public void CanResetLayoutAfterUniqueIdReset()
{
var data = new WinRTCollection(Enumerable.Range(0, 2).Select(i => string.Format("Item #{0}", i)));
object dataSource = null;
RunOnUIThread.Execute(() => dataSource = MockItemsSource.CreateDataSource(data, supportsUniqueIds: true));
ItemsRepeater repeater = SetupRepeater(dataSource);
RunOnUIThread.Execute(() =>
{
var range = new UIElement[] { repeater.TryGetElement(0), repeater.TryGetElement(1) };
var clearedElements = new List <UIElement>();
repeater.ElementClearing += (s, e) =>
{
clearedElements.Add(e.Element);
};
// The realized elements will be sent to the unique id reset pool.
// They haven't been cleared yet.
data.Reset();
Verify.AreEqual(0, clearedElements.Count);
// This also cause elements to be sent to the unique id reset pool.
// We are validating here that we are smart enough not send them there twice.
// Doing so will cause an exception to be thrown.
repeater.Layout = null;
Verify.AreEqual(0, clearedElements.Count);
repeater.UpdateLayout();
// Layout runs. The elements in the reset pool are not used.
// They should be cleared back to the view generator at this point.
Verify.AreEqual(2, clearedElements.Count);
Verify.AreEqual(range[0], clearedElements[0]);
Verify.AreEqual(range[1], clearedElements[1]);
Verify.IsNull(repeater.TryGetElement(0));
Verify.IsNull(repeater.TryGetElement(1));
});
}
// Why does this test work?
// When the elements get created from the RecyclingElementFactory, we get already "existing" data templates.
// However, the reason for the crash in #2384 is that those "empty" data templates actually still had their data context
// If that data context is not null, that means it did not get cleared when the element was recycled, which is the wrong behavior.
// To check if the clearing is working correctly, we are checking this inside the ElementFactory's RecycleElement function.
public void ValidateElementClearingClearsDataContext()
{
ItemsRepeater repeater = null;
MockElementFactory elementFactory = null;
int elementClearingRaisedCount = 0;
Log.Comment("Initialize ItemsRepeater");
RunOnUIThread.Execute(() =>
{
elementFactory = new MockElementFactory()
{
GetElementFunc = delegate(int index, UIElement owner) {
return(new Button()
{
Content = index
});
},
ClearElementFunc = delegate(UIElement element, UIElement owner) {
elementClearingRaisedCount++;
Verify.IsNull((element as FrameworkElement).DataContext);
}
};
repeater = CreateRepeater(Enumerable.Range(0, 100),
elementFactory);
repeater.Layout = new StackLayout();
Content = repeater;
repeater.UpdateLayout();
repeater.ItemsSource = null;
Log.Comment("Verify ItemsRepeater cleared data contexts correctly");
Verify.IsTrue(elementClearingRaisedCount > 0, "ItemsRepeater should have cleared some elements");
});
}
// [TestMethod] Issue #1018
public void CanPinFocusedElements()
{
// Setup a grouped repeater scenario with two groups each containing two items.
var data = new ObservableCollection <ObservableCollection <string> >(Enumerable
.Range(0, 2)
.Select(i => new ObservableCollection <string>(Enumerable
.Range(0, 2)
.Select(j => string.Format("Item #{0}.{1}", i, j)))));
List <ContentControl>[] itemElements = null;
ItemsRepeater[] innerRepeaters = null;
List <StackPanel> groupElements = null;
ItemsRepeater rootRepeater = null;
var gotFocus = new ManualResetEvent(false);
RunOnUIThread.Execute(() =>
{
itemElements = new[] {
Enumerable.Range(0, 2).Select(i => new ContentControl()).ToList(),
Enumerable.Range(0, 2).Select(i => new ContentControl()).ToList()
};
itemElements[0][0].GotFocus += delegate { gotFocus.Set(); };
innerRepeaters = Enumerable.Range(0, 2).Select(i => CreateRepeater(
MockItemsSource.CreateDataSource(data[i], supportsUniqueIds: false),
MockElementFactory.CreateElementFactory(itemElements[i]))).ToArray();
groupElements = Enumerable.Range(0, 2).Select(i =>
{
var panel = new StackPanel();
panel.Children.Add(new ContentControl());
panel.Children.Add(innerRepeaters[i]);
return(panel);
}).ToList();
rootRepeater = CreateRepeater(
MockItemsSource.CreateDataSource(data, supportsUniqueIds: false),
MockElementFactory.CreateElementFactory(groupElements));
Content = rootRepeater;
rootRepeater.UpdateLayout();
itemElements[0][0].Focus(FocusState.Keyboard);
});
Verify.IsTrue(gotFocus.WaitOne(DefaultWaitTimeInMS), "Waiting for focus event on the first element of the first group.");
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment("Recycle focused element 0.0 and validate it's still realized because it is pinned.");
