/// <summary>
/// Enqueues any elements within the specified tree that have invalid measure, arrange, or styles, but
/// were previously removed from the queues as a result of being orphaned by a destroyed window.
/// </summary>
/// <param name="root">The root of the tree to restore.</param>
internal void RestoreToQueues(DependencyObject root)
{
Contract.Require(root, nameof(root));
if (root is UIElement uiElement)
{
if (!uiElement.IsMeasureValid)
{
MeasureQueue.Enqueue(uiElement);
}
if (!uiElement.IsArrangeValid)
{
ArrangeQueue.Enqueue(uiElement);
}
if (!uiElement.IsStyleValid)
{
StyleQueue.Enqueue(uiElement);
}
}
VisualTreeHelper.ForEachChild(root, this, (child, state) =>
{
((PresentationFoundation)state).RestoreToQueues(child);
});
}
/// <summary>
/// Recursively invalidates the measurement state of the
/// specified element and all of its descendants.
/// </summary>
private static void InvalidateMeasureRecursively(UIElement element)
{
element.InvalidateMeasure();
VisualTreeHelper.ForEachChild(element, null, (child, state) =>
{
InvalidateMeasureRecursively((UIElement)child);
});
}
/// <inheritdoc/>
protected override void PositionChildrenOverride()
{
VisualTreeHelper.ForEachChild <UIElement>(this, this, (child, state) =>
{
var offset = ((ContentPresenter)state).ContentOffset;
child.Position(offset);
child.PositionChildren();
});
}
/// <inheritdoc/>
protected override void PositionChildrenOverride()
{
VisualTreeHelper.ForEachChild <UIElement>(this, this, (child, state) =>
{
var scrollCP = (ScrollContentPresenter)state;
var scrollViewer = scrollCP.TemplatedParent as ScrollViewer;
var scrollOffset = scrollViewer == null ? Size2D.Zero : new Size2D(-scrollViewer.ContentHorizontalOffset, -scrollViewer.ContentVerticalOffset);
var frameworkElement = child as FrameworkElement;
if (frameworkElement != null)
{
child.Position(frameworkElement.TemplatedParent == state ? Size2D.Zero : scrollOffset);
}
else
{
child.Position(Size2D.Zero);
}
child.PositionChildren();
});
}