/// <summary>
/// Updates the snapshot that is used to generate an Enumerator
/// </summary>
/// <param name="forceUpdate"></param>
private void UpdateSnapshot()
{
if (_newSnapshotRequired)
{
_snapshotLock.TryEnterWriteLock(Timeout.Infinite);
if (_newSnapshotRequired)
{
_baseSnapshot = new ImmutableCollection <T>(_baseCollection);
_newSnapshotRequired = false;
}
_snapshotLock.ExitWriteLock();
}
}
private void OnCreated(IEnumerable <T> enumerable)
{
_subscribers = new Dictionary <int, IObserver <NotifyCollectionChangedEventArgs> >();
_baseSnapshot = new ImmutableCollection <T>(enumerable);
// subscribers must be initialized befor calling this as it may
// subscribe immediately
_viewModel = new ObservableCollectionViewModel <T>(this);
// Handle when the base collection changes. Event will be passed through
// the IObservable.OnNext method.
_baseCollection.CollectionChanged += HandleBaseCollectionChanged;
// Bubble up the notify collection changed event from the view model
_viewModel.CollectionChanged += (sender, e) => CollectionChanged?.Invoke(sender, e);
}