feat(nip29): grouped view mode + view-mode toggle & persistence (C, part 4)

Completes the Messages-tab integration and makes the view mode user-switchable.

- RelayGroupServerList: the GROUPED mode's relay rows (one per host relay of the
  user's joined groups), tap opens the relay's channel list; rendered above the
  DM feed in MessagesSinglePane only in GROUPED mode (MessagesPager gains a
  modifier param so it weights correctly under the section).
- RelayGroupViewModeToggle: a segmented Inline/By-relay control, shown once the
  user has joined a group; flips AccountSettings.relayGroupViewMode.
- Persistence: the view mode is saved/restored via LocalPreferences (mirrors
  defaultRelayAuthPolicy), with an updateRelayGroupViewMode setter that saves.

The full NIP-29 relay-groups feature is now navigable end-to-end: browse a
relay's channels, chat in a group, and see joined groups in the Messages tab in
either inline (default) or grouped view.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B5MLY4hq5LXJ2D5WeLRyXj

amethyst/src/main/java/com/vitorpamplona/amethyst/LocalPreferences.kt

@@ -26,6 +26,7 @@ import android.content.SharedPreferences
 import androidx.compose.runtime.Immutable
 import androidx.core.content.edit
 import com.vitorpamplona.amethyst.commons.model.clink.ClinkDebitWalletEntry
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupViewMode
 import com.vitorpamplona.amethyst.commons.model.nip47WalletConnect.NwcWalletEntry
 import com.vitorpamplona.amethyst.commons.model.nip47WalletConnect.NwcWalletEntryNorm
 import com.vitorpamplona.amethyst.commons.relayauth.RelayAuthPolicy
@@ -159,6 +160,7 @@ private object PrefKeys {
     const val HIDE_NIP_17_WARNING_DIALOG = "hide_nip24_warning_dialog" // delete later
     const val ALWAYS_ON_NOTIFICATION_SERVICE = "always_on_notification_service"
     const val DEFAULT_RELAY_AUTH_POLICY = "default_relay_auth_policy"
+    const val RELAY_GROUP_VIEW_MODE = "relay_group_view_mode"
     const val SPLIT_NOTIFICATIONS_ENABLED = "split_notifications_enabled"
     const val SHOW_MESSAGES_IN_NOTIFICATIONS = "show_messages_in_notifications"
 
@@ -512,6 +514,7 @@ object LocalPreferences {
                     putBoolean(PrefKeys.CALLS_ENABLED, settings.callsEnabled.value)
                     putBoolean(PrefKeys.ALWAYS_ON_NOTIFICATION_SERVICE, settings.alwaysOnNotificationService.value)
                     putString(PrefKeys.DEFAULT_RELAY_AUTH_POLICY, settings.defaultRelayAuthPolicy.value.name)
+                    putString(PrefKeys.RELAY_GROUP_VIEW_MODE, settings.relayGroupViewMode.value.name)
                     putBoolean(PrefKeys.SPLIT_NOTIFICATIONS_ENABLED, settings.splitNotificationsEnabled.value)
                     putBoolean(PrefKeys.SHOW_MESSAGES_IN_NOTIFICATIONS, settings.showMessagesInNotifications.value)
                     // Any account that reaches a save has its notification filter in its
@@ -632,6 +635,7 @@ object LocalPreferences {
                         getString(PrefKeys.DEFAULT_RELAY_AUTH_POLICY, null)
                             ?.let { runCatching { RelayAuthPolicy.valueOf(it) }.getOrNull() }
                             ?: RelayAuthPolicy.IF_IN_MY_LIST
+                    val relayGroupViewMode = RelayGroupViewMode.fromName(getString(PrefKeys.RELAY_GROUP_VIEW_MODE, null))
                     val splitNotificationsEnabled = getBoolean(PrefKeys.SPLIT_NOTIFICATIONS_ENABLED, false)
                     val showMessagesInNotifications = getBoolean(PrefKeys.SHOW_MESSAGES_IN_NOTIFICATIONS, true)
                     val hasDonatedInVersion = getStringSet(PrefKeys.HAS_DONATED_IN_VERSION, null) ?: setOf()
@@ -839,6 +843,7 @@ object LocalPreferences {
                         hideNIP17WarningDialog = hideNIP17WarningDialog,
                         alwaysOnNotificationService = MutableStateFlow(alwaysOnNotificationService),
                         defaultRelayAuthPolicy = MutableStateFlow(defaultRelayAuthPolicy),
+                        relayGroupViewMode = MutableStateFlow(relayGroupViewMode),
                         splitNotificationsEnabled = MutableStateFlow(splitNotificationsEnabled),
                         showMessagesInNotifications = MutableStateFlow(showMessagesInNotifications),
                         backupUserMetadata = latestUserMetadataResolved,

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSettings.kt

@@ -290,6 +290,13 @@ class AccountSettings(
 
     fun isWriteable(): Boolean = keyPair.privKey != null || externalSignerPackageName != null
 
+    fun updateRelayGroupViewMode(mode: RelayGroupViewMode) {
+        if (relayGroupViewMode.value != mode) {
+            relayGroupViewMode.tryEmit(mode)
+            saveAccountSettings()
+        }
+    }
+
     // ---
     // Always-on Notification Service
     // ---

