rom/utility/gettagdata.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     GetTagData()
   6 */
   7
   8 #include <proto/arossupport.h>
   9
  10 #include "intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <utility/tagitem.h>
  16 #include <proto/utility.h>
  17
  18         AROS_LH3(IPTR, GetTagData,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(Tag                   , tagValue, D0),
  22         AROS_LHA(IPTR                  , defaultVal, D1),
  23         AROS_LHA(const struct TagItem *, tagList, A0),
  24
  25 /*  LOCATION */
  26         struct UtilityBase *, UtilityBase, 6, Utility)
  27
  28 /*  FUNCTION
  29         Searches the TagList for the Tag specified, if it exists, then
  30         returns the ti_Data field of that Tag, otherwise returns the
  31         supplied default value.
  32
  33     INPUTS
  34         tagValue    -   Tag to search for.
  35         defaultVal  -   Default value for the Tag.
  36         tagList     -   Pointer to first TagItem in the list.
  37
  38     RESULT
  39         The data value if the Tag exists, or the default value if it
  40         doesn't.
  41
  42     NOTES
  43         If the input TagList doesn't exist (eg for some reason equals
  44         NULL), then the return value will be NULL. This way you can
  45         check for broken code, whereas returing the default would allow
  46         code that is possibly buggy to still seem to work. (Until you
  47         tried to do anything special at least).
  48
  49     EXAMPLE
  50
  51         struct Window *window;      \* The Window we are creating *\
  52         struct TagItem *wintags;    \* Tags for this window *\
  53
  54         \* Find out the value for the WA_Left tag *\
  55         window->Left = GetTagData( WA_Left, 320, wintags )
  56
  57     BUGS
  58
  59     SEE ALSO
  60         utility/tagitem.h
  61
  62     INTERNALS
  63
  64 *****************************************************************************/
  65 {
  66     AROS_LIBFUNC_INIT
  67
  68     /* Use code from libarossupport */
  69     return LibGetTagData(tagValue, defaultVal, tagList);
  70
  71     AROS_LIBFUNC_EXIT
  72 } /* GetTagData */