rom/boopsi/nextobject.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Iterate through a list of objects
   6     Lang: english
   7 */
   8 #include <exec/types.h>
   9 #include <exec/nodes.h>
  10 #include "intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <intuition/classes.h>
  16 #include <proto/boopsi.h>
  17
  18         AROS_LH1(APTR, NextObject,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(APTR, objectPtrPtr, A0),
  22
  23 /*  LOCATION */
  24         struct Library *, BOOPSIBase, 12, BOOPSI)
  25
  26 /*  FUNCTION
  27         Use this function to iterate through a list of BOOPSI objects.
  28         You may do whatever you want with the object returned, even
  29         remove it from the list or disposing it and then continue to
  30         iterate thought the list.
  31
  32     INPUTS
  33         objectPtrPtr - the pointer to a variable. This must be the same
  34             variable, as long as you iterate though the same list. This
  35             variable must initially be filled with the lh_Head of a list.
  36
  37     RESULT
  38         A BOOPSI object, which can be manipulated.
  39
  40     NOTES
  41
  42     EXAMPLE
  43
  44     BUGS
  45
  46     SEE ALSO
  47         NewObject(),
  48         "Basic Object-Oriented Programming System for Intuition" and
  49         "boopsi Class Reference" Dokument.
  50
  51     INTERNALS
  52
  53     HISTORY
  54
  55 *****************************************************************************/
  56 {
  57     AROS_LIBFUNC_INIT
  58     AROS_LIBBASE_EXT_DECL(struct Library *,BOOPSIBase)
  59
  60     APTR oldobject;
  61     struct _Object *nextobject;
  62
  63     nextobject = (struct _Object *)(*((struct _Object **)objectPtrPtr))->o_Node.mln_Succ;
  64     if (nextobject)
  65     {
  66         oldobject = (Object *)BASEOBJECT(*((struct _Object **)objectPtrPtr));
  67         *((struct _Object **)objectPtrPtr) = nextobject;
  68     }
  69     else
  70     {
  71         oldobject = NULL;
  72     }
  73
  74     return oldobject;
  75     AROS_LIBFUNC_EXIT
  76 } /* NextObject */