internal static ReadOnlyListSubject <TResult> CollectInternal <TResult>(
this FileSystemWatcher watcher,
bool composited,
Func <IObservable <CollectionNotification <string> >, IObservable <CollectionModification <TResult> > > selector,
IScheduler scheduler)
{
Contract.Requires(watcher != null);
Contract.Requires(selector != null);
Contract.Requires(scheduler != null);
Contract.Ensures(Contract.Result <ReadOnlyListSubject <TResult> >() != null);
var existing = Directory
.EnumerateFiles(
watcher.Path,
watcher.Filter,
watcher.IncludeSubdirectories ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
var changes = watcher
.Watch(WatcherChangeTypes.Created | WatcherChangeTypes.Deleted | WatcherChangeTypes.Renamed)
.SelectMany(notification => notification.Change == WatcherChangeTypes.Created
? Observable.Return(CollectionModification.CreateAdd(notification.FullPath))
: notification.Change == WatcherChangeTypes.Deleted
? Observable.Return(CollectionModification.CreateRemove(notification.FullPath))
: Observable.Return(CollectionModification.CreateRemove(notification.OldFullPath)).Concat(Observable.Return(CollectionModification.CreateAdd(notification.FullPath))));
if (composited)
{
changes = changes.Finally(watcher.Dispose);
}
return(existing.ToObservable(scheduler).Collect(changes.ObserveOn(scheduler), selector, StringComparer.OrdinalIgnoreCase));
}
/// <summary>
/// Converts <see cref="INotifyCollectionChanged.CollectionChanged"/> events into an observable sequence of <see cref="CollectionModification{T}"/>.
/// </summary>
/// <typeparam name="T">The object that provides notification information.</typeparam>
/// <param name="source">An implementation of <see cref="INotifyCollectionChanged"/> that raises events when a collection changes.</param>
/// <remarks>
/// An <see cref="NotifyCollectionChangedAction.Add"/> event is projected into zero or more <see cref="CollectionModificationKind.Add"/> modifications.
/// A <see cref="NotifyCollectionChangedAction.Remove"/> event is projected into zero or more <see cref="CollectionModificationKind.Remove"/> modifications.
/// A <see cref="NotifyCollectionChangedAction.Move"/> event is ignored.
/// A <see cref="NotifyCollectionChangedAction.Replace"/> event is projected into zero or more sequential
/// <see cref="CollectionModificationKind.Remove"/> and <see cref="CollectionModificationKind.Add"/> modifications.
/// A <see cref="NotifyCollectionChangedAction.Reset"/> event is projected into a single <see cref="CollectionModificationKind.Clear"/> modification.
/// </remarks>
/// <returns>An observable sequence of <see cref="CollectionModification{T}"/> objects corresponding to raised events.</returns>
#else
/// <summary>
/// Converts <see cref="INotifyCollectionChanged.CollectionChanged"/> events into an observable sequence of <see cref="CollectionModification{T}"/>.
/// </summary>
/// <typeparam name="T">The object that provides notification information.</typeparam>
/// <param name="source">An implementation of <see cref="INotifyCollectionChanged"/> that raises events when a collection changes.</param>
/// <remarks>
/// An <see cref="NotifyCollectionChangedAction.Add"/> event is projected into zero or more <see cref="CollectionModificationKind.Add"/> modifications.
/// A <see cref="NotifyCollectionChangedAction.Remove"/> event is projected into zero or more <see cref="CollectionModificationKind.Remove"/> modifications.
/// A <see cref="NotifyCollectionChangedAction.Replace"/> event is projected into zero or more sequential
/// <see cref="CollectionModificationKind.Remove"/> and <see cref="CollectionModificationKind.Add"/> modifications.
/// A <see cref="NotifyCollectionChangedAction.Reset"/> event is projected into a single <see cref="CollectionModificationKind.Clear"/> modification.
/// </remarks>
/// <returns>An observable sequence of <see cref="CollectionModification{T}"/> objects corresponding to raised events.</returns>
#endif
public static IObservable <CollectionModification <T> > AsCollectionModifications <T>(this INotifyCollectionChanged source)
{
Contract.Requires(source != null);
Contract.Ensures(Contract.Result <IObservable <CollectionModification <T> > >() != null);
return(Observable.FromEventPattern <NotifyCollectionChangedEventHandler, NotifyCollectionChangedEventArgs>(
eh => source.CollectionChanged += eh,
eh => source.CollectionChanged -= eh)
.SelectMany(e =>
{
var args = e.EventArgs;
switch (args.Action)
{
case NotifyCollectionChangedAction.Add:
return Observable.Return(CollectionModification.CreateAdd(EnsureList <T>(args.NewItems)));
case NotifyCollectionChangedAction.Remove:
return Observable.Return(CollectionModification.CreateRemove(EnsureList <T>(args.OldItems)));
#if !SILVERLIGHT
case NotifyCollectionChangedAction.Move:
return Observable.Empty <CollectionModification <T> >();
#endif
case NotifyCollectionChangedAction.Replace:
return Observable.Return(CollectionModification.CreateRemove(EnsureList <T>(args.OldItems)))
.Concat(Observable.Return(CollectionModification.CreateAdd(EnsureList <T>(args.NewItems))));
case NotifyCollectionChangedAction.Reset:
return Observable.Return(CollectionModification.CreateClear <T>());
default:
throw new InvalidOperationException();
}
}));
}
