Merge branch 'fix-viewmodel-memory-retain' into 'develop'

Multiple performance fixes

Closes #67 and #80

See merge request !65

CHANGELOG.md

@@ -12,6 +12,8 @@
 
 * Fix a bug preventing to refresh when subscription lists are empty ([!62](https://git.feneas.org/christophehenry/freshrss-android/merge_requests/62/))
 * Fix [#82](https://git.feneas.org/christophehenry/freshrss-android/issues/82): home and back buttons are sometimes not displayed correctly or not displayed at all ([!71](https://git.feneas.org/christophehenry/freshrss-android/merge_requests/71))
+* Fix [#80](https://git.feneas.org/christophehenry/freshrss-android/issues/80): multiple performance bugs in the subscriptions and subscription's articles pages display ([!65](https://git.feneas.org/christophehenry/freshrss-android/merge_requests/65))
+* Fix [#67](https://git.feneas.org/christophehenry/freshrss-android/issues/67): swipe right to flag article as 'read' sometime doesn't work ([#65](https://git.feneas.org/christophehenry/freshrss-android/merge_requests/65))
 
 ## Refactoring
 
@@ -41,7 +43,7 @@
 * Implements [#74](https://git.feneas.org/christophehenry/freshrss-android/issues/74): Ability to add a new feed ([!54](https://git.feneas.org/christophehenry/freshrss-android/merge_requests/54))
 
 ## Bug fixes
-
+ 
 * [#50](https://git.feneas.org/christophehenry/freshrss-android/issues/50): Categories are not alphabetically sorted
 * [#51](https://git.feneas.org/christophehenry/freshrss-android/issues/51): Unread subscription time groups are not time-sorted
 * [#55](https://git.feneas.org/christophehenry/freshrss-android/issues/55): Links click open page in the webview ([!18](https://git.feneas.org/christophehenry/freshrss-android/merge_requests/18))
@@ -105,4 +107,4 @@ Basic implementation using FreshRSS' GReader HTTP API implmentation. This lets y
  * set an article as read/unread
  * share an article to other android application
  * open the original page of the article
- * refresh your feed
\ No newline at end of file
+ * refresh your feed

app/build.gradle

@@ -106,7 +106,8 @@ spotless {
 }
 
 dependencies {
-    def lifecycle_version = '2.2.0'
+    def appcompat_version = "1.1.0"
+    def lifecycle_version = "2.2.0"
     def room_version = '2.2.3'
     def roomigrant_version = "0.1.7"
     def fuel_version = "2.0.1"
@@ -114,7 +115,6 @@ dependencies {
     def espresso_version = "3.2.0"
     def test_runnner_version = "1.2.0"
     def promise_version = "3.3.0"
-    def android_support_version = "28.0.0"
     def android_navigation = "1.0.0"
     def jsoup_version = "1.12.1"
     def acraVersion = "5.1.3"
@@ -130,36 +130,33 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
 
-    // Compat libraries
-    implementation "com.android.support:appcompat-v7:$android_support_version"
-    implementation "com.android.support:preference-v7:$android_support_version"
-    implementation "com.android.support:support-core-utils:$android_support_version"
-    implementation "com.android.support:support-fragment:$android_support_version"
-    implementation "com.android.support:support-compat:$android_support_version"
-    implementation "com.android.support:support-core-ui:$android_support_version"
+    // AndroidX
+    implementation "androidx.appcompat:appcompat:$appcompat_version"
+    implementation "androidx.appcompat:appcompat-resources:$appcompat_version"
 
-    // AndroidX layout
-    implementation "androidx.appcompat:appcompat:1.1.0"
     implementation "androidx.core:core-ktx:1.1.0"
-    implementation 'com.google.android.material:material:1.2.0-alpha04'
     implementation "androidx.constraintlayout:constraintlayout:1.1.3"
-    implementation 'androidx.recyclerview:recyclerview:1.1.0'
+    implementation "androidx.recyclerview:recyclerview:1.1.0"
+    implementation "androidx.preference:preference-ktx:1.1.0"
+    implementation "com.google.android.material:material:1.2.0-alpha04"
 
     // ViewModel and LiveData
+    implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
     implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
-    implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
-    implementation "androidx.lifecycle:lifecycle-reactivestreams-ktx:$lifecycle_version"
     implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
+    implementation "androidx.lifecycle:lifecycle-reactivestreams-ktx:$lifecycle_version"
     kapt "androidx.lifecycle:lifecycle-common-java8:$lifecycle_version"
     androidTestImplementation "androidx.arch.core:core-testing:2.1.0"
 
