public void ValidateStackLayoutDoesNotRetainIncorrectMinorWidth()
{
RunOnUIThread.Execute(() =>
{
var repeater = new ItemsRepeater()
{
ItemsSource = Enumerable.Range(0, 1)
};
Content = new ScrollViewer()
{
Content = repeater,
Width = 400,
};
Content.UpdateLayout();
// Measure with large width.
repeater.Measure(new Size(600, 100));
Verify.AreEqual(600, repeater.DesiredSize.Width);
// Measure with smaller width again before arrange.
// StackLayout has to pick up the smaller width for its extent.
repeater.Measure(new Size(300, 100));
Verify.AreEqual(300, repeater.DesiredSize.Width);
Content.UpdateLayout();
Verify.AreEqual(400, repeater.ActualWidth);
});
}
private ItemsRepeaterScrollHost CreateAndInitializeRepeater(
object itemsSource,
VirtualizingLayout layout,
object elementFactory,
ref ItemsRepeater repeater,
ref ScrollViewer scrollViewer)
{
repeater = new ItemsRepeater()
{
ItemsSource = itemsSource,
Layout = layout,
ItemTemplate = elementFactory,
HorizontalCacheLength = 0,
VerticalCacheLength = 0,
};
scrollViewer = new ScrollViewer()
{
Content = repeater
};
return(new ItemsRepeaterScrollHost()
{
Width = 400,
Height = 400,
ScrollViewer = scrollViewer
});
}
public void ValidateStackLayoutDisabledVirtualizationWithItemsRepeater()
{
RunOnUIThread.Execute(() =>
{
var repeater = new ItemsRepeater();
var stackLayout = new StackLayout();
stackLayout.DisableVirtualization = true;
repeater.Layout = stackLayout;
repeater.ItemsSource = Enumerable.Range(0, 10);
repeater.ItemTemplate = (DataTemplate)XamlReader.Parse(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<Button Content='{Binding}' Height='100' />
</DataTemplate>");
var scrollViewer = new ScrollViewer()
{
Content = repeater
};
scrollViewer.Height = 100;
Content = scrollViewer;
Content.UpdateLayout();
for (int i = 0; i < repeater.ItemsSourceView.Count; i++)
{
var child = repeater.TryGetElement(i) as Button;
Verify.IsNotNull(child);
}
});
}
public void ValidateNonVirtualLayoutWithItemsRepeater()
{
RunOnUIThread.Execute(() =>
{
var repeater = new ItemsRepeater();
repeater.Layout = new NonVirtualStackLayout();
repeater.ItemsSource = Enumerable.Range(0, 10);
repeater.ItemTemplate = (DataTemplate)XamlReader.Parse(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<Button Content='{Binding}' Height='100' />
</DataTemplate>");
Content = repeater;
Content.UpdateLayout();
double expectedYOffset = 0;
for (int i = 0; i < repeater.ItemsSourceView.Count; i++)
{
var child = repeater.TryGetElement(i) as Button;
Verify.IsNotNull(child);
var layoutBounds = LayoutInformation.GetLayoutSlot(child);
Verify.AreEqual(expectedYOffset, layoutBounds.Y);
Verify.AreEqual(i, child.Content);
expectedYOffset += 100;
}
});
}
public void VerifyClearingItemsSourceClearsElements()
{
var data = new ObservableCollection <string>(Enumerable.Range(0, 4).Select(i => "Item #" + i));
var mapping = (List <ContentControl>)null;
RunOnUIThread.Execute(() =>
{
mapping = Enumerable.Range(0, data.Count).Select(i => new ContentControl {
Width = 40, Height = 40
}).ToList();
var dataSource = MockItemsSource.CreateDataSource(data, supportsUniqueIds: false);
var elementFactory = MockElementFactory.CreateElementFactory(mapping);
ItemsRepeater repeater = new ItemsRepeater();
repeater.ItemsSource = dataSource;
repeater.ItemTemplate = elementFactory;
// This was an issue only for NonVirtualizing layouts
repeater.Layout = new MyCustomNonVirtualizingStackLayout();
Content = repeater;
Content.UpdateLayout();
repeater.ItemsSource = null;
});
foreach (var item in mapping)
{
Verify.IsNull(item.Parent);
}
}
public void ValidateRepeaterDefaults()
{
RunOnUIThread.Execute(() =>
{
var repeater = new ItemsRepeater()
{
ItemsSource = Enumerable.Range(0, 10).Select(i => string.Format("Item #{0}", i)),
};
Content = new ItemsRepeaterScrollHost()
{
Width = 400,
Height = 800,
ScrollViewer = new ScrollViewer
{
Content = repeater
}
};
Content.UpdateLayout();
for (int i = 0; i < 10; i++)
{
var element = repeater.TryGetElement(i);
Verify.IsNotNull(element);
Verify.AreEqual(string.Format("Item #{0}", i), ((TextBlock)element).Text);
Verify.AreEqual(i, repeater.GetElementIndex(element));
}
Verify.IsNull(repeater.TryGetElement(20));
});
}
public void ValidateGetSetItemsSource()
{
RunOnUIThread.Execute(() =>
{
ItemsRepeater repeater = new ItemsRepeater();
var dataSource = new ItemsSourceView(Enumerable.Range(0, 10).Select(i => string.Format("Item #{0}", i)));
repeater.SetValue(ItemsRepeater.ItemsSourceProperty, dataSource);
Verify.AreSame(dataSource, repeater.GetValue(ItemsRepeater.ItemsSourceProperty) as ItemsSourceView);
Verify.AreSame(dataSource, repeater.ItemsSourceView);
});
}
public void ValidateMappingAndAutoRecycling()
{
ItemsRepeater repeater = null;
ScrollViewer scrollViewer = null;
RunOnUIThread.Execute(() =>
{
var layout = new MockVirtualizingLayout()
{
MeasureLayoutFunc = (availableSize, context) =>
{
var element0 = context.GetOrCreateElementAt(index: 0);
// lookup - repeater will give back the same element and note that this element will not
// be pinned - i.e it will be auto recycled after a measure pass where GetElementAt(0) is not called.
