feat(desktop): bring group DM parity with Android

Makes the Desktop DM client a first-class group participant and tightens the shared/Desktop DM paths so they match Android behavior. - commons ChatNewMessageState: actually attach the composed NIP-14 subject to sent messages (the field was previously collected but dropped). - commons ChatroomList: emit a `changes` SharedFlow on add/remove so list UIs can refresh reactively; dedupe the User overloads onto the room ones. - Desktop NewDmDialog: multi-recipient selection (chips + confirm button) so a Desktop user can start a group, not only a 1:1. - Desktop ChatPane/ChatroomHeader: show a group's NIP-14 subject in the header and add a rename dialog that broadcasts a subject change to all members. - Desktop Main.kt DM ingest: route any ChatroomKeyable inner event into the room (covers kind 14/15 and future variants) and store self-authored NIP-37 drafts instead of dropping them. - Desktop ChatroomListState: refresh reactively off ChatroomList.changes (with a slower safety poll), track real per-room unread via a last-seen mark, and hide rooms whose latest message isn't acceptable (mute/filter). https://claude.ai/code/session_01VEukNczAYxNLBjLnqVEoZd
2026-08-09 08:04:45 +00:00 · 2026-06-09 20:16:55 +00:00
parent 3dfe418150
commit 1fbefb2efe
7 changed files with 266 additions and 53 deletions
@@ -28,6 +28,8 @@ import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
 import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKeyable
 import com.vitorpamplona.quartz.utils.cache.LargeCache
 import kotlinx.collections.immutable.persistentSetOf
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow

 class ChatroomList(
    val ownerPubKey: HexKey,
@@ -35,6 +37,11 @@ class ChatroomList(
    var rooms = LargeCache<ChatroomKey, Chatroom>()
        private set

+    // Emits the affected [ChatroomKey] whenever a room gains or loses a message, so list UIs can
+    // refresh reactively instead of polling. Mirrors [MarmotGroupList.groupListChanges].
+    private val _changes = MutableSharedFlow<ChatroomKey>(0, 64, BufferOverflow.DROP_OLDEST)
+    val changes = _changes
+
    // Account-level DM history paging cursors (one scope per account), held here so they share the
    // lifetime of the cached messages and are dropped when the cache prunes them. The account-level
    // history loaders bind their orchestrator to these. (Per-conversation NIP-04 cursors live on the
@@ -81,31 +88,19 @@ class ChatroomList(
            if (msg.author?.pubkeyHex == ownerPubKey) {
                privateChatroom.ownerSentMessage = true
            }
+            _changes.tryEmit(room)
        }
    }

    fun addMessage(
        user: User,
        msg: Note,
-    ) {
-        val privateChatroom = getOrCreatePrivateChatroom(user)
-        if (msg !in privateChatroom.messages) {
-            privateChatroom.addMessageSync(msg)
-            if (msg.author?.pubkeyHex == ownerPubKey) {
-                privateChatroom.ownerSentMessage = true
-            }
-        }
-    }
+    ) = addMessage(ChatroomKey(persistentSetOf(user.pubkeyHex)), msg)

    fun removeMessage(
        user: User,
        msg: Note,
-    ) {
-        val privateChatroom = getOrCreatePrivateChatroom(user)
-        if (msg in privateChatroom.messages) {
-            privateChatroom.removeMessageSync(msg)
-        }
-    }
+    ) = removeMessage(ChatroomKey(persistentSetOf(user.pubkeyHex)), msg)

    fun removeMessage(
        room: ChatroomKey,
@@ -114,6 +109,7 @@ class ChatroomList(
        val privateChatroom = getOrCreatePrivateChatroom(room)
        if (msg in privateChatroom.messages) {
            privateChatroom.removeMessageSync(msg)
+            _changes.tryEmit(room)
        }
    }

@@ -33,6 +33,7 @@ import com.vitorpamplona.quartz.nip10Notes.content.findURLs
 import com.vitorpamplona.quartz.nip17Dm.base.BaseDMGroupEvent
 import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
 import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
+import com.vitorpamplona.quartz.nip17Dm.messages.changeSubject
 import com.vitorpamplona.quartz.nip18Reposts.quotes.quotes
 import com.vitorpamplona.quartz.nip19Bech32.toNpub
 import com.vitorpamplona.quartz.utils.Hex
@@ -144,16 +145,19 @@ class ChatNewMessageState(
            }

        val replyHint = _replyTo.value?.toEventHint<BaseDMGroupEvent>()
+        val subjectText = _subject.value.text.ifBlank { null }

