Utilize events instead of direct calls in main nav view model.

app/src/main/java/org/thoughtcrime/securesms/MainActivity.kt

@@ -82,6 +82,7 @@ import kotlinx.coroutines.withContext
 import org.signal.core.ui.BottomSheetUtil
 import org.signal.core.ui.NavigationType
 import org.signal.core.ui.compose.Snackbars
+import org.signal.core.ui.compose.split.ListDetailEvents
 import org.signal.core.ui.compose.split.ListDetailNavDisplay
 import org.signal.core.ui.compose.split.ListDetailPaneLayout
 import org.signal.core.ui.compose.split.ListDetailPaneMetrics
@@ -145,8 +146,9 @@ import org.thoughtcrime.securesms.main.MainDetailRoute
 import org.thoughtcrime.securesms.main.MainListRoute
 import org.thoughtcrime.securesms.main.MainMegaphoneState
 import org.thoughtcrime.securesms.main.MainNavigationBar
+import org.thoughtcrime.securesms.main.MainNavigationEventSink
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.main.MainNavigationRail
-import org.thoughtcrime.securesms.main.MainNavigationRouter
 import org.thoughtcrime.securesms.main.MainNavigationViewModel
 import org.thoughtcrime.securesms.main.MainSnackbar
 import org.thoughtcrime.securesms.main.MainSnackbarHostKey
@@ -188,7 +190,7 @@ class MainActivity :
   MainNavigator.NavigatorProvider,
   Material3OnScrollHelperBinder,
   ConversationListFragment.Callback,
-  MainNavigationRouter,
+  MainNavigationEventSink,
   CallLogFragment.Callback,
   GooglePayComponent {
 
@@ -263,7 +265,7 @@ class MainActivity :
 
   private val mainBottomChromeCallback = BottomChromeCallback()
   private val megaphoneActionController = MainMegaphoneActionController()
-  private val mainNavigationCallback = MainNavigationCallback()
+  private val mainNavigationCallback: (MainListRoute) -> Unit = { mainNavigationViewModel.onEvent(MainNavigationEvents.GoToTab(it)) }
 
   override val googlePayRepository: GooglePayRepository by lazy { GooglePayRepository(this) }
   override val googlePayResultPublisher: Subject<GooglePayComponent.GooglePayResult> = PublishSubject.create()
@@ -287,7 +289,7 @@ class MainActivity :
 
     AppForegroundObserver.addListener(object : AppForegroundObserver.Listener {
       override fun onForeground() {
-        mainNavigationViewModel.getNextMegaphone()
+        mainNavigationViewModel.onEvent(MainNavigationEvents.RequestNextMegaphone)
       }
     })
 
@@ -397,7 +399,7 @@ class MainActivity :
       val isBackHandlerEnabled = mainToolbarState.destination != MainListRoute.Chats && !isActionModeActive && !isSearchModeActive
 
       BackHandler(enabled = isBackHandlerEnabled) {
-        mainNavigationViewModel.goTo(MainListRoute.Chats)
+        mainNavigationViewModel.onEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
       }
 
       BackHandler(enabled = isActionModeActive) {
@@ -491,8 +493,8 @@ class MainActivity :
             entries = tabEntries,
             isSplitPane = isSplitPane,
             paneAnchor = paneAnchor,
-            onBack = { mainNavigationViewModel.popCurrentDetailLocation() },
-            onExitDetail = { mainNavigationViewModel.exitDetailLocation() },
+            onBack = { mainNavigationViewModel.onEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back)) },
+            onExitDetail = { mainNavigationViewModel.onEvent(MainNavigationEvents.ExitDetail) },
             layout = paneLayout,
             listPaneChrome = listPaneChrome,
             emptyDetailContent = emptyDetailContent,
@@ -540,7 +542,7 @@ class MainActivity :
     return rememberListDetailPaneLayout(
       paneAnchor = paneAnchor,
       maxWidth = maxWidth,
-      onAnchorSelected = { mainNavigationViewModel.onPaneAnchorSelected(it) },
+      onAnchorSelected = { mainNavigationViewModel.onEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.AnchorSelected(it))) },
       metrics = contentLayoutData,
       // Searching hides the rail, leaving nothing of the list pane behind once the detail fills the window.
       collapsedListWidth = when {
@@ -690,29 +692,20 @@ class MainActivity :
     val extras = intent.extras ?: return
 
     if (extras.getBoolean(KEY_EXIT_DETAIL, false)) {
-      mainNavigationViewModel.exitDetailLocation()
+      mainNavigationViewModel.onEvent(MainNavigationEvents.ExitDetail)
       return
     }
 
     val detailLocation = extras.getParcelableCompat(KEY_DETAIL_LOCATION, MainDetailRoute::class.java)
     if (detailLocation != null) {
-      goTo(detailLocation)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(detailLocation))
       return
     }
 
-    val startingTab = extras.getSerializableCompat(KEY_STARTING_TAB, MainListRoute::class.java)
+    val startingTab = extras.getSerializableCompat(KEY_STARTING_TAB, MainListRoute::class.java) ?: return
 
-    when (startingTab) {
-      MainListRoute.Chats -> mainNavigationViewModel.onChatsSelected()
-      MainListRoute.Archive -> mainNavigationViewModel.onArchiveSelected()
-      MainListRoute.Calls -> mainNavigationViewModel.onCallsSelected()
-      MainListRoute.Stories -> {
-        if (Stories.isFeatureEnabled()) {
-          mainNavigationViewModel.onStoriesSelected()
-        }
-      }
-
-      null -> Unit
+    if (startingTab != MainListRoute.Stories || Stories.isFeatureEnabled()) {
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToTab(startingTab))
     }
   }
 
@@ -749,7 +742,7 @@ class MainActivity :
     }
 
     vitalsViewModel.checkSlowNotificationHeuristics()
-    mainNavigationViewModel.refreshNavigationBarState()
+    mainNavigationViewModel.onEvent(MainNavigationEvents.RefreshNavigationBar)
 
     CallQuality.consumeQualityRequest()?.let {
       CallQualityBottomSheetFragment.create(it).show(supportFragmentManager, BottomSheetUtil.STANDARD_BOTTOM_SHEET_FRAGMENT_TAG)
@@ -775,7 +768,7 @@ class MainActivity :
 
     if (resultCode == RESULT_OK && requestCode == CreateSvrPinActivity.REQUEST_NEW_PIN) {
       mainNavigationViewModel.snackbarRegistry.emit(SnackbarState(message = getString(R.string.ConfirmKbsPinFragment__pin_created), hostKey = MainSnackbarHostKey.MainChrome))
-      mainNavigationViewModel.onMegaphoneCompleted(Megaphones.Event.PINS_FOR_ALL)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.MegaphoneCompleted(Megaphones.Event.PINS_FOR_ALL))
     }
 
     if (resultCode == RESULT_OK && requestCode == UsernameEditFragment.REQUEST_CODE) {
@@ -796,7 +789,7 @@ class MainActivity :
           hostKey = MainSnackbarHostKey.MainChrome
         )
       )
-      mainNavigationViewModel.onMegaphoneSnoozed(Megaphones.Event.VERIFY_BACKUP_KEY)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.MegaphoneSnoozed(Megaphones.Event.VERIFY_BACKUP_KEY))
     }
   }
 
