(build-font-list `(("EntryFont" ,entry-font-name) ("HeaderFont" ,header-font-name) ("ItalicFont" ,italic-font-name)))
There are certain callbacks which are of general use, and standard ones are provided for the programmer's convenience. For all callbacks except QUIT-APPLICATION-CALLBACK, you register some number of widgets with ADD-CALLBACK. These will be the widgets acted upon by the callback: