/// <summary>
/// Sets up an event stream and begin emitting events.
/// Invoked when the first listener is registered with the Stream associated to this channel on the Flutter side.
/// </summary>
/// <param name="arguments">Arguments for the stream.</param>
/// <param name="events">
/// A callback to asynchronously emit events.
/// Invoke the callback with a <see cref="FlutterError"/> to emit an error event.
/// Invoke the callback with <see cref="ConstantsEx.FlutterEndOfEventStream"/> to indicate that no more events will be emitted.
/// Any other value, including null, are emitted as successful events.
/// </param>
/// <returns>A <see cref="FlutterError"/> instance, if setup fails.</returns>
public FlutterError OnListen(NSObject arguments, FlutterEventSink events)
{
_events = events;
return(null);
}
/// <summary>
/// Tears down an event stream.
/// Invoked when the last listener is deregistered from the Stream associated to this channel on the Flutter side.
/// </summary>
/// <param name="arguments">Arguments for the stream.</param>
/// <returns>A <see cref="FlutterError"/> instance, if teardown fails.</returns>
public FlutterError OnCancel(NSObject arguments)
{
_events = null;
return(null);
}