@@ -896,8 +889,8 @@ class MainActivity :
         return
       }
 
-      mainNavigationViewModel.goTo(MainListRoute.Chats)
-      mainNavigationViewModel.goTo(MainDetailRoute.Conversation(ConversationIntents.readArgsFromBundle(extras)))
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Conversation(ConversationIntents.readArgsFromBundle(extras))))
       intent.action = null
       setIntent(intent)
     }
@@ -1033,7 +1026,7 @@ class MainActivity :
     }
 
     override fun onOpenArchiveClick() {
-      mainNavigationViewModel.onArchiveSelected()
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToTab(MainListRoute.Archive))
     }
 
     override fun onStarredMessagesClick() {
@@ -1069,11 +1062,11 @@ class MainActivity :
     }
 
     override fun onStoryPrivacyClick() {
-      mainNavigationViewModel.goTo(MainDetailRoute.Stories.PrivacySettings)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Stories.PrivacySettings))
     }
 
     override fun onStoryArchiveClick() {
-      mainNavigationViewModel.goTo(MainDetailRoute.Stories.Archive)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Stories.Archive))
     }
 
     override fun onCloseSearchClick() {
@@ -1125,7 +1118,7 @@ class MainActivity :
     }
 
     override fun onMegaphoneVisible(megaphone: Megaphone) {
-      mainNavigationViewModel.onMegaphoneVisible(megaphone)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.MegaphoneVisible(megaphone))
     }
 
     override fun onSnackbarDismissed() = Unit
@@ -1154,11 +1147,11 @@ class MainActivity :
     }
 
     override fun onMegaphoneSnooze(event: Megaphones.Event) {
-      mainNavigationViewModel.onMegaphoneSnoozed(event)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.MegaphoneSnoozed(event))
     }
 
     override fun onMegaphoneCompleted(event: Megaphones.Event) {
-      mainNavigationViewModel.onMegaphoneCompleted(event)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.MegaphoneCompleted(event))
     }
 
     override fun onMegaphoneDialogFragmentRequested(dialogFragment: DialogFragment) {
@@ -1166,18 +1159,5 @@ class MainActivity :
     }
   }
 
-  private inner class MainNavigationCallback : (MainListRoute) -> Unit {
-    override fun invoke(location: MainListRoute) {
-      when (location) {
-        MainListRoute.Chats -> mainNavigationViewModel.onChatsSelected()
-        MainListRoute.Calls -> mainNavigationViewModel.onCallsSelected()
-        MainListRoute.Stories -> mainNavigationViewModel.onStoriesSelected()
-        MainListRoute.Archive -> mainNavigationViewModel.onArchiveSelected()
-      }
-    }
-  }
-
-  override fun goTo(location: MainListRoute) = mainNavigationViewModel.goTo(location)
-  override fun goTo(location: MainDetailRoute) = mainNavigationViewModel.goTo(location)
-  override fun exitDetailLocation() = mainNavigationViewModel.exitDetailLocation()
+  override fun onEvent(event: MainNavigationEvents) = mainNavigationViewModel.onEvent(event)
 }

app/src/main/java/org/thoughtcrime/securesms/MainNavigator.java

@@ -11,6 +11,7 @@ import org.thoughtcrime.securesms.components.settings.app.AppSettingsActivity;
 import org.thoughtcrime.securesms.conversation.ConversationIntents;
 import org.thoughtcrime.securesms.groups.ui.creategroup.CreateGroupActivity;
 import org.thoughtcrime.securesms.main.MainDetailRoute;
+import org.thoughtcrime.securesms.main.MainNavigationEvents;
 import org.thoughtcrime.securesms.main.MainNavigationViewModel;
 import org.thoughtcrime.securesms.recipients.RecipientId;
 
@@ -50,7 +51,7 @@ public class MainNavigator {
                                                                       .withStartingPosition(startingPosition)
                                                                       .asIncognito(incognito)
                                                                       .toConversationArgs())
-                                               .subscribe(args -> viewModel.goTo(new MainDetailRoute.Conversation(args)));
+                                               .subscribe(args -> viewModel.onEvent(new MainNavigationEvents.GoToDetail(new MainDetailRoute.Conversation(args))));
 
     lifecycleDisposable.add(disposable);
   }

app/src/main/java/org/thoughtcrime/securesms/calls/links/details/CallLinkDetailsScreen.kt

@@ -47,7 +47,8 @@ import org.thoughtcrime.securesms.calls.links.CallLinks
 import org.thoughtcrime.securesms.calls.links.SignalCallRow
 import org.thoughtcrime.securesms.database.CallLinkTable
 import org.thoughtcrime.securesms.main.MainDetailRoute
-import org.thoughtcrime.securesms.main.MainNavigationCallDetailRouter
+import org.thoughtcrime.securesms.main.MainNavigationEventSink
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.main.MainNavigationViewModel
 import org.thoughtcrime.securesms.recipients.RecipientId
 import org.thoughtcrime.securesms.service.webrtc.links.CallLinkCredentials
@@ -63,7 +64,7 @@ fun CallLinkDetailsScreen(
   viewModel: CallLinkDetailsViewModel = viewModel {
     CallLinkDetailsViewModel(roomId)
   },
-  router: MainNavigationCallDetailRouter = viewModel<MainNavigationViewModel>(viewModelStoreOwner = LocalActivity.current as ComponentActivity) {
+  eventSink: MainNavigationEventSink = viewModel<MainNavigationViewModel>(viewModelStoreOwner = LocalActivity.current as ComponentActivity) {
     error("Should already be created.")
   }
 ) {
@@ -72,7 +73,7 @@ fun CallLinkDetailsScreen(
     DefaultCallLinkDetailsCallback(
       activity = activity,
       viewModel = viewModel,
-      router = router
+      eventSink = eventSink
     )
   }
 