-    // Room
+    // Navigation
+    implementation "android.arch.navigation:navigation-fragment-ktx:$android_navigation"
+    implementation "android.arch.navigation:navigation-ui-ktx:$android_navigation"
+
+    // Room & roomigrant
     kapt "androidx.room:room-compiler:$room_version"
     implementation "androidx.room:room-runtime:$room_version"
     implementation "androidx.room:room-rxjava2:$room_version"
-    implementation "androidx.room:room-guava:$room_version"
     androidTestImplementation "androidx.room:room-testing:$room_version"
-    // roomigrant
     implementation "com.github.MatrixDev.Roomigrant:RoomigrantLib:$roomigrant_version"
     kapt "com.github.MatrixDev.Roomigrant:RoomigrantCompiler:$roomigrant_version"
 
@@ -172,13 +169,9 @@ dependencies {
     implementation "nl.komponents.kovenant:kovenant:$promise_version"
     implementation "nl.komponents.kovenant:kovenant-android:$promise_version"
 
-    // Navigation
-    implementation "android.arch.navigation:navigation-fragment-ktx:$android_navigation"
-    implementation "android.arch.navigation:navigation-ui-ktx:$android_navigation"
-
     // Utils
     implementation "org.apache.commons:commons-text:1.8"
-    implementation 'joda-time:joda-time:2.10.5'
+    implementation "joda-time:joda-time:2.10.5"
     implementation "com.squareup.picasso:picasso:2.71828"
     implementation "com.x5dev:chunk-templates:3.5.0"
     implementation "eu.davidea:flexible-adapter:5.1.0"

app/src/main/java/fr/chenry/android/freshrss/activities/LoginActivity.kt

@@ -5,7 +5,6 @@ import android.animation.AnimatorListenerAdapter
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
-import android.os.ResultReceiver
 import android.view.View
 import android.view.inputmethod.EditorInfo
 import android.view.inputmethod.InputMethodManager
@@ -17,17 +16,16 @@ import fr.chenry.android.freshrss.R
 import fr.chenry.android.freshrss.store.Store
 import fr.chenry.android.freshrss.utils.*
 import kotlinx.android.synthetic.main.activity_login.*
-import nl.komponents.kovenant.deferred
-import nl.komponents.kovenant.resolve
 import nl.komponents.kovenant.ui.failUi
 import nl.komponents.kovenant.ui.successUi
 import java.util.Properties
 
-/**
- * A login screen that offers login via email/password.
- */
+
 class LoginActivity : AppCompatActivity() {
     private lateinit var instanceUrl: InstanceUrl
+    private val inputManager by lazy {
+        getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
+    }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -133,15 +131,8 @@ class LoginActivity : AppCompatActivity() {
     }
 
     private fun hideKeyboard() {
-        val deferred = deferred<Unit, Exception>()
-        val view = this.currentFocus
-        view?.let {
-            val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
-            imm.hideSoftInputFromWindow(it.windowToken, 0, object : ResultReceiver(null) {
-                override fun onReceiveResult(resultCode: Int, resultData: Bundle?) = deferred.resolve()
-            })
-        }.whenNull { deferred.resolve() }
-        deferred.promise.get()
+        val token = (this.currentFocus ?: findViewById<View>(android.R.id.content).rootView).windowToken
+        token?.let {inputManager.hideSoftInputFromWindow(it, 0)}
     }
 
     private fun showProgress(show: Boolean) {

app/src/main/java/fr/chenry/android/freshrss/activities/MainActivity.kt

@@ -23,7 +23,7 @@ class MainActivity: AppCompatActivity() {
         Navigation.findNavController(this, R.id.main_activity_host_fragment)
     }
 
-    val drawerLayout: DrawerLayout by lazy {
+    private val drawerLayout: DrawerLayout by lazy {
         findViewById<DrawerLayout>(R.id.activity_main_navigation_drawer)
     }
 
@@ -39,7 +39,6 @@ class MainActivity: AppCompatActivity() {
         restoreState()
         setContentView(R.layout.activity_main)
         F.app.refresherService.value?.apply {refresh()}
-        NavigationUI.setupActionBarWithNavController(this, navigation, appBarConfiguration)
         setupActionBarWithNavController(navigation, appBarConfiguration)
         drawerLayout.addDrawerListener(BurgerMenuDrawerListener(this))
     }

app/src/main/java/fr/chenry/android/freshrss/components/navigationdrawer/SettingsFragment.kt

