[Android] Take 2 on this issue: The latest Android 16 update broke the update for the Search and Favorites widget

app/build.gradle

@@ -417,6 +417,9 @@ dependencies {
     implementation project(':serp-logos-api')
     implementation project(':serp-logos-impl')
 
+    // Widgets
+    implementation "androidx.core:core-remoteviews:1.1.0"
+
     // Deprecated. TODO: Stop using this artifact.
     implementation "androidx.legacy:legacy-support-v4:_"
     debugImplementation Square.leakCanary.android

app/src/main/AndroidManifest.xml

@@ -488,16 +488,6 @@
             android:parentActivityName="com.duckduckgo.app.settings.SettingsActivity"
             />
 
-        <service
-            android:name="com.duckduckgo.widget.FavoritesWidgetService"
-            android:exported="false"
-            android:permission="android.permission.BIND_REMOTEVIEWS" />
-
-        <service
-            android:name="com.duckduckgo.widget.EmptyFavoritesWidgetService"
-            android:exported="false"
-            android:permission="android.permission.BIND_REMOTEVIEWS" />
-
         <service
             android:name="com.duckduckgo.customtabs.impl.service.DuckDuckGoCustomTabService"
             android:exported="true"

app/src/main/java/com/duckduckgo/app/di/AppComponent.kt

@@ -27,8 +27,8 @@ import com.duckduckgo.app.onboarding.di.OnboardingModule
 import com.duckduckgo.app.surrogates.di.ResourceSurrogateModule
 import com.duckduckgo.app.usage.di.AppUsageModule
 import com.duckduckgo.di.scopes.AppScope
-import com.duckduckgo.widget.EmptyFavoritesWidgetService
-import com.duckduckgo.widget.FavoritesWidgetService
+import com.duckduckgo.widget.EmptyFavoritesWidgetItemFactory
+import com.duckduckgo.widget.FavoritesWidgetItemFactory
 import com.duckduckgo.widget.SearchAndFavoritesWidget
 import com.duckduckgo.widget.SearchOnlyWidget
 import com.duckduckgo.widget.SearchWidget
@@ -88,11 +88,11 @@ interface AppComponent : AndroidInjector<DuckDuckGoApplication> {
 
     fun inject(searchOnlyWidget: SearchOnlyWidget)
 
-    fun inject(searchAndFavsWidget: SearchAndFavoritesWidget)
+    fun inject(searchAndFavoritesWidget: SearchAndFavoritesWidget)
 
-    fun inject(favoritesWidgetItemFactory: FavoritesWidgetService.FavoritesWidgetItemFactory)
+    fun inject(favoritesWidgetItemFactory: FavoritesWidgetItemFactory)
 
-    fun inject(emptyFavoritesWidgetItemFactory: EmptyFavoritesWidgetService.EmptyFavoritesWidgetItemFactory)
+    fun inject(emptyFavoritesWidgetItemFactory: EmptyFavoritesWidgetItemFactory)
 
     // accessor to Retrofit instance for test only only for test
     @Named("api")

app/src/main/java/com/duckduckgo/app/widget/FavoritesObserver.kt

@@ -19,9 +19,9 @@ package com.duckduckgo.app.widget
 import android.appwidget.AppWidgetManager
 import android.content.ComponentName
 import android.content.Context
+import android.content.Intent
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.coroutineScope
-import com.duckduckgo.app.browser.R
 import com.duckduckgo.app.lifecycle.MainProcessLifecycleObserver
 import com.duckduckgo.common.utils.DispatcherProvider
 import com.duckduckgo.di.scopes.AppScope
@@ -33,7 +33,7 @@ import javax.inject.Inject
 
 @SingleInstanceIn(AppScope::class)
 class FavoritesObserver @Inject constructor(
-    context: Context,
+    private val context: Context,
     private val savedSitesRepository: SavedSitesRepository,
     private val dispatcherProvider: DispatcherProvider,
 ) : MainProcessLifecycleObserver {
@@ -47,8 +47,13 @@ class FavoritesObserver @Inject constructor(
         owner.lifecycle.coroutineScope.launch(dispatcherProvider.io()) {
             appWidgetManager?.let { instance ->
                 savedSitesRepository.getFavorites().collect {
-                    instance.notifyAppWidgetViewDataChanged(instance.getAppWidgetIds(componentName), R.id.favoritesGrid)
-                    instance.notifyAppWidgetViewDataChanged(instance.getAppWidgetIds(componentName), R.id.emptyfavoritesGrid)
+                    val appWidgetIds = instance.getAppWidgetIds(componentName)
+                    if (appWidgetIds.isNotEmpty()) {
+                        val updateIntent = Intent(context, SearchAndFavoritesWidget::class.java)
+                        updateIntent.action = AppWidgetManager.ACTION_APPWIDGET_UPDATE
+                        updateIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, appWidgetIds)
+                        context.sendBroadcast(updateIntent)
+                    }
                 }
             }
         }

app/src/main/java/com/duckduckgo/widget/EmptyFavoritesWidgetItemFactory.kt

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2021 DuckDuckGo
+ *
+ * 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.duckduckgo.widget
+
+import android.content.Context
+import android.widget.RemoteViews
+import android.widget.RemoteViewsService
+import com.duckduckgo.app.browser.R
+import com.duckduckgo.app.global.DuckDuckGoApplication
+import com.duckduckgo.common.utils.DispatcherProvider
+import com.duckduckgo.savedsites.api.SavedSitesRepository
+import kotlinx.coroutines.withContext
+import logcat.logcat
+import javax.inject.Inject
+
+/**
+ * This RemoteViewsFactory will not render any item. It's used for convenience to simplify executing background operations to show/hide empty widget CTA.
+ * If this RemoteViewsFactory count is 0, SearchAndFavoritesWidget R.id.emptyFavoritesGrid will show the configured EmptyView.
+ */
+class EmptyFavoritesWidgetItemFactory(
+    val context: Context,
+) : RemoteViewsService.RemoteViewsFactory {
+
+    @Inject
+    lateinit var savedSitesRepository: SavedSitesRepository
+
+    @Inject
+    lateinit var dispatchers: DispatcherProvider
+
+    private var count = 0
+
+    override fun onCreate() {
+        inject(context)
+    }
+
+    override fun onDataSetChanged() {
+        // no-op, we use our own update mechanism
+    }
+
+    suspend fun updateEmptyWidgetFavoritesAsync() {
+        runCatching {
+            count = getItemsCountFromFavorites()
+        }.onFailure { error ->
+            logcat { "Failed to update Search and Favorites widget when empty: ${error.message}" }
+        }
+    }
+
+    override fun onDestroy() {
+        // no-op
+    }
+
+    override fun getCount(): Int {
+        return count
+    }
+
+    override fun getViewAt(position: Int): RemoteViews {
+        return RemoteViews(context.packageName, R.layout.empty_view)
+    }
+
+    override fun getLoadingView(): RemoteViews {
+        return RemoteViews(context.packageName, R.layout.empty_view)
+    }
+
+    override fun getViewTypeCount(): Int {
+        return 1
+    }
+
+    override fun getItemId(position: Int): Long {
+        return position.toLong()
+    }
+
+    override fun hasStableIds(): Boolean {
+        return true
+    }
+
+    private suspend fun getItemsCountFromFavorites(): Int {
+        return withContext(dispatchers.io()) {
+            if (savedSitesRepository.hasFavorites()) 1 else 0
+        }
+    }
+
+    private fun inject(context: Context) {
+        val application = context.applicationContext as DuckDuckGoApplication
+        application.daggerAppComponent.inject(this)
+    }
+}