        val template =
            if (replyHint == null) {
                ChatMessageEvent.build(messageText, pTags) {
+                    subjectText?.let { changeSubject(it) }
                    hashtags(findHashtags(messageText))
                    references(findURLs(messageText))
                    quotes(findNostrEventUris(messageText))
                }
            } else {
                ChatMessageEvent.reply(messageText, replyHint) {
+                    subjectText?.let { changeSubject(it) }
                    hashtags(findHashtags(messageText))
                    references(findURLs(messageText))
                    quotes(findNostrEventUris(messageText))
@@ -126,7 +126,9 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.SubscriptionListener
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKeyable
 import com.vitorpamplona.quartz.nip17Dm.settings.ChatMessageRelayListEvent
+import com.vitorpamplona.quartz.nip37Drafts.DraftWrapEvent
 import com.vitorpamplona.quartz.nip47WalletConnect.Nip47WalletConnect
 import com.vitorpamplona.quartz.nip50Search.SearchRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.BlockedRelayListEvent
@@ -1356,28 +1358,31 @@ fun MainContent(
                        scope.launch {
                            val innerEvent = event.unwrapAndUnsealOrNull(iAccount.signer) ?: return@launch
                            when (innerEvent) {
-                                is com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent -> {
-                                    val innerNote = localCache.getOrCreateNote(innerEvent.id)
-                                    val innerAuthor = localCache.getOrCreateUser(innerEvent.pubKey)
-                                    if (innerNote.event == null) {
-                                        innerNote.loadEvent(innerEvent, innerAuthor, emptyList())
+                                // Any DM-group event (kind 14 text, kind 15 encrypted file, and any
+                                // future NIP-17 variant) routes into the room by its participant set.
+                                is ChatroomKeyable -> {
+                                    if (innerEvent.isIncluded(iAccount.pubKey)) {
+                                        val innerNote = localCache.getOrCreateNote(innerEvent.id)
+                                        val innerAuthor = localCache.getOrCreateUser(innerEvent.pubKey)
+                                        if (innerNote.event == null) {
+                                            innerNote.loadEvent(innerEvent, innerAuthor, emptyList())
+                                        }
+                                        iAccount.chatroomList.addMessage(
+                                            innerEvent.chatroomKey(iAccount.pubKey),
+                                            innerNote,
+                                        )
                                    }
-                                    iAccount.chatroomList.addMessage(
-                                        innerEvent.chatroomKey(iAccount.pubKey),
-                                        innerNote,
-                                    )
                                }

-                                is com.vitorpamplona.quartz.nip17Dm.files.ChatMessageEncryptedFileHeaderEvent -> {
-                                    val innerNote = localCache.getOrCreateNote(innerEvent.id)
-                                    val innerAuthor = localCache.getOrCreateUser(innerEvent.pubKey)
-                                    if (innerNote.event == null) {
-                                        innerNote.loadEvent(innerEvent, innerAuthor, emptyList())
+                                // Self-authored NIP-37 draft wrapped to self. Store it so it isn't
+                                // dropped; the desktop chat UI doesn't render drafts in the room feed
+                                // yet, so it is intentionally not added to a chatroom.
+                                is DraftWrapEvent -> {
+                                    val draftNote = localCache.getOrCreateNote(innerEvent.id)
+                                    val draftAuthor = localCache.getOrCreateUser(innerEvent.pubKey)
+                                    if (draftNote.event == null) {
+                                        draftNote.loadEvent(innerEvent, draftAuthor, emptyList())
                                    }
-                                    iAccount.chatroomList.addMessage(
-                                        innerEvent.chatroomKey(iAccount.pubKey),
-                                        innerNote,
-                                    )
                                }

                                is com.vitorpamplona.quartz.nip25Reactions.ReactionEvent -> {
@@ -39,9 +39,11 @@ import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.text.selection.SelectionContainer
+import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Surface
@@ -95,6 +97,8 @@ import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
 import com.vitorpamplona.quartz.nip17Dm.NIP17Factory
 import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
 import com.vitorpamplona.quartz.nip17Dm.files.ChatMessageEncryptedFileHeaderEvent
+import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
+import com.vitorpamplona.quartz.nip17Dm.messages.changeSubject
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.utils.ciphers.AESGCM
 import kotlinx.coroutines.launch
@@ -188,11 +192,26 @@ fun ChatPane(
    val users = roomKey.users.mapNotNull { cacheProvider.getUserIfExists(it) }
    val isGroup = users.size > 1