@@ -6,8 +6,8 @@ import fr.chenry.android.freshrss.F
 import fr.chenry.android.freshrss.R
 
 class SettingsFragment: PreferenceFragmentCompat(), Preference.OnPreferenceChangeListener {
-    private val refreshFrequencyPreference: ListPreference by lazy {
-        findPreference(F.preferences.refreshFrequencyKey) as ListPreference
+    private val refreshFrequencyPreference by lazy {
+        findPreference(F.preferences.refreshFrequencyKey) ?: ListPreference(context)
     }
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {

app/src/main/java/fr/chenry/android/freshrss/components/subscriptionarticles/SubscriptionArticleViewItem.kt

@@ -14,8 +14,12 @@ import fr.chenry.android.freshrss.databinding.FragmentSubscriptionArticleBinding
 import fr.chenry.android.freshrss.store.database.models.Article
 import fr.chenry.android.freshrss.store.database.models.Subscription
 
-class SubscriptionArticleViewItem(val article: Article, private val subscription: Subscription) :
-    AbstractFlexibleItem<ArticleViewHolder>() {
+class SubscriptionArticleViewItem(
+    private val subscription: Subscription,
+    val article: Article
+): AbstractFlexibleItem<ArticleViewHolder>() {
+
+
     init {
         isDraggable = false
         isSelectable = false
@@ -30,7 +34,7 @@ class SubscriptionArticleViewItem(val article: Article, private val subscription
     ) = holder.bind(article)
 
     override fun equals(other: Any?): Boolean {
-        if (other !is SubscriptionArticleViewItem) return false
+        if(other !is SubscriptionArticleViewItem) return false
         return article == other.article
     }
 
@@ -46,7 +50,9 @@ class SubscriptionArticleViewItem(val article: Article, private val subscription
     inner class ArticleViewHolder(
         private val binding: FragmentSubscriptionArticleBinding,
         flexibleAdapter: FlexibleAdapter<*>
-    ) : FlexibleViewHolder(binding.root, flexibleAdapter) {
+    ): FlexibleViewHolder(binding.root, flexibleAdapter) {
+
+
         private val frontView = binding.root.findViewById<View>(R.id.fragment_subscription_article_front_view)
         private val rearLeftView =
             binding.root.findViewById<View>(R.id.fragment_subscription_article_rear_left_view)

app/src/main/java/fr/chenry/android/freshrss/components/subscriptionarticles/SubscriptionArticlesDetailFragment.kt

@@ -27,8 +27,8 @@ import nl.komponents.kovenant.ui.failUi
 class SubscriptionArticlesDetailFragment : Fragment() {
     private lateinit var articleId: String
     private val model: SubscriptionArticleVM by lazy {
-        ViewModelProvider(this, SubscriptionArticleVMF(articleId))
-            .get(SubscriptionArticleVM::class.java)
+        ViewModelProvider(activity!!.viewModelStore, SubscriptionArticleVMF(articleId))
+            .get("articleId=$articleId", SubscriptionArticleVM::class.java)
     }
     private var isFetching = MutableLiveData<Boolean>().apply { value = false }
     private val article: Article get() = model.liveData.value!!
@@ -108,7 +108,7 @@ class SubscriptionArticlesDetailFragment : Fragment() {
             }
 
             mutateUi(article)
-            model.liveData.observe(this, Observer(::mutateUi))
+            model.liveData.observe(viewLifecycleOwner, Observer(::mutateUi))
             it.setOnMenuItemClickListener { setReadStatus(article.readStatus.toggle()) }
         }
     }

app/src/main/java/fr/chenry/android/freshrss/components/subscriptionarticles/SubscriptionArticlesFragment.kt