@@ -90,7 +91,7 @@ fun CallLinkDetailsScreen(
 class DefaultCallLinkDetailsCallback(
   private val activity: FragmentActivity,
   private val viewModel: CallLinkDetailsViewModel,
-  private val router: MainNavigationCallDetailRouter
+  private val eventSink: MainNavigationEventSink
 ) : CallLinkDetailsCallback {
 
   private val lifecycleDisposable = LifecycleDisposable()
@@ -113,10 +114,12 @@ class DefaultCallLinkDetailsCallback(
   }
 
   override fun onEditNameClicked() {
-    router.goToCallDetail(
-      MainDetailRoute.Calls.CallLinks.EditCallLinkName(
-        callLinkRoomId = viewModel.recipientSnapshot!!.requireCallLinkRoomId(),
-        currentName = viewModel.nameSnapshot
+    eventSink.onEvent(
+      MainNavigationEvents.GoToDetail(
+        MainDetailRoute.Calls.CallLinks.EditCallLinkName(
+          callLinkRoomId = viewModel.recipientSnapshot!!.requireCallLinkRoomId(),
+          currentName = viewModel.nameSnapshot
+        )
       )
     )
   }
@@ -157,7 +160,7 @@ class DefaultCallLinkDetailsCallback(
     viewModel.setDisplayRevocationDialog(false)
     activity.lifecycleScope.launch {
       if (viewModel.delete()) {
-        router.exitDetailLocation()
+        eventSink.onEvent(MainNavigationEvents.ExitDetail)
       }
     }
   }

app/src/main/java/org/thoughtcrime/securesms/calls/log/CallLogFragment.kt

@@ -51,6 +51,7 @@ import org.thoughtcrime.securesms.databinding.CallLogFragmentBinding
 import org.thoughtcrime.securesms.dependencies.AppDependencies
 import org.thoughtcrime.securesms.main.MainDetailRoute
 import org.thoughtcrime.securesms.main.MainListRoute
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.main.MainNavigationViewModel
 import org.thoughtcrime.securesms.main.MainSnackbarHostKey
 import org.thoughtcrime.securesms.main.MainToolbarMode
@@ -335,7 +336,7 @@ class CallLogFragment : Fragment(R.layout.call_log_fragment), CallLogAdapter.Cal
     if (viewModel.selectionStateSnapshot.isNotEmpty(binding.recycler.adapter!!.itemCount)) {
       viewModel.toggleSelected(callLogRow.id)
     } else {
-      mainNavigationViewModel.goTo(MainDetailRoute.CallLinkDetails(callLogRow.record.roomId))
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.CallLinkDetails(callLogRow.record.roomId)))
     }
   }
 
@@ -390,7 +391,7 @@ class CallLogFragment : Fragment(R.layout.call_log_fragment), CallLogAdapter.Cal
   }
 
   override fun goToCallLinkDetails(roomId: CallLinkRoomId) {
-    mainNavigationViewModel.goTo(MainDetailRoute.CallLinkDetails(roomId))
+    mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.CallLinkDetails(roomId)))
   }
 
   override fun deleteCall(call: CallLogRow) {

app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/ConversationSettingsFragment.kt

@@ -64,7 +64,8 @@ import org.thoughtcrime.securesms.groups.ui.managegroup.dialogs.GroupDescription
 import org.thoughtcrime.securesms.groups.ui.managegroup.dialogs.GroupInviteSentDialog
 import org.thoughtcrime.securesms.groups.ui.managegroup.dialogs.GroupsLearnMoreBottomSheetDialogFragment
 import org.thoughtcrime.securesms.jobs.AttachmentDownloadJob
-import org.thoughtcrime.securesms.main.MainNavigationChatDetailRouter
+import org.thoughtcrime.securesms.main.MainNavigationEventSink
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.mediaoverview.MediaOverviewActivity
 import org.thoughtcrime.securesms.mediapreview.MediaIntentFactory
 import org.thoughtcrime.securesms.mediapreview.MediaPreviewCache
@@ -117,7 +118,7 @@ class ConversationSettingsFragment : ComposeFragment() {
   )
 
   private var transitionCallback: TransitionCallback? = null
-  private var chatRouter: MainNavigationChatDetailRouter? = null
+  private var mainNavigationEventSink: MainNavigationEventSink? = null
 
   /** The avatar view owns the shared element transition out of this screen. */
   private var avatarView: View? = null
@@ -130,7 +131,7 @@ class ConversationSettingsFragment : ComposeFragment() {
   override fun onAttach(context: Context) {
     super.onAttach(context)
     transitionCallback = context as? TransitionCallback
-    chatRouter = context as? MainNavigationChatDetailRouter
+    mainNavigationEventSink = context as? MainNavigationEventSink
   }
 
   override fun onCreate(savedInstanceState: Bundle?) {
@@ -358,7 +359,7 @@ class ConversationSettingsFragment : ComposeFragment() {
         val builder = ConversationIntents.createBuilderSync(requireContext(), action.recipientId, action.threadId)
         startActivity(builder.withSearchOpen(action.withSearchOpen).build())
 
-        if (action.withSearchOpen && requireActivity() !is MainNavigationChatDetailRouter) {
+        if (action.withSearchOpen && requireActivity() !is MainNavigationEventSink) {
           requireActivity().finish()
         }
       }
@@ -453,7 +454,7 @@ class ConversationSettingsFragment : ComposeFragment() {
       }
       is ConversationSettingsAction.OpenGroupConversation -> {
         CommunicationActions.startConversation(requireActivity(), action.recipient, null)
-        if (requireActivity() !is MainNavigationChatDetailRouter) {
+        if (requireActivity() !is MainNavigationEventSink) {
           requireActivity().finish()
         }
       }
@@ -558,8 +559,9 @@ class ConversationSettingsFragment : ComposeFragment() {
   }
 
   private fun goToConversationList() {
-    if (chatRouter != null) {
-      chatRouter?.exitDetailLocation()
+    val eventSink = mainNavigationEventSink
+    if (eventSink != null) {
+      eventSink.onEvent(MainNavigationEvents.ExitDetail)
     } else {
       startActivity(MainActivity.clearTopAndExitDetail(requireContext()))
     }

app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/ConversationSettingsNavigator.kt

@@ -7,7 +7,8 @@ package org.thoughtcrime.securesms.components.settings.conversation
 
 import androidx.fragment.app.FragmentActivity
 import org.thoughtcrime.securesms.main.MainDetailRoute
-import org.thoughtcrime.securesms.main.MainNavigationChatDetailRouter
+import org.thoughtcrime.securesms.main.MainNavigationEventSink
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.recipients.Recipient
 
 /**
@@ -19,8 +20,8 @@ object ConversationSettingsNavigator {
     activity: FragmentActivity,
     recipient: Recipient
   ) {
-    if (activity is MainNavigationChatDetailRouter) {
-      activity.goToChatDetail(MainDetailRoute.Chats.ConversationSettings(recipient.id))
+    if (activity is MainNavigationEventSink) {
+      activity.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Chats.ConversationSettings(recipient.id)))
       return
     }
 

