/*      $OpenBSD: v_z.c,v 1.6 2014/11/12 04:28:41 bentley Exp $ */

/*-
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *      Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <limits.h>
#include <stdio.h>

#include "../common/common.h"
#include "vi.h"

/*
 * v_z -- [count]z[count][-.+^<CR>]
 *      Move the screen.
 *
 * PUBLIC: int v_z(SCR *, VICMD *);
 */
int
v_z(SCR *sp, VICMD *vp)
{
        recno_t lno;
        u_int value;

        /*
         * The first count is the line to use.  If the value doesn't
         * exist, use the last line.
         */
        if (F_ISSET(vp, VC_C1SET)) {
                lno = vp->count;
                if (!db_exist(sp, lno) && db_last(sp, &lno))
                        return (1);
        } else
                lno = vp->m_start.lno;

        /* Set default return cursor line. */
        vp->m_final.lno = lno;
        vp->m_final.cno = vp->m_start.cno;

        /*
         * The second count is the displayed window size, i.e. the 'z' command
         * is another way to get artificially small windows.  Note, you can't
         * grow beyond the size of the window.
         *
         * !!!
         * A window size of 0 was historically allowed, and simply ignored.
         * This could be much more simply done by modifying the value of the
         * O_WINDOW option, but that's not how it worked historically.
         */
        if (F_ISSET(vp, VC_C2SET) && vp->count2 != 0) {
                if (vp->count2 > O_VAL(sp, O_WINDOW))
                        vp->count2 = O_VAL(sp, O_WINDOW);
                if (vs_crel(sp, vp->count2))
                        return (1);
        }

        switch (vp->character) {
        case '-':               /* Put the line at the bottom. */
                if (vs_sm_fill(sp, lno, P_BOTTOM))
                        return (1);
                break;
        case '.':               /* Put the line in the middle. */
                if (vs_sm_fill(sp, lno, P_MIDDLE))
                        return (1);
                break;
        case '+':
                /*
                 * If the user specified a line number, put that line at the
                 * top and move the cursor to it.  Otherwise, scroll forward
                 * a screen from the current screen.
                 */
                if (F_ISSET(vp, VC_C1SET)) {
                        if (vs_sm_fill(sp, lno, P_TOP))
                                return (1);
                        if (vs_sm_position(sp, &vp->m_final, 0, P_TOP))
                                return (1);
                } else
                        if (vs_sm_scroll(sp, &vp->m_final, sp->t_rows, Z_PLUS))
                                return (1);
                break;
        case '^':
                /*
                 * If the user specified a line number, put that line at the
                 * bottom, move the cursor to it, and then display the screen
                 * before that one.  Otherwise, scroll backward a screen from
                 * the current screen.
                 *
                 * !!!
                 * Note, we match the off-by-one characteristics of historic
                 * vi, here.
                 */
                if (F_ISSET(vp, VC_C1SET)) {
                        if (vs_sm_fill(sp, lno, P_BOTTOM))
                                return (1);
                        if (vs_sm_position(sp, &vp->m_final, 0, P_TOP))
                                return (1);
                        if (vs_sm_fill(sp, vp->m_final.lno, P_BOTTOM))
                                return (1);
                } else
                        if (vs_sm_scroll(sp, &vp->m_final, sp->t_rows, Z_CARAT))
                                return (1);
                break;
        default:                /* Put the line at the top for <cr>. */
                value = KEY_VAL(sp, vp->character);
                if (value != K_CR && value != K_NL) {
                        v_emsg(sp, vp->kp->usage, VIM_USAGE);
                        return (1);
                }
                if (vs_sm_fill(sp, lno, P_TOP))
                        return (1);
                break;
        }
        return (0);
}

/*
 * vs_crel --
 *      Change the relative size of the current screen.
 *
 * PUBLIC: int vs_crel(SCR *, long);
 */
int
vs_crel(SCR *sp, long count)
{
        sp->t_minrows = sp->t_rows = count;
        if (sp->t_rows > sp->rows - 1)
                sp->t_minrows = sp->t_rows = sp->rows - 1;
        TMAP = HMAP + (sp->t_rows - 1);
        F_SET(sp, SC_SCR_REDRAW);
        return (0);
}