 package fr.chenry.android.freshrss.components.subscriptionarticles
 
+import android.annotation.SuppressLint
 import android.os.Bundle
 import android.view.*
 import androidx.fragment.app.Fragment
-import androidx.lifecycle.*
-import androidx.navigation.findNavController
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProvider
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
 import androidx.recyclerview.widget.*
 import androidx.recyclerview.widget.RecyclerView.ViewHolder
 import eu.davidea.flexibleadapter.FlexibleAdapter
-import eu.davidea.flexibleadapter.FlexibleAdapter.OnItemClickListener
 import fr.chenry.android.freshrss.R
 import fr.chenry.android.freshrss.store.Store
 import fr.chenry.android.freshrss.store.database.models.ReadStatus
 import fr.chenry.android.freshrss.store.database.models.ReadStatus.READ
 import fr.chenry.android.freshrss.store.database.models.ReadStatus.UNREAD
+import fr.chenry.android.freshrss.store.database.models.Subscription
 import fr.chenry.android.freshrss.store.viewmodels.SubscriptionArticlesVM
 import fr.chenry.android.freshrss.store.viewmodels.SubscriptionArticlesVMF
 import kotlinx.android.synthetic.main.fragment_subscription_articles.*
 import nl.komponents.kovenant.Promise
 import nl.komponents.kovenant.ui.alwaysUi
 
-class SubscriptionArticlesFragment: Fragment(), Observer<List<SubscriptionArticleViewItem>> {
+class SubscriptionArticlesFragment: Fragment() {
     private val args: SubscriptionArticlesFragmentArgs by navArgs()
-    private val streamId: String by lazy {args.id}
+    private val subscription: Subscription by lazy {args.subscription}
     private val readStatus: ReadStatus by lazy {args.readStatus}
 
     private val model: SubscriptionArticlesVM by lazy {
-        ViewModelProvider(this, SubscriptionArticlesVMF(streamId, readStatus))
-            .get(SubscriptionArticlesVM::class.java).apply {
-                liveData.observe(this@SubscriptionArticlesFragment, this@SubscriptionArticlesFragment)
-            }
-    }
-
-    private val adapter by lazy {
-        ArticleAdapter(model.liveData.value ?: listOf())
+        ViewModelProvider(activity!!.viewModelStore, SubscriptionArticlesVMF(subscription, readStatus))
+            .get("stream=${subscription.id}:readStatus=$readStatus", SubscriptionArticlesVM::class.java)
     }
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
@@ -43,30 +38,13 @@ class SubscriptionArticlesFragment: Fragment(), Observer<List<SubscriptionArticl
 
         view.findViewById<RecyclerView>(R.id.fragment_subscription_article_recycler).apply {
             layoutManager = LinearLayoutManager(context)
-            adapter = this@SubscriptionArticlesFragment.adapter
+            adapter = ArticleAdapter(model.liveData.value ?: listOf())
         }
 
         return view
     }
 
-    override fun onChanged(articlesViewItemSubscriptions: List<SubscriptionArticleViewItem>?) {
-        (articlesViewItemSubscriptions ?: listOf()).let {
-            toggleProgressCircle(it)
-            adapter.updateDataSet(it, true)
-        }
-    }
-
-    fun onItemClick(position: Int): Boolean =
-        adapter.getItem(position)?.article?.id?.let {articleId ->
-            val direction = SubscriptionArticlesFragmentDirections.articlesToArticleDetail(articleId)
-            findNavController().navigate(direction)
-            true
-        } ?: false
-
-    fun toggleArticleReadStatus(position: Int): Promise<Unit, Exception> = adapter.getItem(position)?.let {
-        Store.postReadStatus(it.article, it.article.readStatus.toggle())
-    } ?: Promise.ofSuccess(Unit)
-
+    @SuppressLint("StringFormatInvalid")
     private fun toggleProgressCircle(articles: List<*>) {
         fragment_subscription_article_empty_list.text = when(readStatus) {
             READ -> context?.getString(R.string.empty_subscription_list, model.subscription.title)
@@ -97,29 +75,56 @@ class SubscriptionArticlesFragment: Fragment(), Observer<List<SubscriptionArticl
     }
 
     private inner class ArticleAdapter(items: List<SubscriptionArticleViewItem>):
-        FlexibleAdapter<SubscriptionArticleViewItem>(items, null, true) {
+        FlexibleAdapter<SubscriptionArticleViewItem>(items, null, true),
+        Observer<List<SubscriptionArticleViewItem>>,
+        FlexibleAdapter.OnItemClickListener,
+        FlexibleAdapter.OnItemSwipeListener {
 
 
+        init {
+            model.liveData.observe(viewLifecycleOwner, this)
+        }
+
         override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
             super.onAttachedToRecyclerView(recyclerView)
             isSwipeEnabled = true
             itemTouchHelperCallback.setSwipeFlags(ItemTouchHelper.RIGHT)
 
