listenKey method

VoidCallback listenKey(
  1. String key,
  2. ValueSetter callback
)

Implementation

VoidCallback listenKey(String key, ValueSetter callback) {
  final VoidCallback listen = () {
    if (changes.keys.first == key) {
      callback(changes[key]);
    }
  };

  _keyListeners[callback] = listen;
  return _concrete.subject.addListener(listen);
}