refactored direct chat logic into a shared utility, implemented direct message shortcuts in the participant list and message reactions, and added reaction visibility checks in the message options dialog

lib/view/pages/talk/details/chat_info.dart

@@ -77,7 +77,10 @@ class _ChatInfoState extends State<ChatInfo> {
                 trailing: const Icon(Icons.arrow_right),
                 onTap: () => TalkNavigator.pushSplitView(
                   context,
-                  ParticipantsListView(participants!),
+                  ParticipantsListView(
+                    participants!,
+                    showDirectMessageAction: isGroup,
+                  ),
                 ),
               ),
             ],

lib/view/pages/talk/details/message_reactions.dart

@@ -1,4 +1,3 @@
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 import '../../../../api/marianumcloud/talk/get_reactions/get_reactions.dart';
@@ -7,8 +6,8 @@ import '../../../../model/account_data.dart';
 import '../../../../widget/centered_leading.dart';
 import '../../../../widget/loading_spinner.dart';
 import '../../../../widget/placeholder_view.dart';
-import '../../../../widget/unimplemented_dialog.dart';
 import '../../../../widget/user_avatar.dart';
+import '../data/open_direct_chat.dart';
 
 class MessageReactions extends StatefulWidget {
   final String token;
@@ -63,25 +62,28 @@ class _MessageReactionsState extends State<MessageReactions> {
                 leading: CenteredLeading(Text(entry.key)),
                 title: Text('${entry.value.length} mal reagiert'),
                 children: entry.value.map((e) {
-                  var isSelf = AccountData().getUsername() == e.actorId;
+                  final isSelf = AccountData().getUsername() == e.actorId;
+                  final isGuest =
+                      e.actorType ==
+                      GetReactionsResponseObjectActorType.guests;
                   return ListTile(
                     leading: UserAvatar(id: e.actorId, isGroup: false),
                     title: Text(e.actorDisplayName),
                     subtitle: isSelf
                         ? const Text('Du')
-                        : e.actorType ==
-                              GetReactionsResponseObjectActorType.guests
+                        : isGuest
                         ? const Text('Gast')
                         : null,
-                    trailing: isSelf
+                    trailing: isSelf || isGuest
                         ? null
-                        : Visibility(
-                            visible: kReleaseMode,
-                            child: IconButton(
-                              onPressed: () =>
-                                  UnimplementedDialog.show(context),
-                              icon: const Icon(Icons.textsms_outlined),
+                        : IconButton(
+                            tooltip: 'Private Nachricht',
+                            onPressed: () => openOrCreateDirectChat(
+                              context,
+                              actorId: e.actorId,
+                              actorDisplayName: e.actorDisplayName,
                             ),
+                            icon: const Icon(Icons.textsms_outlined),
                           ),
                   );
                 }).toList(),

lib/view/pages/talk/details/participants_list_view.dart

@@ -2,11 +2,23 @@ import 'package:collection/collection.dart';
 import 'package:flutter/material.dart';
 
 import '../../../../api/marianumcloud/talk/get_participants/get_participants_response.dart';
+import '../../../../model/account_data.dart';
 import '../../../../widget/user_avatar.dart';
+import '../data/open_direct_chat.dart';
 
 class ParticipantsListView extends StatelessWidget {
   final GetParticipantsResponse participantsResponse;
-  const ParticipantsListView(this.participantsResponse, {super.key});
+
+  /// Hide the per-participant direct-message shortcut: in a 1:1 chat the
+  /// only other participant *is* the current chat — the shortcut would
+  /// just navigate back to where the user already is.
+  final bool showDirectMessageAction;
+
+  const ParticipantsListView(
+    this.participantsResponse, {
+    this.showDirectMessageAction = true,
+    super.key,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -24,6 +36,7 @@ class ParticipantsListView extends StatelessWidget {
       (participant) => participant.participantType,
     );
 
+    final selfId = AccountData().getUsername();
     return Scaffold(
       appBar: AppBar(title: const Text('Mitglieder')),
       body: ListView(
@@ -35,15 +48,30 @@ class ParticipantsListView extends StatelessWidget {
                   title: Text(entry.key.prettyName),
                   titleTextStyle: Theme.of(context).textTheme.titleMedium,
                 ),
-                ...entry.value.map(
-                  (participant) => ListTile(
+                ...entry.value.map((participant) {
+                  final canDirectMessage =
+                      showDirectMessageAction &&
+                      participant.actorType == 'users' &&
+                      participant.actorId != selfId;
+                  return ListTile(
                     leading: UserAvatar(id: participant.actorId),
                     title: Text(participant.displayName),
                     subtitle: participant.statusMessage != null
                         ? Text(participant.statusMessage!)
                         : null,
-                  ),
-                ),
+                    trailing: canDirectMessage
+                        ? IconButton(
+                            tooltip: 'Private Nachricht',
+                            onPressed: () => openOrCreateDirectChat(
+                              context,
+                              actorId: participant.actorId,
+                              actorDisplayName: participant.displayName,
+                            ),
+                            icon: const Icon(Icons.textsms_outlined),
+                          )
+                        : null,
+                  );
+                }),
                 Divider(),
               ],
             ),