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 static void SetOrientation(this VirtualizingLayout layout, ScrollOrientation scrollOrientation)
{
// Note:
// The public properties of UniformGridLayout and FlowLayout interpret orientation the opposite to
// how FlowLayoutAlgorithm interprets it.
// For simplicity, all of our test validation code is written in terms that match the implementation.
// For this reason, we need to switch the orientation whenever we set UniformGridLayout.Orientation
// or StackLayout.Orientation.
if (layout is StackLayout)
{
((StackLayout)layout).Orientation = scrollOrientation.ToLayoutOrientation();
}
else if (layout is UniformGridLayout)
{
((UniformGridLayout)layout).Orientation = scrollOrientation.ToOrthogonalLayoutOrientation();
}
else if (layout is FlowLayout)
{
((FlowLayout)layout).Orientation = scrollOrientation.ToOrthogonalLayoutOrientation();
}
else
{
throw new InvalidOperationException("layout unknown");
}
}
private ItemsRepeater SetupRepeater(object dataSource, string itemContent = @"<Button Content='{Binding}' Height='100' />")
{
VirtualizingLayout layout = null;
RunOnUIThread.Execute(() => layout = new StackLayout());
ScrollViewer scrollViewer = null;
return(SetupRepeater(dataSource, layout, itemContent, out scrollViewer));
}
private VirtualizingLayout GetStackLayout()
{
if (_stackLayout == null)
{
_stackLayout = new StackLayout()
{
Spacing = double.Parse(lineSpacing.Text),
Orientation = orientation.IsOn ? Orientation.Horizontal : Orientation.Vertical,
};
}
return(_stackLayout);
}
private VirtualizingLayout GetFlowLayout()
{
if (_flowLayout == null)
{
_flowLayout = new FlowLayout()
{
MinRowSpacing = double.Parse(itemSpacing.Text),
MinColumnSpacing = double.Parse(lineSpacing.Text),
LineAlignment = (FlowLayoutLineAlignment)Enum.Parse(typeof(FlowLayoutLineAlignment), lineAlingment.Text),
Orientation = orientation.IsOn ? Orientation.Vertical : Orientation.Horizontal,
};
}
return(_flowLayout);
}
private VirtualizingLayout GetGridLayout()
{
if (_gridLayout == null)
{
_gridLayout = new UniformGridLayout()
{
MinItemWidth = 150,
MinItemHeight = 150,
MinRowSpacing = double.Parse(itemSpacing.Text),
MinColumnSpacing = double.Parse(lineSpacing.Text),
ItemsJustification = (UniformGridLayoutItemsJustification)Enum.Parse(typeof(UniformGridLayoutItemsJustification), lineAlingment.Text),
Orientation = orientation.IsOn ? Orientation.Vertical : Orientation.Horizontal,
};
}
return(_gridLayout);
}
private ItemsRepeater SetupRepeater(object dataSource, VirtualizingLayout layout, string itemContent, out ScrollViewer scrollViewer)
{
ItemsRepeater repeater = null;
ScrollViewer sv = 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'> " + itemContent + @"</DataTemplate>");
repeater = new ItemsRepeater()
{
ItemsSource = dataSource,
ItemTemplate = elementFactory,
Layout = layout,
HorizontalCacheLength = 0.0,
VerticalCacheLength = 0.0
};
sv = new ScrollViewer
{
Content = repeater
};
Content = new ItemsRepeaterScrollHost()
{
Width = 200,
Height = 200,
ScrollViewer = sv
};
});
IdleSynchronizer.Wait();
scrollViewer = sv;
return(repeater);
}
private ItemsRepeater SetupRepeater(CustomItemsSource dataSource, ElementFactory elementFactory, ref ScrollViewer scrollViewer, VirtualizingLayout layout)
{
var repeater = new ItemsRepeater()
{
ItemsSource = dataSource,
ItemTemplate = elementFactory,
Layout = layout,
VerticalCacheLength = 0,
HorizontalCacheLength = 0
};
scrollViewer = new ScrollViewer
{
Content = repeater
};
Content = new ItemsRepeaterScrollHost()
{
Width = 200,
Height = 200,
ScrollViewer = scrollViewer
};
Content.UpdateLayout();
if (dataSource.Count > 0)
{
int realized = VerifyRealizedRange(repeater, dataSource);
Verify.IsGreaterThan(realized, 0);
}
return(repeater);
}
private ItemsRepeater SetupRepeater(CustomItemsSource dataSource, VirtualizingLayout layout)
{
ScrollViewer sv = null;
return(SetupRepeater(dataSource, GetElementFactory(), ref sv, layout));
}
private ItemsRepeater CreateRepeater(object dataSource, object elementFactory, VirtualizingLayout layout = null)
{
var repeater = new ItemsRepeater
{
ItemsSource = dataSource,
ItemTemplate = elementFactory,
};
repeater.Layout = layout ?? CreateLayout(repeater);
return(repeater);
}
private ItemsRepeater SetupRepeater(object dataSource, VirtualizingLayout layout, out ScrollViewer scrollViewer)
{
return(SetupRepeater(dataSource, layout, @"<Button Content='{Binding}' Height='100' />", out scrollViewer));
}