Continue decoupling of search data provisioning

* Introduce new FOREGROUND_SERVICE permission.
* Use BroadcastReceiver to allow components to sign up.
* Remove reflection from registry.

To use the features introduced here, extend
SearchBroadcastReceiver and FactoryRegistrationService.
Then add them to your feature module's AndroidManifest.
Also add the intent-filter io.plaidapp.register.SEARCH_FACTORY
to the BroadcastReceiver.

SearchActivity fires the required broadcast.

app/src/main/AndroidManifest.xml

@@ -22,6 +22,7 @@
 
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
 
     <application
             android:allowBackup="true"

app/src/main/java/io/plaidapp/registry/FactoryRegistrationService.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2019 Google, Inc.
+ *
+ * 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 io.plaidapp.registry
+
+import android.app.Notification
+import android.app.Service
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import io.plaidapp.core.interfaces.SearchDataSourceFactory
+import io.plaidapp.ui.PlaidApplication
+
+/**
+ * Enable registering #SearchDataSourceFactory.
+ */
+abstract class FactoryRegistrationService : Service() {
+
+    override fun onBind(intent: Intent?): IBinder? {
+        TODO("not implemented")
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        // TODO create an actual notification
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            startForeground(
+                1,
+                Notification.Builder(this, "Plaid").setContentTitle(
+                    "Registering Search Service"
+                ).build()
+            )
+        }
+        registerFactory()
+        return super.onStartCommand(intent, flags, startId)
+    }
+
+    abstract fun getFactory(): SearchDataSourceFactory
+
+    private fun registerFactory() {
+        PlaidApplication.coreComponent(this).registry().add(getFactory())
+        stopSelf()
+    }
+}

app/src/main/java/io/plaidapp/registry/SearchBroadcastReceiver.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2019 Google, Inc.
+ *
+ * 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 io.plaidapp.registry
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+
+/**
+ * Extend this receiver to enable hooking into Plaid's #SearchDataSourceFactoriesRegistry.
+ */
+abstract class SearchBroadcastReceiver(
+    private val target: Class<out FactoryRegistrationService>
+) : BroadcastReceiver() {
+
+    override fun onReceive(context: Context?, intent: Intent?) {
+        // TODO handle intent
+        if (context != null) {
+            val startRegistrationService = Intent(context, target)
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                context.startForegroundService(startRegistrationService)
+            } else {
+                context.startService(startRegistrationService)
+            }
+        }
+    }
+
+    companion object {
+        const val ACTION = "io.plaidapp.register.SEARCH_FACTORY"
+    }
+}

app/src/main/java/io/plaidapp/ui/HomeActivity.java

@@ -73,6 +73,7 @@
 import io.plaidapp.core.feed.FeedProgressUiModel;
 import io.plaidapp.core.ui.ConnectivityChecker;
 import io.plaidapp.core.ui.HomeGridItemAnimator;
+import io.plaidapp.core.ui.Notifications;
 import io.plaidapp.core.ui.PlaidItemsList;
 import io.plaidapp.core.ui.filter.FilterAdapter;
 import io.plaidapp.core.ui.filter.FilterAnimator;
@@ -135,6 +136,7 @@ protected void onCreate(Bundle savedInstanceState) {
         bindResources();
 
         inject(this);
+        Notifications.registerChannel(this);
 
         adapter = new FeedAdapter(this, columns, pocketInstalled);
 

core/src/main/java/io/plaidapp/core/dagger/CoreComponent.kt

@@ -19,6 +19,7 @@ package io.plaidapp.core.dagger
 import com.google.gson.Gson
 import com.jakewharton.retrofit2.adapter.kotlin.coroutines.CoroutineCallAdapterFactory
 import dagger.Component
+import io.plaidapp.core.interfaces.SearchDataSourceFactoriesRegistry
 import okhttp3.OkHttpClient
 import retrofit2.converter.gson.GsonConverterFactory
 import javax.inject.Singleton
@@ -40,4 +41,5 @@ interface CoreComponent {
     fun provideGson(): Gson
     fun provideGsonConverterFactory(): GsonConverterFactory
     fun provideCallAdapterFactory(): CoroutineCallAdapterFactory
+    fun registry(): SearchDataSourceFactoriesRegistry
 }

core/src/main/java/io/plaidapp/core/dagger/CoreDataModule.kt

@@ -24,7 +24,6 @@ import io.plaidapp.core.BuildConfig
 import okhttp3.OkHttpClient
 import okhttp3.logging.HttpLoggingInterceptor
 import retrofit2.converter.gson.GsonConverterFactory
-import javax.inject.Singleton
 
