[Crane] Adds DetailsViewModel with AssistedInjection

Crane/app/build.gradle

@@ -40,6 +40,12 @@ android {
         vectorDrawables.useSupportLibrary = true
         testInstrumentationRunner "androidx.compose.samples.crane.CustomTestRunner"
 
+        javaCompileOptions {
+            annotationProcessorOptions {
+                arguments["dagger.hilt.disableModulesHaveInstallInCheck"] = "true"
+            }
+        }
+
         manifestPlaceholders = [ googleMapsKey : properties.getProperty("google.maps.key", "") ]
     }
 
@@ -113,8 +119,10 @@ dependencies {
     implementation Libs.AndroidX.Lifecycle.viewModelKtx
     implementation Libs.Hilt.android
     implementation Libs.Hilt.AndroidX.viewModel
+    compileOnly Libs.AssistedInjection.dagger
     kapt Libs.Hilt.compiler
     kapt Libs.Hilt.AndroidX.compiler
+    kapt Libs.AssistedInjection.processor
 
     androidTestImplementation Libs.JUnit.junit
     androidTestImplementation Libs.AndroidX.Test.runner
@@ -128,4 +136,5 @@ dependencies {
     androidTestImplementation Libs.Hilt.testing
     kaptAndroidTest Libs.Hilt.compiler
     kaptAndroidTest Libs.Hilt.AndroidX.compiler
+    kaptAndroidTest Libs.AssistedInjection.processor
 }

Crane/app/src/androidTest/java/androidx/compose/samples/crane/details/DetailsActivityTest.kt

@@ -17,6 +17,7 @@
 package androidx.compose.samples.crane.details
 
 import androidx.compose.samples.crane.R
+import androidx.compose.samples.crane.data.DestinationsRepository
 import androidx.compose.samples.crane.data.ExploreModel
 import androidx.compose.samples.crane.data.MADRID
 import androidx.compose.samples.crane.di.DispatchersModule
@@ -35,16 +36,22 @@ import com.google.android.libraries.maps.model.LatLng
 import dagger.hilt.android.testing.HiltAndroidRule
 import dagger.hilt.android.testing.HiltAndroidTest
 import dagger.hilt.android.testing.UninstallModules
+import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 import java.util.concurrent.CountDownLatch
+import javax.inject.Inject
 
 @UninstallModules(DispatchersModule::class)
 @HiltAndroidTest
 class DetailsActivityTest {
 
-    private val expectedDescription = "description"
-    private val testExploreModel = ExploreModel(MADRID, expectedDescription, "imageUrl")
+    @Inject
+    lateinit var destinationsRepository: DestinationsRepository
+    lateinit var cityDetails: ExploreModel
+
+    private val city = MADRID
+    private val testExploreModel = ExploreModel(city, "description", "imageUrl")
 
     @get:Rule(order = 0)
     var hiltRule = HiltAndroidRule(this)
@@ -59,10 +66,16 @@ class DetailsActivityTest {
         )
     )
 
+    @Before
+    fun setUp() {
+        hiltRule.inject()
+        cityDetails = destinationsRepository.getDestination(MADRID.name)!!
+    }
+
     @Test
     fun mapView_cameraPositioned() {
-        composeTestRule.onNodeWithText(MADRID.nameToDisplay).assertIsDisplayed()
-        composeTestRule.onNodeWithText(expectedDescription).assertIsDisplayed()
+        composeTestRule.onNodeWithText(cityDetails.city.nameToDisplay).assertIsDisplayed()
+        composeTestRule.onNodeWithText(cityDetails.description).assertIsDisplayed()
         onView(withId(R.id.map)).check(matches(isDisplayed()))
 
         var cameraPosition: CameraPosition? = null

Crane/app/src/main/java/androidx/compose/samples/crane/data/DestinationsRepository.kt

@@ -19,9 +19,15 @@ package androidx.compose.samples.crane.data
 import javax.inject.Inject
 
 class DestinationsRepository @Inject constructor(
-    destinationsLocalDataSource: DestinationsLocalDataSource
+    private val destinationsLocalDataSource: DestinationsLocalDataSource
 ) {
     val destinations = destinationsLocalDataSource.craneDestinations
     val hotels = destinationsLocalDataSource.craneHotels
     val restaurants = destinationsLocalDataSource.craneRestaurants
+
+    fun getDestination(cityName: String): ExploreModel? {
+        return destinationsLocalDataSource.craneDestinations.firstOrNull {
+            it.city.name == cityName
+        }
+    }
 }

Crane/app/src/main/java/androidx/compose/samples/crane/details/DetailsActivity.kt

@@ -47,11 +47,9 @@ import com.google.android.libraries.maps.MapView
 import com.google.android.libraries.maps.model.LatLng
 import com.google.android.libraries.maps.model.MarkerOptions
 import dagger.hilt.android.AndroidEntryPoint
+import javax.inject.Inject
 
