/// <summary>
/// Override for <seealso cref="UIElement.ArrangeCore" />
/// </summary>
/// <remarks>
/// We need information from AdornerInfo. Since we keep one AdornerInfo per
/// Adorner, and we expect a 1:1 mapping between Adorners and our visual children,
/// it makes more sense for us to iterate across AdornerInfos instead of
/// our visual children here. This means that if someone somehow adds a non-Adorner
/// child to AdornerLayer, it will never render.
/// </remarks>
/// <param name="finalSize">The location reserved for this element by the parent</param>
protected override Size ArrangeOverride(Size finalSize)
{
// Not using an enumerator because the list can be modified during the loop when we call out.
DictionaryEntry[] zOrderMapEntries = new DictionaryEntry[_zOrderMap.Count];
_zOrderMap.CopyTo(zOrderMapEntries, 0);
for (int i = 0; i < zOrderMapEntries.Length; i++)
{
ArrayList adornerInfos = (ArrayList)zOrderMapEntries[i].Value;
Debug.Assert(adornerInfos != null, "No adorners found for element in AdornerLayer._zOrderMap");
int j = 0;
while (j < adornerInfos.Count)
{
AdornerInfo adornerInfo = (AdornerInfo)adornerInfos[j++];
if (!adornerInfo.Adorner.IsArrangeValid) // optimization
{
// We're dependent on Arrange to get the rendersize of the adorner, so Arrange before
// doing our transform magic.
adornerInfo.Adorner.Arrange(new Rect(new Point(), adornerInfo.Adorner.DesiredSize));
GeneralTransform proposedTransform = adornerInfo.Adorner.GetDesiredTransform(adornerInfo.Transform);
GeneralTransform adornerTransform = GetProposedTransform(adornerInfo.Adorner, proposedTransform);
int index = _children.IndexOf(adornerInfo.Adorner);
if (index >= 0)
{
// Get the matrix transform out, skip all non affine transforms
Transform transform = (adornerTransform != null) ? adornerTransform.AffineTransform : null;
((Adorner)(_children[index])).AdornerTransform = transform;
}
}
if (adornerInfo.Adorner.IsClipEnabled)
{
adornerInfo.Adorner.AdornerClip = adornerInfo.Clip;
}
else if (adornerInfo.Adorner.AdornerClip != null)
{
adornerInfo.Adorner.AdornerClip = null;
}
}
}
return finalSize;
}
/// <summary>
/// AdornerLayer always returns a size of (0,0).
/// The AdornerLayer's size should be the same as its parent, but not take up layout space. This means
/// parents containing an AdornerLayer should stretch it to their own size.
/// </summary>
/// <param name="constraint">
/// Sizing constraint.
/// </param>
protected override Size MeasureOverride(Size constraint)
{
// Not using an enumerator because the list can be modified during the loop when we call out.
DictionaryEntry[] zOrderMapEntries = new DictionaryEntry[_zOrderMap.Count];
_zOrderMap.CopyTo(zOrderMapEntries, 0);
for (int i = 0; i < zOrderMapEntries.Length; i++)
{
ArrayList adornerInfos = (ArrayList)zOrderMapEntries[i].Value;
Debug.Assert(adornerInfos != null, "No adorners found for element in AdornerLayer._zOrderMap");
int j = 0;
while (j < adornerInfos.Count)
{
AdornerInfo adornerInfo = (AdornerInfo)adornerInfos[j++];
adornerInfo.Adorner.Measure(constraint);
}
}
// Returning 0,0 prevents an invalidation of Measure for AdornerLayer from unnecessarily dirtying the parent.
return new Size();
}