-            addListener(OnItemClickListener {_, position -> this@SubscriptionArticlesFragment.onItemClick(position)})
-            addListener(object: OnItemSwipeListener {
-                override fun onActionStateChanged(viewHolder: ViewHolder?, actionState: Int) {}
-
-                override fun onItemSwipe(position: Int, direction: Int) {
-                    if(direction == ItemTouchHelper.RIGHT) toggleArticleReadStatus(position).alwaysUi {
-                        if(readStatus == READ) this@ArticleAdapter.notifyItemChanged(position)
-                    }
-                }
-            })
+            addListener(this as OnItemClickListener)
+            addListener(this as OnItemSwipeListener)
         }
 
         override fun getItemId(position: Int) =
             getItem(position)?.article?.id?.hashCode()?.toLong() ?: RecyclerView.NO_ID
 
         override fun isEmpty(): Boolean = (model.liveData.value ?: listOf()).isEmpty()
+
+        override fun onChanged(articlesViewItemSubscriptions: List<SubscriptionArticleViewItem>?) {
+            (articlesViewItemSubscriptions ?: listOf()).let {
+                toggleProgressCircle(it)
+                updateDataSet(it, true)
+            }
+        }
+
+        override fun onItemClick(view: View?, position: Int): Boolean = getArticleId(position)?.let {
+            val direction = SubscriptionArticlesFragmentDirections.articlesToArticleDetail(it)
+            findNavController().navigate(direction)
+            true
+        } ?: false
+
+        override fun onActionStateChanged(viewHolder: ViewHolder?, actionState: Int) {}
+
+        override fun onItemSwipe(position: Int, direction: Int) {
+            if(direction == ItemTouchHelper.RIGHT) toggleArticleReadStatus(position).alwaysUi {
+                if(readStatus == READ) this@ArticleAdapter.notifyItemChanged(position)
+            }
+        }
+
+        private fun getArticleId(position: Int) = getItem(position)?.article?.id
+
+        private fun toggleArticleReadStatus(position: Int): Promise<Unit, Exception> = getItem(position)?.let {
+            Store.postReadStatus(it.article, it.article.readStatus.toggle())
+        } ?: Promise.ofSuccess(Unit)
     }
 }
+

app/src/main/java/fr/chenry/android/freshrss/components/subscriptions/MainSubscriptionFragment.kt

@@ -11,8 +11,7 @@ import androidx.lifecycle.Observer
 import androidx.viewpager.widget.ViewPager.SimpleOnPageChangeListener
 import com.google.android.material.bottomnavigation.BottomNavigationItemView
 import com.google.android.material.bottomnavigation.BottomNavigationView
-import fr.chenry.android.freshrss.MainNavDirections
-import fr.chenry.android.freshrss.R
+import fr.chenry.android.freshrss.*
 import fr.chenry.android.freshrss.store.Store
 import fr.chenry.android.freshrss.store.database.models.VoidCategory
 import kotlinx.android.synthetic.main.fragment_main_subscription.*
@@ -54,6 +53,7 @@ class MainSubscriptionFragment: Fragment(), BottomNavigationView.OnNavigationIte
     }
 
     fun onPageSelected(position: Int) = SubscriptionSection.byPosition(position).let {
+        F.app.preferences.subscriptionSection = it
         Store.subscriptionsSection.value = it
         subcription_bottom_navigation.selectedItemId = it.navigationButtonId
     }

app/src/main/java/fr/chenry/android/freshrss/components/subscriptions/SubscriptionsFragment.kt

@@ -14,29 +14,27 @@ import eu.davidea.fastscroller.FastScroller
 import fr.chenry.android.freshrss.F
 import fr.chenry.android.freshrss.R
 import fr.chenry.android.freshrss.components.subscriptions.SubscriptionSection.*
+import fr.chenry.android.freshrss.components.subscriptions.adapters.SubscriptionViewItems
 import fr.chenry.android.freshrss.components.subscriptions.adapters.SubscriptionsFlexibleAdapter
 import fr.chenry.android.freshrss.store.Store
 import fr.chenry.android.freshrss.store.database.models.*
 import fr.chenry.android.freshrss.store.database.models.ReadStatus.READ
-import fr.chenry.android.freshrss.store.viewmodels.*
+import fr.chenry.android.freshrss.store.viewmodels.SubscriptionsFragmentCategoryVMF
+import fr.chenry.android.freshrss.store.viewmodels.SubscriptionsVM
 import fr.chenry.android.freshrss.utils.EmotionnalImageSubtext
 import kotlinx.android.synthetic.main.fragment_subscriptions.*
 import nl.komponents.kovenant.Promise
 
