Prevent conversation settings screens from stacking when switching recipients.

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

@@ -607,14 +607,6 @@ class MainActivity :
           }
         }
 
-        LaunchedEffect(wrappedNavigator.scaffoldValue.primary) {
-          if (wrappedNavigator.scaffoldValue.primary == PaneAdaptedValue.Hidden &&
-            mainNavigationState.currentListLocation.isChatsTab
-          ) {
-            mainNavigationViewModel.onChatsDetailPaneCollapsed()
-          }
-        }
-
         val noEnterTransitionFactory = remember {
           AppScaffoldAnimationStateFactory(
             enabledStates = AppScaffoldNavigator.NavigationState.entries.filterNot {
@@ -736,16 +728,14 @@ class MainActivity :
           primaryContent = {
             when (mainNavigationState.currentListLocation) {
               MainNavigationListLocation.CHATS, MainNavigationListLocation.ARCHIVE -> {
-                if (mainNavigationViewModel.chatsBackStackEntries.isNotEmpty()) {
-                  NavDisplay(
-                    backStack = mainNavigationViewModel.chatsBackStackEntries,
-                    onBack = { mainNavigationViewModel.popChatsDetailLocation() },
-                    transitionSpec = TransitionSpecs.HorizontalSlide.transitionSpec,
-                    popTransitionSpec = TransitionSpecs.HorizontalSlide.popTransitionSpec,
-                    predictivePopTransitionSpec = TransitionSpecs.HorizontalSlide.predictivePopTransitionSpec,
-                    entryProvider = entryProvider { chatsNavEntries(convoTransitionState) }
-                  )
-                }
+                NavDisplay(
+                  backStack = mainNavigationViewModel.chatsBackStackEntries,
+                  onBack = { mainNavigationViewModel.popChatsDetailLocation() },
+                  transitionSpec = TransitionSpecs.HorizontalSlide.transitionSpec,
+                  popTransitionSpec = TransitionSpecs.HorizontalSlide.popTransitionSpec,
+                  predictivePopTransitionSpec = TransitionSpecs.HorizontalSlide.predictivePopTransitionSpec,
+                  entryProvider = entryProvider { chatsNavEntries(convoTransitionState) }
+                )
               }
 
               MainNavigationListLocation.CALLS -> {

app/src/main/java/org/thoughtcrime/securesms/chats/ChatsBackStack.kt

@@ -33,7 +33,7 @@ class ChatsBackStack(savedStateHandle: SavedStateHandle) {
     key = KEY,
     saver = saver
   ) {
-    mutableStateListOf()
+    mutableStateListOf(MainNavigationDetailLocation.Empty)
   }
 
   val activeRecipientId: RecipientId?
@@ -45,8 +45,8 @@ class ChatsBackStack(savedStateHandle: SavedStateHandle) {
       }
     }
 
-  val hasConversation: Boolean
-    get() = entries.any { it is MainNavigationDetailLocation.Conversation }
+  val isEmpty: Boolean
+    get() = entries.singleOrNull() is MainNavigationDetailLocation.Empty
 
   /**
    * Pushes an entry onto the stack.
@@ -76,21 +76,10 @@ class ChatsBackStack(savedStateHandle: SavedStateHandle) {
   /**
    * Resets the stack to its base empty state.
    */
-  fun reset(isSplitPane: Boolean) {
-    entries.clear()
-    if (isSplitPane) {
+  fun reset() {
+    entries.removeAll { it !is MainNavigationDetailLocation.Empty }
+    if (entries.isEmpty()) {
       entries.add(MainNavigationDetailLocation.Empty)
     }
   }
-
-  /**
-   * Ensures that [MainNavigationDetailLocation.Empty] is present in the stack iff isSplitPane=true.
-   */
-  fun updateEmptyDetailForPaneMode(isSplitPane: Boolean) {
-    val hasEmptyBase = entries.firstOrNull() is MainNavigationDetailLocation.Empty
-    when {
-      isSplitPane && !hasEmptyBase -> entries.add(0, MainNavigationDetailLocation.Empty)
-      !isSplitPane && hasEmptyBase -> entries.removeAll { it is MainNavigationDetailLocation.Empty }
-    }
-  }
 }