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationActivity.kt

@@ -28,7 +28,8 @@ import org.thoughtcrime.securesms.components.voice.VoiceNoteMediaControllerOwner
 import org.thoughtcrime.securesms.conversation.ConversationIntents
 import org.thoughtcrime.securesms.jobs.ConversationShortcutUpdateJob
 import org.thoughtcrime.securesms.main.MainDetailRoute
-import org.thoughtcrime.securesms.main.MainNavigationChatDetailRouter
+import org.thoughtcrime.securesms.main.MainNavigationEventSink
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.messagedetails.MessageDetailsFragment
 import org.thoughtcrime.securesms.util.DynamicNoActionBarTheme
 import java.util.concurrent.TimeUnit
@@ -36,7 +37,7 @@ import java.util.concurrent.TimeUnit
 /**
  * Wrapper activity for ConversationFragment.
  */
-open class ConversationActivity : PassphraseRequiredActivity(), VoiceNoteMediaControllerOwner, GooglePayComponent, MainNavigationChatDetailRouter {
+open class ConversationActivity : PassphraseRequiredActivity(), VoiceNoteMediaControllerOwner, GooglePayComponent, MainNavigationEventSink {
 
   companion object {
     private val TAG = tag(ConversationActivity::class.java)
@@ -141,13 +142,33 @@ open class ConversationActivity : PassphraseRequiredActivity(), VoiceNoteMediaCo
       .commitNowAllowingStateLoss()
   }
 
-  override fun exitDetailLocation() {
+  /**
+   * Only the events a conversation displayed on its own can answer. The rest belong to the main window,
+   * which is where the same screens send them when it is the one hosting them.
+   */
+  override fun onEvent(event: MainNavigationEvents) {
+    when (event) {
+      MainNavigationEvents.ExitDetail -> exitDetail()
+      is MainNavigationEvents.GoToDetail -> {
+        val route = event.route
+        if (route is MainDetailRoute.Chats) {
+          goToChatDetail(route)
+        } else {
+          Log.w(TAG, "Cannot display $route outside of the main window. Ignoring it.")
+        }
+      }
+
+      else -> Log.w(TAG, "Unsupported outside of the main window: $event. Ignoring it.")
+    }
+  }
+
+  private fun exitDetail() {
     if (!supportFragmentManager.popBackStackImmediate()) {
       finish()
     }
   }
 
-  override fun goToChatDetail(location: MainDetailRoute.Chats) {
+  private fun goToChatDetail(location: MainDetailRoute.Chats) {
     when (location) {
       is MainDetailRoute.Chats.ConversationSettings -> {
         lifecycleScope.launch {

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt

@@ -298,7 +298,8 @@ import org.thoughtcrime.securesms.linkpreview.LinkPreviewViewModelV2
 import org.thoughtcrime.securesms.longmessage.LongMessageFragment
 import org.thoughtcrime.securesms.main.MainDetailRoute
 import org.thoughtcrime.securesms.main.MainListRoute
-import org.thoughtcrime.securesms.main.MainNavigationChatDetailRouter
+import org.thoughtcrime.securesms.main.MainNavigationEventSink
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.main.MainNavigationViewModel
 import org.thoughtcrime.securesms.main.MainSnackbarHostKey
 import org.thoughtcrime.securesms.mediaoverview.MediaOverviewActivity
@@ -581,7 +582,7 @@ class ConversationFragment :
   private lateinit var conversationItemDecorations: ConversationItemDecorations
   private lateinit var optionsMenuCallback: ConversationOptionsMenuCallback
 
-  private lateinit var chatRouter: MainNavigationChatDetailRouter
+  private lateinit var mainNavigationEventSink: MainNavigationEventSink
 
   private var animationsAllowed = false
   private var pinnedShortcutReceiver: BroadcastReceiver? = null
@@ -662,7 +663,7 @@ class ConversationFragment :
 
   override fun onAttach(context: Context) {
     super.onAttach(context)
-    chatRouter = context as MainNavigationChatDetailRouter
+    mainNavigationEventSink = context as MainNavigationEventSink
   }
 
   override fun onCreate(savedInstanceState: Bundle?) {
@@ -3004,7 +3005,7 @@ class ConversationFragment :
     ConversationDialogs.displayDeleteDialog(requireContext(), recipient) {
       messageRequestViewModel
         .onDelete()
-        .doAfterSuccess { chatRouter.exitDetailLocation() }
+        .doAfterSuccess { mainNavigationEventSink.onEvent(MainNavigationEvents.ExitDetail) }
         .subscribeWithShowProgress("delete message request")
     }
   }
@@ -3151,7 +3152,8 @@ class ConversationFragment :
 
   private fun handleDisplayDetails(conversationMessage: ConversationMessage) {
     val recipientSnapshot = viewModel.recipientSnapshot ?: return
-    chatRouter.goToChatDetail(MainDetailRoute.Chats.MessageDetails(recipientSnapshot.id, MessageId(conversationMessage.messageRecord.id)))
+    val messageDetails = MainDetailRoute.Chats.MessageDetails(recipientSnapshot.id, MessageId(conversationMessage.messageRecord.id))
+    mainNavigationEventSink.onEvent(MainNavigationEvents.GoToDetail(messageDetails))
   }
 
   private fun handleDeleteMessages(messageParts: Set<MultiselectPart>) {
@@ -3707,7 +3709,7 @@ class ConversationFragment :
       } else if (messageRecord.hasFailedWithNetworkFailures()) {
         ConversationDialogs.displayMessageCouldNotBeSentDialog(requireContext(), messageRecord)
       } else {
-        chatRouter.goToChatDetail(MainDetailRoute.Chats.MessageDetails(recipientId, MessageId(messageRecord.id)))
+        mainNavigationEventSink.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Chats.MessageDetails(recipientId, MessageId(messageRecord.id))))
       }
     }
 
@@ -4388,7 +4390,7 @@ class ConversationFragment :
     override fun handleManageGroup() {
       viewModel.recipientSnapshot?.let { recipient ->
         container.hideKeyboard(composeText)
-        chatRouter.goToChatDetail(MainDetailRoute.Chats.ConversationSettings(recipient.id))
+        mainNavigationEventSink.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Chats.ConversationSettings(recipient.id)))
       }
     }
 
@@ -4426,7 +4428,7 @@ class ConversationFragment :
       viewModel.recipientSnapshot?.let { recipient ->
         if (!viewModel.hasMessageRequestState || recipient.isBlocked) {
           container.hideKeyboard(composeText)
-          chatRouter.goToChatDetail(MainDetailRoute.Chats.ConversationSettings(recipient.id))
+          mainNavigationEventSink.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Chats.ConversationSettings(recipient.id)))
         }
       }
     }

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

@@ -34,6 +34,7 @@ import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.components.snackbars.SnackbarState;
 import org.thoughtcrime.securesms.database.SignalDatabase;
 import org.thoughtcrime.securesms.main.MainListRoute;
+import org.thoughtcrime.securesms.main.MainNavigationEvents;
 import org.thoughtcrime.securesms.main.MainSnackbarHostKey;
 import org.thoughtcrime.securesms.util.ConversationUtil;
 
@@ -77,7 +78,7 @@ public class ConversationListArchiveFragment extends ConversationListFragment
     requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
       @Override
       public void handleOnBackPressed() {
-        mainNavigationViewModel.goTo(MainListRoute.Chats);
+        mainNavigationViewModel.onEvent(new MainNavigationEvents.GoToList(MainListRoute.Chats));
       }
     });
   }

