RecyclerView: introduce view pool

vector/src/main/java/im/vector/riotx/core/di/ScreenComponent.kt

@@ -63,7 +63,8 @@ import im.vector.riotx.features.ui.UiStateRepository
             ViewModelModule::class,
             FragmentModule::class,
             HomeModule::class,
-            RoomListModule::class
+            RoomListModule::class,
+            ScreenModule::class
         ]
 )
 @ScreenScope

vector/src/main/java/im/vector/riotx/core/di/ScreenModule.kt

@@ -17,6 +17,7 @@
 package im.vector.riotx.core.di
 
 import androidx.appcompat.app.AppCompatActivity
+import androidx.recyclerview.widget.RecyclerView
 import dagger.Module
 import dagger.Provides
 import im.vector.riotx.core.glide.GlideApp
@@ -27,4 +28,9 @@ object ScreenModule {
     @Provides
     @JvmStatic
     fun providesGlideRequests(context: AppCompatActivity) = GlideApp.with(context)
+
+    @Provides
+    @JvmStatic
+    @ScreenScope
+    fun providesSharedViewPool() = RecyclerView.RecycledViewPool()
 }

vector/src/main/java/im/vector/riotx/core/extensions/RecyclerView.kt

@@ -26,9 +26,13 @@ import com.airbnb.epoxy.EpoxyController
  */
 fun RecyclerView.configureWith(epoxyController: EpoxyController,
                                itemAnimator: RecyclerView.ItemAnimator? = null,
+                               viewPool: RecyclerView.RecycledViewPool? = null,
                                showDivider: Boolean = false,
                                hasFixedSize: Boolean = true) {
-    layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
+    layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false).apply {
+        recycleChildrenOnDetach = viewPool != null
+    }
+    setRecycledViewPool(viewPool)
     itemAnimator?.let { this.itemAnimator = it }
     if (showDivider) {
         addItemDecoration(DividerItemDecoration(context, DividerItemDecoration.VERTICAL))

vector/src/main/java/im/vector/riotx/features/home/room/list/RoomListFragment.kt

@@ -59,7 +59,8 @@ data class RoomListParams(
 class RoomListFragment @Inject constructor(
         private val roomController: RoomSummaryController,
         val roomListViewModelFactory: RoomListViewModel.Factory,
-        private val notificationDrawerManager: NotificationDrawerManager
+        private val notificationDrawerManager: NotificationDrawerManager,
+        private val sharedViewPool: RecyclerView.RecycledViewPool
 
 ) : VectorBaseFragment(), RoomSummaryController.Listener, OnBackPressed, FabMenuView.Listener {
 
@@ -95,7 +96,6 @@ class RoomListFragment @Inject constructor(
         setupCreateRoomButton()
         setupRecyclerView()
         sharedActionViewModel = activityViewModelProvider.get(RoomListQuickActionsSharedActionViewModel::class.java)
-
         roomListViewModel.subscribe { renderState(it) }
         roomListViewModel.viewEvents
                 .observe()
@@ -193,6 +193,8 @@ class RoomListFragment @Inject constructor(
         val stateRestorer = LayoutManagerStateRestorer(layoutManager).register()
         roomListView.layoutManager = layoutManager
         roomListView.itemAnimator = RoomListAnimator()
+        roomListView.setRecycledViewPool(sharedViewPool)
+        layoutManager.recycleChildrenOnDetach = true
         roomController.listener = this
         modelBuildListener = OnModelBuildFinishedListener { it.dispatchTo(stateRestorer) }
         roomController.addModelBuildListener(modelBuildListener)

vector/src/main/java/im/vector/riotx/features/home/room/list/actions/RoomListQuickActionsBottomSheet.kt

@@ -46,6 +46,7 @@ data class RoomListActionsArgs(
 class RoomListQuickActionsBottomSheet : VectorBaseBottomSheetDialogFragment(), RoomListQuickActionsEpoxyController.Listener {
 
     private lateinit var sharedActionViewModel: RoomListQuickActionsSharedActionViewModel
+    @Inject lateinit var sharedViewPool: RecyclerView.RecycledViewPool
     @Inject lateinit var roomListActionsViewModelFactory: RoomListQuickActionsViewModel.Factory
     @Inject lateinit var roomListActionsEpoxyController: RoomListQuickActionsEpoxyController
     @Inject lateinit var navigator: Navigator
@@ -70,7 +71,7 @@ class RoomListQuickActionsBottomSheet : VectorBaseBottomSheetDialogFragment(), R
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
         sharedActionViewModel = activityViewModelProvider.get(RoomListQuickActionsSharedActionViewModel::class.java)
-        recyclerView.configureWith(roomListActionsEpoxyController, hasFixedSize = false)
+        recyclerView.configureWith(roomListActionsEpoxyController, viewPool = sharedViewPool, hasFixedSize = false)
         // Disable item animation
         recyclerView.itemAnimator = null
         roomListActionsEpoxyController.listener = this