perf(conversation list): drop a deleted conversation from the list at once

Deleting left the row in place until the worker had finished and the list
had been fetched again. It now disappears on confirmation, reusing the
guard that hides a conversation being left, and comes back if the delete
fails.

Assisted-by: Claude Code:claude-opus-5
Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

Author: AndyScherzinger

app/src/main/java/com/nextcloud/talk/conversationlist/ConversationsListActivity.kt

@@ -1288,15 +1288,15 @@ class ConversationsListActivity : BaseActivity() {
     @SuppressLint("StringFormatInvalid")
     private fun showLeaveConversationSnackbar(conversation: ConversationModel) {
         val token = conversation.token ?: return
-        conversationsListViewModel.markConversationPendingLeave(token)
+        conversationsListViewModel.markConversationPendingRemoval(token)
         lifecycleScope.launch {
             val result = snackbarHostState.showSnackbar(
                 message = String.format(resources.getString(R.string.left_conversation), conversation.displayName),
                 actionLabel = getString(R.string.nc_undo),
                 duration = SnackbarDuration.Long
             )
             when (result) {
-                SnackbarResult.ActionPerformed -> conversationsListViewModel.clearConversationPendingLeave(token)
+                SnackbarResult.ActionPerformed -> conversationsListViewModel.clearConversationPendingRemoval(token)
                 SnackbarResult.Dismissed -> leaveConversation(conversation)
             }
         }
@@ -1324,12 +1324,12 @@ class ConversationsListActivity : BaseActivity() {
                             resources.getString(R.string.nc_shortcut_conversation_deleted)
                         )
                     }
-                    conversationsListViewModel.clearConversationPendingLeave(token)
+                    conversationsListViewModel.clearConversationPendingRemoval(token)
                     fetchRooms()
                 }
                 WorkInfo.State.FAILED -> {
                     logger.e(TAG, "LeaveConversationWorker failed for token $token")
-                    conversationsListViewModel.clearConversationPendingLeave(token)
+                    conversationsListViewModel.clearConversationPendingRemoval(token)
                     showSnackbar(resources.getString(R.string.nc_common_error_sorry))
                 }
                 else -> {}
@@ -1346,6 +1346,7 @@ class ConversationsListActivity : BaseActivity() {
             .setTitle(R.string.nc_delete_call)
             .setMessage(R.string.nc_delete_conversation_more)
             .setPositiveButton(R.string.nc_delete) { _, _ ->
+                conversation.token?.let { conversationsListViewModel.markConversationPendingRemoval(it) }
                 deleteConversation(conversation)
             }
             .setNegativeButton(R.string.nc_cancel) { _, _ ->
@@ -1567,32 +1568,40 @@ class ConversationsListActivity : BaseActivity() {
 
         WorkManager.getInstance(context).getWorkInfoByIdLiveData(deleteConversationWorker.id)
             .observeForever { workInfo: WorkInfo? ->
-                if (workInfo != null) {
-                    when (workInfo.state) {
-                        WorkInfo.State.SUCCEEDED -> {
-                            currentUser.id?.let { userId ->
-                                ShortcutManagerHelper.disableConversationShortcut(
-                                    context,
-                                    conversation.token,
-                                    userId,
-                                    context.resources.getString(R.string.nc_shortcut_conversation_deleted)
-                                )
-                            }
-                            showSnackbar(
-                                String.format(
-                                    context.resources.getString(R.string.deleted_conversation),
-                                    conversation.displayName
-                                )
+                when (workInfo?.state) {
+                    WorkInfo.State.SUCCEEDED -> {
+                        currentUser.id?.let { userId ->
+                            ShortcutManagerHelper.disableConversationShortcut(
+                                context,
+                                conversation.token,
+                                userId,
+                                context.resources.getString(R.string.nc_shortcut_conversation_deleted)
                             )
                         }
+                        conversation.token?.let { conversationsListViewModel.clearConversationPendingRemoval(it) }
+                        // the worker only deletes the room on the server, so without this the entry
+                        // comes back as soon as it stops being hidden
+                        fetchRooms()
+                        showSnackbar(
+                            String.format(
+                                context.resources.getString(R.string.deleted_conversation),
+                                conversation.displayName
+                            )
+                        )
+                    }
 
-                        WorkInfo.State.FAILED -> {
-                            logger.e(TAG, "DeleteConversationWorker failed for token ${conversation.token}")
-                            showSnackbar(context.resources.getString(R.string.nc_common_error_sorry))
-                        }
+                    WorkInfo.State.FAILED -> {
+                        logger.e(TAG, "DeleteConversationWorker failed for token ${conversation.token}")
+                        conversation.token?.let { conversationsListViewModel.clearConversationPendingRemoval(it) }
+                        showSnackbar(context.resources.getString(R.string.nc_common_error_sorry))
+                    }
 
-                        else -> {
-                        }
+                    WorkInfo.State.CANCELLED -> {
+                        // nothing was deleted, so the entry must not stay hidden
+                        conversation.token?.let { conversationsListViewModel.clearConversationPendingRemoval(it) }
+                    }
+
+                    else -> {
                     }
                 }
             }

app/src/main/java/com/nextcloud/talk/conversationlist/viewmodels/ConversationsListViewModel.kt

@@ -242,10 +242,10 @@ class ConversationsListViewModel @AssistedInject constructor(
 
     private val hideRoomToken = MutableStateFlow<String?>(null)
 
-    /** Tokens of rooms being left; hidden optimistically while the leave-undo snackbar is showing. */
-    private val pendingLeaveTokens = MutableStateFlow<Set<String>>(emptySet())
+    /** Tokens of rooms being left or deleted; hidden optimistically until the request finished. */
+    private val pendingRemovalTokens = MutableStateFlow<Set<String>>(emptySet())
 
-    private val excludedRoomTokens = combine(hideRoomToken, pendingLeaveTokens) { hideToken, pendingTokens ->
+    private val excludedRoomTokens = combine(hideRoomToken, pendingRemovalTokens) { hideToken, pendingTokens ->
         if (hideToken != null) pendingTokens + hideToken else pendingTokens
     }
 
@@ -387,14 +387,14 @@ class ConversationsListViewModel @AssistedInject constructor(
         hideRoomToken.value = token
     }
 
-    /** Optimistically hide a room while its leave-undo snackbar is showing. */
-    fun markConversationPendingLeave(token: String) {
-        pendingLeaveTokens.value = pendingLeaveTokens.value + token
+    /** Optimistically hide a room that is being left or deleted. */
+    fun markConversationPendingRemoval(token: String) {
+        pendingRemovalTokens.value = pendingRemovalTokens.value + token
     }
 
-    /** Un-hide a room, either because the leave was undone or because it finished/failed. */
-    fun clearConversationPendingLeave(token: String) {
-        pendingLeaveTokens.value = pendingLeaveTokens.value - token
+    /** Un-hide a room, either because the removal was undone or because it finished or failed. */
+    fun clearConversationPendingRemoval(token: String) {
+        pendingRemovalTokens.value = pendingRemovalTokens.value - token
     }
 
     fun getFederationInvitations() {