a RectangleF in document coordinates, within the limits imposed by MinimumSize and MaximumSize
Remarks
If SnapsToGrid is true, the resulting box will have its top-left and bottom-right points snapped to the view's grid. However, the MinimumSize and MaximumSize limits still apply, so you probably want to set the MinimumSize to be the same as the GoView.GridCellSize.