+    // NIP-14 group subject/name, updated reactively as subject-tagged messages arrive.
+    val subjectFlow = remember(roomKey) { account.chatroomList.getOrCreatePrivateChatroom(roomKey).subject }
+    val subject by subjectFlow.collectAsState()
+    var showSubjectDialog by remember { mutableStateOf(false) }
+
    // Load room into message state
    LaunchedEffect(roomKey) {
        messageState.load(roomKey)
    }

+    if (showSubjectDialog) {
+        GroupSubjectDialog(
+            roomKey = roomKey,
+            currentSubject = subject ?: "",
+            account = account,
+            cacheProvider = cacheProvider,
+            onClose = { showSubjectDialog = false },
+        )
+    }
+
    Box(modifier = modifier.fillMaxSize()) {
        Column(
            modifier =
@@ -230,6 +249,7 @@ fun ChatPane(
                    if (isGroup) {
                        GroupChatroomHeader(
                            users = users,
+                            subject = subject,
                            onClick = { users.firstOrNull()?.let { onNavigateToProfile(it.pubkeyHex) } },
                        )
                    } else {
@@ -248,6 +268,21 @@ fun ChatPane(
                        }
                    }
                }
+
+                // Rename group (set NIP-14 subject) — groups only
+                if (isGroup) {
+                    IconButton(
+                        onClick = { showSubjectDialog = true },
+                        modifier = Modifier.size(40.dp),
+                    ) {
+                        Icon(
+                            MaterialSymbols.Edit,
+                            contentDescription = "Rename group",
+                            modifier = Modifier.size(18.dp),
+                            tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                    }
+                }
            }

            HorizontalDivider()
@@ -874,3 +909,72 @@ private suspend fun sendEncryptedFiles(
        account.sendNip17EncryptedFile(template)
    }
 }
+
+/**
+ * Dialog to set or change a group's NIP-14 subject (name). Mirrors Android's
+ * NewChatroomSubjectDialog: it sends a normal NIP-17 message carrying a
+ * `subject` tag (plus an optional accompanying message) to every room member,
+ * so all participants pick up the new name.
+ */
+@Composable
+private fun GroupSubjectDialog(
+    roomKey: ChatroomKey,
+    currentSubject: String,
+    account: IAccount,
+    cacheProvider: ICacheProvider,
+    onClose: () -> Unit,
+) {
+    val scope = rememberCoroutineScope()
+    var groupName by remember { mutableStateOf(currentSubject) }
+    var message by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onClose,
+        title = { Text("Group name") },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
+                OutlinedTextField(
+                    value = groupName,
+                    onValueChange = { groupName = it },
+                    modifier = Modifier.fillMaxWidth(),
+                    label = { Text("Subject") },
+                    placeholder = { Text("A name for this group") },
+                    singleLine = true,
+                )
+                OutlinedTextField(
+                    value = message,
+                    onValueChange = { message = it },
+                    modifier = Modifier.fillMaxWidth().heightIn(min = 80.dp),
+                    label = { Text("Message (optional)") },
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                enabled = groupName.isNotBlank(),
+                onClick = {
+                    scope.launch {
+                        try {
+                            val pTags = roomKey.users.mapNotNull { cacheProvider.getUserIfExists(it)?.toPTag() }
+                            val template =
+                                ChatMessageEvent.build(message, pTags) {
+                                    groupName.ifBlank { null }?.let { changeSubject(it) }
+                                }
+                            account.sendNip17PrivateMessage(template)
+                        } catch (e: Exception) {
+                            println("Failed to set group subject: ${e.message}")
+                        }
+                    }
+                    onClose()
+                },
+            ) {
+                Text("Save")
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onClose) {
+                Text("Cancel")
+            }
+        },
+    )
+}
@@ -91,16 +91,23 @@ fun ChatroomHeader(
 * Shared chatroom header for a group conversation.
 * Displays multiple user avatars and a combined room name.
 *
+ * When the group has a NIP-14 [subject] (group name), it is shown as the bold
+ * title with the participant list as a secondary line; otherwise the participant
+ * list is the title.
+ *
 * @param users List of users in the group conversation
+ * @param subject Optional NIP-14 group subject/name
 * @param modifier Layout modifier (defaults to standard padding)
 * @param onClick Called when the header is tapped
 */
@Composable
 fun GroupChatroomHeader(
    users: List<User>,
+    subject: String? = null,
    modifier: Modifier = ChatStdPadding,
    onClick: () -> Unit,
 ) {
+    val participants = users.joinToString(", ") { it.toBestDisplayName() }
    Column(
        modifier =
            Modifier
@@ -124,12 +131,21 @@ fun GroupChatroomHeader(

