/*
    $Id: filtertagitems.c,v 1.2 1997/01/27 00:32:30 ldp Exp $
    $Log: filtertagitems.c,v $
    Revision 1.2  1997/01/27 00:32:30  ldp
    Polish

    Revision 1.1  1997/01/08 03:36:13  iaint
    A few more utility.lib functions

    Desc: FilterTagItems() - filter an array of TagItems.
    Lang: english
*/
#include "utility_intern.h"

/*****************************************************************************

    NAME */
#include <proto/utility.h>

        AROS_LH3(ULONG, FilterTagItems,

/*  SYNOPSIS */
        AROS_LHA(struct TagItem *, tagList, A0),
        AROS_LHA(Tag            *, filterArray, A1),
        AROS_LHA(ULONG           , logic, D0),

/*  LOCATION */
        struct Library *, UtilityBase, 16, Utility)

/*  FUNCTION
        Scans a tag list and removes tag items from the list depending
        upon whether the tag's Tag value is found in an array of tag
        values.

        If 'logic' is TAGFILTER_AND, then all the tags that are NOT
        in the array filterArray will be removed from the tagList.

        If 'logic' is TAGFILTER_NOT, then all the tags that ARE in
        the array filterArray will be removed from the tagList.

        Tags are removed by setting their ti_Tag value to TAG_IGNORE.

    INPUTS
        tagList         -   A TagList to filter items from.
        filterArray     -   An array (as described by TagInArray())
                            to determine which tag items are to be
                            removed.
        logic           -   Whether the tags in filterArray are to be
                            included or excluded from the tag list.

    RESULT
        The number of valid items left in the resulting filtered list.

    NOTES

    EXAMPLE

    BUGS

    SEE ALSO
        TagInArray()

    INTERNALS

    HISTORY
        29-10-95    digulla automatically created from
                            utility_lib.fd and clib/utility_protos.h

*****************************************************************************/
{
    AROS_LIBFUNC_INIT

    ULONG valid = 0;
    if(tagList && filterArray)
    {
        struct TagItem *ti;

        while((ti = NextTagItem(&tagList)))
        {
            if(logic == TAGFILTER_AND)
            {
                if(TagInArray(ti->ti_Tag, filterArray))
                    valid++;
                else
                    ti->ti_Tag = TAG_IGNORE;
            }
            else if(logic == TAGFILTER_NOT)
            {
                if(TagInArray(ti->ti_Tag, filterArray))
                    ti->ti_Tag = TAG_IGNORE;
                else
                    valid++;
            }
        }
    }
    return valid;

    AROS_LIBFUNC_EXIT
} /* FilterTagItems */