var element0lookup = context.GetOrCreateElementAt(index: 0, options: ElementRealizationOptions.None);
var element1 = context.GetOrCreateElementAt(index: 1, options: ElementRealizationOptions.ForceCreate | ElementRealizationOptions.SuppressAutoRecycle);
// forcing a new element for index 1 that will be pinned (not auto recycled). This will be
// a completely new element. Repeater does not do the mapping/lookup when forceCreate is true.
var element1Clone = context.GetOrCreateElementAt(index: 1, options: ElementRealizationOptions.ForceCreate | ElementRealizationOptions.SuppressAutoRecycle);
Verify.AreSame(element0, element0lookup);
Verify.AreNotSame(element1, element1Clone);
element0.Measure(availableSize);
element1.Measure(availableSize);
element1Clone.Measure(availableSize);
return(new Size(100, 100));
},
};
Content = CreateAndInitializeRepeater(
itemsSource: Enumerable.Range(0, 5),
layout: layout,
elementFactory: GetDataTemplate("<Button>Hello</Button>"),
repeater: ref repeater,
scrollViewer: ref scrollViewer);
Content.UpdateLayout();
Verify.IsNotNull(repeater.TryGetElement(0));
Verify.IsNotNull(repeater.TryGetElement(1));
layout.MeasureLayoutFunc = null;
repeater.InvalidateMeasure();
Content.UpdateLayout();
Verify.IsNull(repeater.TryGetElement(0)); // not pinned, should be auto recycled.
Verify.IsNotNull(repeater.TryGetElement(1)); // pinned, should stay alive
});
}
public void VerifyRepeaterDoesNotLeakItemContainers()
{
ObservableCollection <int> items = new ObservableCollection <int>();
for (int i = 0; i < 10; i++)
{
items.Add(i);
}
ItemsRepeater repeater = null;
RunOnUIThread.Execute(() =>
{
var template = (DataTemplate)XamlReader.Parse("<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' "
+ "xmlns:local='clr-namespace:MUXControlsTestApp.Samples;assembly=MUXControlsTestApp'>"
+ "<local:DisposableUserControl Number='{Binding}'/>"
+ "</DataTemplate>");
Verify.IsNotNull(template);
Verify.AreEqual(0, MUXControlsTestApp.Samples.DisposableUserControl.OpenItems, "Verify we start with 0 DisposableUserControl");
repeater = new ItemsRepeater()
{
ItemsSource = items,
ItemTemplate = template,
VerticalAlignment = VerticalAlignment.Top,
HorizontalAlignment = HorizontalAlignment.Left
};
Content = repeater;
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Verify.IsGreaterThanOrEqual(MUXControlsTestApp.Samples.DisposableUserControl.OpenItems, 10, "Verify we created at least 10 DisposableUserControl");
// Clear out the repeater and make sure everything gets cleaned up.
Content = null;
repeater = null;
});
IdleSynchronizer.Wait();
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
Verify.AreEqual(0, MUXControlsTestApp.Samples.DisposableUserControl.OpenItems, "Verify we cleaned up all the DisposableUserControl that were created");
}
public void VerifyUniformGridLayoutDoesntCrashWhenTryingToScrollToEnd()
{
ItemsRepeater repeater = null;
ScrollViewer scrollViewer = null;
RunOnUIThread.Execute(() =>
{
repeater = new ItemsRepeater
{
ItemsSource = Enumerable.Range(0, 1000).Select(i => new Border
{
Background = new SolidColorBrush(Colors.Blue),
Child = new TextBlock {
Text = "#" + i
}
}).ToArray(),
Layout = new UniformGridLayout
{
MinItemWidth = 100,
MinItemHeight = 40,
MinRowSpacing = 10,
MinColumnSpacing = 10
}
};
scrollViewer = new ScrollViewer {
Content = repeater
};
Content = scrollViewer;
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
scrollViewer.ChangeView(0, repeater.ActualHeight, null);
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
scrollViewer.ChangeView(0, 0, null);
});
IdleSynchronizer.Wait();
// The test guards against an app crash, so this is enough to verify
Verify.IsTrue(true);
}
public void ValidateGetSetBackground()
{
RunOnUIThread.Execute(() =>
{
ItemsRepeater repeater = new ItemsRepeater();
var redBrush = new SolidColorBrush(Colors.Red);
repeater.SetValue(ItemsRepeater.BackgroundProperty, redBrush);
Verify.AreSame(redBrush, repeater.GetValue(ItemsRepeater.BackgroundProperty) as Brush);
Verify.AreSame(redBrush, repeater.Background);
var blueBrush = new SolidColorBrush(Colors.Blue);
repeater.Background = blueBrush;
Verify.AreSame(blueBrush, repeater.Background);
});
}
public void VerifyUIElementsInItemsSource()
{
ItemsRepeater repeater = null;
RunOnUIThread.Execute(() =>
{
var scrollhost = (ItemsRepeaterScrollHost)XamlReader.Parse(
@"<controls:ItemsRepeaterScrollHost
xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:local='clr-namespace:MUXControlsTestApp.Samples;assembly=MUXControlsTestApp'