 /**
  * Dagger module to provide core data functionality.
@@ -49,11 +48,9 @@ class CoreDataModule {
     @Provides
     fun provideCallAdapterFactory(): CoroutineCallAdapterFactory = CoroutineCallAdapterFactory()
 
-    @Singleton
     @Provides
     fun provideGson(): Gson = Gson()
 
-    @Singleton
     @Provides
     fun provideGsonConverterFactory(gson: Gson): GsonConverterFactory =
         GsonConverterFactory.create(gson)

core/src/main/java/io/plaidapp/core/interfaces/SearchDataSourceFactoriesRegistry.kt

@@ -20,38 +20,25 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import javax.inject.Inject
 
-private const val designerNewsSearchDataSourceFactoryProviderClassName =
-    "io.plaidapp.designernews.domain.search.DesignerNewsSearchFactoryProvider"
-
-// TODO add dribbble as well
-private val factoryClassNames =
-    listOf(designerNewsSearchDataSourceFactoryProviderClassName)
-
 class SearchDataSourceFactoriesRegistry @Inject constructor() {
 
     private val _dataSourceFactories =
-        MutableLiveData<List<SearchDataSourceFactory>>(getAlreadyAvailableDataSourceFactories())
+        MutableLiveData<List<SearchDataSourceFactory>>()
 
     val dataSourceFactories: LiveData<List<SearchDataSourceFactory>>
         get() = _dataSourceFactories
 
     fun add(dataSourceFactory: SearchDataSourceFactory) {
         val existingDataSources = _dataSourceFactories.value.orEmpty().toMutableList()
+        if (existingDataSources.contains(dataSourceFactory)) return
         existingDataSources.add(dataSourceFactory)
         _dataSourceFactories.postValue(existingDataSources)
     }
 
     fun remove(dataSourceFactory: SearchDataSourceFactory) {
         val existingDataSources = _dataSourceFactories.value.orEmpty().toMutableList()
+        if (existingDataSources.contains(dataSourceFactory)) return
         existingDataSources.remove(dataSourceFactory)
         _dataSourceFactories.postValue(existingDataSources)
     }
-
-    private fun getAlreadyAvailableDataSourceFactories(): List<SearchDataSourceFactory> {
-        return factoryClassNames.map {
-            val clazz = Class.forName(it)
-            val instance = clazz.newInstance() as SearchFactoryProvider
-            instance.getFactory()
-        }
-    }
 }

core/src/main/java/io/plaidapp/core/ui/Notifications.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2019 Google, Inc.
+ *
+ * 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 io.plaidapp.core.ui
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.content.Context
+import android.content.Context.NOTIFICATION_SERVICE
+import android.os.Build
+
+class Notifications {
+
+    companion object {
+        @JvmStatic
+        fun registerChannel(context: Context) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                // Create the NotificationChannel
+                val name = "Plaid"
+                val descriptionText = "Plaid default notification registerChannel"
+                val importance = NotificationManager.IMPORTANCE_DEFAULT
+                val mChannel = NotificationChannel(name, name, importance)
+                mChannel.description = descriptionText
+                // Register the registerChannel with the system; you can't change the importance
+                // or other notification behaviors after this
+                val notificationManager = context.getSystemService(NOTIFICATION_SERVICE) as
+                    NotificationManager
+                notificationManager.createNotificationChannel(mChannel)
+            }
+        }
+    }
+}

designernews/src/main/AndroidManifest.xml

@@ -74,6 +74,15 @@
         <service
             android:name="io.plaidapp.core.designernews.data.votes.UpvoteStoryService"
             android:exported="false" />
+
+        <!-- Enable decoupled registration of search sources. -->
+        <service android:name=".DesignerNewsFactoryRegistrationService" android:exported="false"/>
+
+        <receiver android:name=".DesignerNewsSearchBroadcastReceiver">
+            <intent-filter>
+                <action android:name="io.plaidapp.register.SEARCH_FACTORY" />
+            </intent-filter>
+        </receiver>
     </application>
 
