Delete conversation => leave conversation

lib/models/conversation.dart

@@ -50,6 +50,9 @@ class Conversation extends SerializableElement<Conversation> {
   /// Check out whether current user of the application is an admin
   bool get isAdmin => membership.isAdmin;
 
+  /// Check if current user is the last admin of the conversation
+  bool get isLastAdmin => isAdmin && adminsID.length == 1;
+
   /// Check it current user is following the conversation or not
   bool get following => membership.following;
 

lib/ui/screens/conversations_list_screen.dart

@@ -123,30 +123,13 @@ class _ConversationScreenState extends SafeState<ConversationsListScreen> {
   }
 
   /// Handle conversation deletion request
-  Future<void> _requestDeleteConversation(Conversation conversation) async {
-    final result = await showDialog<bool>(
-      context: context,
-      builder: (c) {
-        return AlertDialog(
-          title: Text(tr("Delete conversation")),
-          content: Text(tr(
-              "Do you really want to remove this conversation from your list of conversations ? If you are the owner of this conversation, it will be completely deleted!")),
-          actions: <Widget>[
-            FlatButton(
-              onPressed: () => Navigator.pop(context, false),
-              child: Text(tr("cancel").toUpperCase()),
-            ),
-            FlatButton(
-              onPressed: () => Navigator.pop(context, true),
-              child: Text(
-                tr("delete").toUpperCase(),
-                style: TextStyle(color: Colors.red),
-              ),
-            )
-          ],
-        );
-      },
-    );
+  Future<void> _requestLeaveConversation(Conversation conversation) async {
+    final result = await showConfirmDialog(
+        context: context,
+        message: conversation.isLastAdmin
+            ? tr(
+                "Do you really want to leave this conversation ? As you are its last admin, it will be completely deleted!")
+            : tr("Do you really want to leave this conversation ?"));
 
     if (result == null || !result) return;
 
@@ -154,9 +137,9 @@ class _ConversationScreenState extends SafeState<ConversationsListScreen> {
     try {
       await _conversationsHelper.deleteConversation(conversation.id);
     } catch (e, s) {
-      print("Failed to delete conversation! $e => $s");
+      print("Failed to leave conversation! $e => $s");
       Scaffold.of(context).showSnackBar(
-          SnackBar(content: Text(tr("Could not delete the conversation!"))));
+          SnackBar(content: Text(tr("Could not leave the conversation!"))));
     }
 
     // Reload the list of conversations
@@ -191,7 +174,7 @@ class _ConversationScreenState extends SafeState<ConversationsListScreen> {
                         _openConversation(c.id);
                       },
                       onRequestUpdate: _updateConversation,
-                      onRequestDelete: _requestDeleteConversation,
+                      onRequestLeave: _requestLeaveConversation,
                     );
                   },
                   itemCount: _list.length,

lib/ui/tiles/conversation_tile.dart

@@ -13,17 +13,17 @@ import 'package:flutter/material.dart';
 /// @author Pierre HUBERT
 
 typedef OpenConversationCallback = void Function(Conversation);
-typedef RequestDeleteConversationCallback = void Function(Conversation);
+typedef RequestLeaveConversationCallback = void Function(Conversation);
 typedef RequestUpdateConversationCallback = void Function(Conversation);
 
-enum _PopupMenuChoices { UPDATE, DELETE }
+enum _PopupMenuChoices { UPDATE, LEAVE }
 
 class ConversationTile extends StatelessWidget {
   final Conversation conversation;
   final UsersList usersList;
   final OpenConversationCallback onOpen;
   final RequestUpdateConversationCallback onRequestUpdate;
-  final RequestDeleteConversationCallback onRequestDelete;
+  final RequestLeaveConversationCallback onRequestLeave;
 
   const ConversationTile({
     Key key,
@@ -31,12 +31,12 @@ class ConversationTile extends StatelessWidget {
     @required this.usersList,
     @required this.onOpen,
     @required this.onRequestUpdate,
-    @required this.onRequestDelete,
+    @required this.onRequestLeave,
   })  : assert(conversation != null),
         assert(usersList != null),
         assert(onOpen != null),
         assert(onRequestUpdate != null),
-        assert(onRequestDelete != null),
+        assert(onRequestLeave != null),
         super(key: key);
 
   _buildSubInformation(IconData icon, String content) {
@@ -110,8 +110,8 @@ class ConversationTile extends StatelessWidget {
                   value: _PopupMenuChoices.UPDATE,
                 ),
                 PopupMenuItem(
-                  child: Text(tr("Delete")),
-                  value: _PopupMenuChoices.DELETE,
+                  child: Text(tr("Leave")),
+                  value: _PopupMenuChoices.LEAVE,
                 )
               ]).then(_conversationMenuCallback);
         },
@@ -140,8 +140,8 @@ class ConversationTile extends StatelessWidget {
         onRequestUpdate(conversation);
         break;
 
-      case _PopupMenuChoices.DELETE:
-        onRequestDelete(conversation);
+      case _PopupMenuChoices.LEAVE:
+        onRequestLeave(conversation);
         break;
     }
   }