rom/oop/getmethod.c

   1 /*
   2     Copyright © 1995-2014, 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
  32         implementation. The pointer should ONLY be used on the object you
  33         acquired.
  34
  35     INPUTS
  36         obj      - pointer to object to get method for.
  37         mid      - method id for method to get. This may be obtained with GetMethodID()
  38         classPtr - A pointer to a location where implementation class pointer will be stored.
  39                    The obtained method must be called with this class pointer. This pointer
  40                    is mandatory!
  41
  42     RESULT
  43         The method asked for, or NULL if the method does not exist in
  44         the object's class.
  45
  46     NOTES
  47         !!! Use with EXTREME CAUTION. Very few programs need the extra speed gained
  48             by calling a method directly
  49         !!!
  50
  51     EXAMPLE
  52
  53     BUGS
  54
  55     SEE ALSO
  56         OOP_GetMethodID()
  57
  58     INTERNALS
  59
  60 *****************************************************************************/
  61 {
  62     AROS_LIBFUNC_INIT
  63
  64     struct IFMethod *ifm;
  65
  66     /* First get mid */
  67     /* Get the method from the object's class */
  68     ifm = meta_findmethod((OOP_Object *)OOP_OCLASS(obj), mid, (struct Library *)OOPBase);
  69     if (NULL == ifm)
  70         return NULL;
  71
  72     /* Set class pointer */
  73     *classPtr = ifm->mClass;
  74
  75     /* Paranoia */
  76     D(if (NULL == ifm->MethodFunc) bug("!!! OOP/GetMethod(): IFMethod instance had no methodfunc. This should NEVER happen !!!\n");)
  77
  78     return ifm->MethodFunc;
  79
  80     AROS_LIBFUNC_EXIT
  81 } /* OOP_GetMethod */