public void ItemCollectionItemsSourceTest()
{
ObservableCollection<string> collection = new ObservableCollection<string>(new[] { "collection1", "collection2", "collection3" });
InnerCollectionView view = new InnerCollectionView();
view.Add("view1");
view.Add("view2");
view.Add("view3");
view.CurrentItemIndex = 1;
ItemCollection itemCollection = new ItemCollection();
NotifyCollectionChangedEventArgs lastChangeArgs = null;
int currentChangedCount = 0;
itemCollection.CollectionChanged += (sender, e) => lastChangeArgs = e;
itemCollection.CurrentChanged += (sender, e) => currentChangedCount++;
itemCollection.SetItemsSource(collection);
Assert.AreEqual(-1, itemCollection.CurrentItemIndex);
Assert.AreEqual(1, currentChangedCount);
collection.Add("collection4");
Assert.AreEqual(NotifyCollectionChangedAction.Add, lastChangeArgs.Action);
CollectionAssert.AreEqual(new[] { "collection4" }, lastChangeArgs.NewItems.Cast<string>().ToArray());
Assert.AreEqual(-1, itemCollection.CurrentItemIndex);
Assert.AreEqual(1, currentChangedCount);
itemCollection.CurrentItemIndex = 0;
Assert.AreEqual(0, itemCollection.CurrentItemIndex);
Assert.AreEqual(2, currentChangedCount);
itemCollection.SetItemsSource(view);
Assert.AreEqual(NotifyCollectionChangedAction.Reset, lastChangeArgs.Action);
CollectionAssert.AreEqual(new[] { "collection1", "collection2", "collection3", "collection4" }, lastChangeArgs.OldItems.Cast<string>().ToArray());
CollectionAssert.AreEqual(new[] { "view1", "view2", "view3" }, lastChangeArgs.NewItems.Cast<string>().ToArray());
Assert.AreEqual(1, itemCollection.CurrentItemIndex);
Assert.AreEqual(3, currentChangedCount);
itemCollection.SetItemsSource(collection);
lastChangeArgs = null;
view.Add("view4");
Assert.IsNull(lastChangeArgs);
}