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

@@ -20,7 +20,7 @@ object ConversationSettingsNavigator {
     recipient: Recipient
   ) {
     if (activity is MainNavigationChatDetailRouter) {
-      activity.goToChatDetail(MainNavigationDetailLocation.Chats.ConversationSettings(recipient.id, isContentRoot = true))
+      activity.goToChatDetail(MainNavigationDetailLocation.Chats.ConversationSettings(recipient.id))
       return
     }
 

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

@@ -92,9 +92,12 @@ sealed interface MainNavigationDetailLocation : Parcelable, NavKey {
 
     @Serializable
     data class ConversationSettings(
-      val recipientId: RecipientId,
-      override val isContentRoot: Boolean = false
+      val recipientId: RecipientId
     ) : Chats {
+      @Transient
+      @IgnoredOnParcel
+      override val isContentRoot: Boolean = false
+
       @Transient
       @IgnoredOnParcel
       override val controllerKey: RecipientId = recipientId

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

@@ -6,7 +6,6 @@
 package org.thoughtcrime.securesms.main
 
 import androidx.compose.material3.adaptive.ExperimentalMaterial3AdaptiveApi
-import androidx.compose.material3.adaptive.layout.PaneAdaptedValue
 import androidx.compose.material3.adaptive.layout.ThreePaneScaffoldRole
 import androidx.compose.material3.adaptive.navigation.BackNavigationBehavior
 import androidx.compose.material3.adaptive.navigation.ThreePaneScaffoldNavigator
@@ -172,15 +171,12 @@ class MainNavigationViewModel(
 
   fun onSplitPaneChanged(isSplitPane: Boolean) {
     this@MainNavigationViewModel.isSplitPane = isSplitPane
-    chatsBackStack.updateEmptyDetailForPaneMode(isSplitPane)
 
-    // if no conversation is selected, clear the empty detail pane when switching from split pane to single pane mode.
-    if (!isSplitPane &&
-      internalMainNavigationState.value.currentListLocation.isChatsTab &&
-      !chatsBackStack.hasConversation &&
-      navigator?.scaffoldValue?.primary == PaneAdaptedValue.Expanded
-    ) {
-      navigatorScope?.launch { navigator?.navigateBack() }
+    if (!isSplitPane) {
+      if (chatsBackStack.isEmpty) {
+        lockPaneToSecondary = true
+        setFocusedPane(ThreePaneScaffoldRole.Secondary)
+      }
     }
   }
 
@@ -295,7 +291,7 @@ class MainNavigationViewModel(
     val currentListLocation = internalMainNavigationState.value.currentListLocation
 
     when (location) {
-      is MainNavigationDetailLocation.Empty if currentListLocation.isChatsTab -> chatsBackStack.reset(isSplitPane)
+      is MainNavigationDetailLocation.Empty if currentListLocation.isChatsTab -> clearDetailLocation(chatsBackStack)
       is MainNavigationDetailLocation.Chats -> pushChatsDetailLocation(location)
       is MainNavigationDetailLocation.Conversation -> goToConversation(location)
 
@@ -329,26 +325,27 @@ class MainNavigationViewModel(
   }
 
   private fun pushChatsDetailLocation(location: MainNavigationDetailLocation) {
+    if (location is MainNavigationDetailLocation.Chats && chatsBackStack.activeRecipientId != location.controllerKey) {
+      chatsBackStack.reset()
+    }
+
     chatsBackStack.push(location)
-    updateActiveStateForLocation(location)
     setFocusedPane(ThreePaneScaffoldRole.Primary)
   }
 
-  /**
-   * Inverse of [pushChatsDetailLocation]. Pops the top chats detail entry and, if no conversation
-   * remains, records the user's intent to stay on the list pane (so a subsequent config change does
-   * not errantly restore them to the Primary/detail pane).
-   */
   fun popChatsDetailLocation() {
     chatsBackStack.pop()
-    if (!chatsBackStack.hasConversation) {
+    if (chatsBackStack.isEmpty) {
       lockPaneToSecondary = true
+      setFocusedPane(ThreePaneScaffoldRole.Secondary)
     }
   }
 
-  fun onChatsDetailPaneCollapsed() {
-    if (!chatsBackStack.hasConversation) {
-      chatsBackStack.reset(isSplitPane)
+  private fun clearDetailLocation(backStack: ChatsBackStack) {
+    backStack.reset()
+    if (!isSplitPane) {
+      lockPaneToSecondary = true
+      setFocusedPane(ThreePaneScaffoldRole.Secondary)
     }
   }