// Handle with function, for layer event, allow other three options
LuaEventHandler * handle(int handler, bool multiTouches = false, int priority = 0, bool swallows = false){
unhandle();
_handler = handler;
_multiTouches = multiTouches;
_priority = priority;
_swallows = swallows;
_handlerRef = lua_ref(_lua, _handler);
return this;
}
LuaEventHandler::~LuaEventHandler(){
unhandle();
}