/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */


/* Copyright (c) 1981 Regents of the University of California */

#include "ex.h"
#include "ex_tune.h"
#include "ex_tty.h"
#include "ex_vis.h"

/*
 * Routines to deal with management of logical versus physical
 * display, opening and redisplaying lines on the screen, and
 * use of intelligent terminal operations.  Routines to deal with
 * screen cleanup after a change.
 */

/*
 * Display a new line at physical line p, returning
 * the depth of the newly displayed line.  We may decide
 * to expand the window on an intelligent terminal if it is
 * less than a full screen by deleting a line above the top of the
 * window before doing an insert line to keep all the good text
 * on the screen in which case the line may actually end up
 * somewhere other than line p.
 */
void
vopen(line *tp, int p)
{
        int cnt;
        struct vlinfo *vp, *vpc;

#ifdef ADEBUG
        if (trace != NULL)
                tfixnl(), fprintf(trace, "vopen(%d, %d)\n", lineno(tp), p);
#endif
        if (state != VISUAL) {
                if (vcnt)
                        if (hold & HOLDROL)
                                vup1();
                        else
                                vclean();

                /*
                 * Forget all that we once knew.
                 */
                vcnt = vcline = 0;
                p = WBOT; LASTLINE = WBOT + 1;
                state = bastate;
                WTOP = basWTOP;
                WLINES = basWLINES;
        }
        vpc = &vlinfo[vcline];
        for (vp = &vlinfo[vcnt]; vp >= vpc; vp--)
                vlcopy(vp[1], vp[0]);
        vcnt++;
        if (Pline == numbline)
                /*
                 * Dirtying all the lines is rather inefficient
                 * internally, but number mode is used rarely
                 * and so it's not worth optimizing.
                 */
                vdirty(vcline+1, WECHO);
        getaline(*tp);

        /*
         * If we are opening at the top of the window, can try a window
         * expansion at the top.
         */
        if (state == VISUAL && vcline == 0 && vcnt > 1 && p > ZERO) {
                cnt = p + vdepth() - LINE(1);
                if (cnt > 0) {
                        p -= cnt;
                        if (p < ZERO)
                                p = ZERO;
                        WTOP = p;
                        WLINES = WBOT - WTOP + 1;
                }
        }
        vpc->vliny = p, vpc->vdepth = 0, vpc->vflags = 0;
        cnt = vreopen(p, lineno(tp), vcline);
        if (vcline + 1 == vcnt)
                LINE(vcnt) = LINE(vcline) + cnt;
}

/*
 * Redisplay logical line l at physical line p with line number lineno.
 */
int
vreopen(int p, int lineno, int l)
{
        int d;
        struct vlinfo *vp = &vlinfo[l];

        d = vp->vdepth;
        if (d == 0 || (vp->vflags & VDIRT))
                vp->vdepth = d = vdepth();
        vp->vliny = p, vp->vflags &= ~VDIRT;

        /*
         * Try to win by making the screen larger rather than inserting
         * a line and driving text off the bottom.
         */
        p = vglitchup(l, 0);

        /*
         * BUG: Should consider using clr_eol here to clear to end of line.
         *      As it stands we always strike over the current text.
         *      Since often the current text is the same as what
         *      we are overstriking with, it tends not to show.
         *      On the other hand if it is different and we end up
         *      spacing out a lot of text, we could have won with
         *      a clr_eol.  This is probably worthwhile at low speed
         *      only however, since clearly computation will be
         *      necessary to determine which way to go.
         */
        vigoto(p, 0);
        pline(lineno);

        if (state == VISUAL && l == vcline && vp->vliny < 0) {
                vp->vliny = 0;
                vscrap();
                return (d);
        }

        /*
         * When we are typing part of a line for hardcopy open, don't
         * want to type the '$' marking an end of line if in list mode.
         */
        if (hold & HOLDDOL)
                return (d);
        if (Putchar == listchar)
                putchar('$');

        /*
         * Optimization of cursor motion may prevent screen rollup if the
         * line has blanks/tabs at the end unless we force the cursor to appear
         * on the last line segment.
         */
        if (vp->vliny + d - 1 > WBOT)
                vcsync();

        /*
         * Switch into hardcopy open mode if we are in one line (adm3)
         * open mode and this line is now too long.  If in hardcopy
         * open mode, then call sethard to move onto the next line
         * with appropriate positioning.
         */
        if (state == ONEOPEN) {
                WCOLS = OCOLUMNS;
                if (vdepth() > 1) {
                        WCOLS = TUBECOLS;
                        sethard();
                } else
                        WCOLS = TUBECOLS;
        } else if (state == HARDOPEN)
                sethard();

