First Draft: Support for pinned messages.

lib/controllers/room_pins_controller.dart

@@ -0,0 +1,92 @@
+import "package:collection/collection.dart";
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:nexus/controllers/client_controller.dart";
+import "package:nexus/controllers/rooms_controller.dart";
+import "package:nexus/models/content/content.dart";
+import "package:nexus/models/content/pinned_events.dart";
+import "package:nexus/models/event.dart";
+
+class RoomPinsController extends AsyncNotifier<IList<Event>> {
+  final String roomId;
+  RoomPinsController(this.roomId);
+
+  @override
+  Future<IList<Event>> build() async {
+    final room = ref.watch(
+      RoomsController.provider.select((rooms) => rooms[roomId]),
+    );
+
+    if (room == null) return .new();
+
+    final pinnedRowId = room.state[EventType.pinnedEvents.type]?[""];
+    final pinnedStateEvent = pinnedRowId == null
+        ? null
+        : room.events[pinnedRowId];
+
+    if (pinnedStateEvent == null) return .new();
+
+    final pinnedContent = switch (pinnedStateEvent.content) {
+      PinnedEventsContent content => content,
+      _ => null,
+    };
+
+    if (pinnedContent == null || pinnedContent.pinned.isEmpty) {
+      return .new();
+    }
+
+    final localEvents = <Event>[];
+    final missingIds = <String>[];
+
+    for (final eventId in pinnedContent.pinned) {
+      final localEvent = room.events.values.firstWhereOrNull(
+        (e) => e.eventId == eventId,
+      );
+
+      if (localEvent != null) {
+        localEvents.add(localEvent);
+      } else {
+        missingIds.add(eventId);
+      }
+    }
+
+    if (missingIds.isNotEmpty) {
+      final client = ref.read(ClientController.provider.notifier);
+      final fetched = await Future.wait(
+        missingIds.map(
+          (id) => client.getEvent(.new(roomId: roomId, eventId: id)),
+        ),
+      );
+
+      localEvents.addAll(fetched.whereType<Event>());
+    }
+
+    return localEvents.toIList();
+  }
+
+  Future<void> togglePin(Event event) async {
+    final client = ref.read(ClientController.provider.notifier);
+    final current = await future;
+
+    final updatedPinnedIds = current.any((e) => e.eventId == event.eventId)
+        ? current
+              .where((e) => e.eventId != event.eventId)
+              .map((e) => e.eventId)
+              .toList()
+        : [...current.map((e) => e.eventId), event.eventId];
+
+    await client.sendEvent(
+      .new(
+        roomId: roomId,
+        type: EventType.pinnedEvents.type,
+        stateKey: "",
+        content: {"pinned": updatedPinnedIds},
+      ),
+    );
+  }
+
+  static final provider = AsyncNotifierProvider.family
+      .autoDispose<RoomPinsController, IList<Event>, String>(
+        RoomPinsController.new,
+      );
+}

lib/models/requests/send_event_request.dart

@@ -8,6 +8,7 @@ abstract class SendEventRequest with _$SendEventRequest {
     required String roomId,
     required String type,
     required Map<String, dynamic> content,
+    @Default(null) String? stateKey,
     @Default(false) bool synchronous,
     @Default(false) bool disableEncryption,
   }) = _SendEventRequest;