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

@@ -144,6 +144,7 @@ import org.thoughtcrime.securesms.jobs.RefreshOwnProfileJob;
 import org.thoughtcrime.securesms.keyvalue.AccountValues;
 import org.thoughtcrime.securesms.keyvalue.SignalStore;
 import org.thoughtcrime.securesms.main.MainListRoute;
+import org.thoughtcrime.securesms.main.MainNavigationEvents;
 import org.thoughtcrime.securesms.main.MainNavigationViewModel;
 import org.thoughtcrime.securesms.main.MainSnackbarHostKey;
 import org.thoughtcrime.securesms.main.MainToolbarMode;
@@ -702,7 +703,7 @@ public class ConversationListFragment extends MainFragment implements Conversati
   @Override
   public void onShowArchiveClick() {
     if (viewModel.currentSelectedConversations().isEmpty()) {
-      mainNavigationViewModel.goTo(MainListRoute.Archive);
+      mainNavigationViewModel.onEvent(new MainNavigationEvents.GoToList(MainListRoute.Archive));
     }
   }
 
@@ -765,7 +766,7 @@ public class ConversationListFragment extends MainFragment implements Conversati
           } else if (event instanceof MainToolbarViewModel.Event.Chats.ClearFilter) {
             onClearFilterClick();
           } else if (event instanceof MainToolbarViewModel.Event.Chats.CloseArchive) {
-            mainNavigationViewModel.goTo(MainListRoute.Chats);
+            mainNavigationViewModel.onEvent(new MainNavigationEvents.GoToList(MainListRoute.Chats));
           }
         })
     );

app/src/main/java/org/thoughtcrime/securesms/main/MainNavigationEventSink.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.main
+
+/**
+ * An activity that hosts main navigation content and can answer its events.
+ *
+ * The main window hands them to [MainNavigationViewModel]. The standalone conversation activity answers
+ * the few that still mean something outside the main window with its own fragment transactions. Screens
+ * that either one can host send their events here, and check for it to tell the two hosts apart.
+ */
+fun interface MainNavigationEventSink {
+  fun onEvent(event: MainNavigationEvents)
+}

app/src/main/java/org/thoughtcrime/securesms/main/MainNavigationEvents.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.main
+
+import org.signal.core.ui.compose.split.ListDetailEvents
+import org.thoughtcrime.securesms.megaphone.Megaphone
+import org.thoughtcrime.securesms.megaphone.Megaphones
+
+/**
+ * UI Events to drive the main navigation view model.
+ */
+sealed interface MainNavigationEvents {
+
+  /**
+   * The user clicked [tab] in the navigation bar or rail. Clicking the tab already displayed reveals its
+   * list and tells that tab's screen about the click, rather than navigating anywhere.
+   */
+  data class GoToTab(val tab: MainListRoute) : MainNavigationEvents
+
+  /** Display [route], which comes back to whatever detail content its tab had open. */
+  data class GoToList(val route: MainListRoute) : MainNavigationEvents
+
+  /** Open [route] above the list of whichever tab owns it. */
+  data class GoToDetail(val route: MainDetailRoute) : MainNavigationEvents
+
+  /** Drop the detail above the displayed list, leaving that list on its own. */
+  data object ExitDetail : MainNavigationEvents
+
+  /** Open the camera straight into story capture. */
+  data object GoToCameraFirstStoryCapture : MainNavigationEvents
+
+  /** Re-read the settings that shape the navigation bar. */
+  data object RefreshNavigationBar : MainNavigationEvents
+
+  /** Ask for the next megaphone to display, if there is one. */
+  data object RequestNextMegaphone : MainNavigationEvents
+
+  /** [megaphone] was displayed to the user. */
+  data class MegaphoneVisible(val megaphone: Megaphone) : MainNavigationEvents
+
+  /** The user put [event]'s megaphone off until later. */
+  data class MegaphoneSnoozed(val event: Megaphones.Event) : MainNavigationEvents
+
+  /** [event]'s megaphone is done with, and should not come back. */
+  data class MegaphoneCompleted(val event: Megaphones.Event) : MainNavigationEvents
+
+  /** Something that is navigation and nothing else, so the navigator can answer it unaided. */
+  data class ListDetailEvent(val event: ListDetailEvents) : MainNavigationEvents
+}

app/src/main/java/org/thoughtcrime/securesms/main/MainNavigationRouter.kt

@@ -1,33 +0,0 @@
-/*
- * Copyright 2025 Signal Messenger, LLC
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-package org.thoughtcrime.securesms.main
-
-/**
- * Handles navigation for sub-screens within the chats detail pane.
- */
-interface MainNavigationChatDetailRouter {
-  fun exitDetailLocation()
-  fun goToChatDetail(location: MainDetailRoute.Chats)
-}
-
-/**
- * Handles navigation for sub-screens within the calls detail pane.
- */
-interface MainNavigationCallDetailRouter {
-  fun exitDetailLocation()
-  fun goToCallDetail(location: MainDetailRoute.Calls)
-}
-
-/**
- * Handles navigation to all [MainListRoute]s and [MainDetailRoute]s, including the top-level roots.
- */
-interface MainNavigationRouter : MainNavigationChatDetailRouter, MainNavigationCallDetailRouter {
-  fun goTo(location: MainListRoute)
-  fun goTo(location: MainDetailRoute)
-
-  override fun goToChatDetail(location: MainDetailRoute.Chats) = goTo(location)
-  override fun goToCallDetail(location: MainDetailRoute.Calls) = goTo(location)
-}

app/src/main/java/org/thoughtcrime/securesms/main/MainNavigationViewModel.kt

@@ -27,6 +27,7 @@ import kotlinx.coroutines.reactive.asFlow
 import kotlinx.coroutines.rx3.asObservable
 import kotlinx.coroutines.withContext
 import kotlinx.coroutines.withTimeoutOrNull
+import org.signal.core.ui.compose.EventDrivenViewModel
 import org.signal.core.ui.compose.split.ListDetailEvents
 import org.signal.core.ui.compose.split.ListDetailNavigator
 import org.signal.core.ui.compose.split.PaneAnchor
@@ -49,7 +50,7 @@ import kotlin.time.Duration.Companion.milliseconds
 class MainNavigationViewModel(
   savedStateHandle: SavedStateHandle,
   initialListLocation: MainListRoute = MainListRoute.Chats
-) : ViewModel(), MainNavigationRouter {
+) : EventDrivenViewModel<MainNavigationEvents>(TAG), MainNavigationEventSink {
 
   companion object {
     private val TAG = Log.tag(MainNavigationViewModel::class)
@@ -156,11 +157,20 @@ class MainNavigationViewModel(
     }
   }
 
