Scroll to top on chat press when already on that tab.

app/src/main/java/org/thoughtcrime/securesms/conversationlist/ConversationListFragment.java

@@ -137,11 +137,14 @@ import org.thoughtcrime.securesms.search.SearchResult;
 import org.thoughtcrime.securesms.service.KeyCachingService;
 import org.thoughtcrime.securesms.sms.MessageSender;
 import org.thoughtcrime.securesms.storage.StorageSyncHelper;
+import org.thoughtcrime.securesms.stories.tabs.ConversationListTab;
+import org.thoughtcrime.securesms.stories.tabs.ConversationListTabsViewModel;
 import org.thoughtcrime.securesms.util.AppForegroundObserver;
 import org.thoughtcrime.securesms.util.AppStartup;
 import org.thoughtcrime.securesms.util.BottomSheetUtil;
 import org.thoughtcrime.securesms.util.ConversationUtil;
 import org.thoughtcrime.securesms.util.FeatureFlags;
+import org.thoughtcrime.securesms.util.LifecycleDisposable;
 import org.thoughtcrime.securesms.util.PlayStoreUtil;
 import org.thoughtcrime.securesms.util.ServiceUtil;
 import org.thoughtcrime.securesms.util.SignalLocalMetrics;
@@ -185,6 +188,8 @@ public class ConversationListFragment extends MainFragment implements ActionMode
   public static final short MESSAGE_REQUESTS_REQUEST_CODE_CREATE_NAME = 32562;
   public static final short SMS_ROLE_REQUEST_CODE                     = 32563;
 
+  private static final int LIST_SMOOTH_SCROLL_TO_TOP_THRESHOLD = 25;
+
   private static final String TAG = Log.tag(ConversationListFragment.class);
 
   private static final int MAXIMUM_PINNED_CONVERSATIONS = 4;
@@ -213,10 +218,12 @@ public class ConversationListFragment extends MainFragment implements ActionMode
   private VoiceNotePlayerView            voiceNotePlayerView;
   private SignalBottomActionBar          bottomActionBar;
   private SignalContextMenu              activeContextMenu;
+  private LifecycleDisposable            lifecycleDisposable;
 
   protected ConversationListArchiveItemDecoration archiveDecoration;
   protected ConversationListItemAnimator          itemAnimator;
   private   Stopwatch                             startupStopwatch;
+  private   ConversationListTabsViewModel         conversationListTabsViewModel;
 
   public static ConversationListFragment newInstance() {
     return new ConversationListFragment();
@@ -317,6 +324,21 @@ public class ConversationListFragment extends MainFragment implements ActionMode
         }
       }
     });
+
+    lifecycleDisposable           = new LifecycleDisposable();
+    conversationListTabsViewModel = new ViewModelProvider(requireActivity()).get(ConversationListTabsViewModel.class);
+
+    lifecycleDisposable.bindTo(getViewLifecycleOwner());
+    lifecycleDisposable.add(conversationListTabsViewModel.getTabClickEvents().filter(tab -> tab == ConversationListTab.CHATS)
+                                                         .subscribe(unused -> {
+                                                           LinearLayoutManager layoutManager = (LinearLayoutManager) list.getLayoutManager();
+                                                           int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
+                                                           if (firstVisibleItemPosition <= LIST_SMOOTH_SCROLL_TO_TOP_THRESHOLD) {
+                                                             list.smoothScrollToPosition(0);
+                                                           } else {
+                                                             list.scrollToPosition(0);
+                                                           }
+                                                         }));
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/stories/landing/StoriesLandingFragment.kt

@@ -16,6 +16,7 @@ import androidx.core.app.ActivityOptionsCompat
 import androidx.core.app.SharedElementCallback
 import androidx.core.view.ViewCompat
 import androidx.fragment.app.viewModels
+import androidx.recyclerview.widget.LinearLayoutManager
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import com.google.android.material.floatingactionbutton.FloatingActionButton
 import com.google.android.material.snackbar.BaseTransientBottomBar
@@ -43,6 +44,7 @@ import org.thoughtcrime.securesms.stories.dialogs.StoryContextMenu
 import org.thoughtcrime.securesms.stories.dialogs.StoryDialogs
 import org.thoughtcrime.securesms.stories.my.MyStoriesActivity
 import org.thoughtcrime.securesms.stories.settings.StorySettingsActivity
+import org.thoughtcrime.securesms.stories.tabs.ConversationListTab
 import org.thoughtcrime.securesms.stories.tabs.ConversationListTabsViewModel
 import org.thoughtcrime.securesms.stories.viewer.StoryViewerActivity
 import org.thoughtcrime.securesms.util.LifecycleDisposable
@@ -54,6 +56,10 @@ import java.util.concurrent.TimeUnit
  */
 class StoriesLandingFragment : DSLSettingsFragment(layoutId = R.layout.stories_landing_fragment) {
 
+  companion object {
+    private const val LIST_SMOOTH_SCROLL_TO_TOP_THRESHOLD = 25
+  }
+
   private lateinit var emptyNotice: View
   private lateinit var cameraFab: FloatingActionButton
 
@@ -137,6 +143,17 @@ class StoriesLandingFragment : DSLSettingsFragment(layoutId = R.layout.stories_l
         }
       }
     )
+
+    lifecycleDisposable += tabsViewModel.tabClickEvents
+      .filter { it == ConversationListTab.STORIES }
+      .subscribeBy(onNext = {
+        val layoutManager = recyclerView?.layoutManager as? LinearLayoutManager ?: return@subscribeBy
+        if (layoutManager.findFirstVisibleItemPosition() <= LIST_SMOOTH_SCROLL_TO_TOP_THRESHOLD) {
+          recyclerView?.smoothScrollToPosition(0)
+        } else {
+          recyclerView?.scrollToPosition(0)
+        }
+      })
   }
 
   private fun getConfiguration(state: StoriesLandingState): DSLConfiguration {

app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsViewModel.kt

@@ -3,8 +3,11 @@ package org.thoughtcrime.securesms.stories.tabs
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
+import io.reactivex.rxjava3.core.Observable
 import io.reactivex.rxjava3.disposables.CompositeDisposable
 import io.reactivex.rxjava3.kotlin.plusAssign
+import io.reactivex.rxjava3.subjects.PublishSubject
+import io.reactivex.rxjava3.subjects.Subject
 import org.thoughtcrime.securesms.util.livedata.Store
 
 class ConversationListTabsViewModel(repository: ConversationListTabRepository) : ViewModel() {
@@ -14,6 +17,9 @@ class ConversationListTabsViewModel(repository: ConversationListTabRepository) :
   val state: LiveData<ConversationListTabsState> = store.stateLiveData
   val disposables = CompositeDisposable()
 
+  private val internalTabClickEvents: Subject<ConversationListTab> = PublishSubject.create()
+  val tabClickEvents: Observable<ConversationListTab> = internalTabClickEvents
+
   init {
     disposables += repository.getNumberOfUnreadConversations().subscribe { unreadChats ->
       store.update { it.copy(unreadChatsCount = unreadChats) }
@@ -29,10 +35,12 @@ class ConversationListTabsViewModel(repository: ConversationListTabRepository) :
   }
 
   fun onChatsSelected() {
+    internalTabClickEvents.onNext(ConversationListTab.CHATS)
     store.update { it.copy(tab = ConversationListTab.CHATS) }
   }
 
   fun onStoriesSelected() {
+    internalTabClickEvents.onNext(ConversationListTab.STORIES)
     store.update { it.copy(tab = ConversationListTab.STORIES) }
   }