Can delete group logo

lib/helpers/groups_helper.dart

@@ -237,6 +237,12 @@ class GroupsHelper {
           .addBytesFile("logo", BytesFile("logo.png", bytes))
           .execWithFilesAndThrow();
 
+  /// Delete group logo
+  static Future<void> deleteLogo(int groupID) async =>
+      await APIRequest(uri: "groups/delete_logo", needLogin: true)
+          .addInt("id", groupID)
+          .execWithThrow();
+
   /// Turn an API entry into a group object
   Group _getGroupFromAPI(Map<String, dynamic> map) {
     return Group(

lib/ui/screens/group_settings_screen.dart

@@ -261,7 +261,13 @@ class _GroupSettingsScreenState extends SafeState<GroupSettingsScreen> {
         SettingsTile(
           title: tr("Generate a new random logo"),
           onTap: _generateRandomLogo,
-        )
+        ),
+
+        // Delete current logo
+        SettingsTile(
+          title: tr("Delete logo"),
+          onTap: _deleteLogo,
+        ),
       ],
     );
   }
@@ -294,4 +300,20 @@ class _GroupSettingsScreenState extends SafeState<GroupSettingsScreen> {
     await GroupsHelper.uploadNewLogo(_groupSettings.id, bytes);
     _key.currentState.refresh();
   }
+
+  /// Delete previous group logo
+  void _deleteLogo() async {
+    try {
+      if (!await showConfirmDialog(
+          context: context,
+          message: tr("Do you really want to delete the logo of this group ?")))
+        return;
+
+      await GroupsHelper.deleteLogo(_groupSettings.id);
+      _key.currentState.refresh();
+    } catch (e, s) {
+      print("Could not delete group logo! $e\n$s");
+      showSimpleSnack(context, tr("Could not delete group logo!"));
+    }
+  }
 }