private void SelectFormItem(IFormItem formItemToSelect) { if (formItemToSelect is null) { return; } foreach (IFormItem formItem in FormItems) { if (formItem == formItemToSelect) { formItemToSelect.IsSelected = !formItemToSelect.IsSelected; } else { formItem.IsSelected = false; } } OnPropertyChanged(nameof(SelectedFormItem)); m_messengerHub.Send(new FormSurfaceItemSelectionMessage(formItemToSelect)); }