protected override Size ArrangeOverride(Size finalSize) {
EnsureFormattedText();
// update the formatted text with the final size
_FormattedText.MaxTextWidth = finalSize.Width;
_FormattedText.MaxTextHeight = Math.Max(0.0001d, finalSize.Height);
// need to re-generate the geometry now that the dimensions have changed
_TextGeometry = null;
return finalSize;
}