported="true"
-            android:theme="@style/Theme.Nav3Recipes"/>
-        <activity
-            android:name=".migration.step6.Step6MigrationActivity"
-            android:exported="true"
-            android:theme="@style/Theme.Nav3Recipes"/>
-        <activity
-            android:name=".migration.step7.Step7MigrationActivity"
+            android:name=".migration.atomic.end.EndAtomicMigrationActivity"
             android:exported="true"
             android:theme="@style/Theme.Nav3Recipes"/>
         <activity

app/src/main/java/com/example/nav3recipes/migration/atomic/README.md

@@ -0,0 +1,7 @@
+# Migration Recipe
+
+This recipe demonstrates how to migrate Navigation 2 code to Navigation 3. It has two packages: 
+
+- `begin` - an app that is using Navigation 2
+- `end` - the same app migrated to Navigation 3
+

app/src/main/java/com/example/nav3recipes/migration/start/StartMigrationActivity.kt → app/src/main/java/com/example/nav3recipes/migration/atomic/begin/BeginAtomicMigrationActivity.kt

@@ -14,29 +14,21 @@
  * limitations under the License.
  */
 
-package com.example.nav3recipes.migration.start
+package com.example.nav3recipes.migration.atomic.begin
 
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.padding
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Camera
-import androidx.compose.material.icons.filled.Face
-import androidx.compose.material.icons.filled.Home
-import androidx.compose.material3.Button
 import androidx.compose.material3.Icon
 import androidx.compose.material3.NavigationBar
 import androidx.compose.material3.NavigationBarItem
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.runtime.getValue
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.navigation.NavDestination
 import androidx.navigation.NavDestination.Companion.hasRoute
 import androidx.navigation.NavDestination.Companion.hierarchy
@@ -49,67 +41,34 @@ import androidx.navigation.compose.navigation
 import androidx.navigation.compose.rememberNavController
 import androidx.navigation.navOptions
 import androidx.navigation.toRoute
-import com.example.nav3recipes.content.ContentBlue
-import com.example.nav3recipes.content.ContentGreen
-import com.example.nav3recipes.content.ContentMauve
-import com.example.nav3recipes.content.ContentPink
-import com.example.nav3recipes.content.ContentPurple
-import com.example.nav3recipes.content.ContentRed
+import com.example.nav3recipes.migration.content.ScreenA
+import com.example.nav3recipes.migration.content.ScreenA1
+import com.example.nav3recipes.migration.content.ScreenB
+import com.example.nav3recipes.migration.content.ScreenB1
+import com.example.nav3recipes.migration.content.ScreenC
 import com.example.nav3recipes.ui.setEdgeToEdgeConfig
-import kotlinx.serialization.Serializable
 import kotlin.reflect.KClass
 
 /**
  * Basic Navigation2 example with the following navigation graph:
  *
- * A -> A, A1, E
- * B -> B, B1, E
- * C -> C, E
+ * A -> A, A1
+ * B -> B, B1
+ * C -> C
  * D
  *
  * - The starting destination (or home screen) is A.
  * - A, B and C are top level destinations that appear in a navigation bar.
  * - D is a dialog destination.
- * - E is a shared destination that can appear under any of the top level destinations.
- * - Navigating to a top level destination pops all other top level destinations off the stack,
+  * - Navigating to a top level destination pops all other top level destinations off the stack,
  * except for the start destination.
  * - Navigating back from the start destination exits the app.
  *
  * This will be the starting point for migration to Navigation 3.
  *
- * @see `MigrationActivityNavigationTest` for instrumented tests that verify this behavior.
+ * @see `AtomicMigrationTest` for instrumented tests that verify this behavior.
  */
-
-// Feature module A
-@Serializable private data object BaseRouteA
-@Serializable private data object RouteA
-@Serializable private data object RouteA1
-
-// Feature module B
-@Serializable private data object BaseRouteB
-@Serializable private data object RouteB
-@Serializable private data class RouteB1(val id: String)
-
-// Feature module C
-@Serializable private data object BaseRouteC
-@Serializable private data object RouteC
-
-// Common UI modules
-@Serializable private data object RouteD
-@Serializable private data object RouteE
-
-private val TOP_LEVEL_ROUTES = mapOf(
-    BaseRouteA to NavBarItem(icon = Icons.Default.Home, description = "Route A"),
-    BaseRouteB to NavBarItem(icon = Icons.Default.Face, description = "Route B"),
-    BaseRouteC to NavBarItem(icon = Icons.Default.Camera, description = "Route C"),
-)
-
-class NavBarItem(
-    val icon: ImageVector,
-    val description: String
-)
-
-class StartMigrationActivity : ComponentActivity() {
+class BeginAtomicMigrationActivity : ComponentActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         setEdgeToEdgeConfig()
@@ -150,16 +109,13 @@ class StartMigrationActivity : ComponentActivity() {
                     featureASection(
                         onSubRouteClick = { navController.navigate(RouteA1) },
                         onDialogClick = { navController.navigate(RouteD) },
-                        onOtherClick = { navController.navigate(RouteE) }
                     )
                     featureBSection(
                         onDetailClick = { id -> navController.navigate(RouteB1(id)) },
                         onDialogClick = { navController.navigate(RouteD) },
-                        onOtherClick = { navController.navigate(RouteE) }
                     )
                     featureCSection(
                         onDialogClick = { navController.navigate(RouteD) },
-                        onOtherClick = { navController.navigate(RouteE) }
                     )
                     dialog<RouteD> { key ->
                         Text(modifier = Modifier.background(Color.White), text = "Route D title (dialog)")
@@ -173,78 +129,32 @@ class StartMigrationActivity : ComponentActivity() {
 // Feature module A
 private fun NavGraphBuilder.featureASection(
     onSubRouteClick: () -> Unit,
-    onDialogClick: () -> Unit,
-    onOtherClick: () -> Unit,
+    onDialogClick: () -> Unit
 ) {
     navigation<BaseRouteA>(startDestination = RouteA) {
-        composable<RouteA> {
-            ContentRed("Route A title") {
-                Column(horizontalAlignment = Alignment.CenterHorizontally) {
-                    Button(onClick = onSubRouteClick) {
-                        Text("Go to A1")
-                    }
-                    Button(onClick = onDialogClick) {
-                        Text("Open dialog D")
-                    }
-                    Button(onClick = onOtherClick) {
-                        Text("Go to E")
-                    }
-                }
-            }
-        }
-        composable<RouteA1> { ContentPink("Route A1 title") }
-        composable<RouteE> { ContentBlue("Route E title") }
+        composable<RouteA> { ScreenA(onSubRouteClick, onDialogClick) }
+        composable<RouteA1> { ScreenA1() }
     }
 }
 
