rom/oop/getmethod.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Get a pointer to a method for an object
   6     Lang: english
   7 */
   8 #include <exec/lists.h>
   9 #include <proto/exec.h>
  10 #include <oop/oop.h>
  11 #include <aros/debug.h>
  12 #include "intern.h"
  13
  14 /*****************************************************************************
  15
  16     NAME */
  17 #include <proto/oop.h>
  18
  19         AROS_LH3(OOP_MethodFunc, OOP_GetMethod,
  20
  21 /*  SYNOPSIS */
  22         AROS_LHA(OOP_Object  *, obj,    A0),
  23         AROS_LHA(OOP_MethodID,  mid,    D0),
  24         AROS_LHA(OOP_Class **, classPtr, A1),
  25
  26 /*  LOCATION */
  27         struct Library *, OOPBase, 21, OOP)
  28
  29 /*  FUNCTION
  30         Get a specific method function for a specific object and
  31         a specific interface. This a direct pointer to the method implementation.
  32         The pointer should ONLY be used on the object you aquired.
  33
  34     INPUTS
  35         obj      - pointer to object to get method for.
  36         mid      - method id for method to get. This may be obtained with GetMethodID()
  37         classPtr - A pointer to a location where implementation class pointer will be stored.
  38                    The obtained method must be called with this class pointer. This pointer
  39                    is mandatory!
  40
  41     RESULT
  42         The method asked for, or NULL if the method does not exist in
  43         the object's class.
  44
  45     NOTES
  46         !!! Use with EXTREME CAUTION. Very few programs need the extra speed gained
  47             by calling a method directly
  48         !!!
  49
  50     EXAMPLE
  51
  52     BUGS
  53
  54     SEE ALSO
  55         OOP_GetMethodID()
  56
  57     INTERNALS
  58
  59     HISTORY
  60         29-10-95    digulla automatically created from
  61                             intuition_lib.fd and clib/intuition_protos.h
  62
  63 *****************************************************************************/
  64 {
  65     AROS_LIBFUNC_INIT
  66
  67     struct IFMethod *ifm;
  68
  69     /* First get mid */
  70     /* Get the method from the object's class */
  71     ifm = meta_findmethod((OOP_Object *)OOP_OCLASS(obj), mid, (struct Library *)OOPBase);
  72     if (NULL == ifm)
  73         return NULL;
  74
  75     /* Set class pointer */
  76     *classPtr = ifm->mClass;
  77
  78     /* Paranoia */
  79     D(if (NULL == ifm->MethodFunc) bug("!!! OOP/GetMethod(): IFMethod instance had no methodfunc. This should NEVER happen !!!\n");)
  80
  81     return ifm->MethodFunc;
  82
  83     AROS_LIBFUNC_EXIT
  84 } /* OOP_GetMethod */