xmlns:controls='http://schemas.modernwpf.com/2019'>
<ScrollViewer>
<controls:ItemsRepeater x:Name='repeater'>
<controls:ItemsRepeater.ItemsSource>
<local:UICollection>
<Button>0</Button>
<Button>1</Button>
<Button>2</Button>
<Button>3</Button>
<Button>4</Button>
<Button>5</Button>
<Button>6</Button>
<Button>7</Button>
<Button>8</Button>
<Button>9</Button>
</local:UICollection>
</controls:ItemsRepeater.ItemsSource>
</controls:ItemsRepeater>
</ScrollViewer>
</controls:ItemsRepeaterScrollHost>");
repeater = (ItemsRepeater)scrollhost.FindName("repeater");
Content = scrollhost;
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
for (int i = 0; i < 10; i++)
{
var element = repeater.TryGetElement(i) as Button;
Verify.AreEqual(i.ToString(), element.Content);
}
});
}
public void ValidateElementToIndexMapping()
{
ItemsRepeater repeater = null;
RunOnUIThread.Execute(() =>
{
var elementFactory = new RecyclingElementFactory();
elementFactory.RecyclePool = new RecyclePool();
elementFactory.Templates["Item"] = (DataTemplate)XamlReader.Parse(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<TextBlock Text='{Binding}' Height='50' />
</DataTemplate>");
repeater = new ItemsRepeater()
{
ItemsSource = Enumerable.Range(0, 10).Select(i => string.Format("Item #{0}", i)),
ItemTemplate = elementFactory,
// Default is StackLayout, so do not have to explicitly set.
// Layout = new StackLayout(),
};
Content = new ItemsRepeaterScrollHost()
{
Width = 400,
Height = 800,
ScrollViewer = new ScrollViewer
{
Content = repeater
}
};
Content.UpdateLayout();
for (int i = 0; i < 10; i++)
{
var element = repeater.TryGetElement(i);
Verify.IsNotNull(element);
Verify.AreEqual(string.Format("Item #{0}", i), ((TextBlock)element).Text);
Verify.AreEqual(i, repeater.GetElementIndex(element));
}
Verify.IsNull(repeater.TryGetElement(20));
});
}
public void CanSetItemsSource()
{
// In bug 12042052, we crash when we set ItemsSource to null because we try to subscribe to
// the DataSourceChanged event on a null instance.
RunOnUIThread.Execute(() =>
{
{
var repeater = new ItemsRepeater();
repeater.ItemsSource = null;
repeater.ItemsSource = Enumerable.Range(0, 5).Select(i => string.Format("Item #{0}", i));
}
{
var repeater = new ItemsRepeater();
repeater.ItemsSource = Enumerable.Range(0, 5).Select(i => string.Format("Item #{0}", i));
repeater.ItemsSource = Enumerable.Range(5, 5).Select(i => string.Format("Item #{0}", i));
repeater.ItemsSource = null;
repeater.ItemsSource = Enumerable.Range(10, 5).Select(i => string.Format("Item #{0}", i));
repeater.ItemsSource = null;
}
});
}
private UIElement GetElementFromElementFactory(int index)
{
// The view generator is the provider of last resort.
var data = m_owner.ItemsSourceView.GetAt(index);
UIElement initElement()
{
var providedElementFactory = m_owner.ItemTemplateShim;
if (providedElementFactory == null)
{
if (data is UIElement dataAsElement)
{
return(dataAsElement);
}
}
IElementFactoryShim initElementFactory()
{
if (providedElementFactory == null)
{
var factory = XamlReader.Parse("<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'><TextBlock Text='{Binding}'/></DataTemplate>") as DataTemplate;
m_owner.ItemTemplate = factory;
return(m_owner.ItemTemplateShim);
}
return(providedElementFactory);
}
var elementFactory = initElementFactory();
ElementFactoryGetArgs initArgs()
{
if (m_ElementFactoryGetArgs == null)
{
m_ElementFactoryGetArgs = new ElementFactoryGetArgs();
}
return(m_ElementFactoryGetArgs);
}
var args = initArgs();
try
{
args.Data = data;
args.Parent = m_owner;
args.Index = index;
return(elementFactory.GetElement(args));
}
finally
{
args.Data = null;
args.Parent = null;
}
}
var element = initElement();
var virtInfo = ItemsRepeater.TryGetVirtualizationInfo(element);
if (virtInfo == null)
{
virtInfo = ItemsRepeater.CreateAndInitializeVirtualizationInfo(element);
}
else
{
// View obtained from ElementFactory already has a VirtualizationInfo attached to it
// which means that the element has been recycled and not created from scratch.
}
// Clear flag
virtInfo.MustClearDataContext = false;
if (data != element)
{
if (element is FrameworkElement elementAsFE)
{
// Set data context only if no x:Bind was used. ie. No data template component on the root.
// If the passed in data is a UIElement and is different from the element returned by
// the template factory then we need to propagate the DataContext.
