drag-selection in layout?

[Gary Scavone <gary ccrma stanford edu>]

I have a bunch of buttons in a layout widget that the user can move
around.  I'd like to be able to have the user do a standard click-drag
over a region to select the buttons that fall into that region.  I can
do that ... no problem.  But I'd like to be able to have the
click-drag also draw a light "outline" of the area that is being
selected ... which is pretty standard with click-drag selections.  Is
there a way to do that?  Do I have to revert to doing all my own
drawing and lose the functionality that the layout widget gives me?

Any help would be appreciated.  Thanks.

*******************************************************
* Gary Scavone                                        *
* Center for Computer Research in Music & Acoustics   *
* Stanford University                                 *
* gary@ccrma.stanford.edu                             *
* http://www-ccrma.stanford.edu/~gary/                *
*******************************************************