{
var ctx = (VirtualizingLayoutContext)innerRepeaters[0].Tag;
ctx.RecycleElement(itemElements[0][0]);
Verify.AreEqual(0, innerRepeaters[0].GetElementIndex(itemElements[0][0]));
}
Log.Comment("Recycle element 0.1 and validate it's no longer realized because it is not pinned.");
{
var ctx = (VirtualizingLayoutContext)innerRepeaters[0].Tag;
ctx.RecycleElement(itemElements[0][1]);
Verify.AreEqual(-1, innerRepeaters[0].GetElementIndex(itemElements[0][1]));
}
Log.Comment("Recycle group 0 and validate it's still realized because one of its items is pinned.");
{
var ctx = (VirtualizingLayoutContext)rootRepeater.Tag;
ctx.RecycleElement(groupElements[0]);
Verify.AreEqual(0, rootRepeater.GetElementIndex(groupElements[0]));
}
itemElements[1][1].GotFocus += delegate { gotFocus.Set(); };
itemElements[1][1].Focus(FocusState.Keyboard);
});
Verify.IsTrue(gotFocus.WaitOne(DefaultWaitTimeInMS), "Waiting for focus event on the second element of the second group.");
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment(@"Move focus to item 1.1 and validate item 0.0 and group 0 are recycled because
the only thing keeping them around is the fact that item 0.0 was focus pinned" );
{
((VirtualizingLayoutContext)rootRepeater.Tag).RecycleElement(groupElements[0]);
((VirtualizingLayoutContext)innerRepeaters[0].Tag).RecycleElement(itemElements[0][0]);
Verify.AreEqual(-1, rootRepeater.GetElementIndex(groupElements[0]));
Verify.AreEqual(-1, innerRepeaters[0].GetElementIndex(itemElements[0][0]));
Verify.AreEqual(1, innerRepeaters[0].GetElementIndex(itemElements[1][1]));
}
Log.Comment(@"Delete item 1.1 from the data. This will force the element to get recycled even if it's pinned.");
{
data[1].RemoveAt(1);
rootRepeater.UpdateLayout();
Verify.AreEqual(-1, innerRepeaters[1].GetElementIndex(itemElements[1][1]));
}
});
}
// [TestMethod] Issue 1018
public void CanReuseElementsDuringUniqueIdReset()
{
var data = new WinRTCollection(Enumerable.Range(0, 2).Select(i => string.Format("Item #{0}", i)));
List <UIElement> mapping = null;
ItemsRepeater repeater = null;
MockElementFactory elementFactory = null;
ContentControl focusedElement = null;
RunOnUIThread.Execute(() =>
{
mapping = new List <UIElement> {
new ContentControl(), new ContentControl()
};
repeater = CreateRepeater(
MockItemsSource.CreateDataSource(data, supportsUniqueIds: true),
MockElementFactory.CreateElementFactory(mapping));
elementFactory = (MockElementFactory)repeater.ItemTemplate;
Content = repeater;
repeater.UpdateLayout();
focusedElement = (ContentControl)repeater.TryGetElement(1);
focusedElement.Focus(FocusState.Keyboard);
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
elementFactory.ValidateGetElementCalls(
new MockElementFactory.GetElementCallInfo(0, repeater),
new MockElementFactory.GetElementCallInfo(1, repeater));
elementFactory.ValidateRecycleElementCalls();
data.ResetWith(new[] { data[0], "New item" });
Verify.AreEqual(0, repeater.GetElementIndex(mapping[0]));
Verify.AreEqual(1, repeater.GetElementIndex(mapping[1]));
Verify.IsNull(repeater.TryGetElement(0));
Verify.IsNull(repeater.TryGetElement(1));
elementFactory.ValidateGetElementCalls(/* GetElement should not be called */);
elementFactory.ValidateRecycleElementCalls(/* RecycleElement should not be called */);
mapping[1] = new ContentControl(); // For "New Item"
repeater.UpdateLayout();
Verify.AreEqual(0, repeater.GetElementIndex(mapping[0]));
Verify.AreEqual(1, repeater.GetElementIndex(mapping[1]));
Verify.AreEqual(mapping[0], repeater.TryGetElement(0));
Verify.AreEqual(mapping[1], repeater.TryGetElement(1));
elementFactory.ValidateGetElementCalls(
new MockElementFactory.GetElementCallInfo(1, repeater));
elementFactory.ValidateRecycleElementCalls(
new MockElementFactory.RecycleElementCallInfo(focusedElement, repeater));
// If the focused element survived the reset, we will keep focus on it. If not, we
// try to find one based on the index. In this case, the focused element (index 1)
// got recycled, and we still have index 1 after the stable reset, so the new index 1
// will get focused. Note that recycling the elements to view generator in the case of
// stable reset happens during the arrange, so by that time we will have pulled elements
// from the stable reset pool and maybe created some new elements as well.
int index = repeater.GetElementIndex(focusedElement);
Log.Comment("focused index " + index);
Verify.AreEqual(mapping[1], FocusManager.GetFocusedElement());
});
}