How to tell a Tk widget to tell me what (or who, as the case may be) his children? Is there a team for this?
For example, if you see a canvas widget .cvswith a label, button and other decorations ... How to poll the canvas?
.cvs
winfo children $widget
see http://www.tcl.tk/man/tcl8.5/TkCmd/winfo.htm#M8