-  /**
-   * The user dragged the pane divider to [anchor].
-   */
-  fun onPaneAnchorSelected(anchor: PaneAnchor) {
-    navigator.processEvent(ListDetailEvents.AnchorSelected(anchor))
+  override suspend fun processEvent(event: MainNavigationEvents) {
+    when (event) {
+      is MainNavigationEvents.GoToTab -> goToTab(event.tab)
+      is MainNavigationEvents.GoToList -> goToList(event.route)
+      is MainNavigationEvents.GoToDetail -> goToDetail(event.route)
+      MainNavigationEvents.ExitDetail -> navigator.processEvent(ListDetailEvents.ExitDetail)
+      MainNavigationEvents.GoToCameraFirstStoryCapture -> internalNavigationEvents.emit(NavigationEvent.STORY_CAMERA_FIRST)
+      MainNavigationEvents.RefreshNavigationBar -> refreshNavigationBarState()
+      MainNavigationEvents.RequestNextMegaphone -> requestNextMegaphone()
+      is MainNavigationEvents.MegaphoneVisible -> megaphoneRepository.markVisible(event.megaphone.event)
+      is MainNavigationEvents.MegaphoneSnoozed -> onMegaphoneSnoozed(event.event)
+      is MainNavigationEvents.MegaphoneCompleted -> onMegaphoneCompleted(event.event)
+      is MainNavigationEvents.ListDetailEvent -> navigator.processEvent(event.event)
+    }
   }
 
   /** Set from the MainActivity composition, and cleared when it is disposed. */
@@ -168,7 +178,38 @@ class MainNavigationViewModel(
     captureChatListSnapshot = capture
   }
 
-  override fun goTo(location: MainDetailRoute) = setDetailLocation(location)
+  /**
+   * Clicking the tab already displayed reveals its list and tells that tab's screen about the click —
+   * scrolling to the top, and the like — rather than navigating anywhere.
+   */
+  private suspend fun goToTab(tab: MainListRoute) {
+    if (navigator.displayedList.value == tab) {
+      navigator.processEvent(ListDetailEvents.RevealList)
+      internalTabClickEvents.emit(tab)
+    } else {
+      goToList(tab)
+    }
+  }
+
+  /** Switching tabs only changes which stack is displayed; each tab comes back to whatever it had open. */
+  private fun goToList(route: MainListRoute) {
+    navigator.processEvent(
+      ListDetailEvents.GoToList(
+        listRoute = route,
+        root = route.tab,
+        push = route == MainListRoute.Archive
+      )
+    )
+  }
+
+  private suspend fun goToDetail(route: MainDetailRoute) {
+    when (route) {
+      is MainDetailRoute.Chats -> pushChatsDetailLocation(route)
+      is MainDetailRoute.Conversation -> goToConversation(route)
+      is MainDetailRoute.Calls, is MainDetailRoute.CallLinkDetails -> pushCallsDetailLocation(route)
+      is MainDetailRoute.Stories -> navigator.processEvent(ListDetailEvents.Push(route, MainListRoute.Stories))
+    }
+  }
 
   private suspend fun MainDetailRoute.Conversation.withPreloadedWallpaper(): MainDetailRoute.Conversation {
     val args = conversationArgs
@@ -196,33 +237,15 @@ class MainNavigationViewModel(
     return copy(conversationArgs = updatedArgs)
   }
 
-  private fun setDetailLocation(location: MainDetailRoute) {
-    when (location) {
-      is MainDetailRoute.Chats -> pushChatsDetailLocation(location)
-      is MainDetailRoute.Conversation -> goToConversation(location)
-      is MainDetailRoute.Calls, is MainDetailRoute.CallLinkDetails -> pushCallsDetailLocation(location)
-      is MainDetailRoute.Stories -> pushStoriesDetailLocation(location)
-    }
-  }
-
-  /**
-   * Drops the detail content above the current list, leaving that list displayed on its own.
-   */
-  override fun exitDetailLocation() {
-    navigator.processEvent(ListDetailEvents.ExitDetail)
-  }
-
-  private fun goToConversation(location: MainDetailRoute.Conversation) {
+  private suspend fun goToConversation(location: MainDetailRoute.Conversation) {
     val captureSnapshot = captureChatListSnapshot
 
     if (captureSnapshot == null) {
-      // share intent or process restore - push synchronously, since there's no chat-list snapshot to capture and no need to preload a wallpaper
+      // share intent or process restore - there's no chat-list snapshot to capture and no need to preload a wallpaper
       pushChatsDetailLocation(location)
     } else {
-      viewModelScope.launch {
-        captureSnapshot()
-        pushChatsDetailLocation(location.withPreloadedWallpaper())
-      }
+      captureSnapshot()
+      pushChatsDetailLocation(location.withPreloadedWallpaper())
     }
   }
 
@@ -244,53 +267,23 @@ class MainNavigationViewModel(
     navigator.processEvent(ListDetailEvents.Push(location, MainListRoute.Calls))
   }
 
-  private fun pushStoriesDetailLocation(location: MainDetailRoute) {
-    navigator.processEvent(ListDetailEvents.Push(location, MainListRoute.Stories))
-  }
-
-  /** Pops the stack belonging to whichever tab the user is currently on. */
-  fun popCurrentDetailLocation() {
-    navigator.processEvent(ListDetailEvents.Back)
-  }
-
-  /** Switching tabs only changes which stack is displayed; each tab comes back to whatever it had open. */
-  override fun goTo(location: MainListRoute) {
-    navigator.processEvent(
-      ListDetailEvents.GoToList(
-        listRoute = location,
-        root = location.tab,
-        push = location == MainListRoute.Archive
-      )
-    )
-  }
-
-  fun goToCameraFirstStoryCapture() {
-    viewModelScope.launch {
-      internalNavigationEvents.emit(NavigationEvent.STORY_CAMERA_FIRST)
-    }
-  }
-
-  fun getNextMegaphone() {
+  private fun requestNextMegaphone() {
     megaphoneRepository.getNextMegaphone { next ->
       internalMegaphone.update { next ?: Megaphone.NONE }
     }
   }
 
-  fun onMegaphoneSnoozed(event: Megaphones.Event) {
+  private fun onMegaphoneSnoozed(event: Megaphones.Event) {
     megaphoneRepository.markInteractedWith(event)
     internalMegaphone.update { Megaphone.NONE }
   }
 
-  fun onMegaphoneCompleted(event: Megaphones.Event) {
+  private fun onMegaphoneCompleted(event: Megaphones.Event) {
     internalMegaphone.update { Megaphone.NONE }
     megaphoneRepository.markFinished(event)
   }
 
-  fun onMegaphoneVisible(visible: Megaphone) {
-    megaphoneRepository.markVisible(visible.event)
-  }
-
-  fun refreshNavigationBarState() {
+  private fun refreshNavigationBarState() {
     internalMainNavigationBarState.update {
       it.copy(
         compact = SignalStore.settings.useCompactNavigationBar,
@@ -305,34 +298,6 @@ class MainNavigationViewModel(
     return notificationProfilesRepository.getProfiles().asFlow()
   }
 