// Otherwise just set the DataContext on the element as the data.
object initElementDataContext()
{
if (data is FrameworkElement dataAsElement)
{
var dataDataContext = dataAsElement.DataContext;
if (dataDataContext != null)
{
return(dataDataContext);
}
}
return(data);
}
var elementDataContext = initElementDataContext();
elementAsFE.DataContext = elementDataContext;
virtInfo.MustClearDataContext = true;
}
else
{
Debug.Assert(false, "Element returned by factory is not a FrameworkElement!");
}
}
virtInfo.MoveOwnershipToLayoutFromElementFactory(
index,
/* uniqueId: */
m_owner.ItemsSourceView.HasKeyIndexMapping ?
m_owner.ItemsSourceView.KeyFromIndex(index) :
string.Empty);
// The view generator is the only provider that prepares the element.
var repeater = m_owner;
// Add the element to the children collection here before raising OnElementPrepared so
// that handlers can walk up the tree in case they want to find their IndexPath in the
// nested case.
var children = repeater.Children;
if (CachedVisualTreeHelpers.GetParent(element) != repeater)
{
children.Add(element);
}
repeater.AnimationManager.OnElementPrepared(element);
repeater.OnElementPrepared(element, index);
// Update realized indices
m_firstRealizedElementIndexHeldByLayout = Math.Min(m_firstRealizedElementIndexHeldByLayout, index);
m_lastRealizedElementIndexHeldByLayout = Math.Max(m_lastRealizedElementIndexHeldByLayout, index);
return(element);
}
public void VerifyStoreScenarioCache()
{
ItemsRepeater rootRepeater = null;
RunOnUIThread.Execute(() =>
{
var scrollhost = (ItemsRepeaterScrollHost)XamlReader.Parse(
@" <controls:ItemsRepeaterScrollHost Width='400' Height='200'
xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:controls='http://schemas.modernwpf.com/2019'>
<controls:ItemsRepeaterScrollHost.Resources>
<DataTemplate x:Key='ItemTemplate' >
<TextBlock Text='{Binding}' Height='100' Width='100'/>
</DataTemplate>
<DataTemplate x:Key='GroupTemplate'>
<StackPanel>
<TextBlock Text='{Binding}' />
<controls:ItemsRepeaterScrollHost>
<ScrollViewer HorizontalScrollBarVisibility='Auto' VerticalScrollBarVisibility='Hidden'>
<controls:ItemsRepeater ItemTemplate='{StaticResource ItemTemplate}' ItemsSource='{Binding}'>
<controls:ItemsRepeater.Layout>
<controls:StackLayout Orientation='Horizontal' />
</controls:ItemsRepeater.Layout>
</controls:ItemsRepeater>
</ScrollViewer>
</controls:ItemsRepeaterScrollHost>
</StackPanel>
</DataTemplate>
</controls:ItemsRepeaterScrollHost.Resources>
<ScrollViewer x:Name='scrollviewer'>
<controls:ItemsRepeater x:Name='rootRepeater' ItemTemplate='{StaticResource GroupTemplate}'/>
</ScrollViewer>
</controls:ItemsRepeaterScrollHost>");
rootRepeater = (ItemsRepeater)scrollhost.FindName("rootRepeater");
List <List <int> > items = new List <List <int> >();
for (int i = 0; i < 100; i++)
{
items.Add(Enumerable.Range(0, 4).ToList());
}
rootRepeater.ItemsSource = items;
Content = scrollhost;
});
IdleSynchronizer.Wait();
// Verify that first items outside the visible range but in the realized range
// for the inner of the nested repeaters are realized.
RunOnUIThread.Execute(() =>
{
// Group2 will be outside the visible range but within the realized range.
var group2 = rootRepeater.TryGetElement(2) as StackPanel;
Verify.IsNotNull(group2);
var group2Repeater = ((ItemsRepeaterScrollHost)group2.Children[1]).ScrollViewer.Content as ItemsRepeater;
Verify.IsNotNull(group2Repeater);
Verify.IsNotNull(group2Repeater.TryGetElement(0));
});
}
public void VerifyCorrectionsInNonScrollableDirection()
{
ItemsRepeater rootRepeater = null;
ScrollViewer scrollViewer = null;
ItemsRepeaterScrollHost scrollhost = null;
ManualResetEvent viewChanged = new ManualResetEvent(false);
RunOnUIThread.Execute(() =>
{
scrollhost = (ItemsRepeaterScrollHost)XamlReader.Parse(
@"<controls:ItemsRepeaterScrollHost Width='400' Height='600'
xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:controls='http://schemas.modernwpf.com/2019'>
<ScrollViewer Width='400' Height='400' x:Name='scrollviewer'>
<controls:ItemsRepeater x:Name='repeater'>
<DataTemplate>
<StackPanel>
<controls:ItemsRepeater ItemsSource='{Binding}'>
<controls:ItemsRepeater.Layout>
<controls:StackLayout Orientation='Horizontal' />
</controls:ItemsRepeater.Layout>
</controls:ItemsRepeater>
</StackPanel>
</DataTemplate>
</controls:ItemsRepeater>
</ScrollViewer>
</controls:ItemsRepeaterScrollHost>");
rootRepeater = (ItemsRepeater)scrollhost.FindName("repeater");
scrollViewer = (ScrollViewer)scrollhost.FindName("scrollviewer");
scrollViewer.ScrollChanged += (sender, args) =>
{
if (args.HorizontalChange != 0 || args.VerticalChange != 0)
{
viewChanged.Set();
}
};
List <List <int> > items = new List <List <int> >();
for (int i = 0; i < 100; i++)
{
items.Add(Enumerable.Range(0, 4).ToList());
}
rootRepeater.ItemsSource = items;
Content = scrollhost;
});
// scroll down several times and validate no crash
for (int i = 1; i < 5; i++)
{
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
scrollViewer.ChangeView(null, i * 200, null);
});
Verify.IsTrue(viewChanged.WaitOne(DefaultWaitTimeInMS));
viewChanged.Reset();
}
}
private void NestedRepeaterWithDataTemplateScenario(bool disableAnimation)
{
/*if (!disableAnimation && PlatformConfiguration.IsOsVersionGreaterThanOrEqual(OSVersion.Redstone5))
* {
* Log.Warning("This test is showing consistent issues with not scrolling enough on RS5 and 19H1 when animations are enabled, tracked by microsoft-ui-xaml#779");
* return;
* }*/
// Example of how to include debug tracing in an ApiTests.ItemsRepeater test's output.
