protected void RecalculateDisplayBox()
{
int w = 0;
int h = 0;
if (PangoLayout != null)
PangoLayout.GetPixelSize(out w, out h);
RectangleD r = new RectangleD (DisplayBox.X + Padding, DisplayBox.Y + Padding,
(double) w, (double) h);
r.Inflate (Padding, Padding);
_displayBox = r;
}