rom/graphics/gfxlookup.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <exec/types.h>
  10 #include <graphics/gfxnodes.h>
  11 #include <graphics/monitor.h>
  12 #include <graphics/view.h>
  13 #include <graphics/gfxbase.h>
  14 #include <proto/exec.h>
  15 #include <proto/graphics.h>
  16 #include "graphics_intern.h"
  17
  18 /*****************************************************************************
  19
  20     NAME */
  21
  22       AROS_LH1( struct ExtendedNode *, GfxLookUp,
  23
  24 /*  SYNOPSIS */
  25
  26       AROS_LHA( void *, pointer, A0),
  27
  28 /*  LOCATION */
  29
  30       struct GfxBase *, GfxBase, 117, Graphics)
  31
  32 /*  FUNCTION
  33       Finds a special graphics extended data structure (if an) associated
  34       with the pointer to a data structure (e.g.: ViewExtra associated with
  35       a View structure).
  36
  37     INPUTS
  38       pointer = a pointer to a data structure which may have an
  39                 ExtendedNode associated with it (typically a View)
  40
  41     RESULT
  42       result = a pointer to the ExtendedNode that has previously been
  43                associated with the pointer
  44
  45     NOTES
  46
  47     EXAMPLE
  48
  49     BUGS
  50
  51     SEE ALSO
  52       graphics/gfxnodes.h GfxNew(), GfxAssociate(), GfxFree()
  53
  54     INTERNALS
  55
  56     HISTORY
  57
  58 ******************************************************************************/
  59 {
  60   AROS_LIBFUNC_INIT
  61
  62   LONG * Hash = GfxBase -> hash_table;
  63   ULONG Index = CalcHashIndex((ULONG)pointer);
  64
  65   /* Whatever structure we get as node we put the pointer in the space
  66      following immediately after the ExtendedNode structure.
  67      ViewExtra -> View
  68      ViewPortExtra -> ViewPort
  69   */
  70
  71   struct ExtendedNode * node = (struct ExtendedNode *)(Hash[Index]);
  72   while (NULL != node)
  73   {
  74     if (pointer == (void *) ((struct ViewExtra *)node)->View )
  75       return node;
  76     else
  77       /* examine the next element */
  78       node = (struct ExtendedNode *)node -> xln_Succ;
  79   }
  80   /* no associated pointer was found! */
  81   return NULL;
  82
  83   AROS_LIBFUNC_EXIT
  84 } /* GfxFree */
  85