addEventListener method
Add a Spline runtime event listener (e.g. mouseDown, mouseUp, start ...) Returns an integer id that can be used to remove a specific callback.
Implementation
int addEventListener(String eventName, Function(Map<String, dynamic>) callback) {
final list = _eventListeners.putIfAbsent(eventName, () => []);
list.add(callback);
final id = ++_eventCallbackSerial;
_callbackById[id] = callback;
// Fire JS attach command (best-effort; scene may not be ready yet) - JS bridge will ignore duplicates.
runJavaScript('window.SplineFlutterBridge?.addEventListener?.(${_jsString(eventName)});');
return id;
}