rom/boopsi/freeclass.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Free a BOOPSI Class
   6     Lang: english
   7 */
   8 #include <proto/exec.h>
   9 #include "intern.h"
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <intuition/classes.h>
  15 #include <proto/boopsi.h>
  16
  17         AROS_LH1(BOOL, FreeClass,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct IClass *, classPtr, A0),
  21
  22 /*  LOCATION */
  23         struct Library *, BOOPSIBase, 8, BOOPSI)
  24
  25 /*  FUNCTION
  26         Only for class implementatores.
  27
  28         Tries to free a class which has been created with MakeClass() in the
  29         first place. This will not succeed in all cases: Classes which
  30         still have living objects or which are still beeing used by subclasses
  31         can't simply be freed. In this case this call will fail.
  32
  33         Public classes will always be removed with RemoveClass() no matter
  34         if FreeClass() would succeed or not. This gurantees that after the
  35         call to FreeClass() no new objects can be created.
  36
  37         If you have a pointer to allocated memory in cl_UserData, you must
  38         make a copy of that pointer, call FreeClass() and if the call
  39         succeeded, you may free the memory. If you don't follow these rules,
  40         you might end up with a class which is partially freed.
  41
  42     INPUTS
  43         classPtr - The pointer you got from MakeClass().
  44
  45     RESULT
  46         FALSE if the class couldn't be freed at this time. This can happen
  47         either if there are still objects from this class or if the class
  48         is used a SuperClass of at least another class.
  49
  50         TRUE if the class could be freed. You must not use classPtr after
  51         that.
  52
  53     NOTES
  54         *Always* calls RemoveClass().
  55
  56     EXAMPLE
  57         // Free a public class with dynamic memory in cl_UserD
  58
  59         int freeMyClass (Class * cl)
  60         {
  61             struct MyPerClassData * mpcd;
  62
  63             mpcd = (struct MyPerClassData *)cl->cl_UserData;
  64
  65             if (FreeClass (cl)
  66             {
  67                 FreeMem (mpcd, sizeof (struct MyPerClassData));
  68                 return (TRUE);
  69             }
  70
  71             return (FALSE);
  72         }
  73
  74     BUGS
  75
  76     SEE ALSO
  77
  78     INTERNALS
  79         MakeClass(), "Basic Object-Oriented Programming System for Intuition"
  80         and "boopsi Class Reference" Dokument.
  81
  82     HISTORY
  83         29-10-95    digulla automatically created from
  84                             intuition_lib.fd and clib/intuition_protos.h
  85
  86 *****************************************************************************/
  87 {
  88     AROS_LIBFUNC_INIT
  89     AROS_LIBBASE_EXT_DECL(struct Library *,BOOPSIBase)
  90
  91     /* Make sure no one creates another object from this class. For private
  92         classes, this call does nothing. */
  93     RemoveClass (classPtr);
  94
  95     if (!classPtr->cl_SubclassCount && !classPtr->cl_ObjectCount)
  96     {
  97         classPtr->cl_Super->cl_SubclassCount --;
  98
  99         FreeMem (classPtr, sizeof (Class));
 100
 101         return (TRUE);
 102     }
 103
 104     return (FALSE);
 105     AROS_LIBFUNC_EXIT
 106 } /* FreeClass */