private void UpdateClip(Size arrangeSize)
{
if (!this.isClipPropertySet && (this.rootElement != null))
{
this.clippingRectangle = new RectangleGeometry();
this.rootElement.Clip = this.clippingRectangle;
this.isClipPropertySet = true;
}
if (this.clippingRectangle != null)
{
this.clippingRectangle.Rect = new Rect(0.0, 0.0, arrangeSize.Width, arrangeSize.Height);
}
}