/***************************************************************************/
/*									   */
/* SmartIcon, release 1.0 - An Intuition object iconifier for the Amiga    */
/* Copyright (c) 1988 Gauthier H. Groult                                   */
/*									   */
/* Written in January 1988 by Gauthier H. Groult			   */
/*			      33, Boulevard Saint Denis,		   */
/*			      92400 Courbevoie				   */
/*			      France - Europe				   */
/*			      Tel: (16) 1 47 89 09 54                      */
/*			      email: mcvax!inria!litp!germinal!groult	   */
/*									   */
/* This source code is not in public domain, please do not distribute.	   */
/* The binary program is shareaware. Read docs files for details.	   */
/*									   */
/***************************************************************************/

#include <exec/types.h>

typedef  LONG	(*PFL)();

extern	 struct   ExecBase	 *SysBase;
extern	 struct   IntuitionBase  *IntuitionBase;

extern	 LONG  OWentry_point(), CWentry_point(), MIentry_point(),
	       PMentry_point();
extern	 VOID  MyOpenWindow(), MyCloseWindow(), MyPutMsg();

/* The SetHooks() and CleanHooks() functions set the parameters for     */
/* the SetFunction() calls and execute those. By doing so, the          */
/* libraries (namely Exec and Intuition) vector tables are patched so   */
/* that calls to the specified functions go trough our code before or	*/
/* after doing their normal stuff.					*/
/* We must save the old pointers to restore them when exiting.		*/
/*									*/
/* This is derived from DropShadow's hooks.                             */

VOID	 SetHooks(), CleanHooks();

struct	 hook
   {
   LONG  hk_SysFunc;
   PFL	 hk_MyFunc;
   PFL	 hk_Entry;
   LONG  hk_LVO;
   };

struct	 hook  owhook =
   {
   0,
   (PFL)MyOpenWindow,
   (PFL)OWentry_point,
   -204
   };

struct	 hook  cwhook =
   {
   0,
   (PFL)MyCloseWindow,
   (PFL)CWentry_point,
   -72
   };

struct	 hook  mihook =
   {
   0,
   NULL,
   (PFL)MIentry_point,
   -150
   };

struct	 hook  pmhook =
   {
   0,
   (PFL)MyPutMsg,
   (PFL)PMentry_point,
   -366
   };

VOID
SetHooks()
{
   Forbid();
   owhook.hk_SysFunc = SetFunction(IntuitionBase,owhook.hk_LVO,owhook.hk_Entry);
   cwhook.hk_SysFunc = SetFunction(IntuitionBase,cwhook.hk_LVO,cwhook.hk_Entry);
   mihook.hk_SysFunc = SetFunction(IntuitionBase,mihook.hk_LVO,mihook.hk_Entry);
   pmhook.hk_SysFunc = SetFunction(SysBase,pmhook.hk_LVO,pmhook.hk_Entry);
   Permit();
}

VOID
CleanHooks()
{
   SetFunction(IntuitionBase,owhook.hk_LVO,owhook.hk_SysFunc);
   SetFunction(IntuitionBase,cwhook.hk_LVO,cwhook.hk_SysFunc);
   SetFunction(IntuitionBase,mihook.hk_LVO,mihook.hk_SysFunc);
   SetFunction(SysBase,pmhook.hk_LVO,pmhook.hk_SysFunc);
}