// using (PrivateLoggingHelper privateLoggingHelper = new PrivateLoggingHelper("Repeater"))
// {
ItemsRepeater rootRepeater = null;
ScrollViewer scrollViewer = null;
ManualResetEvent viewChanged = new ManualResetEvent(false);
RunOnUIThread.Execute(() =>
{
var anchorProvider = (ItemsRepeaterScrollHost)XamlReader.Parse(
@"<controls:ItemsRepeaterScrollHost Width='400' Height='600'
xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:controls='http://schemas.modernwpf.com/2019'>
<controls:ItemsRepeaterScrollHost.Resources>
<DataTemplate x:Key='ItemTemplate' >
<TextBlock Text='{Binding}' />
</DataTemplate>
<DataTemplate x:Key='GroupTemplate'>
<StackPanel>
<TextBlock Text='{Binding}' />
<controls:ItemsRepeater ItemTemplate='{StaticResource ItemTemplate}' ItemsSource='{Binding}' VerticalCacheLength='0'/>
</StackPanel>
</DataTemplate>
</controls:ItemsRepeaterScrollHost.Resources>
<ScrollViewer x:Name='scrollviewer'>
<controls:ItemsRepeater x:Name='rootRepeater' ItemTemplate='{StaticResource GroupTemplate}' VerticalCacheLength='0' />
</ScrollViewer>
</controls:ItemsRepeaterScrollHost>");
rootRepeater = (ItemsRepeater)anchorProvider.FindName("rootRepeater");
rootRepeater.SizeChanged += (sender, args) =>
{
Log.Comment($"SizeChanged: Size=({rootRepeater.ActualWidth} x {rootRepeater.ActualHeight})");
};
scrollViewer = (ScrollViewer)anchorProvider.FindName("scrollviewer");
/*scrollViewer.ViewChanging += (sender, args) =>
* {
* Log.Comment($"ViewChanging: Next VerticalOffset={args.NextView.VerticalOffset}, Final VerticalOffset={args.FinalView.VerticalOffset}");
* };*/
scrollViewer.ScrollChanged += (sender, args) =>
{
if (args.HorizontalChange != 0 || args.VerticalChange != 0)
{
Log.Comment($"ViewChanged: VerticalOffset={scrollViewer.VerticalOffset}");
viewChanged.Set();
}
};
var itemsSource = new ObservableCollection <ObservableCollection <int> >();
for (int i = 0; i < 100; i++)
{
itemsSource.Add(new ObservableCollection <int>(Enumerable.Range(0, 5)));
}
;
rootRepeater.ItemsSource = itemsSource;
Content = anchorProvider;
});
// scroll down several times to cause recycling of elements
for (int i = 1; i < 10; i++)
{
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment($"Size=({rootRepeater.ActualWidth} x {rootRepeater.ActualHeight})");
Log.Comment($"ChangeView(VerticalOffset={i * 200})");
scrollViewer.ChangeView(null, i * 200, null, disableAnimation);
});
Log.Comment("Waiting for view change completion...");
Verify.IsTrue(viewChanged.WaitOne(DefaultWaitTimeInMS));
viewChanged.Reset();
Log.Comment("View change completed");
RunOnUIThread.Execute(() =>
{
Verify.AreEqual(i * 200, scrollViewer.VerticalOffset);
});
}
// }
}
public void VerifyFocusedItemIsRecycledOnCollectionReset()
{
List <Layout> layouts = new List <Layout>();
RunOnUIThread.Execute(() =>
{
layouts.Add(new MyCustomNonVirtualizingStackLayout());
layouts.Add(new StackLayout());
});
foreach (var layout in layouts)
{
List <string> items = new List <string> {
"item0", "item1", "item2", "item3", "item4", "item5", "item6", "item7", "item8", "item9"
};
const int targetIndex = 4;
string targetItem = items[targetIndex];
ItemsRepeater repeater = null;
RunOnUIThread.Execute(() =>
{
repeater = new ItemsRepeater()
{
ItemsSource = items,
ItemTemplate = CreateDataTemplateWithContent(@"<Button Content='{Binding}'/>"),
Layout = layout
};
Content = repeater;
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment("Setting Focus on item " + targetIndex);
Button toFocus = (Button)repeater.TryGetElement(targetIndex);
Verify.AreEqual(targetItem, toFocus.Content as string);
toFocus.Focus();
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment("Removing focused element from collection");
items.Remove(targetItem);
Log.Comment("Reset the collection with an empty list");
repeater.ItemsSource = new List <string>();
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment("Verify new elements");
for (int i = 0; i < items.Count; i++)
{
Button currentButton = (Button)repeater.TryGetElement(i);
Verify.IsNull(currentButton);
}
});
}
}
public void VerifyCurrentAnchor()
{
if (PlatformConfiguration.IsDebugBuildConfiguration())
{
// Test is failing in chk configuration due to:
// Bug #1726 Test Failure: RepeaterTests.VerifyCurrentAnchor
Log.Warning("Skipping test for Debug builds.");
return;
}
ItemsRepeater rootRepeater = null;
ScrollViewer scrollViewer = null;
ItemsRepeaterScrollHost scrollhost = null;
ManualResetEvent viewChanged = new ManualResetEvent(false);
