/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_extension.c,v 1.4.2.1 2010-06-08 18:50:42 bfriesen Exp $ */

/*

 * Copyright (c) 1988-1997 Sam Leffler

 * Copyright (c) 1991-1997 Silicon Graphics, Inc.

 *

 * Permission to use, copy, modify, distribute, and sell this software and 

 * its documentation for any purpose is hereby granted without fee, provided

 * that (i) the above copyright notices and this permission notice appear in

 * all copies of the software and related documentation, and (ii) the names of

 * Sam Leffler and Silicon Graphics may not be used in any advertising or

 * publicity relating to the software without the specific, prior written

 * permission of Sam Leffler and Silicon Graphics.

 * 

 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 

 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  

 * 

 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR

 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,

 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 

 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 

 * OF THIS SOFTWARE.

 */

/*

 * TIFF Library.

 *

 * Various routines support external extension of the tag set, and other

 * application extension capabilities. 

 */

#include "tiffiop.h"

int TIFFGetTagListCount( TIFF *tif )

{

    TIFFDirectory* td = &tif->tif_dir;

    return td->td_customValueCount;

}

ttag_t TIFFGetTagListEntry( TIFF *tif, int tag_index )

{

    TIFFDirectory* td = &tif->tif_dir;

    if( tag_index < 0 || tag_index >= td->td_customValueCount )

        return (ttag_t) -1;

    else

        return td->td_customValues[tag_index].info->field_tag;

}

/*

** This provides read/write access to the TIFFTagMethods within the TIFF

** structure to application code without giving access to the private

** TIFF structure.

*/

TIFFTagMethods *TIFFAccessTagMethods( TIFF *tif )

{

    return &(tif->tif_tagmethods);

}

void *TIFFGetClientInfo( TIFF *tif, const char *name )

{

    TIFFClientInfoLink *link = tif->tif_clientinfo;

    while( link != NULL && strcmp(link->name,name) != 0 )

        link = link->next;

    if( link != NULL )

        return link->data;

    else

        return NULL;

}

void TIFFSetClientInfo( TIFF *tif, void *data, const char *name )

{

    TIFFClientInfoLink *link = tif->tif_clientinfo;

    /*

    ** Do we have an existing link with this name?  If so, just

    ** set it.

    */

    while( link != NULL && strcmp(link->name,name) != 0 )

        link = link->next;

    if( link != NULL )

    {

        link->data = data;

        return;

    }

    /*

    ** Create a new link.

    */

    link = (TIFFClientInfoLink *) _TIFFmalloc(sizeof(TIFFClientInfoLink));

    assert (link != NULL);

    link->next = tif->tif_clientinfo;

    link->name = (char *) _TIFFmalloc(strlen(name)+1);

    assert (link->name != NULL);

    strcpy(link->name, name);

    link->data = data;

    tif->tif_clientinfo = link;

}

/*

 * Local Variables:

 * mode: c

 * c-basic-offset: 8

 * fill-column: 78

 * End:

 */