public void ValidateNoSizeWhenEmptyDataTemplate()
{
ItemsRepeater repeater = null;
RunOnUIThread.Execute(() =>
{
var elementFactory = new RecyclingElementFactory();
elementFactory.RecyclePool = new RecyclePool();
elementFactory.Templates["Item"] = (DataTemplate)XamlReader.Load(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' />");
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(),
};
repeater.UpdateLayout();
// Asserting render size is zero
Verify.IsLessThan(repeater.RenderSize.Width, 0.0001);
Verify.IsLessThan(repeater.RenderSize.Height, 0.0001);
});
}
public void ValidateBindingAndTemplateSelection()
{
RunOnUIThread.Execute(() =>
{
var staticTemplate = (DataTemplate)XamlReader.Load(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<TextBlock Text='static' />
</DataTemplate>" );
var bindTemplate = (DataTemplate)XamlReader.Load(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<TextBlock Text='{Binding}' />
</DataTemplate>" );
var elementFactory = new RecyclingElementFactory()
{
RecyclePool = new RecyclePool(),
Templates =
{
{ "static", staticTemplate },
{ "bind", bindTemplate }
}
};
elementFactory.SelectTemplateKey +=
delegate(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = ((int)args.DataContext % 2 == 0) ? "bind" : "static";
};
const int numItems = 10;
ItemsRepeater repeater = null;
Content = CreateAndInitializeRepeater
(
itemsSource: Enumerable.Range(0, numItems),
elementFactory: elementFactory,
layout: new StackLayout(),
repeater: ref repeater
);
Content.UpdateLayout();
Verify.AreEqual(numItems, VisualTreeHelper.GetChildrenCount(repeater));
for (int i = 0; i < numItems; i++)
{
var element = (TextBlock)repeater.TryGetElement(i);
if (i % 2 == 0)
{
// Text is bound to the data for even indicies
Verify.AreEqual(i.ToString(), element.Text);
Verify.AreEqual(i, element.DataContext);
}
else
{
// Text explicitly set on the element only for odd indicies
Verify.AreEqual("static", element.Text);
}
}
});
}
public VirtualizingUniformStackLayoutSamplePage()
{
this.InitializeComponent();
elementFactory = (RecyclingElementFactory)Resources[nameof(elementFactory)];
repeater.ItemTemplate = elementFactory;
repeater.ItemsSource = data;
bringIntoView.Click += BringIntoView_Click;
insert.Click += Insert_Click;
}
public FlatSample()
{
this.InitializeComponent();
selectionModel = (SelectionModel)Resources[nameof(selectionModel)];
elementFactory = (RecyclingElementFactory)Resources[nameof(elementFactory)];
repeater.ItemTemplate = elementFactory;
repeater.ItemsSource = _data;
selectionModel.Source = _data;
repeater.ElementPrepared += Repeater_ElementPrepared;
repeater.ElementIndexChanged += Repeater_ElementIndexChanged;
selectionModel.PropertyChanged += SelectionModel_PropertyChanged;
}
public VirtualizingStackLayoutSamplePage()
{
this.InitializeComponent();
elementFactory = (RecyclingElementFactory)Resources[nameof(elementFactory)];
repeater.ItemTemplate = elementFactory;
var rnd = new Random();
var data = new ObservableCollection <Recipe>(Enumerable.Range(0, 300).Select(k =>
new Recipe
{
ImageUri = new Uri(string.Format("pack://application:,,,/Images/recipe{0}.png", k % 8 + 1)),
Description = k + " - " + _lorem.Substring(0, rnd.Next(50, 350))
}));
repeater.ItemsSource = data;
bringIntoView.Click += BringIntoView_Click;
}
private void OnSelectTemplateKey(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = (((int)args.DataContext) % 2 == 0) ? "even" : "odd";
}
private void OnSelectTemplateKey(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = args.DataContext is string? "RepeaterItemTemplate" : "RepeaterGroupTemplate";
}
public void ValidateRecycling()
{
RunOnUIThread.Execute(() =>
{
var elementFactory = new RecyclingElementFactory()
{
RecyclePool = new RecyclePool(),
};
elementFactory.Templates["even"] = (DataTemplate)XamlReader.Load(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<TextBlock Text='even' />
</DataTemplate>" );
elementFactory.Templates["odd"] = (DataTemplate)XamlReader.Load(
@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
<TextBlock Text='odd' />
</DataTemplate>" );
elementFactory.SelectTemplateKey +=
delegate(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = ((int)args.DataContext % 2 == 0) ? "even" : "odd";
};
const int numItems = 10;
ItemsRepeater repeater = new ItemsRepeater()
{
ItemsSource = Enumerable.Range(0, numItems),
ItemTemplate = elementFactory,
};
var context = (ElementFactoryGetArgs)RepeaterTestHooks.CreateRepeaterElementFactoryGetArgs();
context.Parent = repeater;
var clearContext = (ElementFactoryRecycleArgs)RepeaterTestHooks.CreateRepeaterElementFactoryRecycleArgs();
clearContext.Parent = repeater;
// Element0 is of type even, a new one should be created
context.Data = 0;
var element0 = elementFactory.GetElement(context);
Verify.IsNotNull(element0);
Verify.AreEqual("even", (element0 as TextBlock).Text);
clearContext.Element = element0;
elementFactory.RecycleElement(clearContext);
// Element1 is of type odd, a new one should be created
context.Data = 1;
var element1 = elementFactory.GetElement(context);
Verify.IsNotNull(element1);
Verify.AreNotSame(element0, element1);
Verify.AreEqual("odd", (element1 as TextBlock).Text);
clearContext.Element = element1;
elementFactory.RecycleElement(clearContext);
// Element0 should be recycled for element2
context.Data = 2;
var element2 = elementFactory.GetElement(context);
Verify.AreEqual("even", (element2 as TextBlock).Text);
Verify.AreSame(element0, element2);
// Element1 should be recycled for element3
context.Data = 3;
var element3 = elementFactory.GetElement(context);
Verify.AreEqual("odd", (element3 as TextBlock).Text);
Verify.AreSame(element1, element3);
});
}
private void OnSelectTemplateKey(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = (int.Parse(args.DataContext.ToString()) % 2 == 0) ? "even" : "odd";
}
private void OnSelectTemplateKey(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = args.DataContext is Category ? "Category" : "Item";
}
private void ElementFactory_SelectTemplateKey(RecyclingElementFactory sender, SelectTemplateEventArgs args)
{
args.TemplateKey = args.DataContext is IEnumerable ? "group" : "item";
}
