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);
void DoPhasedWorkCallback()
{
MarkCallbackRecieved();
if (m_pendingElements.Count > 0 && !BuildTreeScheduler.ShouldYield())
{
var visibleWindow = m_owner.VisibleWindow;
SortElements(visibleWindow);
int currentIndex = m_pendingElements.Count - 1;
do
{
var info = m_pendingElements[currentIndex];
var element = info.Element;
var virtInfo = info.VirtInfo;
var dataIndex = virtInfo.Index;
int currentPhase = virtInfo.Phase;
if (currentPhase > 0)
{
int nextPhase = VirtualizationInfo.PhaseReachedEnd;
virtInfo.DataTemplateComponent.ProcessBindings(virtInfo.Data, -1 /* item index unused */, currentPhase, out nextPhase);
ValidatePhaseOrdering(currentPhase, nextPhase);
var previousAvailableSize = LayoutInformation.GetAvailableSize(element);
element.Measure(previousAvailableSize);
if (nextPhase > 0)
{
virtInfo.Phase = nextPhase;
// If we are the first item or
// If the current items phase is higher than the next items phase, then move to the next item.
if (currentIndex == 0 ||
virtInfo.Phase > m_pendingElements[currentIndex - 1].VirtInfo.Phase)
{
currentIndex--;
}
}
else
{
m_pendingElements.RemoveAt(currentIndex);
currentIndex--;
}
}
else
{
throw new InvalidOperationException("Cleared element found in pending list which is not expected");
}
var pendingCount = (int)(m_pendingElements.Count);
if (currentIndex == -1)
{
// Reached the top, start from the bottom again
currentIndex = pendingCount - 1;
}
else if (currentIndex > -1 && currentIndex < pendingCount - 1)
{
// If the next element is oustide the visible window and there are elements in the visible window
// go back to the visible window.
bool nextItemIsVisible = SharedHelpers.DoRectsIntersect(visibleWindow, m_pendingElements[currentIndex].VirtInfo.ArrangeBounds);
if (!nextItemIsVisible)
{
bool haveVisibleItems = SharedHelpers.DoRectsIntersect(visibleWindow, m_pendingElements[pendingCount - 1].VirtInfo.ArrangeBounds);
if (haveVisibleItems)
{
currentIndex = pendingCount - 1;
}
}
}
} while (m_pendingElements.Count > 0 && !BuildTreeScheduler.ShouldYield());
}
if (m_pendingElements.Count > 0)
{
RegisterForCallback();
}
}