                Column(modifier = Modifier.padding(start = 10.dp)) {
                    Text(
-                        text = users.joinToString(", ") { it.toBestDisplayName() },
+                        text = subject?.takeIf { it.isNotBlank() } ?: participants,
                        style = MaterialTheme.typography.titleSmall,
                        fontWeight = FontWeight.Bold,
                        maxLines = 1,
                        overflow = TextOverflow.Ellipsis,
                    )
+                    if (!subject.isNullOrBlank()) {
+                        Text(
+                            text = participants,
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            maxLines = 1,
+                            overflow = TextOverflow.Ellipsis,
+                        )
+                    }
                }
            }
        }
@@ -101,11 +101,22 @@ class ChatroomListState(
    // Track pubkeys we've already requested metadata for
    private val fetchedMetadataKeys = mutableSetOf<String>()

+    // Timestamp (createdAt) of the newest message seen by the user per room, set when a room is
+    // opened. A room is unread when its newest incoming message is newer than this mark.
+    private val lastSeen = mutableMapOf<ChatroomKey, Long>()
+
    init {
+        // Reactive: refresh as soon as a room gains/loses a message.
+        scope.launch(Dispatchers.IO) {
+            account.chatroomList.changes.collect {
+                refreshRooms()
+            }
+        }
+        // Safety poll: catches metadata/profile arrivals that don't emit a chatroom change.
        scope.launch(Dispatchers.IO) {
            while (isActive) {
                refreshRooms()
-                delay(2000)
+                delay(10000)
            }
        }
    }
@@ -116,6 +127,14 @@ class ChatroomListState(

    fun selectRoom(roomKey: ChatroomKey) {
        _selectedRoom.value = roomKey
+        // Mark everything currently in the room as seen so it stops showing as unread.
+        val newest =
+            account.chatroomList.rooms
+                .get(roomKey)
+                ?.newestMessage
+                ?.createdAt() ?: 0L
+        lastSeen[roomKey] = maxOf(lastSeen[roomKey] ?: 0L, newest)
+        scope.launch(Dispatchers.IO) { refreshRooms() }
    }

    fun clearSelection() {
@@ -199,6 +218,10 @@ class ChatroomListState(
            // Skip rooms with no messages
            if (chatroom.messages.isEmpty()) continue

+            // Hide rooms whose latest message is from a muted/blocked author or otherwise filtered.
+            val newestMessage = chatroom.newestMessage
+            if (newestMessage != null && !account.isAcceptable(newestMessage)) continue
+
            val users = key.users.mapNotNull { cacheProvider.getUserIfExists(it) }

            // Collect pubkeys without profile info
@@ -219,10 +242,14 @@ class ChatroomListState(
                        ?.let { "$it..." } ?: "Unknown"
                }

-            val newestMessage = chatroom.newestMessage
            val lastPreview = decryptPreview(newestMessage?.event)
            val lastTimestamp = newestMessage?.createdAt() ?: 0L

+            // Unread when the newest message is incoming (not authored by us) and newer than the
+            // last time the user opened this room.
+            val incoming = newestMessage != null && newestMessage.author?.pubkeyHex != account.pubKey
+            val hasUnread = incoming && lastTimestamp > (lastSeen[key] ?: 0L)
+
            val item =
                ConversationItem(
                    roomKey = key,
@@ -232,7 +259,7 @@ class ChatroomListState(
                    lastMessagePreview = lastPreview,
                    lastMessageTimestamp = lastTimestamp,
                    isGroup = key.users.size > 1,
-                    hasUnread = !chatroom.ownerSentMessage && newestMessage != null,
+                    hasUnread = hasUnread,
                )

            if (chatroom.ownerSentMessage) {
@@ -20,15 +20,19 @@
 */
 package com.vitorpamplona.amethyst.desktop.ui.chats

