public static ReadOnlyDispatcherCollection <TViewModel> CreateReadOnlyDispatcherCollection <TModel, TViewModel>(IList <TModel> source, Func <TModel, TViewModel> converter, Dispatcher dispatcher)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
var sourceAsNotifyCollection = source as INotifyCollectionChanged;
if (sourceAsNotifyCollection == null)
{
throw new ArgumentException("sourceがINotifyCollectionChangedを実装していません");
}
var initCollection = new ObservableCollection <TViewModel>();
var internalLock = new object();
lock (internalLock)
{
var target = new DispatcherCollection <TViewModel>(initCollection, dispatcher);
var result = new ReadOnlyDispatcherCollection <TViewModel>(target);
var collectionChangedListener = new CollectionChangedEventListener(sourceAsNotifyCollection);
result.EventListeners.Add(collectionChangedListener);
collectionChangedListener.RegisterHandler((sender, e) =>
{
lock (internalLock)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
target.Insert(e.NewStartingIndex, converter((TModel)e.NewItems[0]));
break;
case NotifyCollectionChangedAction.Move:
target.Move(e.OldStartingIndex, e.NewStartingIndex);
break;
case NotifyCollectionChangedAction.Remove:
if (typeof(IDisposable).IsAssignableFrom(typeof(TViewModel)))
{
((IDisposable)target[e.OldStartingIndex]).Dispose();
}
target.RemoveAt(e.OldStartingIndex);
break;
case NotifyCollectionChangedAction.Replace:
if (typeof(IDisposable).IsAssignableFrom(typeof(TViewModel)))
{
((IDisposable)target[e.NewStartingIndex]).Dispose();
}
target[e.NewStartingIndex] = converter((TModel)e.NewItems[0]);
break;
case NotifyCollectionChangedAction.Reset:
if (typeof(IDisposable).IsAssignableFrom(typeof(TViewModel)))
{
foreach (IDisposable item in target)
{
item.Dispose();
}
}
target.Clear();
break;
default:
throw new ArgumentException();
}
}
});
foreach (var model in source)
{
initCollection.Add(converter(model));
}
return(result);
}
}
