[plt-scheme] saved window configurations

Shouldn't IDE's merely dictate default behavior?  Why can't the user  
define a few functions to be used when (for example) files are opened  
or closed?  Example:

(define  (do-this-when-any-file-is-open  file-to-be-opened
                                          all-open-files
                                          files-in-front-window)
   (cond  ((equal? file-to-be-opened "a-file-with-significant- 
relatives.scm")
           (open-in-tab (list "this-file.scm" "that-file.scm"))
           (cond
             ((< 8 (length files-in-front-window))
              (open-in-tabs-in-front-window (all-files-in-path "path- 
containing-relatives")))
             (else
              (open-in-tabs-in-new-window (all-files-in-path "path- 
containing-relatives"))))
           (my-charge-to-task 'gibberish-task-ref)
           (my-send-email-to-boss "I'm work'n on the payroll program;  
feed me.")
           #t) ; disables default
          (else
           #f))) ; enables default

(define  (do-this-when-any-file-is-closed  file-to-be-closed
                                            all-open-files
                                            files-in-front-window)
   ... ) ; some sort of inverse of the above, perhaps

rac