make hovering a reaction show its shortcode

lib/controllers/emoji_shortcodes.dart

@@ -0,0 +1,31 @@
+import "package:collection/collection.dart";
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:material_emoji_picker/material_emoji_picker.dart";
+
+/// Maps each unicode emoji, without variation selectors, to its shortcode.
+class EmojiShortcodesController extends Notifier<IMap<String, String>> {
+  static final _variationSelectors = RegExp("[\uFE0E\uFE0F]");
+
+  static String normalize(String emoji) =>
+      emoji.replaceAll(_variationSelectors, "");
+
+  @override
+  IMap<String, String> build() => .fromEntries(
+    ref
+        .watch(EmojiController.provider)
+        .requireValue
+        .map((category) => category.emojis)
+        .flattened
+        .where((emoji) => emoji.aliases.isNotEmpty)
+        .map(
+          (emoji) =>
+              MapEntry(normalize(emoji.value), ":${emoji.aliases.first}:"),
+        ),
+  );
+
+  static final provider =
+      NotifierProvider<EmojiShortcodesController, IMap<String, String>>(
+        EmojiShortcodesController.new,
+      );
+}

lib/controllers/reactions.dart

@@ -1,14 +1,18 @@
 import "package:fast_immutable_collections/fast_immutable_collections.dart";
 import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:nexus/controllers/client.dart";
+import "package:nexus/controllers/emoji_shortcodes.dart";
 import "package:nexus/controllers/rooms.dart";
 import "package:nexus/models/configs/event.dart";
 import "package:nexus/models/content/reaction.dart";
+import "package:nexus/models/reaction_group.dart";
 
 class ReactionsController(final EventConfig config)
-    extends AsyncNotifier<IMap<String, IList<String>>> {
+    extends AsyncNotifier<IMap<String, ReactionGroup>> {
   @override
-  Future<IMap<String, IList<String>>> build() async {
+  Future<IMap<String, ReactionGroup>> build() async {
+    final unicodeShortcodes = ref.watch(EmojiShortcodesController.provider);
+
     final eventInfo = ref.watch(
       RoomsController.provider.select((value) {
         final event = value[config.roomId]?.events[config.eventRowId];
@@ -30,12 +34,25 @@ class ReactionsController(final EventConfig config)
 
     return reactionEvents
             ?.where((event) => event.redactedBy == null)
-            .fold<IMap<String, IList<String>>>(.new(), (acc, event) {
-              if (event.content case ReactionContent(:final key?)) {
+            .fold<IMap<String, ReactionGroup>>(.new(), (acc, event) {
+              if (event.content case ReactionContent(
+                :final key?,
+                :final shortcode,
+              )) {
                 return acc.update(
                   key,
-                  (list) => list.add(event.sender),
-                  ifAbsent: () => .new([event.sender]),
+                  (group) => group.copyWith(
+                    senders: group.senders.add(event.sender),
+                    shortcode: group.shortcode ?? shortcode,
+                  ),
+                  ifAbsent: () => .new(
+                    senders: .new([event.sender]),
+                    shortcode:
+                        shortcode ??
+                        unicodeShortcodes[EmojiShortcodesController.normalize(
+                          key,
+                        )],
+                  ),
                 );
               }
 
@@ -47,7 +64,7 @@ class ReactionsController(final EventConfig config)
   static final provider =
       AsyncNotifierProvider.family<
         ReactionsController,
-        IMap<String, IList<String>>,
+        IMap<String, ReactionGroup>,
         EventConfig
       >(ReactionsController.new);
 }

lib/models/reaction_group.dart

@@ -0,0 +1,10 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:freezed_annotation/freezed_annotation.dart";
+
+part "reaction_group.freezed.dart";
+
+@Freezed(toJson: false, fromJson: false)
+class const ReactionGroup({
+  required final IList<String> senders,
+  final String? shortcode,
+}) with _$ReactionGroup;

lib/widgets/reactions/reaction_row.dart

@@ -7,6 +7,7 @@ import "package:nexus/controllers/reactions.dart";
 import "package:nexus/controllers/room_chat.dart";
 import "package:material_adaptive_sheets/material_adaptive_sheets.dart";
 import "package:nexus/models/event.dart";
+import "package:nexus/models/reaction_group.dart";
 import "package:nexus/widgets/common/error_dialog.dart";
 import "package:nexus/widgets/reactions/reaction_key.dart";
 import "package:nexus/widgets/reactions/reactions_popover.dart";
@@ -25,7 +26,7 @@ class const ReactionRow(final Event event, {super.key}) extends ConsumerWidget {
           .new(roomId: event.roomId, eventRowId: event.rowId),
         ),
       )) {
-        AsyncData(value: final IMap<String, IList<String>>? reactors) ||
+        AsyncData(value: final IMap<String, ReactionGroup>? reactors) ||
         AsyncLoading(value: final reactors) => Wrap(
           spacing: 4,
           runSpacing: 4,
@@ -37,7 +38,9 @@ class const ReactionRow(final Event event, {super.key}) extends ConsumerWidget {
                     final enabled = useState(true);
 
                     final selected =
-                        reactors?[reaction]?.contains(clientState!.userId) ??
+                        reactors?[reaction]?.senders.contains(
+                          clientState!.userId,
+                        ) ??
                         false;
                     void showReactions(PositionedGestureDetails details) =>
                         context.showAdaptivePopover(
@@ -52,7 +55,7 @@ class const ReactionRow(final Event event, {super.key}) extends ConsumerWidget {
                       onSecondaryTapUp: showReactions,
                       onLongPressStart: showReactions,
                       child: Tooltip(
-                        message: reactors?[reaction]?.join(", ") ?? "",
+                        message: reactors?[reaction]?.shortcode ?? reaction,
                         child: ChoiceChip(
                           showCheckmark: false,
                           selected: selected,

lib/widgets/reactions/reactions_popover.dart

@@ -81,7 +81,7 @@ class const ReactionsPopover(
                       spacing: 8,
                       children: [
                         ReactionKey(reaction, height: 20),
-                        Text(reactions[reaction]!.length.toString()),
+                        Text(reactions[reaction]!.senders.length.toString()),
                       ],
                     ),
                   ),
@@ -98,7 +98,7 @@ class const ReactionsPopover(
                   padding: .symmetric(vertical: 8),
                   child: Column(
                     crossAxisAlignment: .stretch,
-                    children: reactions[reaction]!
+                    children: reactions[reaction]!.senders
                         .map(
                           (userId) => Consumer(
                             builder: (context, ref, _) {