How to implement resizing handles?

[Linuxer Wang <linuxerwang gmail com>]

Hi, all

Does anybody know how to add resizing handles to a goocanvas item?  I 
mean the eight small squares surrounding a widget so that you can use 
your mouse to drag them to resize the widget.  Is it an existing 
function in goocanvas?  Or do I need to implement it with children items 
and event handling?  If it's the latter, could anybody give a 
not-too-concise description of the implementation?

Thanks a lot.