rom/intuition/nextpubscreen.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     Copyright © 2001-2003, The MorphOS Development Team. All Rights Reserved.
   4     $Id$
   5 */
   6
   7 #include <string.h>
   8 #include "intuition_intern.h"
   9
  10 /*****************************************************************************
  11
  12     NAME */
  13 #include <proto/intuition.h>
  14
  15         AROS_LH2(UBYTE *, NextPubScreen,
  16
  17 /*  SYNOPSIS */
  18         AROS_LHA(struct Screen *, screen  , A0),
  19         AROS_LHA(UBYTE *        , namebuff, A1),
  20
  21 /*  LOCATION */
  22         struct IntuitionBase *, IntuitionBase, 89, Intuition)
  23
  24 /*  FUNCTION
  25         Gets the next public screen in the system; this allows visitor windows
  26         to jump among public screens in a cycle.
  27
  28     INPUTS
  29         screen   - Pointer to the public screen your window is open in or
  30                    NULL if you don't have a pointer to a public screen.
  31         namebuff - Pointer to a buffer with (at least) MAXPUBSCREENNAME+1
  32                    characters to put the name of the next public screen in.
  33
  34     RESULT
  35         Returns 'namebuff' or NULL if there are no public screens.
  36
  37     NOTES
  38         We cannot guarantee that the public screen, the name of which you got
  39         by using this function, is available when you call for instance
  40         LockPubScreen(). Therefore you must be prepared to handle failure of
  41         that kind of functions.
  42
  43         This function may return the name of a public screen which is in
  44         private mode.
  45
  46         The cycle order is undefined, so draw no conclusions based on it!
  47
  48     EXAMPLE
  49
  50     BUGS
  51
  52     SEE ALSO
  53         OpenScreen(), PubScreenStatus()
  54
  55     INTERNALS
  56         Maybe we should correct the + 1 stupidity.
  57
  58 *****************************************************************************/
  59 {
  60     AROS_LIBFUNC_INIT
  61
  62     struct PubScreenNode *ps;
  63     struct IntScreen     *scr = (struct IntScreen *)screen;
  64     struct List          *list;
  65
  66     list = LockPubScreenList();
  67
  68     if(scr == NULL)
  69     {
  70         ps = (struct PubScreenNode *)list->lh_Head;
  71         ASSERT(ps != NULL);
  72     }
  73     else
  74     {
  75         ps = scr->pubScrNode;
  76         if (ps != NULL)
  77         {
  78             ps = (struct PubScreenNode *)ps->psn_Node.ln_Succ;
  79             ASSERT(ps != NULL);
  80         }
  81         else
  82             namebuff = NULL;
  83     }
  84
  85     /* A "valid" node in a list must have ln_Succ != NULL */
  86
  87     if (ps->psn_Node.ln_Succ == NULL)
  88         namebuff = NULL;
  89
  90     if (namebuff != NULL)
  91         strcpy(namebuff, ps->psn_Node.ln_Name);
  92
  93     UnlockPubScreenList();
  94
  95     return namebuff;
  96
  97     AROS_LIBFUNC_EXIT
  98 } /* NextPubScreen */