rom/utility/refreshtagitemclones.c

   1 /*
   2     Copyright © 1995-2017, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: RefreshTagItemClones()
   6     Lang: english
   7 */
   8 #include "intern.h"
   9
  10 /*****************************************************************************
  11
  12     NAME */
  13 #include <utility/tagitem.h>
  14 #include <proto/utility.h>
  15
  16         AROS_LH2(void, RefreshTagItemClones,
  17
  18 /*  SYNOPSIS */
  19         AROS_LHA(struct TagItem *, clone, A0),
  20         AROS_LHA(const struct TagItem *, original, A1),
  21
  22 /*  LOCATION */
  23         struct UtilityBase *, UtilityBase, 14, Utility)
  24
  25 /*  FUNCTION
  26         If (and only if) the Tag list 'clone' was created by calling
  27         CloneTagItems on the Tag list 'original', and the list original
  28         has NOT been changed in any way, then this function will change
  29         the list 'clone' back to its original state.
  30
  31     INPUTS
  32         original    - The source TagList (unaltered)
  33         clone       - The destination TagList (MUST be allocated by
  34                         CloneTagItems())
  35
  36     RESULT
  37         The second TagList now has the same values as the first.
  38
  39     NOTES
  40         If either of the inputs is NULL, then the function will not do
  41         anything.
  42
  43     EXAMPLE
  44         struct TagItem *orig, clone;
  45
  46         \* TagList orig has some values already *\
  47         clone = CloneTagList( orig );
  48
  49         \* In between here we do something to the TagItems in clone,
  50             but we need to have them restored.
  51         *\
  52
  53         RefreshTagItemClones( clone, orig );
  54
  55     BUGS
  56         None, however if either of the two pre-conditions is not fulfilled
  57         then this function will probably be unreliable, or trash memory.
  58
  59         We warned you...
  60
  61     SEE ALSO
  62         CloneTagItems()
  63
  64     INTERNALS
  65
  66 *****************************************************************************/
  67 {
  68     AROS_LIBFUNC_INIT
  69
  70     struct TagItem *current;
  71
  72     if( !clone )
  73         return;
  74
  75     /* If we don't have an original, but do have a clone, set the
  76        clone to have a definite end of TagList.
  77
  78        This is because CloneTagItems(NULL) is valid.
  79     */
  80     if(!original)
  81     {
  82         clone->ti_Tag = TAG_DONE;
  83         return;
  84     }
  85
  86     /* Remember, the clone list is a straight memory block, however
  87         the original list may not be.
  88     */
  89     while ((current = NextTagItem ((struct TagItem **)&original)))
  90     {
  91         *clone = *current; /* Copies both tag and data */
  92         clone++;
  93     }
  94
  95     AROS_LIBFUNC_EXIT
  96 } /* RefreshTagItemClones */