RunOnUIThread.Execute(() =>
{
scrollhost = (ItemsRepeaterScrollHost)XamlReader.Parse(
@"<controls:ItemsRepeaterScrollHost Width='400' Height='600'
xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:controls='http://schemas.modernwpf.com/2019'>
<controls:ItemsRepeaterScrollHost.Resources>
<DataTemplate x:Key='ItemTemplate' >
<TextBlock Text='{Binding}' Height='50'/>
</DataTemplate>
</controls:ItemsRepeaterScrollHost.Resources>
<ScrollViewer x:Name='scrollviewer'>
<controls:ItemsRepeater x:Name='rootRepeater' ItemTemplate='{StaticResource ItemTemplate}' VerticalCacheLength='0' />
</ScrollViewer>
</controls:ItemsRepeaterScrollHost>");
rootRepeater = (ItemsRepeater)scrollhost.FindName("rootRepeater");
scrollViewer = (ScrollViewer)scrollhost.FindName("scrollviewer");
scrollViewer.ScrollChanged += (sender, args) =>
{
if (args.HorizontalChange != 0 || args.VerticalChange != 0)
{
viewChanged.Set();
}
};
rootRepeater.ItemsSource = Enumerable.Range(0, 500);
Content = scrollhost;
});
// scroll down several times and validate current anchor
for (int i = 1; i < 10; i++)
{
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
scrollViewer.ChangeView(null, i * 200, null);
});
Verify.IsTrue(viewChanged.WaitOne(DefaultWaitTimeInMS));
viewChanged.Reset();
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Verify.AreEqual(i * 200, scrollViewer.VerticalOffset);
var anchor = scrollhost.CurrentAnchor;
var anchorIndex = rootRepeater.GetElementIndex(anchor);
Log.Comment("CurrentAnchor: " + anchorIndex);
Verify.AreEqual(i * 4, anchorIndex);
});
}
}
public AnimationManager(ItemsRepeater owner)
{
m_owner = owner;
// ItemsRepeater is not fully constructed yet. Don't interact with it.
}
public void BringIntoViewOfExistingItemsDoesNotChangeScrollOffset()
{
System.Windows.Controls.ScrollViewerEx scrollViewer = null;
ItemsRepeater repeater = null;
AutoResetEvent scrollViewerScrolledEvent = new AutoResetEvent(false);
RunOnUIThread.Execute(() =>
{
repeater = new ItemsRepeater();
repeater.ItemsSource = Enumerable.Range(0, 100).Select(x => x.ToString()).ToList();
scrollViewer = new System.Windows.Controls.ScrollViewerEx()
{
Content = repeater,
MaxHeight = 400,
MaxWidth = 200
};
Content = scrollViewer;
Content.UpdateLayout();
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment("Scroll to end");
scrollViewer.ViewChanged += (object sender, ScrollViewerViewChangedEventArgs e) =>
{
if (!e.IsIntermediate)
{
Log.Comment("ScrollViewer scrolling finished");
scrollViewerScrolledEvent.Set();
}
};
scrollViewer.ChangeView(null, repeater.ActualHeight, null);
scrollViewer.UpdateLayout();
});
Log.Comment("Wait for scrolling");
if (Debugger.IsAttached)
{
scrollViewerScrolledEvent.WaitOne();
}
else
{
if (!scrollViewerScrolledEvent.WaitOne(TimeSpan.FromMilliseconds(5000)))
{
throw new Exception("Timeout expiration in WaitForEvent.");
}
}
IdleSynchronizer.Wait();
double endOfScrollOffset = 0;
RunOnUIThread.Execute(() =>
{
Log.Comment("Determine scrolled offset");
endOfScrollOffset = scrollViewer.VerticalOffset;
// Idea: we might not have scrolled to the end, however we should at least have moved so much that the end is not too far away
Verify.IsTrue(Math.Abs(endOfScrollOffset - repeater.ActualHeight) < 500, $"We should at least have scrolled some amount. " +
$"ScrollOffset:{endOfScrollOffset} Repeater height: {repeater.ActualHeight}");
var lastItem = (FrameworkElement)repeater.GetOrCreateElement(99);
lastItem.UpdateLayout();
Log.Comment("Bring last element into view");
lastItem.BringIntoView();
});
IdleSynchronizer.Wait();
RunOnUIThread.Execute(() =>
{
Log.Comment("Verify position did not change");
Verify.IsTrue(Math.Abs(endOfScrollOffset - scrollViewer.VerticalOffset) < 1);
});
}
public UniqueIdElementPool(ItemsRepeater owner)
{
m_owner = owner;
// ItemsRepeater is not fully constructed yet. Don't interact with it.
}
public PinnedElementInfo(UIElement element)
{
PinnedElement = element;
VirtualizationInfo = ItemsRepeater.GetVirtualizationInfo(element);
}
private UIElement GetElementFromElementFactory(int index)
{
// The view generator is the provider of last resort.
var data = m_owner.ItemsSourceView.GetAt(index);
var itemTemplateFactory = m_owner.ItemTemplateShim;
UIElement element = null;
bool itemsSourceContainsElements = false;
if (itemTemplateFactory == null)
{
element = data as UIElement;
// No item template provided and ItemsSource contains objects derived from UIElement.
