protected override Size ArrangeOverride(Size slotSize)
{
var child = this.GetChildren().FirstOrDefault();
if (child != null)
{
var desiredChildSize = LayoutInformation.GetDesiredSize(child);
var occludedPadding = ScrollContentPresenter._padding;
slotSize.Width -= occludedPadding.Left + occludedPadding.Right;
slotSize.Height -= occludedPadding.Top + occludedPadding.Bottom;
var width = Math.Max(slotSize.Width, desiredChildSize.Width);
var height = Math.Max(slotSize.Height, desiredChildSize.Height);
ArrangeChild(child, new Rect(
0,
0,
width,
height
));
ScrollContentPresenter.ScrollOwner?.TryApplyPendingScrollTo();
// Give opportunity to the the content to define the viewport size itself
(child as ICustomScrollInfo)?.ApplyViewport(ref slotSize);
}
return(slotSize);
}
protected override Size ArrangeOverride(Size slotSize)
{
var child = this.GetChildren().FirstOrDefault();
if (child != null)
{
var desiredChildSize = LayoutInformation.GetDesiredSize(child);
var occludedPadding = ScrollContentPresenter._occludedRectPadding;
slotSize.Width -= occludedPadding.Left + occludedPadding.Right;
slotSize.Height -= occludedPadding.Top + occludedPadding.Bottom;
var width = Math.Max(slotSize.Width, desiredChildSize.Width);
var height = Math.Max(slotSize.Height, desiredChildSize.Height);
ArrangeChild(child, new Rect(
0,
0,
width,
height
));
}
return(slotSize);
}
public void When_UpdateLayout_Then_TreeNotMeasuredUsingCachedValue()
{
if (Window.Current.RootElement is Panel root)
{
var sut = new Grid
{
HorizontalAlignment = HorizontalAlignment.Stretch,
VerticalAlignment = VerticalAlignment.Stretch
};
var originalRootAvailableSize = LayoutInformation.GetAvailableSize(root);
var originalRootDesiredSize = LayoutInformation.GetDesiredSize(root);
var originalRootLayoutSlot = LayoutInformation.GetLayoutSlot(root);
Size availableSize;
Rect layoutSlot;
try
{
LayoutInformation.SetAvailableSize(root, default);
LayoutInformation.SetDesiredSize(root, default);
LayoutInformation.SetLayoutSlot(root, default);
root.Children.Add(sut);
sut.UpdateLayout();
availableSize = LayoutInformation.GetAvailableSize(sut);
layoutSlot = LayoutInformation.GetLayoutSlot(sut);
}
finally
{
LayoutInformation.SetAvailableSize(root, originalRootAvailableSize);
LayoutInformation.SetDesiredSize(root, originalRootDesiredSize);
LayoutInformation.SetLayoutSlot(root, originalRootLayoutSlot);
root.Children.Remove(sut);
try { root.UpdateLayout(); }
catch { } // Make sure to restore visual tree if test has failed!
}
Assert.AreNotEqual(default, availableSize);