        /*
         * Unless we filled (completely) the last line we typed on,
         * we have to clear to the end of the line
         * in case stuff is left from before.
         */
        if (vp->vliny + d > destline) {
                if (insert_null_glitch && destcol == WCOLS)
                        vigoto(vp->vliny + d - 1, 0);
                vclreol();
        }
        return (d);
}

/*
 * Real work for winning growing of window at top
 * when inserting in the middle of a partially full
 * screen on an intelligent terminal.  We have as argument
 * the logical line number to be inserted after, and the offset
 * from that line where the insert will go.
 * We look at the picture of depths and positions, and if we can
 * delete some (blank) lines from the top of the screen so that
 * later inserts will not push stuff off the bottom.
 */
int
vglitchup(int l, int o)
{
        struct vlinfo *vp = &vlinfo[l];
        int need;
        int p = vp->vliny;
        short oldhold, oldheldech;
        bool glitched = 0;

        if (l < vcnt - 1) {
                need = p + vp->vdepth - (vp+1)->vliny;
                if (need > 0) {
                        if (state == VISUAL && WTOP - ZERO >= need && insert_line && delete_line) {
                                glitched++;
                                WTOP -= need;
                                WLINES = WBOT - WTOP + 1;
                                p -= need;
                                if (p + o == WTOP) {
                                        vp->vliny = WTOP;
                                        return (WTOP + o);
                                }
                                vdellin(WTOP, need, -1);
                                oldheldech = heldech;
                                oldhold = hold;
                                hold |= HOLDECH;
                        }
                        vinslin((vp+1)->vliny, need, l);
                        if (glitched) {
                                hold = oldhold;
                                heldech = oldheldech;
                        }
                }
        } else
                vp[1].vliny = vp[0].vliny + vp->vdepth;
        return (p + o);
}

/*
 * Insert cnt blank lines before line p,
 * logically and (if supported) physically.
 */
void
vinslin(int p, int cnt, int l)
{
        int i;
        bool could = 1;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vinslin(%d, %d, %d)\n", p, cnt, l);
#endif
        if (p + cnt > WBOT && clr_eos) {
                /*
                 * Really quick -- clear to end of screen.
                 */
                cnt = WECHO + 1 - p;
                vgoto(p, 0), vputp(clr_eos, cnt);
                vclrech(1);
                vadjAL(p, cnt);
        } else if (scroll_reverse && p == WTOP && costSR < costAL) {
                /*
                 * Use reverse scroll mode of the terminal, at
                 * the top of the window.  Reverse linefeed works
                 * too, since we only use it from line WTOP.
                 */
                for (i = cnt; i > 0; i--) {
                        vgoto(p, 0), vputp(scroll_reverse, 0);
                        if (i > 1 && (hold & HOLDAT) == 0)
                                putchar('@');
                        /*
                         * If we are at the top of the screen, and the
                         * terminal retains display above, then we
                         * should try to clear to end of line.
                         * Have to use clr_eol since we don't remember what is
                         * actually on the line.
                         */
                        if (clr_eol && (memory_above || p != 0))
                                vputp(clr_eol, 1);
                }
                vadjAL(p, cnt);
        } else if (insert_line) {
                /*
                 * Use insert line.
                 */
                vgoto(p, 0);
                if (parm_insert_line && (cnt>1 || *insert_line==0)) {
                        /* insert cnt lines.  Should do @'s too. */
                        vputp(tparm(parm_insert_line, cnt, p), WECHO+1-p);
                }
                else if (change_scroll_region && *insert_line==0) {
                        /* vt100 change scrolling region to fake insert_line */
                        vputp(save_cursor, 1);
                        vputp(tparm(change_scroll_region, p, lines-1), 1);
                        vputp(restore_cursor, 1);       /* change_scroll_region homes stupid cursor */
                        for (i=cnt; i>0; i--)
                                vputp(scroll_reverse, 1);       /* should do @'s */
                        vputp(tparm(change_scroll_region, 0, lines-1), 1);
                        vputp(restore_cursor, 1);       /* Once again put it back */
                }
                else {
                        vputp(insert_line, WECHO + 1 - p);
                        for (i = cnt - 1; i > 0; i--) {
                                vgoto(outline+1, 0);
                                vputp(insert_line, WECHO + 1 - outline);
                                if ((hold & HOLDAT) == 0)
                                        putchar('@');
                        }
                }
                vadjAL(p, cnt);
        } else
                could = 0;
        vopenup(cnt, could, l);
}

