glade begginer - callbacks.c

["nuser" <fakeact bol com br>]

 hi,

 my application is writen in c, and I use a file for the functions, another one to hold the several structs 
are being used (using typedef), and the functions prots.
 another "application" uses these "methods" to manipulate data. so in the other source.c, in the main() 
function i declared the pointers to those custom data types (the structs), and include the header file I 
wrote. this way all the "menu" options know that those functions I tell them to run, and the data types I 
give as args, they exist somewhere.
 my problem, i use anjuta and open glade from there when I need to edit something on the GUI. I don't know 
yet what each file does on this default template glade uses to save projects (on anjuta i started a GTK2 APP 
on the wizard). where should i put:

 - the declaration of those (pointers to) structs i'm going to use?
 - where should i put those functions that manipulate data (create an "instance" of those structs, destroy 
them, add information, retrieve information), and that are going to be called from the GUI widgets (buttons, 
etc)?
 - depending on what is on certain data field of a given struct (those that I made, which sometimes create 
sub structs that are another custom type of data), some of these widgets may or may not be active (clickable, 
etc).

 so forgive me if these are annoying and frequent questions, but i 'm somewhat lost.

 thanks!!