/// <summary>
/// Updates the snapshot that is used to generate an Enumerator
/// </summary>
void UpdateSnapshot()
{
if (NewSnapshotRequired)
{
SnapshotLock.TryEnterWriteLock(Timeout.Infinite);
if (NewSnapshotRequired)
{
BaseSnapshot = new ImmutableCollection <T>(BaseCollection);
NewSnapshotRequired = false;
}
SnapshotLock.ExitWriteLock();
}
}
/// <summary>
/// Constructor that takes an eumerable
/// </summary>
protected ConcurrentCollectionBase(IEnumerable <T> Items)
{
Subscribers = new Dictionary <int, IObserver <NotifyCollectionChangedEventArgs> >();
BaseCollection = new ObservableCollection <T>(Items);
BaseSnapshot = new ImmutableCollection <T>(Items);
// subscribers must be initialized befor calling this as it may
// subscribe immediately
viewModel = new ConcurrentCollectionViewModel <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);
}