/*
 * Logically open up after line l, cnt of them.
 * We need to know if it was done ``physically'' since in this
 * case we accept what the hardware gives us.  If we have to do
 * it ourselves (brute force) we will squish out @ lines in the process
 * if this will save us work.
 */
void
vopenup(int cnt, bool could, int l)
{
        struct vlinfo *vc = &vlinfo[l + 1];
        struct vlinfo *ve = &vlinfo[vcnt];

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vopenup(%d, %d, %d)\n", cnt, could, l);
#endif
        if (could)
                /*
                 * This will push @ lines down the screen,
                 * just as the hardware did.  Since the default
                 * for intelligent terminals is to never have @
                 * lines on the screen, this should never happen,
                 * and the code makes no special effort to be nice in this
                 * case, e.g. squishing out the @ lines by delete lines
                 * before doing append lines.
                 */
                for (; vc <= ve; vc++)
                        vc->vliny += cnt;
        else {
                /*
                 * Will have to clean up brute force eventually,
                 * so push the line data around as little as possible.
                 */
                vc->vliny += cnt, vc->vflags |= VDIRT;
                while (vc < ve) {
                        int i = vc->vliny + vc->vdepth;

                        vc++;
                        if (i <= vc->vliny)
                                break;
                        vc->vliny = i, vc->vflags |= VDIRT;
                }
        }
        vscrap();
}

/*
 * Adjust data structure internally to account for insertion of
 * blank lines on the screen.
 */
void
vadjAL(int p, int cnt)
{
        wchar_t *tlines[TUBELINES];
        int from, to;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vadjal(%d, %d)\n", p, cnt);
#endif
        copy(tlines, vtube, sizeof vtube);      /*SASSIGN*/
        for (from = p, to = p + cnt; to <= WECHO; from++, to++)
                vtube[to] = tlines[from];
        for (to = p; from <= WECHO; from++, to++) {
                vtube[to] = tlines[from];
                vclrbyte(vtube[to], WCOLS);
        }
        /*
         * Have to clear the echo area since its contents aren't
         * necessarily consistent with the rest of the display.
         */
        vclrech(0);
}

/*
 * Roll the screen up logically and physically
 * so that line dl is the bottom line on the screen.
 */
void
vrollup(int dl)
{
        int cnt;
        int dc = destcol;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vrollup(%d)\n", dl);
#endif
        cnt = dl - (splitw ? WECHO : WBOT);
        if (splitw && (state == VISUAL || state == CRTOPEN))
                holdupd = 1;
        vmoveitup(cnt, 1);
        vscroll(cnt);
        destline = dl - cnt, destcol = dc;
}

void
vup1(void)
{

        vrollup(WBOT + 1);
}

/*
 * Scroll the screen up cnt lines physically.
 * If doclr is true, do a clear eol if the terminal
 * has standout (to prevent it from scrolling up)
 */
void
vmoveitup(int cnt, bool doclr)
{

        if (cnt == 0)
                return;
#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vmoveitup(%d)\n", cnt);
#endif
        if (doclr)
                vclrech(0);
        if (scroll_forward) {
                destline = WECHO;
                destcol = (NONL ? 0 : outcol % WCOLS);
                fgoto();
                while (cnt > 0)
                        vputp(scroll_forward, 0), cnt--;
        }
        else {
                destline = WECHO + cnt;
                destcol = (NONL ? 0 : outcol % WCOLS);
                fgoto();
                if (state == ONEOPEN || state == HARDOPEN) {
                        outline = destline = 0;
                        vclrbyte(vtube[0], WCOLS);
                }
        }
        /* Get rid of line we just rolled up */
        if (doclr && memory_below && clr_eol)
                vclrech(0);
}

/*
 * Scroll the screen up cnt lines logically.
 */
void
vscroll(int cnt)
{
        int from, to;
        wchar_t *tlines[TUBELINES];

