private void UpdateSnapshot()
{
if (_newSnapshotRequired)
{
_snapshotLock.TryEnterWriteLock(Timeout.Infinite);
if (_newSnapshotRequired)
{
_baseSnapshot = new ImmutableCollection <T>(_baseCollection);
_newSnapshotRequired = false;
}
_snapshotLock.ExitWriteLock();
}
}
protected ConcurrentObservableBase(IEnumerable <T> enumerable)
{
_subscribers = new Dictionary <int, IObserver <NotifyCollectionChangedEventArgs> >();
_baseCollection = new ObservableCollection <T>(enumerable);
_baseSnapshot = new ImmutableCollection <T>(enumerable);
_viewModel = new ObservableCollectionViewModel <T>(this);
_baseCollection.CollectionChanged += HandleBaseCollectionChanged;
_viewModel.CollectionChanged += (sender, e) =>
{
CollectionChanged?.Invoke(sender, e);
};
}