Interacting with Dialogs


 Dialogs are  the most  complex components  of any user interface.  They can
 contain a  variety of  items, each of which responds to the user in its own
 way.   Some dialog  items, such  as buttons,  check boxes  or  list  boxes,
 provide a  means for the user to trigger an action, choose from a known set
 of choices,  or turn  a switch on or off.  Other dialog items, such as edit
 fields and  combo boxes,  allow the  user to  enter  data  that  cannot  be
 predetermined.   TUI provides  a mechanism  for dealing  with all this.  To
 illustrate how  dialogs work,  we'll use  as an  example the program WINSM,
 which provides a TUI-based front end for Programmer's Super-Maint, the make
 utility distributed  with TCXL.   Only  excerpts from  WINSM will  be shown
 here, but  the full  source is  shipped with  TCXL.   (Caveat: the  release
 version of  WINSM may differ from what is discussed in this document.)  But
 first, we'll discuss the overall workings of dialogs in TUI.