#ifdef ADEBUG
        if (trace)
                fprintf(trace, "vscroll(%d)\n", cnt);
#endif
        if (cnt < 0 || cnt > TUBELINES)
                error(gettext("Internal error: vscroll"));
        if (cnt == 0)
                return;
        copy(tlines, vtube, sizeof vtube);
        for (to = ZERO, from = ZERO + cnt; to <= WECHO - cnt; to++, from++)
                vtube[to] = tlines[from];
        for (from = ZERO; to <= WECHO; to++, from++) {
                vtube[to] = tlines[from];
                vclrbyte(vtube[to], WCOLS);
        }
        for (from = 0; from <= vcnt; from++)
                LINE(from) -= cnt;
}

/*
 * Discard logical lines due to physical wandering off the screen.
 */
void
vscrap(void)
{
        int i, j;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vscrap\n"), tvliny();
#endif
        if (splitw)
                return;
        if (vcnt && WBOT != WECHO && LINE(0) < WTOP && LINE(0) >= ZERO) {
                WTOP = LINE(0);
                WLINES = WBOT - WTOP + 1;
        }
        for (j = 0; j < vcnt; j++)
                if (LINE(j) >= WTOP) {
                        if (j == 0)
                                break;
                        /*
                         * Discard the first j physical lines off the top.
                         */
                        vcnt -= j, vcline -= j;
                        for (i = 0; i <= vcnt; i++)
                                vlcopy(vlinfo[i], vlinfo[i + j]);
                        break;
                }
        /*
         * Discard lines off the bottom.
         */
        if (vcnt) {
                for (j = 0; j <= vcnt; j++)
                        if (LINE(j) > WBOT || LINE(j) + DEPTH(j) - 1 > WBOT) {
                                vcnt = j;
                                break;
                        }
                if (vcnt == 0)
                        LASTLINE = 0;
                else
                        LASTLINE = LINE(vcnt-1) + DEPTH(vcnt-1);
        }
#ifdef ADEBUG
        if (trace)
                tvliny();
#endif
        /*
         * May have no lines!
         */
}

/*
 * Repaint the screen, with cursor at curs, aftern an arbitrary change.
 * Handle notification on large changes.
 */
void
vrepaint(unsigned char *curs)
{

        wdot = NOLINE;
        /*
         * In open want to notify first.
         */
        noteit(0);
        vscrap();

        /*
         * Deal with a totally useless display.
         */
        if (vcnt == 0 || vcline < 0 || vcline > vcnt || holdupd && state != VISUAL) {
                line *odol = dol;

                vcnt = 0;
                if (holdupd)
                        if (state == VISUAL)
                                (void)peekkey();
                        else
                                vup1();
                holdupd = 0;
                if (odol == zero)
                        fixzero();
                vcontext(dot, '.');
                noteit(1);
                if (noteit(1) == 0 && odol == zero) {
                        CATCH
                                error(gettext("No lines in buffer"));
                        ENDCATCH
                        linebuf[0] = 0;
                        splitw = 0;
                }
                vnline(curs);
                return;
        }

        /*
         * Have some useful displayed text; refresh it.
         */
        getDOT();

        /*
         * This is for boundary conditions in open mode.
         */
        if (FLAGS(0) & VDIRT)
                vsync(WTOP);

        /*
         * If the current line is after the last displayed line
         * or the bottom of the screen, then special effort is needed
         * to get it on the screen.  We first try a redraw at the
         * last line on the screen, hoping it will fill in where @
         * lines are now.  If this doesn't work, then roll it onto
         * the screen.
         */
        if (vcline >= vcnt || LINE(vcline) > WBOT) {
                short oldhold = hold;
                hold |= HOLDAT, vredraw(LASTLINE), hold = oldhold;
                if (vcline >= vcnt) {
                        int i = vcline - vcnt + 1;

                        dot -= i;
                        vcline -= i;
                        vroll(i);
                } else
                        vsyncCL();
        } else
                vsync(vcline > 0 ? LINE(vcline - 1) : WTOP);

        /*
         * Notification on large change for visual
         * has to be done last or we may lose
         * the echo area with redisplay.
         */
        noteit(1);

        /*
         * Finally.  Move the cursor onto the current line.
         */
        vnline(curs);
}

/*
 * Fully cleanup the screen, leaving no @ lines except at end when
 * line after last won't completely fit.  The routine vsync is
 * more conservative and much less work on dumb terminals.
 */
void
vredraw(int p)
{
        int l;
        line *tp;
        unsigned char temp[LBSIZE];
        bool anydl = 0;
        short oldhold = hold;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vredraw(%d)\n", p), tvliny();
#endif
        if (holdupd) {
                holdupd = 3;
                return;
        }
        if (state == HARDOPEN || splitw)
                return;
        if (p < 0 /* || p > WECHO */)
                error(gettext("Internal error: vredraw"));

