-- ! SpecTcl, by S. A. Uhler -- -- Copyright (c) 1994-1995 Sun Microsystems, Inc. -- -- See the file "license.txt" for information on usage and redistribution -- of this file, and for a DISCLAIMER OF ALL WARRANTIES. -->
Unlike the main grid, which starts off 2x2, sub-grids start off with a single cell. Additional rows and columns may be added to the sub-grid as needed, either by clicking on an existing grid line, or dropping a widget past the current end of the grid.