public String getCommandName(KeyboardEvent event) {
if (event == null) return null;
for (int i = 0; i < items.size(); i++) {
Item item = items.get(i);
if (item.event.equals(event)) return item.actionName;
}
return null;
}
public void addMapping(KeyboardEvent event, String actionName) {
if (event == null || actionName == null) return;
if (getCommandName(event) != null) return;
items.add(new Item(event, actionName));
}