+import androidx.compose.foundation.border
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.heightIn
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyRow
 import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
@@ -39,6 +43,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
@@ -49,6 +54,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.window.Dialog
 import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
 import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+import com.vitorpamplona.amethyst.commons.model.User
 import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
 import com.vitorpamplona.amethyst.commons.search.SearchResult
 import com.vitorpamplona.amethyst.commons.ui.components.UserSearchCard
@@ -71,6 +77,15 @@ fun NewDmDialog(
    onDismiss: () -> Unit,
 ) {
    val scope = rememberCoroutineScope()
+    // Recipients selected so far. One → 1:1 chat, more than one → group chat.
+    val selected = remember { mutableStateListOf<User>() }
+
+    fun toggle(user: User) {
+        val existing = selected.firstOrNull { it.pubkeyHex == user.pubkeyHex }
+        if (existing != null) selected.remove(existing) else selected.add(user)
+    }
+
+    fun isSelected(user: User) = selected.any { it.pubkeyHex == user.pubkeyHex }
    val searchState = remember { SearchBarState(cacheProvider, scope) }
    val searchText by searchState.searchText.collectAsState()
    val bech32Results by searchState.bech32Results.collectAsState()
@@ -146,10 +161,38 @@ fun NewDmDialog(
                verticalArrangement = Arrangement.spacedBy(16.dp),
            ) {
                Text(
-                    "New Message",
+                    if (selected.size > 1) "New Group" else "New Message",
                    style = MaterialTheme.typography.titleLarge,
                )

+                // Selected recipients as removable chips. Add more to form a group.
+                if (selected.isNotEmpty()) {
+                    LazyRow(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.spacedBy(8.dp),
+                    ) {
+                        items(selected) { user ->
+                            Surface(
+                                color = MaterialTheme.colorScheme.secondaryContainer,
+                                shape = MaterialTheme.shapes.small,
+                            ) {
+                                Row(
+                                    verticalAlignment = Alignment.CenterVertically,
+                                    modifier = Modifier.padding(start = 10.dp, end = 4.dp, top = 2.dp, bottom = 2.dp),
+                                ) {
+                                    Text(
+                                        user.toBestDisplayName(),
+                                        style = MaterialTheme.typography.labelLarge,
+                                    )
+                                    IconButton(onClick = { toggle(user) }, modifier = Modifier.size(24.dp)) {
+                                        Icon(MaterialSymbols.Clear, contentDescription = "Remove", modifier = Modifier.size(16.dp))
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+
                OutlinedTextField(
                    value = searchText,
                    onValueChange = { searchState.updateSearchText(it) },
@@ -184,11 +227,8 @@ fun NewDmDialog(
                        if (user != null) {
                            UserSearchCard(
                                user = user,
-                                onClick = {
-                                    onUserSelected(
-                                        ChatroomKey(setOf(user.pubkeyHex)),
-                                    )
-                                },
+                                onClick = { toggle(user) },
+                                modifier = selectedModifier(isSelected(user)),
                            )
                        } else {
                            // Minimal card for unloaded users
@@ -210,11 +250,8 @@ fun NewDmDialog(
                    items(cachedUsers) { user ->
                        UserSearchCard(
                            user = user,
-                            onClick = {
-                                onUserSelected(
-                                    ChatroomKey(setOf(user.pubkeyHex)),
-                                )
-                            },
+                            onClick = { toggle(user) },
+                            modifier = selectedModifier(isSelected(user)),
                        )
                    }

@@ -222,11 +259,8 @@ fun NewDmDialog(
                    items(relaySearchResults) { user ->
                        UserSearchCard(
                            user = user,
-                            onClick = {
-                                onUserSelected(
-                                    ChatroomKey(setOf(user.pubkeyHex)),
-                                )
-                            },
+                            onClick = { toggle(user) },
+                            modifier = selectedModifier(isSelected(user)),
                        )
                    }

@@ -262,7 +296,34 @@ fun NewDmDialog(
                        }
                    }
                }
+
+                Button(
+                    onClick = {
+                        onUserSelected(ChatroomKey(selected.map { it.pubkeyHex }.toSet()))
+                    },
+                    enabled = selected.isNotEmpty(),
+                    modifier = Modifier.fillMaxWidth(),
+                ) {
+                    Text(
+                        when (selected.size) {
+                            0 -> "Select recipients"
+                            1 -> "Message"
+                            else -> "Create group (${selected.size})"
+                        },
+                    )
+                }
            }
        }
    }
 }
+
+/** Border highlight for a selected recipient card in the new-DM picker. */
+@Composable
+private fun selectedModifier(selected: Boolean): Modifier =
+    if (selected) {
+        Modifier
+            .fillMaxWidth()
+            .border(2.dp, MaterialTheme.colorScheme.primary, MaterialTheme.shapes.medium)
+    } else {
+        Modifier
+    }