Can delete a conversation from the list of conversations

lib/ui/tiles/conversation_tile.dart

@@ -10,20 +10,26 @@ import 'package:flutter/material.dart';
 /// @author Pierre HUBERT
 
 typedef OpenConversationCallback = void Function(Conversation);
+typedef RequestDeleteConversationCallback = void Function(Conversation);
+
+enum _PopupMenuChoices { DELETE }
 
 class ConversationTile extends StatelessWidget {
   final Conversation conversation;
   final UsersList usersList;
   final OpenConversationCallback onOpen;
+  final RequestDeleteConversationCallback onRequestDelete;
 
   const ConversationTile(
       {Key key,
       @required this.conversation,
       @required this.usersList,
-      @required this.onOpen})
+      @required this.onOpen,
+      @required this.onRequestDelete})
       : assert(conversation != null),
         assert(usersList != null),
         assert(onOpen != null),
+        assert(onRequestDelete != null),
         super(key: key);
 
   _buildSubInformation(IconData icon, String content) {
@@ -80,6 +86,26 @@ class ConversationTile extends StatelessWidget {
           ),
         ],
       ),
+
+      // Trailing information
+      trailing: PopupMenuButton<_PopupMenuChoices>(
+        itemBuilder: (b) => <PopupMenuEntry<_PopupMenuChoices>>[
+              PopupMenuItem(
+                child: Text(tr("Delete")),
+                value: _PopupMenuChoices.DELETE,
+              )
+            ],
+        onSelected: _conversationMenuCallback,
+      ),
     );
   }
+
+  /// Method called each time an option of the menu is selected
+  void _conversationMenuCallback(_PopupMenuChoices c) {
+    switch (c) {
+      case _PopupMenuChoices.DELETE:
+        onRequestDelete(conversation);
+        break;
+    }
+  }
 }