        /*
         * Trim the ragged edges (lines which are off the screen but
         * not yet logically discarded), save the current line, and
         * search for first logical line affected by the redraw.
         */
        vscrap();
        CP(temp, linebuf);
        l = 0;
        tp = dot - vcline;
        if (vcnt == 0)
                LINE(0) = WTOP;
        while (l < vcnt && LINE(l) < p)
                l++, tp++;

        /*
         * We hold off echo area clearing during the redraw in deference
         * to a final clear of the echo area at the end if appropriate.
         */
        heldech = 0;
        hold |= HOLDECH;
        for (; l < vcnt && Peekkey != ATTN; l++) {
                if (l == vcline)
                        strcLIN(temp);
                else
                        getaline(*tp);

                /*
                 * Delete junk between displayed lines.
                 */
                if (LINE(l) != LINE(l + 1) && LINE(l) != p) {
                        if (anydl == 0 && memory_below && clr_eos) {
                                hold = oldhold;
                                vclrech(0);
                                anydl = 1;
                                hold |= HOLDECH;
                                heldech = 0;
                        }
                        vdellin(p, LINE(l) - p, l);
                }

                /*
                 * If line image is not know to be up to date, then
                 * redisplay it;  else just skip onward.
                 */
                LINE(l) = p;
                if (FLAGS(l) & VDIRT) {
                        DEPTH(l) = vdepth();
                        if (l != vcline && p + DEPTH(l) - 1 > WBOT) {
                                vscrap();
                                break;
                        }
                        FLAGS(l) &= ~VDIRT;
                        (void) vreopen(p, lineno(tp), l);
                        p = LINE(l) + DEPTH(l);
                } else
                        p += DEPTH(l);
                tp++;
        }

        /*
         * That takes care of lines which were already partially displayed.
         * Now try to fill the rest of the screen with text.
         */
        if (state == VISUAL && p <= WBOT) {
                int ovcline = vcline;

                vcline = l;
                for (; tp <= dol && Peekkey != ATTN; tp++) {
                        getaline(*tp);
                        if (p + vdepth() - 1 > WBOT)
                                break;
                        vopen(tp, p);
                        p += DEPTH(vcline);
                        vcline++;
                }
                vcline = ovcline;
        }

        /*
         * That's all the text we can get on.
         * Now rest of lines (if any) get either a ~ if they
         * are past end of file, or an @ if the next line won't fit.
         */
        for (; p <= WBOT && Peekkey != ATTN; p++)
                vclrlin(p, tp);
        strcLIN(temp);
        hold = oldhold;
        if (heldech)
                vclrech(0);
#ifdef ADEBUG
        if (trace)
                tvliny();
#endif
}

/*
 * Do the real work in deleting cnt lines starting at line p from
 * the display.  First affected line is line l.
 */
void
vdellin(int p, int cnt, int l)
{
        int i;

        if (cnt == 0)
                return;
        if (delete_line == NOSTR || cnt < 0) {
                /*
                 * Can't do it; just remember that line l is munged.
                 */
                FLAGS(l) |= VDIRT;
                return;
        }
#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vdellin(%d, %d, %d)\n", p, cnt, l);
#endif
        /*
         * Send the deletes to the screen and then adjust logical
         * and physical internal data structures.
         */
        vgoto(p, 0);
        if (parm_delete_line && (cnt>1 || *delete_line==0)) {
                vputp(tparm(parm_delete_line, cnt, p), WECHO-p);
        }
        else if (change_scroll_region && *delete_line==0) {
                /* vt100: fake delete_line by changing scrolling region */
                vputp(save_cursor, 1);  /* Save since change_scroll_region homes stupid cursor */
                vputp(tparm(change_scroll_region, p, lines-1), 1);
                vputp(tparm(cursor_address, lines-1, 0), 1);/* Go to lower left corner */
                for (i=0; i<cnt; i++)           /* .. and scroll cnt times */
                        (void) putch('\n');     /* should check NL too */
                vputp(tparm(change_scroll_region, 0, lines-1), 1);/* restore scrolling region */
                vputp(restore_cursor, 1);                       /* put cursor back */
        }
        else {
                for (i = 0; i < cnt; i++)
                        vputp(delete_line, WECHO - p);
        }
        vadjDL(p, cnt);
        vcloseup(l, cnt);
}
/*
 * Adjust internal physical screen image to account for deleted lines.
 */
void
vadjDL(int p, int cnt)
{
        wchar_t *tlines[TUBELINES];
        int from, to;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vadjDL(%d, %d)\n", p, cnt);
#endif
        /*
         * Would like to use structured assignment but early
         * v7 compiler (released with phototypesetter for v6)
         * can't hack it.
         */
        copy(tlines, vtube, sizeof vtube);      /*SASSIGN*/
        for (from = p + cnt, to = p; from <= WECHO; from++, to++)
                vtube[to] = tlines[from];
        for (from = p; to <= WECHO; from++, to++) {
                vtube[to] = tlines[from];
                vclrbyte(vtube[to], WCOLS);
        }
}
/*
 * Sync the screen, like redraw but more lazy and willing to leave
 * @ lines on the screen.  VsyncCL syncs starting at the current line.
 * In any case, if the redraw option is set then all syncs map to redraws
 * as if vsync didn't exist.
 */
void
vsyncCL(void)
{