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/RelayGroupServerList.kt

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.displayUrl
+
+/**
+ * The "grouped" Messages view: one row per host relay of the user's joined NIP-29
+ * groups. Tapping a relay opens its channel list. Rendered above the DM feed only
+ * in [com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupViewMode.GROUPED].
+ */
+@Composable
+fun RelayGroupServerList(
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val servers by accountViewModel.account.relayGroupList.liveRelayGroupServers
+        .collectAsStateWithLifecycle()
+
+    if (servers.isEmpty()) return
+
+    Column(Modifier.fillMaxWidth()) {
+        servers.sorted().forEach { server ->
+            RelayServerRow(server) { nav.nav(Route.RelayGroupServer(server)) }
+            HorizontalDivider(thickness = 0.25.dp)
+        }
+    }
+}
+
+@Composable
+private fun RelayServerRow(
+    relayUrl: String,
+    onClick: () -> Unit,
+) {
+    val label = RelayUrlNormalizer.normalizeOrNull(relayUrl)?.displayUrl() ?: relayUrl
+
+    Row(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onClick)
+                .padding(horizontal = 16.dp, vertical = 14.dp),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        Text(
+            text = label,
+            fontWeight = FontWeight.SemiBold,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.weight(1f),
+        )
+        Text(
+            text = "›",
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/RelayGroupViewModeToggle.kt

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup
+
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.SegmentedButton
+import androidx.compose.material3.SegmentedButtonDefaults
+import androidx.compose.material3.SingleChoiceSegmentedButtonRow
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupViewMode
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+
+/**
+ * A compact toggle to switch how the user's NIP-29 groups appear in the Messages
+ * tab — [RelayGroupViewMode.INLINE] (channels as rows with a relay chip) vs
+ * [RelayGroupViewMode.GROUPED] (a row per relay, drill in for its channels).
+ * Only shown once the user has joined at least one group.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun RelayGroupViewModeToggle(accountViewModel: AccountViewModel) {
+    val groups by accountViewModel.account.relayGroupList.liveRelayGroupList
+        .collectAsStateWithLifecycle()
+    if (groups.isEmpty()) return
+
+    val mode by accountViewModel.account.settings.relayGroupViewMode
+        .collectAsStateWithLifecycle()
+
+    SingleChoiceSegmentedButtonRow(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 16.dp, vertical = 6.dp),
+    ) {
+        SegmentedButton(
+            selected = mode == RelayGroupViewMode.INLINE,
+            onClick = { accountViewModel.account.settings.updateRelayGroupViewMode(RelayGroupViewMode.INLINE) },
+            shape = SegmentedButtonDefaults.itemShape(index = 0, count = 2),
+        ) {
+            Text(stringRes(R.string.relay_group_view_inline))
+        }
+        SegmentedButton(
+            selected = mode == RelayGroupViewMode.GROUPED,
+            onClick = { accountViewModel.account.settings.updateRelayGroupViewMode(RelayGroupViewMode.GROUPED) },
+            shape = SegmentedButtonDefaults.itemShape(index = 1, count = 2),
+        ) {
+            Text(stringRes(R.string.relay_group_view_grouped))
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/rooms/feed/ChatroomListTabs.kt

@@ -119,12 +119,13 @@ fun MessagesPager(
     tabs: List<MessagesTabItem>,
     accountViewModel: AccountViewModel,
     nav: INav,
+    modifier: Modifier = Modifier,
 ) {
     HorizontalPager(
         state = pagerState,
         userScrollEnabled = true,
         modifier =
-            Modifier.zonedDrawerSwipe(
+            modifier.zonedDrawerSwipe(
                 pagerState = pagerState,
                 openDrawer = nav::openDrawer,
             ),

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/rooms/singlepane/MessagesSinglePane.kt

@@ -26,7 +26,10 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupViewMode
 import com.vitorpamplona.amethyst.commons.ui.feeds.FeedContentState
 import com.vitorpamplona.amethyst.ui.feeds.ScrollStateKeys
 import com.vitorpamplona.amethyst.ui.feeds.WatchLifecycleAndUpdateModel
@@ -38,6 +41,8 @@ import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.navigation.topbars.AmethystClickableIcon
 import com.vitorpamplona.amethyst.ui.navigation.topbars.UserDrawerSearchTopBar
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupServerList
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.RelayGroupViewModeToggle
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.ChannelFabColumn
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.datasource.ChatroomListFilterAssemblerSubscription
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.feed.MessagesPager
@@ -98,11 +103,21 @@ fun MessagesSinglePane(
         },
         accountViewModel = accountViewModel,
     ) {
-        MessagesPager(
-            pagerState,
-            tabs,
-            accountViewModel,
-            nav,
-        )
+        val viewMode by accountViewModel.account.settings.relayGroupViewMode
+            .collectAsStateWithLifecycle()
+
+        Column {
+            RelayGroupViewModeToggle(accountViewModel)
+            if (viewMode == RelayGroupViewMode.GROUPED) {
+                RelayGroupServerList(accountViewModel, nav)
+            }
+            MessagesPager(
+                pagerState,
+                tabs,
+                accountViewModel,
+                nav,
+                modifier = Modifier.weight(1f),
+            )
+        }
     }
 }

amethyst/src/main/res/values/strings.xml

@@ -1929,6 +1929,8 @@
     <string name="messages_create_public_chat">Public</string>
     <string name="messages_create_group">Group</string>
     <string name="messages_create_public_private_chat_description">New Public or Private Group</string>
+    <string name="relay_group_view_inline">Inline</string>
+    <string name="relay_group_view_grouped">By relay</string>
     <string name="messages_new_message">Private</string>
     <string name="messages_new_message_to">To</string>
     <string name="messages_new_message_subject">Subject</string>