// In this case, just use the data directly as elements.
itemsSourceContainsElements = element != null;
}
if (element == null)
{
if (itemTemplateFactory == null)
{
// If no ItemTemplate was provided, use a default
var factory = XamlReader.Parse("<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'><TextBlock Text='{Binding}'/></DataTemplate>") as DataTemplate;
m_owner.ItemTemplate = factory;
itemTemplateFactory = m_owner.ItemTemplateShim;
}
if (m_ElementFactoryGetArgs == null)
{
// Create one.
m_ElementFactoryGetArgs = new ElementFactoryGetArgs();
}
var args = m_ElementFactoryGetArgs;
args.Data = data;
args.Parent = m_owner;
args.Index = index;
element = itemTemplateFactory.GetElement(args);
args.Data = null;
args.Parent = null;
}
var virtInfo = ItemsRepeater.TryGetVirtualizationInfo(element);
if (virtInfo == null)
{
virtInfo = ItemsRepeater.CreateAndInitializeVirtualizationInfo(element);
}
else
{
// View obtained from ElementFactory already has a VirtualizationInfo attached to it
// which means that the element has been recycled and not created from scratch.
}
if (!itemsSourceContainsElements)
{
// Set data context only if no x:Bind was used. ie. No data template component on the root.
var elementAsFE = element as FrameworkElement;
elementAsFE.DataContext = data;
}
virtInfo.MoveOwnershipToLayoutFromElementFactory(
index,
/* uniqueId: */
m_owner.ItemsSourceView.HasKeyIndexMapping ?
m_owner.ItemsSourceView.KeyFromIndex(index) :
string.Empty);
// The view generator is the only provider that prepares the element.
var repeater = m_owner;
// Add the element to the children collection here before raising OnElementPrepared so
// that handlers can walk up the tree in case they want to find their IndexPath in the
// nested case.
var children = repeater.Children;
if (CachedVisualTreeHelpers.GetParent(element) != repeater)
{
children.Add(element);
}
repeater.AnimationManager.OnElementPrepared(element);
repeater.OnElementPrepared(element, index);
// Update realized indices
m_firstRealizedElementIndexHeldByLayout = Math.Min(m_firstRealizedElementIndexHeldByLayout, index);
m_lastRealizedElementIndexHeldByLayout = Math.Max(m_lastRealizedElementIndexHeldByLayout, index);
return(element);
}
public void ValidateNonVirtualLayoutDoesNotGetMeasuredForViewportChanges()
{
RunOnUIThread.Execute(() =>
{
int measureCount = 0;
int arrangeCount = 0;
var repeater = new ItemsRepeater();
// with a non virtualizing layout, repeater will just
// run layout once.
repeater.Layout = new MockNonVirtualizingLayout()
{
MeasureLayoutFunc = (size, context) =>
{
measureCount++;
return(new Size(100, 800));
},
ArrangeLayoutFunc = (size, context) =>
{
arrangeCount++;
return(new Size(100, 800));
}
};
repeater.ItemsSource = Enumerable.Range(0, 10);
repeater.ItemTemplate = (DataTemplate)XamlReader.Parse(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<Button Content='{Binding}' Height='100' />
</DataTemplate>");
Content = new ScrollViewer()
{
Content = repeater
};
Content.UpdateLayout();
Verify.AreEqual(1, measureCount);
Verify.AreEqual(1, arrangeCount);
measureCount = 0;
arrangeCount = 0;
// Once we switch to a virtualizing layout we should
// get at least two passes to update the viewport.
repeater.Layout = new MockVirtualizingLayout()
{
MeasureLayoutFunc = (size, context) =>
{
measureCount++;
return(new Size(100, 800));
},
ArrangeLayoutFunc = (size, context) =>
{
arrangeCount++;
return(new Size(100, 800));
}
};
Content.UpdateLayout(true);
Verify.IsGreaterThan(measureCount, 1);
Verify.IsGreaterThan(arrangeCount, 1);
});
}
public void OnItemsSourceChanged(object source, NotifyCollectionChangedEventArgs args)
{
// Note: For items that have been removed, the index will not be touched. It will hold
// the old index before it was removed. It is not valid anymore.
switch (args.Action)
{
case NotifyCollectionChangedAction.Add:
{
var newIndex = args.NewStartingIndex;
var newCount = args.NewItems.Count;
EnsureFirstLastRealizedIndices();
if (newIndex <= m_lastRealizedElementIndexHeldByLayout)
{
m_lastRealizedElementIndexHeldByLayout += newCount;
var children = m_owner.Children;
var childCount = children.Count;
for (int i = 0; i < childCount; ++i)
{
var element = children[i];
var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
var dataIndex = virtInfo.Index;
if (virtInfo.IsRealized && dataIndex >= newIndex)
{
UpdateElementIndex(element, virtInfo, dataIndex + newCount);
}
}
}
else
{
// Indices held by layout are not affected
// We could still have items in the pinned elements that need updates. This is usually a very small vector.
for (int i = 0; i < m_pinnedPool.Count; ++i)
{
var elementInfo = m_pinnedPool[i];
var virtInfo = elementInfo.VirtualizationInfo;
var dataIndex = virtInfo.Index;
if (virtInfo.IsRealized && dataIndex >= newIndex)
{
var element = elementInfo.PinnedElement;
UpdateElementIndex(element, virtInfo, dataIndex + newCount);
}
}
}
break;
}
case NotifyCollectionChangedAction.Replace:
{
// Requirement: oldStartIndex == newStartIndex. It is not a replace if this is not true.