-class SubscriptionsFragment: Fragment(), Observer<Subscriptions> {
+class SubscriptionsFragment: Fragment(), Observer<SubscriptionViewItems> {
     private val args: SubscriptionsFragmentArgs by navArgs()
     private val section by lazy {args.section}
     private val category by lazy {args.category}
 
     val model by lazy {
-        if(category != VoidCategory)
-            ViewModelProvider(this, SubscriptionsFragmentCategoryVMF(category, section))
-                .get(AllSubscriptionsVM::class.java)
-        else when(section) {
-            ALL -> ViewModelProvider(this).get(AllSubscriptionsVM::class.java)
-            UNREAD -> ViewModelProvider(this).get(UnreadSubscriptionsVM::class.java)
-            FAVORITES -> ViewModelProvider(this).get(FavoritesSubscriptionsVM::class.java)
-        }
+        val key = "section=${section.name}${if(category != VoidCategory) ":category=${category.id}" else ""}"
+
+        ViewModelProvider(activity!!.viewModelStore, SubscriptionsFragmentCategoryVMF(category, section))
+            .get(key, SubscriptionsVM::class.java)
     }
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
@@ -44,9 +42,7 @@ class SubscriptionsFragment: Fragment(), Observer<Subscriptions> {
 
         initRecyclerView(view)
 
-        Store.refreshingPromise.observe(
-            viewLifecycleOwner,
-            Observer {toggleProgressCircle(model.subscriptions.value ?: listOf())})
+        Store.refreshingPromise.observe(viewLifecycleOwner, Observer {toggleProgressCircle(model.isEmpty())})
         model.subscriptions.observe(viewLifecycleOwner, this)
 
         val contentDescription = if(category != VoidCategory) {
@@ -86,12 +82,13 @@ class SubscriptionsFragment: Fragment(), Observer<Subscriptions> {
         return view
     }
 
-    override fun onChanged(subscriptions: Subscriptions?) = toggleProgressCircle((subscriptions ?: listOf()))
+    override fun onChanged(subscriptions: SubscriptionViewItems?)
+        = toggleProgressCircle((subscriptions.isNullOrEmpty()))
 
     fun onClick(subscription: Subscription) = when(section) {
-        FAVORITES -> subscription.id to READ
-        ALL -> subscription.id to READ
-        UNREAD -> subscription.id to ReadStatus.UNREAD
+        FAVORITES -> subscription to READ
+        ALL -> subscription to READ
+        UNREAD -> subscription to ReadStatus.UNREAD
     }.let {
         val direction = if(category == VoidCategory)
             MainSubscriptionFragmentDirections.mainSubscriptionsToArticles(it.first, it.second) else
@@ -117,8 +114,8 @@ class SubscriptionsFragment: Fragment(), Observer<Subscriptions> {
         }
     }
 
-    private fun toggleProgressCircle(subscriptions: Subscriptions) {
-        if(subscriptions.isNotEmpty()) {
+    private fun toggleProgressCircle(isEmpty: Boolean) {
+        if(!isEmpty) {
             fragment_subscriptions_list.visibility = View.VISIBLE
             fast_scroller.visibility = View.VISIBLE
 

app/src/main/java/fr/chenry/android/freshrss/components/subscriptions/adapters/AbstractSubscriptionViewItem.kt

@@ -14,6 +14,7 @@ import fr.chenry.android.freshrss.databinding.FragmentSubscriptionBinding
 import fr.chenry.android.freshrss.store.database.models.Subscription
 import fr.chenry.android.freshrss.store.database.models.SubscriptionCategory
 