        vsync(LINE(vcline));
}

void
vsync(int p)
{

        if (value(vi_REDRAW))
                vredraw(p);
        else
                vsync1(p);
}

/*
 * The guts of a sync.  Similar to redraw but
 * just less ambitious.
 */
void
vsync1(int p)
{
        int l;
        unsigned char temp[LBSIZE];
        struct vlinfo *vp = &vlinfo[0];
        short oldhold = hold;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vsync1(%d)\n", p), tvliny();
#endif
        if (holdupd) {
                if (holdupd < 3)
                        holdupd = 2;
                return;
        }
        if (state == HARDOPEN || splitw)
                return;
        vscrap();
        CP(temp, linebuf);
        if (vcnt == 0)
                LINE(0) = WTOP;
        l = 0;
        while (l < vcnt && vp->vliny < p)
                l++, vp++;
        heldech = 0;
        hold |= HOLDECH;
        while (p <= WBOT && Peekkey != ATTN) {
                /*
                 * Want to put a line here if not in visual and first line
                 * or if there are lies left and this line starts before
                 * the current line, or if this line is piled under the
                 * next line (vreplace does this and we undo it).
                 */
                if (l == 0 && state != VISUAL ||
                    (l < vcnt && (vp->vliny <= p || vp[0].vliny == vp[1].vliny))) {
                        if (l == 0 || vp->vliny < p || (vp->vflags & VDIRT)) {
                                if (l == vcline)
                                        strcLIN(temp);
                                else
                                        getaline(dot[l - vcline]);
                                /*
                                 * Be careful that a long line doesn't cause the
                                 * screen to shoot up.
                                 */
                                if (l != vcline && (vp->vflags & VDIRT)) {
                                        vp->vdepth = vdepth();
                                        vp->vflags &= ~VDIRT;
                                        if (p + vp->vdepth - 1 > WBOT)
                                                break;
                                }
                                (void) vreopen(p, lineDOT() + (l - vcline), l);
                        }
                        p = vp->vliny + vp->vdepth;
                        vp++;
                        l++;
                } else
                        /*
                         * A physical line between logical lines,
                         * so we settle for an @ at the beginning.
                         */
                        vclrlin(p, dot + (l - vcline)), p++;
        }
        strcLIN(temp);
        hold = oldhold;
        if (heldech)
                vclrech(0);
}

/*
 * Subtract (logically) cnt physical lines from the
 * displayed position of lines starting with line l.
 */
void
vcloseup(int l, int cnt)
{
        int i;

#ifdef ADEBUG
        if (trace)
                tfixnl(), fprintf(trace, "vcloseup(%d, %d)\n", l, cnt);
#endif
        for (i = l + 1; i <= vcnt; i++)
                LINE(i) -= cnt;
}

/*
 * Workhorse for rearranging line descriptors on changes.
 * The idea here is that, starting with line l, cnt lines
 * have been replaced with newcnt lines.  All of these may
 * be ridiculous, i.e. l may be -1000, cnt 50 and newcnt 0,
 * since we may be called from an undo after the screen has
 * moved a lot.  Thus we have to be careful.
 *
 * Many boundary conditions here.
 */
void
vreplace(int l, int cnt, int newcnt)
{
        int from, to, i;
        bool savenote = 0;

