/*
 * Class def of a Athena-style function button, with a call-back function
 * associated with the button.  Here's the idea:
 *
 *	-- FuncButton is a subclass iv's PushButton
 *	-- The member CallBack points to the callback for the button.
 *	-- The FuncButton constructor takes the name of the callback as a parm
 *	   and initializes the CallBack member to the parm value.
 *	-- The callback decl is parameterized with a two formal parms: (1) a
 *	   void* StaticParm that is set when the function button is
 *	   constructed; (2) an Event* DynamicParm that is sent in by Press when
 *	   the function button is pressed.
 *	-- FuncButton reimplements PushButton's virtual Press function to call
 *	   the CallBack member.
 */

#include <InterViews/button.h>

/*
 * Note: the following type def is REQUIRED to avoid a g++ error (version 1.39)
 * described in ~gfisher/c++/func-parm-bug.c
 */
typedef void (*FuncPtr)(void*, Event*);

class FuncButton : public PushButton {
  public:
    FuncButton(FuncPtr Func, char* Label, void* StaticParm);
    void (*CallBack)(void* StaticParm, Event* DynamicParm);
  protected:
    void Press(Event*);
    void Handle (register Event&);
    void *CallBackParm;
};