public void Detach(IDataChangedObserver observer) { if (_observers.Contains(observer)) { _observers.Remove(observer); } }
public void Attach(IDataChangedObserver observer) { if (!_observers.Contains(observer)) { _observers.Add(observer); } }
public void DeleteObserver(IDataChangedObserver observer) { int index = dataChangedObservers.IndexOf(observer); if (index != -1) { dataChangedObservers.RemoveAt(index); } }
public void AddObserver(IDataChangedObserver observer) { dataChangedObservers.Add(observer); }