onSinksUpdated property
This is fired whenever the list of available sinks changes. A sink is a device or a software surface that you can cast to.
Implementation
Stream<List<Sink>> get onSinksUpdated => _client.onEvent
.where((event) => event.name == 'Cast.sinksUpdated')
.map((event) => (event.parameters['sinks'] as List)
.map((e) => Sink.fromJson(e as Map<String, dynamic>))
.toList());