#ifdef ADEBUG
        if (trace) {
                tfixnl(), fprintf(trace, "vreplace(%d, %d, %d)\n", l, cnt, newcnt);
                tvliny();
        }
#endif
        if (l >= vcnt)
                return;
        if (l < 0) {
                if (l + cnt < 0) {
                        /*
                         * Nothing on the screen is relevant.
                         * Settle for redrawing from scratch (later).
                         */
                        vcnt = 0;
                        return;
                }
                /*
                 * Normalize l to top of screen; the add is
                 * really a subtract from cnt since l is negative.
                 */
                cnt += l;
                l = 0;

                /*
                 * Unseen lines were affected so notify (later).
                 */
                savenote++;
        }

        /*
         * These shouldn't happen
         * but would cause great havoc.
         */
        if (cnt < 0)
                cnt = 0;
        if (newcnt < 0)
                newcnt = 0;

        /*
         * Surely worthy of note if more than report
         * lines were changed.
         */
        if (cnt > value(vi_REPORT) || newcnt > value(vi_REPORT))
                savenote++;

        /*
         * Same number of lines affected as on screen, and we
         * can insert and delete lines.  Thus we just type
         * over them, since otherwise we will push them
         * slowly off the screen, a clear lose.
         */
        if (cnt == newcnt || vcnt - l == newcnt && insert_line && delete_line) {
                if (cnt > 1 && l + cnt > vcnt)
                        savenote++;
                vdirty(l, newcnt);
        } else {
                /*
                 * Lines are going away, squish them out.
                 */
                if (cnt > 0) {
                        /*
                         * If non-displayed lines went away,
                         * always notify.
                         */
                        if (cnt > 1 && l + cnt > vcnt)
                                savenote++;
                        if (l + cnt >= vcnt)
                                cnt = vcnt - l;
                        else
                                for (from = l + cnt, to = l; from <= vcnt; to++, from++)
                                        vlcopy(vlinfo[to], vlinfo[from]);
                        vcnt -= cnt;
                }
                /*
                 * Open up space for new lines appearing.
                 * All new lines are piled in the same place,
                 * and will be unpiled by vredraw/vsync, which
                 * inserts lines in front as it unpiles.
                 */
                if (newcnt > 0) {
                        /*
                         * Newlines are appearing which may not show,
                         * so notify (this is only approximately correct
                         * when long lines are present).
                         */
                        if (newcnt > 1 && l + newcnt > vcnt + 1)
                                savenote++;

                        /*
                         * If there will be more lines than fit, then
                         * just throw way the rest of the stuff on the screen.
                         */
                        if (l + newcnt > WBOT && insert_line && delete_line) {
                                vcnt = l;
                                goto skip;
                        }
                        from = vcnt, to = vcnt + newcnt;
                        i = TUBELINES - to;
                        if (i < 0)
                                from += i, to += i;
                        vcnt = to;
                        for (; from >= l; from--, to--)
                                vlcopy(vlinfo[to], vlinfo[from]);
                        for (from = to + 1, to = l; to < l + newcnt && to <= WBOT + 1; to++) {
                                LINE(to) = LINE(from);
                                DEPTH(to) = 0;
                                FLAGS(to) = VDIRT;
                        }
                }
        }
skip:
        if (Pline == numbline && cnt != newcnt)
                /*
                 * When lines positions are shifted, the numbers
                 * will be wrong.
                 */
                vdirty(l, WECHO);
        if (!savenote)
                notecnt = 0;
#ifdef ADEBUG
        if (trace)
                tvliny();
#endif
}

/*
 * Start harcopy open.
 * Print an image of the line to the left of the cursor
 * under the full print of the line and position the cursor.
 * If we are in a scroll ^D within hardcopy open then all this
 * is suppressed.
 */
void
sethard(void)
{

        if (state == VISUAL)
                return;
        rubble = 0;
        state = HARDOPEN;
        if (hold & HOLDROL)
                return;
        vup1();
        LINE(0) = WBOT;
        if (Pline == numbline)
                vgoto(WBOT, 0), viprintf("%6d  ", lineDOT());
}

/*
 * Mark the lines starting at base for i lines
 * as dirty so that they will be checked for correct
 * display at next sync/redraw.
 */
void
vdirty(int base, int i)
{
        int l;

        for (l = base; l < vcnt; l++) {
                if (--i < 0)
                        return;
                FLAGS(l) |= VDIRT;
        }
}