public FFTypeDescriptor SetContext([CanBeNull] object obj, [CanBeNull] IEnumerable <ITitled> scope, [CanBeNull] Action <object, FFTypeDescriptor> onSelectedObjectChanged) { _SelectedObjectChanged = onSelectedObjectChanged; ComboBox.ObjectCollection items = cbScope.Items; items.Clear(); if (cbScope.Enabled = scope != null && obj != null) { foreach (var t in scope) { items.AddTitledItem(t); } } else { var t = obj as ITitled; if (t != null) { items.AddTitledItem(t); } else { if (obj != null) { items.Add(obj.ToString()); } } } return(SetCurrentObject(obj)); }