// Clears grid with groups
this.formItemsGroupsGrid.clear();
// Gets groups array from form
IFormItemsGroup[] groups = form.getGroups();
// create
this.groupWidgets = new FormItemsGroupWidgetCollection();
// check data row
if (this.dataRow == null)
throw new NullPointerException(FrameworkLocale.messages()
.error_rowisnull());
// Builds groups in group grid: