/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */


/*
 *      Copyright (c) 1997, by Sun Microsystems, Inc.
 *      All rights reserved.
 */

/*LINTLIBRARY*/

#include <sys/types.h>
#include "utility.h"

#define first(f)        (f->field [Pmin(f, P(f))])
#define last(f)         (f->field [Pmax(f, P(f))])
#define sfirst(f)       (f->field [Smin(f, P(f))])
#define slast(f)        (f->field [Smax(f, P(f))])

#define Active(f)       (Opt(f, O_ACTIVE) && Opt(f, O_VISIBLE))

/* next - return next active field on page after f(user defined order) */
static FIELD *
next(FIELD *f)
{
        FORM    *t      = f->form;
        FIELD   **p     = t->field + f->index;
        FIELD   **pmin  = t->field + Pmin(t, P(t));
        FIELD   **pmax  = t->field + Pmax(t, P(t));

        do
                p = p == pmax ? pmin : p+1;

        while ((!Active(*p)) && (*p != f));

        return (*p);
}

/* prev - return previous active field on page before f */
static FIELD *
prev(FIELD *f)
{
        FORM  *t        = f->form;
        FIELD **p       = t->field + f->index;
        FIELD **pmin    = t->field + Pmin(t, P(t));
        FIELD **pmax    = t->field + Pmax(t, P(t));

        do
                p = p == pmin ? pmax : p-1;

        while ((!Active(*p)) && (*p != f));

        return (*p);
}

/* snext - return next active field on page after f(sorted order) */
static FIELD *
snext(FIELD *f)
{
        FIELD *x = f;

        do
                f = f->snext;

        while ((!Active(f)) && (f != x));

        return (f);
}

/* sprev - return previous active field on page before f(sorted order) */
static FIELD *
sprev(FIELD *f)
{
        FIELD *x = f;

        do
                f = f->sprev;

        while ((!Active(f)) && (f != x));

        return (f);
}

/* left - return active field on page left of f */
static FIELD *
left(FIELD *f)
{
        int row = f->frow;

        do
                f = sprev(f);

        while (f->frow != row);

        return (f);
}

/* right - return active field on page right of f */
static FIELD *
right(FIELD *f)
{
        int row = f->frow;

        do
                f = snext(f);

        while (f->frow != row);

        return (f);
}

/* up - return active field on page above f */
static FIELD *
up(FIELD *f)
{
        int row = f->frow;
        int col = f->fcol;

        do
                f = sprev(f);

        while (f->frow == row && f->fcol != col);

        if (f->frow != row) {
                row = f->frow;

                while (f->frow == row && f->fcol > col)
                        f = sprev(f);

                if (f->frow != row)
                        f = snext(f);
        }
        return (f);
}

/* down - return active field on page below f */
static FIELD *
down(FIELD *f)
{
        int row = f->frow;
        int col = f->fcol;

        do
                f = snext(f);

        while (f->frow == row && f->fcol != col);

        if (f->frow != row) {
                row = f->frow;

                while (f->frow == row && f->fcol < col)
                        f = snext(f);

                if (f ->frow != row)
                        f = sprev(f);
        }
        return (f);
}

        /*
         *  _next_field
         */

int
_next_field(FORM *f)
{
        return (_set_current_field(f, next(C(f))));
}

int
_prev_field(FORM *f)
{
        return (_set_current_field(f, prev(C(f))));
}

int
_first_field(FORM *f)
{
        return (_set_current_field(f, next(last(f))));
}

int
_last_field(FORM *f)
{
        return (_set_current_field(f, prev(first(f))));
}

int
_snext_field(FORM *f)
{
        return (_set_current_field(f, snext(C(f))));
}

int
_sprev_field(FORM *f)
{
        return (_set_current_field(f, sprev(C(f))));
}

int
_sfirst_field(FORM *f)
{
        return (_set_current_field(f, snext(slast(f))));
}

int
_slast_field(FORM *f)
{
        return (_set_current_field(f, sprev(sfirst(f))));
}

int
_left_field(FORM *f)
{
        return (_set_current_field(f, left(C(f))));
}

int
_right_field(FORM *f)
{
        return (_set_current_field(f, right(C(f))));
}

int
_up_field(FORM *f)
{
        return (_set_current_field(f, up(C(f))));
}

int
_down_field(FORM *f)
{
        return (_set_current_field(f, down(C(f))));
}

FIELD *
_first_active(FORM *f)
{
        return (next(last(f)));
}