src/tiff/tif_extension.c

   1 /* $Header$ */
   2
   3 /*
   4  * Copyright (c) 1988-1997 Sam Leffler
   5  * Copyright (c) 1991-1997 Silicon Graphics, Inc.
   6  *
   7  * Permission to use, copy, modify, distribute, and sell this software and
   8  * its documentation for any purpose is hereby granted without fee, provided
   9  * that (i) the above copyright notices and this permission notice appear in
  10  * all copies of the software and related documentation, and (ii) the names of
  11  * Sam Leffler and Silicon Graphics may not be used in any advertising or
  12  * publicity relating to the software without the specific, prior written
  13  * permission of Sam Leffler and Silicon Graphics.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  17  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  18  *
  19  * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
  20  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  21  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  22  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  23  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  24  * OF THIS SOFTWARE.
  25  */
  26
  27 /*
  28  * TIFF Library.
  29  *
  30  * Various routines support external extension of the tag set, and other
  31  * application extension capabilities.
  32  */
  33
  34 #include "tiffiop.h"
  35 #include <assert.h>
  36
  37 int TIFFGetTagListCount( TIFF *tif )
  38
  39 {
  40     TIFFDirectory* td = &tif->tif_dir;
  41
  42     return td->td_customValueCount;
  43 }
  44
  45 ttag_t TIFFGetTagListEntry( TIFF *tif, int tag_index )
  46
  47 {
  48     TIFFDirectory* td = &tif->tif_dir;
  49
  50     if( tag_index < 0 || tag_index >= td->td_customValueCount )
  51         return (ttag_t) -1;
  52     else
  53         return td->td_customValues[tag_index].info->field_tag;
  54 }
  55
  56 /*
  57 ** This provides read/write access to the TIFFTagMethods within the TIFF
  58 ** structure to application code without giving access to the private
  59 ** TIFF structure.
  60 */
  61 TIFFTagMethods *TIFFAccessTagMethods( TIFF *tif )
  62
  63 {
  64     return &(tif->tif_tagmethods);
  65 }
  66
  67 void *TIFFGetClientInfo( TIFF *tif, const char *name )
  68
  69 {
  70     TIFFClientInfoLink *link = tif->tif_clientinfo;
  71
  72     while( link != NULL && strcmp(link->name,name) != 0 )
  73         link = link->next;
  74
  75     if( link != NULL )
  76         return link->data;
  77     else
  78         return NULL;
  79 }
  80
  81 void TIFFSetClientInfo( TIFF *tif, void *data, const char *name )
  82
  83 {
  84     TIFFClientInfoLink *link = tif->tif_clientinfo;
  85
  86     /*
  87     ** Do we have an existing link with this name?  If so, just
  88     ** set it.
  89     */
  90     while( link != NULL && strcmp(link->name,name) != 0 )
  91         link = link->next;
  92
  93     if( link != NULL )
  94     {
  95         link->data = data;
  96         return;
  97     }
  98
  99     /*
 100     ** Create a new link.
 101     */
 102
 103     link = (TIFFClientInfoLink *) _TIFFmalloc(sizeof(TIFFClientInfoLink));
 104     assert (link != NULL);
 105     link->next = tif->tif_clientinfo;
 106     link->name = (char *) _TIFFmalloc(strlen(name)+1);
 107     assert (link->name != NULL);
 108     strcpy(link->name, name);
 109     link->data = data;
 110
 111     tif->tif_clientinfo = link;
 112 }