protected virtual void InternalZoomOut()
        {
            IZoomable zoomable = GetZoomable();

            if ((zoomable != null) && (zoomable.CanZoomOut()))
            {
                zoomable.ZoomOut();
            }
            else
            if (_surfaceStack.Count > 1)
            {
                Pop();
            }
        }
        public virtual bool CanZoomOut()
        {
            IZoomable zoomable = GetZoomable();

            return((_surfaceStack.Count > 1) || ((zoomable != null) && (zoomable.CanZoomOut())));
        }