/*
 * 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 SizePrev(f, v)  ((v) - Buf(f))          /* from beginning to v  */
#define SizeNext(f, v)  (BufSize(f) - SizePrev(f, v))
                                        /* from v through end   */
#define OffscreenRows(c)        ((c)->drows - (c)->rows)
#define OffscreenCols(c)        ((c)->dcols - (c)->cols)

/* _next_char move to next char with wrap to next line at end of line */
int
_next_char(FORM *f)
{
        if (++X(f) == Xmax(f)) {
                if (++Y(f) == Ymax(f)) {
                        --X(f);
                        --Y(f);
                        return (E_REQUEST_DENIED);      /* at last char */
                }
                X(f) = 0;
        }
        return (E_OK);
}

/*
 * _prev_char - move to previous char with
 * wrap to previous line at beginning of line
 */
int
_prev_char(FORM *f)
{
        if (--X(f) < 0) {
                if (--Y(f) < 0) {
                        ++X(f);
                        ++Y(f);
                        return (E_REQUEST_DENIED);      /* at first char */
                }
                X(f) = Xmax(f) - 1;
        }
        return (E_OK);
}

/* _next_line - move to beginning of next line */
int
_next_line(FORM *f)
{
        if (++Y(f) == Ymax(f)) {
                --Y(f);
                return (E_REQUEST_DENIED);      /* at last line */
        }
        X(f) = 0;
        return (E_OK);
}

/* _prev_line - move to beginning of previous line */
int
_prev_line(FORM *f)
{
        if (--Y(f) < 0) {
                ++Y(f);
                return (E_REQUEST_DENIED);      /* at first line */
        }
        X(f) = 0;
        return (E_OK);
}

/* _next_word - move to beginning of next word */
int
_next_word(FORM *f)
{
        FIELD *         c = C(f);
        char *          v = LineBuf(c, Y(f)) + X(f);    /* position in buffer */
        char *          t;

        _sync_buffer(f);

        t = _whsp_beg(v, (int) SizeNext(c, v));
        v = _data_beg(t, (int) SizeNext(c, t));

        if (v == t)
                return (E_REQUEST_DENIED);      /* at last word */

        if (OneRow(c) && c->dcols != c->cols) {
        /* one row and field has grown */
                t = v;

                while (*t != ' ' && *t != '\0')  /* find end of word + 1 */
                        t++;

                if (t - (Buf(c) + B(f)) > c->cols) {
                        if (t - v > c->cols) {
                        /* word longer than visible field */
                                B(f) = (int) (v - Buf(c));
                        } else {
                                B(f) = (int) (t - (Buf(c) + c->cols));
                        }

                        X(f) = (int) (v - Buf(c));
                        return (E_OK);
                }
        }

        _adjust_cursor(f, v);
        return (E_OK);
}

/* _prev_word - move to beginning of previous word */
int
_prev_word(FORM *f)
{
        FIELD *         c = C(f);
        char *          v = LineBuf(c, Y(f)) + X(f);    /* position in buffer */
        char *          t;

        _sync_buffer(f);

        t = _data_end(Buf(c), (int) SizePrev(c, v));
        v = _whsp_end(Buf(c), (int) SizePrev(c, t));

        if (v == t)
                return (E_REQUEST_DENIED);      /* at first word */

        _adjust_cursor(f, v);
        return (E_OK);
}

/* _beg_field - move to first non-pad char in field */
int
_beg_field(FORM *f)
{
        FIELD * c = C(f);

        _sync_buffer(f);
        _adjust_cursor(f, _data_beg(Buf(c), BufSize(c)));
        return (E_OK);
}

/* _end_field - move after last non-pad char in field */
int
_end_field(FORM *f)
{
        FIELD * c = C(f);
        char *  end;

        _sync_buffer(f);
        end = _data_end(Buf(c), BufSize(c));

        if (end == Buf(c) + BufSize(c))
                end--;

        _adjust_cursor(f, end);
        return (E_OK);
}

/* _beg_line - move to first non-pad char on current line */
int
_beg_line(FORM *f)
{
        FIELD *c = C(f);

        _sync_buffer(f);
        _adjust_cursor(f, _data_beg(LineBuf(c, Y(f)), Xmax(f)));
        return (E_OK);
}

/* _end_line - move after last non-pad char on current line */
int
_end_line(FORM *f)
{
        FIELD   *c = C(f);
        char    *end;

        _sync_buffer(f);
        end = _data_end(LineBuf(c, Y(f)), Xmax(f));

        if (end == LineBuf(c, Y(f)) + Xmax(f))
                end--;

        _adjust_cursor(f, end);
        return (E_OK);
}

/* _left_char - move left */
int
_left_char(FORM *f)
{
        if (--X(f) < 0) {
                ++X(f);
                return (E_REQUEST_DENIED);      /* at left side */
        }
        return (E_OK);
}

/* _right_char - move right */
int
_right_char(FORM *f)
{
        if (++X(f) == Xmax(f)) {
                --X(f);
                return (E_REQUEST_DENIED);      /* at right side */
        }
        return (E_OK);
}

