private void Parts_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.OldItems != null)
{
RemoveGeoPointCollectionEvents(e.OldItems);
}
if (e.NewItems != null)
{
AddGeoPointCollectionEvents(e.NewItems);
}
savedBounds = new Rectangle2D();
base.RaiseGeometryChanged();
}