// Two cases here
// case 1: oldCount == newCount
// indices are not affected. nothing to do here.
// case 2: oldCount != newCount
// Replaced with less or more items. This is like an insert or remove
// depending on the counts.
var oldStartIndex = args.OldStartingIndex;
var newStartingIndex = args.NewStartingIndex;
var oldCount = args.OldItems.Count;
var newCount = args.NewItems.Count;
if (oldStartIndex != newStartingIndex)
{
throw new Exception("Replace is only allowed with OldStartingIndex equals to NewStartingIndex.");
}
if (oldCount == 0)
{
throw new Exception("Replace notification with args.OldItemsCount value of 0 is not allowed. Use Insert action instead.");
}
if (newCount == 0)
{
throw new Exception("Replace notification with args.NewItemCount value of 0 is not allowed. Use Remove action instead.");
}
int countChange = newCount - oldCount;
if (countChange != 0)
{
// countChange > 0 : countChange items were added
// countChange < 0 : -countChange items were removed
var children = m_owner.Children;
for (int i = 0; i < children.Count; ++i)
{
var element = children[i];
var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
var dataIndex = virtInfo.Index;
if (virtInfo.IsRealized)
{
if (dataIndex >= oldStartIndex + oldCount)
{
UpdateElementIndex(element, virtInfo, dataIndex + countChange);
}
}
}
EnsureFirstLastRealizedIndices();
m_lastRealizedElementIndexHeldByLayout += countChange;
}
break;
}
case NotifyCollectionChangedAction.Remove:
{
var oldStartIndex = args.OldStartingIndex;
var oldCount = args.OldItems.Count;
var children = m_owner.Children;
for (int i = 0; i < children.Count; ++i)
{
var element = children[i];
var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
var dataIndex = virtInfo.Index;
if (virtInfo.IsRealized)
{
if (virtInfo.AutoRecycleCandidate && oldStartIndex <= dataIndex && dataIndex < oldStartIndex + oldCount)
{
// If we are doing the mapping, remove the element who's data was removed.
m_owner.ClearElementImpl(element);
}
else if (dataIndex >= (oldStartIndex + oldCount))
{
UpdateElementIndex(element, virtInfo, dataIndex - oldCount);
}
}
}
InvalidateRealizedIndicesHeldByLayout();
break;
}
case NotifyCollectionChangedAction.Reset:
{
// If we get multiple resets back to back before
// running layout, we dont have to clear all the elements again.
if (!m_isDataSourceStableResetPending)
{
#if DEBUG
// There should be no elements in the reset pool at this time.
Debug.Assert(m_resetPool.IsEmpty);
#endif
if (m_owner.ItemsSourceView.HasKeyIndexMapping)
{
m_isDataSourceStableResetPending = true;
}
// Walk through all the elements and make sure they are cleared, they will go into
// the stable id reset pool.
var children = m_owner.Children;
for (int i = 0; i < children.Count; ++i)
{
var element = children[i];
var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
if (virtInfo.IsRealized && virtInfo.AutoRecycleCandidate)
{
m_owner.ClearElementImpl(element);
}
}
}
InvalidateRealizedIndicesHeldByLayout();
break;
}
}
}
public ViewManager(ItemsRepeater owner)
{
m_owner = owner;
m_resetPool = new UniqueIdElementPool(owner);
// ItemsRepeater is not fully constructed yet. Don't interact with it.
}
private UIElement FindFocusCandidate(int clearedIndex, ref UIElement focusedChild)
{
// Walk through all the children and find elements with index before and after the cleared index.
// Note that during a delete the next element would now have the same index.
int previousIndex = int.MinValue;
int nextIndex = int.MaxValue;
UIElement nextElement = null;
UIElement previousElement = null;
var children = m_owner.Children;
for (int i = 0; i < children.Count; ++i)
{
var child = children[i];
var virtInfo = ItemsRepeater.TryGetVirtualizationInfo(child);
if (virtInfo != null && virtInfo.IsHeldByLayout)
{
int currentIndex = virtInfo.Index;
if (currentIndex < clearedIndex)
{
if (currentIndex > previousIndex)
{
previousIndex = currentIndex;
previousElement = child;
}
}
else if (currentIndex >= clearedIndex)
{
// Note that we use >= above because if we deleted the focused element,
// the next element would have the same index now.
if (currentIndex < nextIndex)
{
nextIndex = currentIndex;
nextElement = child;
}
}
}
}
// Find the next element if one exists, if not use the previous element.
// If the container itself is not focusable, find a descendent that is.
UIElement focusCandidate = null;
if (nextElement != null)
{
focusedChild = nextElement as UIElement;
if (nextElement.Focus())
{
focusCandidate = nextElement;
}
else if (nextElement.MoveFocus(new TraversalRequest(FocusNavigationDirection.First)))
{
focusCandidate = FocusManager.GetFocusedElement(nextElement) as UIElement;
}
}
if (focusCandidate == null && previousElement != null)
{
focusedChild = previousElement as UIElement;
if (previousElement.Focus())
{
focusCandidate = previousElement;
}
else if (previousElement.MoveFocus(new TraversalRequest(FocusNavigationDirection.Last)))
{
focusCandidate = FocusManager.GetFocusedElement(previousElement) as UIElement;
}
}
return(focusCandidate);
}
public RepeaterLayoutContext(ItemsRepeater owner)
{
m_owner = new WeakReference <ItemsRepeater>(owner);
}