/* _up_char - move up */
int
_up_char(FORM *f)
{
        if (--Y(f) < 0) {
                ++Y(f);
                return (E_REQUEST_DENIED);      /* at top */
        }
        return (E_OK);
}

/* _down_char - move down */
int
_down_char(FORM *f)
{
        if (++Y(f) == Ymax(f)) {
                --Y(f);
                return (E_REQUEST_DENIED);      /* at bottom */
        }
        return (E_OK);
}

/* _scr_fline - scroll forward one line */
int
_scr_fline(FORM *f)
{
        FIELD   *c = C(f);

        if (++T(f) > OffscreenRows(c)) {
                --T(f);
                return (E_REQUEST_DENIED);      /* at bottom */
        }
        ++Y(f);
        Set(c, TOP_CHG);
        return (E_OK);
}

/* _scr_bline - scroll backward one line */
int
_scr_bline(FORM *f)
{
        FIELD   *c = C(f);

        if (--T(f) < 0) {
                ++T(f);
                return (E_REQUEST_DENIED);      /* at top */
        }
        --Y(f);
        Set(c, TOP_CHG);
        return (E_OK);
}

/* _scr_fpage - scroll forward one page(C(f) -> rows) */
int
_scr_fpage(FORM *f)
{
        FIELD *         c = C(f);
        int             m = OffscreenRows(c) - T(f);
        int             n = c -> rows < m ? c -> rows : m;

        if (n) {
                Y(f) += n;
                T(f) += n;
                Set(c, TOP_CHG);
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at bottom */
}

/* _scr_bpage - scroll backward one page(C(f) -> rows) */
int
_scr_bpage(FORM *f)
{
        FIELD *         c = C(f);
        int             m = T(f);
        int             n = c -> rows < m ? c -> rows : m;

        if (n) {
                Y(f) -= n;
                T(f) -= n;
                Set(c, TOP_CHG);
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at top */
}

/* _scr_fhpage - scroll forward one half page(C(f)->rows + 1)/2) */
int
_scr_fhpage(FORM *f)
{
        FIELD *         c = C(f);
        int             m = OffscreenRows(c) - T(f);
        int             h = (c->rows + 1)/2;
        int             n = h < m ? h : m;

        if (n) {
                Y(f) += n;
                T(f) += n;
                Set(c, TOP_CHG);
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at bottom */
}

/* _scr_bhpage - scroll backward one half page(C(f)->rows + 1)/2) */
int
_scr_bhpage(FORM *f)
{
        FIELD *         c = C(f);
        int             m = T(f);
        int             h = (c->rows + 1)/2;
        int             n = h < m ? h : m;

        if (n) {
                Y(f) -= n;
                T(f) -= n;
                Set(c, TOP_CHG);
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at top */
}

/* _scr_fchar - horizontal scroll forward one char */
int
_scr_fchar(FORM *f)
{
        FIELD   *c = C(f);

        if (++B(f) > OffscreenCols(c)) {
                --B(f);
                return (E_REQUEST_DENIED);      /* at end */
        }
        ++X(f);
        return (E_OK);
}

/* _scr_bchar - horizontal scroll backward one char */
int
_scr_bchar(FORM *f)
{

        if (--B(f) < 0) {
                ++B(f);
                return (E_REQUEST_DENIED);      /* at beginning */
        }
        --X(f);
        return (E_OK);
}

/* _scr_hfline - horizontal scroll forward one line(C(f)->cols) */
int
_scr_hfline(FORM *f)
{
        FIELD   *c = C(f);
        int     m = OffscreenCols(c) - B(f);
        int     n = c -> cols < m ? c -> cols : m;

        if (n) {
                X(f) += n;
                B(f) += n;
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at end */
}

/* _scr_hbline - horizontal scroll backward one line(C(f)->cols) */
int
_scr_hbline(FORM *f)
{
        FIELD   *c = C(f);
        int     m = B(f);
        int     n = c -> cols < m ? c -> cols : m;

        if (n) {
                X(f) -= n;
                B(f) -= n;
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at end */
}

/* _scr_hfhalf - horizontal scroll forward one half line(C(f)->cols/2) */
int
_scr_hfhalf(FORM *f)
{
        FIELD   *c = C(f);
        int     m = OffscreenCols(c) - B(f);
        int     h = (c->cols + 1)/2;
        int     n = h < m ? h : m;

        if (n) {
                X(f) += n;
                B(f) += n;
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at end */
}

/* _scr_hbhalf - horizontal scroll backward one half line(C(f)->cols/2) */
int
_scr_hbhalf(FORM *f)
{
        FIELD   *c = C(f);
        int     m = B(f);
        int     h = (c->cols + 1)/2;
        int     n = h < m ? h : m;

        if (n) {
                X(f) -= n;
                B(f) -= n;
                return (E_OK);
        }
        return (E_REQUEST_DENIED);      /* at top */
}