-  fun onChatsSelected() {
-    onTabSelected(MainListRoute.Chats)
-  }
-
-  fun onArchiveSelected() {
-    onTabSelected(MainListRoute.Archive)
-  }
-
-  fun onCallsSelected() {
-    onTabSelected(MainListRoute.Calls)
-  }
-
-  fun onStoriesSelected() {
-    onTabSelected(MainListRoute.Stories)
-  }
-
-  private fun onTabSelected(destination: MainListRoute) {
-    viewModelScope.launch {
-      val displayed = navigator.displayedList.value
-      if (displayed == destination) {
-        navigator.processEvent(ListDetailEvents.RevealList)
-        internalTabClickEvents.emit(destination)
-      } else {
-        goTo(destination)
-      }
-    }
-  }
-
   private fun <T : Any> performStoreUpdate(flow: Flow<T>, fn: (T, MainNavigationBarState) -> MainNavigationBarState) {
     viewModelScope.launch {
       flow.collectLatest { item ->

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

@@ -34,6 +34,7 @@ import org.thoughtcrime.securesms.database.model.StoryViewState
 import org.thoughtcrime.securesms.dependencies.AppDependencies
 import org.thoughtcrime.securesms.main.MainDetailRoute
 import org.thoughtcrime.securesms.main.MainListRoute
+import org.thoughtcrime.securesms.main.MainNavigationEvents
 import org.thoughtcrime.securesms.main.MainNavigationViewModel
 import org.thoughtcrime.securesms.main.MainSnackbarHostKey
 import org.thoughtcrime.securesms.main.MainToolbarViewModel
@@ -188,7 +189,7 @@ class StoriesLandingFragment : DSLSettingsFragment(layoutId = R.layout.stories_l
           MyStoriesItem.Model(
             lifecycleOwner = viewLifecycleOwner,
             onClick = {
-              mainNavigationViewModel.goToCameraFirstStoryCapture()
+              mainNavigationViewModel.onEvent(MainNavigationEvents.GoToCameraFirstStoryCapture)
             }
           )
         )
@@ -258,7 +259,7 @@ class StoriesLandingFragment : DSLSettingsFragment(layoutId = R.layout.stories_l
         openStoryViewer(model, preview, true)
       },
       onAvatarClick = {
-        mainNavigationViewModel.goToCameraFirstStoryCapture()
+        mainNavigationViewModel.onEvent(MainNavigationEvents.GoToCameraFirstStoryCapture)
       },
       onLockList = {
         recyclerView?.suppressLayout(true)
@@ -271,7 +272,7 @@ class StoriesLandingFragment : DSLSettingsFragment(layoutId = R.layout.stories_l
 
   private fun openStoryViewer(model: StoriesLandingItem.Model, preview: View, isFromInfoContextMenuAction: Boolean) {
     if (model.data.storyRecipient.isMyStory) {
-      mainNavigationViewModel.goTo(MainDetailRoute.Stories.MyStories)
+      mainNavigationViewModel.onEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Stories.MyStories))
     } else if (model.data.primaryStory.messageRecord.isOutgoing && model.data.primaryStory.messageRecord.isFailed) {
       if (model.data.primaryStory.messageRecord.isIdentityMismatchFailure) {
         SafetyNumberBottomSheet

app/src/test/java/org/thoughtcrime/securesms/main/MainNavigationViewModelTest.kt

@@ -25,6 +25,7 @@ import org.junit.Test
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
 import org.robolectric.annotation.Config
+import org.signal.core.ui.compose.split.ListDetailEvents
 import org.signal.core.ui.compose.split.PaneAnchor
 import org.thoughtcrime.securesms.database.SignalDatabase
 import org.thoughtcrime.securesms.database.model.MessageId
@@ -33,9 +34,8 @@ import org.thoughtcrime.securesms.service.webrtc.links.CallLinkRoomId
 import org.thoughtcrime.securesms.testutil.MockAppDependenciesRule
 
 /**
- * Covers the view model as the sole owner of the tab back stacks: everything a screen can ask for goes
- * through [MainNavigationRouter] or [MainNavigationViewModel.popCurrentDetailLocation], and the stacks it
- * hands the display are what those calls leave behind.
+ * Covers the view model as the sole owner of the tab back stacks: everything a screen can ask for arrives
+ * as a [MainNavigationEvents], and the stacks it hands the display are what those events leave behind.
  */
 @OptIn(ExperimentalCoroutinesApi::class)
 @RunWith(RobolectricTestRunner::class)
@@ -79,6 +79,12 @@ class MainNavigationViewModelTest {
     Dispatchers.resetMain()
   }
 
+  /** Events are answered off the view model's own channel, so every one of them is drained before asserting. */
+  private fun MainNavigationViewModel.sendEvent(event: MainNavigationEvents) {
+    onEvent(event)
+    testDispatcher.scheduler.advanceUntilIdle()
+  }
+
   @Test
   fun `given a new view model, then chats is displayed with no detail`() {
     assertEquals(MainListRoute.Chats, viewModel.currentTab.value)
@@ -87,41 +93,41 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `when going to a detail location, then it is pushed onto the displayed tab`() {
-    viewModel.goTo(conversationSettings)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
 
     assertEquals(listOf(MainListRoute.Chats, conversationSettings), viewModel.navigator[MainListRoute.Chats])
   }
 
   @Test
   fun `given stacked detail, when popping, then only the top of the stack is dropped`() {
-    viewModel.goTo(conversationSettings)
-    viewModel.goTo(messageDetails)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(messageDetails))
 
-    viewModel.popCurrentDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back))
 
     assertEquals(listOf(MainListRoute.Chats, conversationSettings), viewModel.navigator[MainListRoute.Chats])
   }
 
   @Test
   fun `given stacked detail, when exiting detail, then all of it is dropped`() {
-    viewModel.goTo(conversationSettings)
-    viewModel.goTo(messageDetails)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(messageDetails))
 
-    viewModel.exitDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ExitDetail)
 
     assertEquals(listOf(MainListRoute.Chats), viewModel.navigator[MainListRoute.Chats])
   }
 
   @Test
   fun `given a stack at its root, when popping, then nothing is dropped`() {
-    viewModel.popCurrentDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back))
 
     assertEquals(listOf(MainListRoute.Chats), viewModel.navigator[MainListRoute.Chats])
   }
 
   @Test
   fun `when going to the archive, then it is pushed onto the chats stack rather than becoming a tab`() {
-    viewModel.goTo(MainListRoute.Archive)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Archive))
 
     assertEquals(MainListRoute.Chats, viewModel.currentTab.value)
     assertEquals(
@@ -132,9 +138,9 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `given the archive is displayed, when going back to chats, then the archive is popped`() {
-    viewModel.goTo(MainListRoute.Archive)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Archive))
 