+
 // Feature module B
 private fun NavGraphBuilder.featureBSection(
     onDetailClick: (id: String) -> Unit,
-    onDialogClick: () -> Unit,
-    onOtherClick: () -> Unit
+    onDialogClick: () -> Unit
 ) {
     navigation<BaseRouteB>(startDestination = RouteB) {
-        composable<RouteB> {
-            ContentGreen("Route B title") {
-                Column(horizontalAlignment = Alignment.CenterHorizontally) {
-                    Button(onClick = { onDetailClick("ABC") }) {
-                        Text("Go to B1")
-                    }
-                    Button(onClick = onDialogClick) {
-                        Text("Open dialog D")
-                    }
-                    Button(onClick = onOtherClick) {
-                        Text("Go to E")
-                    }
-                }
-            }
-        }
-        composable<RouteB1> { key ->
-            ContentPurple("Route B1 title. ID: ${key.toRoute<RouteB1>().id}")
-        }
-        composable<RouteE> { ContentBlue("Route E title") }
+        composable<RouteB> { ScreenB(onDetailClick, onDialogClick) }
+        composable<RouteB1> { key -> ScreenB1(id = key.toRoute<RouteB1>().id) }
     }
 }
 
 // Feature module C
 private fun NavGraphBuilder.featureCSection(
-    onDialogClick: () -> Unit,
-    onOtherClick: () -> Unit,
+    onDialogClick: () -> Unit
 ) {
     navigation<BaseRouteC>(startDestination = RouteC) {
-        composable<RouteC> {
-            ContentMauve("Route C title") {
-                Column(horizontalAlignment = Alignment.CenterHorizontally) {
-                    Button(onClick = onDialogClick) {
-                        Text("Open dialog D")
-                    }
-                    Button(onClick = onOtherClick) {
-                        Text("Go to E")
-                    }
-                }
-            }
-        }
-        composable<RouteE> { ContentBlue("Route E title") }
+        composable<RouteC> { ScreenC(onDialogClick) }
     }
 }
 

app/src/main/java/com/example/nav3recipes/migration/atomic/begin/NavRoutes.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2025 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
+ *
+ *     http://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.nav3recipes.migration.atomic.begin
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Camera
+import androidx.compose.material.icons.filled.Face
+import androidx.compose.material.icons.filled.Home
+import androidx.compose.ui.graphics.vector.ImageVector
+import kotlinx.serialization.Serializable
+
+// Feature module A
+@Serializable data object BaseRouteA
+@Serializable data object RouteA
+@Serializable data object RouteA1
+
+// Feature module B
+@Serializable data object BaseRouteB
+@Serializable data object RouteB
+@Serializable data class RouteB1(val id: String)
+
+// Feature module C
+@Serializable data object BaseRouteC
+@Serializable data object RouteC
+
+// Common UI modules
+@Serializable data object RouteD
+
+
+val TOP_LEVEL_ROUTES = mapOf(
+    BaseRouteA to NavBarItem(icon = Icons.Default.Home, description = "Route A"),
+    BaseRouteB to NavBarItem(icon = Icons.Default.Face, description = "Route B"),
+    BaseRouteC to NavBarItem(icon = Icons.Default.Camera, description = "Route C"),
+)
+
+class NavBarItem(
+    val icon: ImageVector,
+    val description: String
+)