-private const val DETAILS_NAME = "DETAILS_NAME"
-private const val DETAILS_DESCRIPTION = "DETAILS_DESCRIPTION"
-private const val DETAILS_LATITUDE = "DETAILS_LATITUDE"
-private const val DETAILS_LONGITUDE = "DETAILS_LONGITUDE"
+private const val DETAILS_CITY_NAME = "DETAILS_CITY_NAME"
 
 fun launchDetailsActivity(context: Context, item: ExploreModel) {
     context.startActivity(createDetailsActivityIntent(context, item))
@@ -60,57 +58,62 @@ fun launchDetailsActivity(context: Context, item: ExploreModel) {
 @VisibleForTesting
 fun createDetailsActivityIntent(context: Context, item: ExploreModel): Intent {
     val intent = Intent(context, DetailsActivity::class.java)
-    intent.putExtra(DETAILS_NAME, item.city.nameToDisplay)
-    intent.putExtra(DETAILS_DESCRIPTION, item.description)
-    intent.putExtra(DETAILS_LATITUDE, item.city.latitude)
-    intent.putExtra(DETAILS_LONGITUDE, item.city.longitude)
+    intent.putExtra(DETAILS_CITY_NAME, item.city.name)
     return intent
 }
 
 data class DetailsActivityArg(
-    val name: String,
-    val description: String,
-    val latitude: String,
-    val longitude: String
+    val cityName: String
 )
 
 @AndroidEntryPoint
 class DetailsActivity : ComponentActivity() {
 
+    @Inject
+    lateinit var viewModelFactory: DetailsViewModel.AssistedFactory
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-
-        val args = DetailsActivityArg(
-            name = intent.getStringExtra(DETAILS_NAME)!!,
-            description = intent.getStringExtra(DETAILS_DESCRIPTION)!!,
-            latitude = intent.getStringExtra(DETAILS_LATITUDE)!!,
-            longitude = intent.getStringExtra(DETAILS_LONGITUDE)!!
-        )
+        val args = DetailsActivityArg(intent.getStringExtra(DETAILS_CITY_NAME)!!)
 
         setContent {
             CraneScaffold {
-                DetailsScreen(args = args)
+                DetailsScreen(args, viewModelFactory, onErrorLoading = { finish() })
             }
         }
     }
 }
 
 @Composable
-fun DetailsScreen(args: DetailsActivityArg) {
+fun DetailsScreen(
+    args: DetailsActivityArg,
+    viewModelFactory: DetailsViewModel.AssistedFactory,
+    onErrorLoading: () -> Unit
+) {
+    val viewModel: DetailsViewModel = viewModelFactory.create(args.cityName)
+    if (viewModel.cityDetails != null) {
+        DetailsContent(viewModel.cityDetails)
+    } else {
+        onErrorLoading()
+    }
+}
+
+@Composable
+fun DetailsContent(exploreModel: ExploreModel) {
     Column(verticalArrangement = Arrangement.Center) {
         Spacer(Modifier.preferredHeight(32.dp))
         Text(
             modifier = Modifier.align(Alignment.CenterHorizontally),
-            text = args.name,
+            text = exploreModel.city.nameToDisplay,
             style = MaterialTheme.typography.h4
         )
         Text(
             modifier = Modifier.align(Alignment.CenterHorizontally),
-            text = args.description,
+            text = exploreModel.description,
             style = MaterialTheme.typography.h6
         )
         Spacer(Modifier.preferredHeight(16.dp))
-        CityMapView(args.latitude, args.longitude)
+        CityMapView(exploreModel.city.latitude, exploreModel.city.longitude)
     }
 }
 

Crane/app/src/main/java/androidx/compose/samples/crane/details/DetailsViewModel.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2020 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 androidx.compose.samples.crane.details
+
+import androidx.compose.samples.crane.data.DestinationsRepository
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import com.squareup.inject.assisted.Assisted
+import com.squareup.inject.assisted.AssistedInject
+import com.squareup.inject.assisted.dagger2.AssistedModule
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ActivityRetainedComponent
+
+class DetailsViewModel @AssistedInject constructor(
+    destinationsRepository: DestinationsRepository,
+    @Assisted cityName: String
+) : ViewModel() {
+
+    val cityDetails = destinationsRepository.getDestination(cityName)
+
+    @AssistedInject.Factory
+    interface AssistedFactory {
+        fun create(cityName: String): DetailsViewModel
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    companion object {
+        fun provideFactory(
+            assistedFactory: AssistedFactory,
+            cityName: String
+        ): ViewModelProvider.Factory = object : ViewModelProvider.Factory {
+            override fun <T : ViewModel?> create(modelClass: Class<T>): T {
+                return assistedFactory.create(cityName) as T
+            }
+        }
+    }
+}
+
+@InstallIn(ActivityRetainedComponent::class)
+@AssistedModule
+@Module(includes = [AssistedInject_AssistedInjectModule::class])
+interface AssistedInjectModule

Crane/buildSrc/src/main/java/com/example/crane/buildsrc/Dependencies.kt

@@ -98,6 +98,13 @@ object Libs {
         private const val version = "4.13"
         const val junit = "junit:junit:$version"
     }
+
+    object AssistedInjection {
+        private const val version = "0.5.2"
+
+        const val dagger = "com.squareup.inject:assisted-inject-annotations-dagger2:$version"
+        const val processor = "com.squareup.inject:assisted-inject-processor-dagger2:$version"
+    }
 }
 
 object Urls {