Can remove conversation logo

lib/helpers/conversations_helper.dart

@@ -109,6 +109,14 @@ class ConversationsHelper {
           .addBytesFile("file", file)
           .execWithFilesAndThrow();
 
+  /// Remove conversation logo
+  ///
+  /// Throws in case of failure
+  static Future<void> removeLogo(int convID) async =>
+      await APIRequest.withLogin("conversations/delete_image")
+          .addInt("convID", convID)
+          .execWithThrow();
+
   /// Delete a conversation specified by its [id]
   Future<void> deleteConversation(int id) async =>
       await APIRequest.withLogin("conversations/delete")

lib/ui/screens/update_conversation_screen.dart

@@ -175,9 +175,6 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
               ],
             ),
 
-            // Conversation image
-            isUpdating ? _buildConversationImageWidget() : Container(),
-
             // Add a member to the conversation
             PickUserWidget(
                 resetOnChoose: true,
@@ -190,6 +187,9 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
             Column(
               children: _members.map((f) => _buildMemberTile(f)).toList(),
             ),
+
+            // Conversation image
+            isUpdating ? _buildConversationImageWidget() : Container(),
           ],
         ),
       ),
@@ -335,9 +335,22 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
               : CachedNetworkImage(imageUrl: _image),
           SizedBox(height: 5),
           isAdmin
-              ? OutlineButton(
+              ? Row(
-                  onPressed: _uploadNewLogo,
+                  mainAxisAlignment: MainAxisAlignment.center,
-                  child: Text(tr("Change logo")),
+                  children: [
+                    OutlineButton(
+                      onPressed: _uploadNewLogo,
+                      child: Text(tr("Change logo")),
+                    ),
+                    SizedBox(width: 5),
+                    _image == null
+                        ? Container()
+                        : OutlineButton(
+                            onPressed: _deleteLogo,
+                            child: Text(tr("Delete logo")),
+                            highlightedBorderColor: Colors.red,
+                          ),
+                  ],
                 )
               : Container(),
           SizedBox(height: 10),
@@ -366,4 +379,20 @@ class _UpdateConversationScreen extends State<UpdateConversationScreen> {
       snack(context, tr("Failed to change conversation logo !"));
     }
   }
+
+  /// Delete conversation logo
+  Future<void> _deleteLogo() async {
+    try {
+      if (!await showConfirmDialog(
+          context: context,
+          message: tr("Do you really want to delete this logo?"))) return;
+
+      await ConversationsHelper.removeLogo(_conversation.id);
+
+      setState(() => _image = null);
+    } catch (e, s) {
+      logError(e, s);
+      snack(context, tr("Failed to remove conversation logo!"));
+    }
+  }
 }