-    viewModel.goTo(MainListRoute.Chats)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
 
     assertEquals(listOf(MainListRoute.Chats), viewModel.navigator[MainListRoute.Chats])
   }
@@ -145,10 +151,10 @@ class MainNavigationViewModelTest {
    */
   @Test
   fun `given detail opened from the archive, when exiting detail, then the archive stays displayed`() {
-    viewModel.goTo(MainListRoute.Archive)
-    viewModel.goTo(conversationSettings)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Archive))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
 
-    viewModel.exitDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ExitDetail)
 
     assertEquals(
       listOf(MainListRoute.Chats, MainListRoute.Archive),
@@ -158,9 +164,9 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `given detail is open, when opening the archive, then the detail stays displayed above it`() {
-    viewModel.goTo(conversationSettings)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
 
-    viewModel.goTo(MainListRoute.Archive)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Archive))
 
     assertEquals(
       listOf(MainListRoute.Chats, MainListRoute.Archive, conversationSettings),
@@ -170,8 +176,8 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `when going to a calls destination, then it is pushed onto the calls stack`() {
-    viewModel.goTo(MainListRoute.Calls)
-    viewModel.goTo(callLinkDetails)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Calls))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(callLinkDetails))
 
     assertEquals(MainListRoute.Calls, viewModel.currentTab.value)
     assertEquals(listOf(MainListRoute.Calls, callLinkDetails), viewModel.navigator[MainListRoute.Calls])
@@ -183,11 +189,11 @@ class MainNavigationViewModelTest {
    */
   @Test
   fun `given detail open on another tab, when switching away and back, then that stack is unchanged`() {
-    viewModel.goTo(MainListRoute.Calls)
-    viewModel.goTo(callLinkDetails)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Calls))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(callLinkDetails))
 
-    viewModel.goTo(MainListRoute.Chats)
-    viewModel.goTo(MainListRoute.Calls)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Calls))
 
     assertEquals(listOf(MainListRoute.Calls, callLinkDetails), viewModel.navigator[MainListRoute.Calls])
   }
@@ -198,12 +204,12 @@ class MainNavigationViewModelTest {
    */
   @Test
   fun `given detail open on both tabs, when popping from calls, then only the calls stack is affected`() {
-    viewModel.goTo(MainListRoute.Chats)
-    viewModel.goTo(conversationSettings)
-    viewModel.goTo(MainListRoute.Calls)
-    viewModel.goTo(callLinkDetails)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Calls))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(callLinkDetails))
 
-    viewModel.popCurrentDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back))
 
     assertEquals(listOf(MainListRoute.Calls), viewModel.navigator[MainListRoute.Calls])
     assertEquals(listOf(MainListRoute.Chats, conversationSettings), viewModel.navigator[MainListRoute.Chats])
@@ -211,12 +217,12 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `given detail open on both tabs, when exiting detail from calls, then only the calls stack is affected`() {
-    viewModel.goTo(MainListRoute.Chats)
-    viewModel.goTo(conversationSettings)
-    viewModel.goTo(MainListRoute.Calls)
-    viewModel.goTo(callLinkDetails)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Calls))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(callLinkDetails))
 
-    viewModel.exitDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ExitDetail)
 
     assertEquals(listOf(MainListRoute.Calls), viewModel.navigator[MainListRoute.Calls])
     assertEquals(listOf(MainListRoute.Chats, conversationSettings), viewModel.navigator[MainListRoute.Chats])
@@ -224,12 +230,12 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `given detail open on another tab, when popping from chats, then only the chats stack is affected`() {
-    viewModel.goTo(MainListRoute.Calls)
-    viewModel.goTo(callLinkDetails)
-    viewModel.goTo(MainListRoute.Chats)
-    viewModel.goTo(conversationSettings)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Calls))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(callLinkDetails))
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Chats))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
 
-    viewModel.popCurrentDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back))
 
     assertEquals(listOf(MainListRoute.Chats), viewModel.navigator[MainListRoute.Chats])
     assertEquals(listOf(MainListRoute.Calls, callLinkDetails), viewModel.navigator[MainListRoute.Calls])
@@ -237,8 +243,8 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `when going to a stories destination, then it is pushed onto the stories stack`() {
-    viewModel.goTo(MainListRoute.Stories)
-    viewModel.goTo(MainDetailRoute.Stories.MyStories)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Stories))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Stories.MyStories))
 
     assertEquals(
       listOf(MainListRoute.Stories, MainDetailRoute.Stories.MyStories),
@@ -252,10 +258,10 @@ class MainNavigationViewModelTest {
    */
   @Test
   fun `given a stories destination is open, when opening another, then it replaces the first`() {
-    viewModel.goTo(MainListRoute.Stories)
-    viewModel.goTo(MainDetailRoute.Stories.MyStories)
+    viewModel.sendEvent(MainNavigationEvents.GoToList(MainListRoute.Stories))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Stories.MyStories))
 
-    viewModel.goTo(MainDetailRoute.Stories.PrivacySettings)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(MainDetailRoute.Stories.PrivacySettings))
 
     assertEquals(
       listOf(MainListRoute.Stories, MainDetailRoute.Stories.PrivacySettings),
@@ -265,30 +271,30 @@ class MainNavigationViewModelTest {
 
   @Test
   fun `given the list fills the window, when detail content opens, then the detail is revealed`() {
-    viewModel.onPaneAnchorSelected(PaneAnchor.LIST_ONLY)
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.AnchorSelected(PaneAnchor.LIST_ONLY)))
 
-    viewModel.goTo(conversationSettings)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
 
     assertEquals(PaneAnchor.DETAIL_ONLY, viewModel.paneAnchor.value)
   }
 
   @Test
   fun `given the detail fills the window, when the last detail is popped, then the list is revealed`() {
-    viewModel.goTo(conversationSettings)
-    viewModel.onPaneAnchorSelected(PaneAnchor.DETAIL_ONLY)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.AnchorSelected(PaneAnchor.DETAIL_ONLY)))
 
-    viewModel.popCurrentDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back))
 
     assertEquals(PaneAnchor.LIST_ONLY, viewModel.paneAnchor.value)
   }
 
   @Test
   fun `given stacked detail, when the top is popped, then the detail pane stays revealed`() {
-    viewModel.goTo(conversationSettings)
-    viewModel.goTo(messageDetails)
-    viewModel.onPaneAnchorSelected(PaneAnchor.DETAIL_ONLY)
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(conversationSettings))
+    viewModel.sendEvent(MainNavigationEvents.GoToDetail(messageDetails))
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.AnchorSelected(PaneAnchor.DETAIL_ONLY)))
 
-    viewModel.popCurrentDetailLocation()
+    viewModel.sendEvent(MainNavigationEvents.ListDetailEvent(ListDetailEvents.Back))
 
     assertEquals(PaneAnchor.DETAIL_ONLY, viewModel.paneAnchor.value)
   }