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/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(),