 </manifest>

designernews/src/main/java/io/plaidapp/designernews/DesignerNewsFactoryRegistrationService.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2019 Google, Inc.
+ *
+ * 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 io.plaidapp.designernews
+
+import io.plaidapp.core.dagger.SharedPreferencesModule
+import io.plaidapp.core.designernews.data.login.LoginLocalDataSource
+import io.plaidapp.core.interfaces.SearchDataSourceFactory
+import io.plaidapp.designernews.dagger.DaggerDesignerNewsSearchComponent
+import io.plaidapp.registry.FactoryRegistrationService
+
+class DesignerNewsFactoryRegistrationService : FactoryRegistrationService() {
+
+    override fun getFactory(): SearchDataSourceFactory {
+        return DaggerDesignerNewsSearchComponent.builder()
+            .sharedPreferencesModule(
+                SharedPreferencesModule(this, LoginLocalDataSource.DESIGNER_NEWS_PREF)
+            ).build()
+            .factory()
+    }
+}

designernews/src/main/java/io/plaidapp/designernews/DesignerNewsSearchBroadcastReceiver.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2019 Google, Inc.
+ *
+ * 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 io.plaidapp.designernews
+
+import io.plaidapp.registry.SearchBroadcastReceiver
+
+class DesignerNewsSearchBroadcastReceiver :
+    SearchBroadcastReceiver(DesignerNewsFactoryRegistrationService::class.java)

designernews/src/main/java/io/plaidapp/designernews/dagger/DesignerNewsSearchComponent.kt

@@ -17,8 +17,24 @@
 package io.plaidapp.designernews.dagger
 
 import dagger.Component
+import io.plaidapp.core.dagger.CoreDataModule
+import io.plaidapp.core.dagger.SharedPreferencesModule
+import io.plaidapp.core.dagger.designernews.DesignerNewsDataModule
+import io.plaidapp.core.dagger.scope.FeatureScope
+import io.plaidapp.designernews.domain.search.DesignerNewsSearchDataSourceFactory
 
 @Component(
-    modules = [SearchDataModule::class]
+    modules = [
+        CoreDataModule::class,
+        DataModule::class,
+        DesignerNewsDataModule::class,
+        SearchDataModule::class,
+        SharedPreferencesModule::class
+    ]
 )
-interface DesignerNewsSearchComponent
+@FeatureScope
+interface DesignerNewsSearchComponent {
+
+    @FeatureScope
+    fun factory(): DesignerNewsSearchDataSourceFactory
+}

designernews/src/main/java/io/plaidapp/designernews/dagger/Injector.kt

@@ -22,7 +22,6 @@ import `in`.uncod.android.bypass.Bypass
 import android.util.TypedValue
 import androidx.core.content.ContextCompat
 import io.plaidapp.core.dagger.MarkdownModule
-import io.plaidapp.designernews.domain.search.DesignerNewsSearchFactoryProvider
 import io.plaidapp.designernews.ui.login.LoginActivity
 import io.plaidapp.designernews.ui.story.StoryActivity
 import io.plaidapp.ui.coreComponent
@@ -63,8 +62,3 @@ fun inject(activity: LoginActivity) {
         .build()
         .inject(activity)
 }
-
-fun DesignerNewsSearchFactoryProvider.inject() {
-
-    DaggerDesignerNewsSearchComponent.create()
-}

designernews/src/main/java/io/plaidapp/designernews/dagger/SearchDataModule.kt

@@ -18,20 +18,18 @@ package io.plaidapp.designernews.dagger
 
 import dagger.Module
 import dagger.Provides
+import io.plaidapp.core.dagger.scope.FeatureScope
 import io.plaidapp.core.designernews.data.stories.StoriesRepository
-import io.plaidapp.core.interfaces.SearchDataSourceFactoriesRegistry
 import io.plaidapp.designernews.domain.search.DesignerNewsSearchDataSourceFactory
 
 @Module
 class SearchDataModule {
 
     @Provides
+    @FeatureScope
     fun designerNewsSearchDataSourceFactory(
-        repository: StoriesRepository,
-        registry: SearchDataSourceFactoriesRegistry
+        repository: StoriesRepository
     ): DesignerNewsSearchDataSourceFactory {
-        val factory = DesignerNewsSearchDataSourceFactory(repository)
-        registry.add(factory)
-        return factory
+        return DesignerNewsSearchDataSourceFactory(repository)
     }
 }