+typealias SubscriptionViewItems = List<AbstractSubscriptionViewItem>
 sealed class AbstractSubscriptionViewItem(header: SubscriptionViewHeaderItem) :
     AbstractSectionableItem<SubscriptionViewHolder, SubscriptionViewHeaderItem>(header) {
     abstract val virtualSubscription: Subscription

app/src/main/java/fr/chenry/android/freshrss/components/subscriptions/adapters/SubscriptionsFlexibleAdapter.kt

 package fr.chenry.android.freshrss.components.subscriptions.adapters
 
 import android.view.View
-import androidx.lifecycle.MediatorLiveData
 import androidx.lifecycle.Observer
 import eu.davidea.flexibleadapter.FlexibleAdapter
 import eu.davidea.flexibleadapter.FlexibleAdapter.OnItemClickListener
 import eu.davidea.flexibleadapter.items.IFlexible
 import fr.chenry.android.freshrss.components.subscriptions.SubscriptionsFragment
-import fr.chenry.android.freshrss.store.database.models.SubscriptionCategories
-import fr.chenry.android.freshrss.store.database.models.Subscriptions
-import nl.komponents.kovenant.Promise
-import nl.komponents.kovenant.task
 
 class SubscriptionsFlexibleAdapter(private val fragment: SubscriptionsFragment) :
     FlexibleAdapter<AbstractSubscriptionViewItem>(listOf(), null, true),
     OnItemClickListener {
-    private val mediator = MediatorLiveData<List<AbstractSubscriptionViewItem>>()
-    private val subscriptionCategories
-        get() = fragment.model.subscriptionCategories.value ?: listOf()
-    private val subscriptions
-        get() = fragment.model.subscriptions.value ?: listOf()
-    private val grouper get() = fragment.model.grouper
 
     init {
         setStickyHeaders(true)
         setDisplayHeadersAtStartUp(true)
-        mediator.observe(fragment.viewLifecycleOwner, Observer { updateDataSet(it, true) })
-        mediator.addSource(fragment.model.subscriptions) {
-            computeNewDataSet(it, subscriptionCategories) success { res -> mediator.postValue(res) }
-        }
-        mediator.addSource(fragment.model.subscriptionCategories) {
-            computeNewDataSet(subscriptions, it) success { res -> mediator.postValue(res) }
-        }
+        fragment.model.subscriptions.observe(fragment.viewLifecycleOwner, Observer { updateDataSet(it, true) })
         addListener(this)
+
     }
 
-    override fun isEmpty(): Boolean = fragment.model.subscriptions.value.isNullOrEmpty()
+    override fun isEmpty(): Boolean = fragment.model.isEmpty()
 
     override fun onCreateBubbleText(position: Int): String? {
         return when (val item = getGenericItem(position)) {
@@ -55,26 +39,6 @@ class SubscriptionsFlexibleAdapter(private val fragment: SubscriptionsFragment)
 
     private fun getGenericItem(position: Int): IFlexible<*>? = (this as FlexibleAdapter<*>).getItem(position)
 
-    private fun computeNewDataSet(
-        subscriptions: Subscriptions,
-        subscriptionCategories: SubscriptionCategories
-    ): Promise<ArrayList<AbstractSubscriptionViewItem>, Exception> = task {
-        val targetSize = subscriptionCategories.size + subscriptions.size
-        val result = ArrayList<AbstractSubscriptionViewItem>(targetSize)
-        (0 until targetSize).forEach {
-            val newElt = if (it < subscriptionCategories.size)
-                SubscriptionCategoryViewItem(subscriptionCategories[it]) else
-                SubscriptionViewItem(
-                    subscriptions[it - subscriptionCategories.size],
-                    grouper(subscriptions[it - subscriptionCategories.size])
-                )
-
-            result.add(newElt)
-        }
-
-        result
-    }
-
     override fun getItemId(position: Int): Long = getGenericItem(position)?.let {
         when (it) {
             is SubscriptionViewItem -> it.subscription.id.hashCode().toLong()

app/src/main/java/fr/chenry/android/freshrss/store/FreshRSSPreferences.kt

 package fr.chenry.android.freshrss.store
 
 import android.content.SharedPreferences
+import androidx.core.content.edit
 import androidx.preference.PreferenceManager
 import fr.chenry.android.freshrss.FreshRSSApplication
 import fr.chenry.android.freshrss.R
@@ -30,7 +31,7 @@ class FreshRSSPreferences(private val application: FreshRSSApplication) {
             return Try{SubscriptionSection.valueOf(pref)}.getOrDefault(SubscriptionSection.ALL)
         }
         set(value) {
-            sharedPreferences.edit().putString(subscriptionSectionKey, value.name).apply()
+            sharedPreferences.edit {putString(subscriptionSectionKey, value.name)}
         }
 
     private val refreshFrequencies by lazy {application.resources.getStringArray(R.array.refresh_frequencies)}