lib/widgets/pinned_messages.dart

@@ -0,0 +1,109 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter/material.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:nexus/controllers/room_pins_controller.dart";
+import "package:nexus/models/event.dart";
+import "package:nexus/widgets/loading.dart";
+import "package:nexus/widgets/renderers/event.dart";
+
+class PinnedMessages extends HookConsumerWidget {
+  final String roomId;
+  final IList<PopupMenuEntry> Function(Event event)? getEventOptions;
+  const PinnedMessages(this.roomId, {this.getEventOptions, super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final pinsAsync = ref.watch(RoomPinsController.provider(roomId));
+    final theme = Theme.of(context);
+
+    return Column(
+      children: [
+        if (Scaffold.of(context).hasEndDrawer)
+          AppBar(
+            scrolledUnderElevation: 0,
+            leading: Icon(Icons.pin),
+            title: Text("Pinned Messages"),
+            actionsPadding: .only(right: 4),
+            actions: [
+              IconButton(
+                onPressed: Scaffold.of(context).closeEndDrawer,
+                icon: Icon(Icons.close),
+                tooltip: "Close pinned messages",
+              ),
+            ],
+          ),
+        Expanded(
+          child: switch (pinsAsync) {
+            AsyncData(:final value) when value.isEmpty => Center(
+              child: Column(
+                children: [
+                  Icon(
+                    Icons.push_pin_outlined,
+                    size: 48,
+                    color: theme.colorScheme.surfaceContainerHigh,
+                  ),
+                  SizedBox(height: 12),
+                  Text(
+                    "No pinned messages.",
+                    style: theme.textTheme.headlineSmall,
+                  ),
+                ],
+              ),
+            ),
+            AsyncData(:final value) => ListView.builder(
+              padding: .symmetric(vertical: 18),
+              itemCount: value.length,
+              itemBuilder: (context, index) {
+                final event = value[index];
+
+                return Card(
+                  margin: .only(bottom: 8),
+                  child: InkWell(
+                    borderRadius: .circular(12),
+                    onTap: () {
+                      Navigator.pop(context);
+                      // TODO: // Close drawer, then scroll to the message
+                    },
+                    child: Padding(
+                      padding: .all(12),
+                      child: Row(
+                        crossAxisAlignment: CrossAxisAlignment.start,
+                        children: [
+                          Icon(
+                            Icons.push_pin,
+                            size: 16,
+                            color: theme.colorScheme.primary,
+                          ),
+                          SizedBox(width: 8),
+                          Expanded(
+                            child: EventRenderer(
+                              event,
+                              textOnly: true,
+                              maxLines: 2,
+                              isGrouped: false,
+                              getEventOptions: getEventOptions,
+                            ),
+                          ),
+                        ],
+                      ),
+                    ),
+                  ),
+                );
+              },
+            ),
+            AsyncLoading() => Center(child: Loading()),
+            AsyncError(:final error) => Center(
+              child: Column(
+                children: [
+                  Icon(Icons.error_outline, color: theme.colorScheme.error),
+                  SizedBox(height: 8),
+                  Text("$error"),
+                ],
+              ),
+            ),
+          },
+        ),
+      ],
+    );
+  }
+}

lib/widgets/room_appbar.dart

@@ -12,6 +12,7 @@ import "package:nexus/widgets/room_menu.dart";
 class RoomAppbar extends ConsumerWidget implements PreferredSizeWidget {
   final bool isDesktop;
   final void Function(BuildContext context)? onOpenMemberList;
+  final void Function(BuildContext context)? onOpenPinnedMessagesList;
   final void Function(BuildContext context) onOpenDrawer;
   final String? roomId;
   const RoomAppbar({
@@ -19,6 +20,7 @@ class RoomAppbar extends ConsumerWidget implements PreferredSizeWidget {
     required this.isDesktop,
     required this.onOpenDrawer,
     this.onOpenMemberList,
+    this.onOpenPinnedMessagesList,
     super.key,
   });
 
@@ -128,7 +130,7 @@ class RoomAppbar extends ConsumerWidget implements PreferredSizeWidget {
           ? .new()
           : .new([
               IconButton(
-                onPressed: null,
+                onPressed: () => onOpenPinnedMessagesList?.call(context),
                 icon: Icon(Icons.push_pin),
                 tooltip: "Open pinned messages",
               ),

lib/widgets/room_chat.dart

@@ -17,6 +17,7 @@ import "package:nexus/models/event.dart";
 import "package:nexus/models/relation_type.dart";
 import "package:nexus/widgets/composer/composer.dart";
 import "package:nexus/widgets/emoji_picker_button.dart";
+import "package:nexus/widgets/pinned_messages.dart";
 import "package:nexus/widgets/renderers/event.dart";
 import "package:nexus/widgets/member_list.dart";
 import "package:nexus/widgets/room_appbar.dart";
@@ -63,6 +64,7 @@ class RoomChat extends HookConsumerWidget {
           isDesktop: isDesktop,
           onOpenDrawer: (_) => Scaffold.of(context).openDrawer(),
           onOpenMemberList: null,
+          onOpenPinnedMessagesList: null,
         ),
         body: nothing,
       );
@@ -390,7 +392,15 @@ class RoomChat extends HookConsumerWidget {
         onOpenDrawer: (_) => Scaffold.of(context).openDrawer(),
         onOpenMemberList: (thisContext) {
           memberListOpened.value = !memberListOpened.value;
+          if (!showMembersByDefault) {
             Scaffold.of(thisContext).openEndDrawer();
+          }
+        },
+        onOpenPinnedMessagesList: (thisContext) {
+          memberListOpened.value = false;
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            Scaffold.of(thisContext).openEndDrawer();
+          });
         },
       ),
       body: Row(
@@ -508,7 +518,14 @@ class RoomChat extends HookConsumerWidget {
             MemberList(roomId),
         ],
       ),
-      endDrawer: showMembersByDefault ? null : MemberList(roomId),
+      endDrawer: showMembersByDefault && memberListOpened.value
+          ? null
+          : Drawer(
+              shape: Border(),
+              child: memberListOpened.value
+                  ? MemberList(roomId)
+                  : PinnedMessages(roomId, getEventOptions: getEventOptions),
+            ),
     );
   }
 }