(* button-bar.sig *)

(* Copyright (C) 2006 Alley Stoughton

   This file is part of crypto, a cryptogram encoder/decoder.  See the
   file COPYING.txt for copying and usage restrictions *)

(* button-bar widget *)

signature BUTTON_BAR =
sig

type button_bar

(* create a button-bar widget with buttons labeled by the supplied strings;
   buttons may be active or inactive; initially, and after a button-press,
   they are all inactive

   the widget may be customized using the following resource attributes:

     Name          Type    Default      Semantics
     -----------------------------------------------------------------------
     background    color   grey         background color of widget's window
     foreground    color   black        foreground color of widget's window
     font          font    9x15         font of widget's window
     pad           int     5 (pixels)   inter-button padding
     borderWidth   int     4 (pixels)   border width of buttons *)

val buttonBar :
      Widget.root * Widget.view * Widget.arg list -> string list -> button_bar

(* returns an event that, when synchronized with, will return the
   label of the active button that the user clicked on (pressed and
   then released while staying within the button); it is safe for an
   application to fail to synchronize on this event for an arbitrary
   period of time *)

val labEvtOf : button_bar -> string CML.event

exception WrongNumber

(* setActive returns a function that, when called with a list of
   booleans whose length is equal to the number of buttons of the
   button-bar, will make the corresponding buttons active (true) or
   inactive (false); if the function is called with a list of
   a different length, then WrongNumber is raised *)

val setActive : button_bar -> bool list -> unit

(* returns the widget of a button-bar *)

val widgetOf : button_bar -> Widget.widget

end;