handleCharCodeKey method
Implementation
@override
void handleCharCodeKey(KeyboardEvent event) {
if (itemRenderer != null && !disabled) {
// Don't activate or select if the widget is disabled.
// Don't select if the selection model is multi-select.
activateOnKeyPress(activeModel, event.charCode, options, itemRenderer,
!visible && isSingleSelect ? selection : null);
}
}