BSD 4_1c_2 release

[unix-history] / usr / src / ucb / ex / ex_vwind.c

/* Copyright (c) 1981 Regents of the University of California */
static char *sccsid = "@(#)ex_vwind.c   7.1     7/8/81";
#include "ex.h"
#include "ex_tty.h"
#include "ex_vis.h"

/*
* Routines to adjust the window, showing specified lines
* in certain positions on the screen, and scrolling in both
* directions.  Code here is very dependent on mode (open versus visual).
*/

/*
* Move in a nonlocal way to line addr.
* If it isn't on screen put it in specified context.
* New position for cursor is curs.
* Like most routines here, we vsave().
*/
vmoveto(addr, curs, context)
       register line *addr;
       char *curs;
       char context;
{

       markit(addr);
       vsave();
       vjumpto(addr, curs, context);
}

/*
* Vjumpto is like vmoveto, but doesn't mark previous
* context or save linebuf as current line.
*/
vjumpto(addr, curs, context)
       register line *addr;
       char *curs;
       char context;
{

       noteit(0);
       if (context != 0)
               vcontext(addr, context);
       else
               vshow(addr, NOLINE);
       noteit(1);
       vnline(curs);
}

/*
* Go up or down cnt (negative is up) to new position curs.
*/
vupdown(cnt, curs)
       register int cnt;
       char *curs;
{

       if (cnt > 0)
               vdown(cnt, 0, 0);
       else if (cnt < 0)
               vup(-cnt, 0, 0);
       if (vcnt == 0)
               vrepaint(curs);
       else
               vnline(curs);
}

/*
* Go up cnt lines, afterwards preferring to be ind
* logical lines from the top of the screen.
* If scroll, then we MUST use a scroll.
* Otherwise clear and redraw if motion is far.
*/
vup(cnt, ind, scroll)
       register int cnt, ind;
       bool scroll;
{
       register int i, tot;

       if (dot == one) {
               beep();
               return;
       }
       vsave();
       i = lineDOT() - 1;
       if (cnt > i) {
               ind -= cnt - i;
               if (ind < 0)
                       ind = 0;
               cnt = i;
       }
       if (!scroll && cnt <= vcline) {
               vshow(dot - cnt, NOLINE);
               return;
       }
       cnt -= vcline, dot -= vcline, vcline = 0;
       if (hold & HOLDWIG)
               goto contxt;
       if (state == VISUAL && !AL && !SR &&
           cnt <= WTOP - ZERO && vfit(dot - cnt, cnt) <= WTOP - ZERO)
               goto okr;
       tot = WECHO - ZERO;
       if (state != VISUAL || (!AL && !SR) || (!scroll && (cnt > tot || vfit(dot - cnt, cnt) > tot / 3 + 1))) {
               if (ind > basWLINES / 2)
                       ind = basWLINES / 3;
contxt:
               vcontext(dot + ind - cnt, '.');
               return;
       }
okr:
       vrollR(cnt);
       if (scroll) {
               vcline += ind, dot += ind;
               if (vcline >= vcnt)
                       dot -= vcline - vcnt + 1, vcline = vcnt - 1;
               getDOT();
       }
}

/*
* Like vup, but scrolling down.
*/
vdown(cnt, ind, scroll)
       register int cnt, ind;
       bool scroll;
{
       register int i, tot;

       if (dot == dol) {
               beep();
               return;
       }
       vsave();
       i = dol - dot;
       if (cnt > i) {
               ind -= cnt - i;
               if (ind < 0)
                       ind = 0;
               cnt = i;
       }
       i = vcnt - vcline - 1;
       if (!scroll && cnt <= i) {
               vshow(dot + cnt, NOLINE);
               return;
       }
       cnt -= i, dot += i, vcline += i;
       if (hold & HOLDWIG)
               goto dcontxt;
       if (!scroll) {
               tot = WECHO - ZERO;
               if (state != VISUAL || cnt - tot > 0 || vfit(dot, cnt) > tot / 3 + 1) {
dcontxt:
                       vcontext(dot + cnt, '.');
                       return;
               }
       }
       if (cnt > 0)
               vroll(cnt);
       if (state == VISUAL && scroll) {
               vcline -= ind, dot -= ind;
               if (vcline < 0)
                       dot -= vcline, vcline = 0;
               getDOT();
       }
}

/*
* Show line addr in context where on the screen.
* Work here is in determining new top line implied by
* this placement of line addr, since we always draw from the top.
*/
vcontext(addr, where)
       register line *addr;
       char where;
{
       register line *top;

       getline(*addr);
       if (state != VISUAL)
               top = addr;
       else switch (where) {

       case '^':
               addr = vback(addr, basWLINES - vdepth());
               getline(*addr);
               /* fall into ... */

       case '-':
               top = vback(addr, basWLINES - vdepth());
               getline(*addr);
               break;

       case '.':
               top = vback(addr, basWLINES / 2 - vdepth());
               getline(*addr);
               break;

       default:
               top = addr;
               break;
       }
       if (state == ONEOPEN && LINE(0) == WBOT)
               vup1();
       vcnt = vcline = 0;
       vclean();
       if (state == CRTOPEN)
               vup1();
       vshow(addr, top);
}

/*
* Get a clean line.  If we are in a hard open
* we may be able to reuse the line we are on
* if it is blank.  This is a real win.
*/
vclean()
{

       if (state != VISUAL && state != CRTOPEN) {
               destcol = 0;
               if (!ateopr())
                       vup1();
               vcnt = 0;
       }
}

/*
* Show line addr with the specified top line on the screen.
* Top may be 0; in this case have vcontext compute the top
* (and call us recursively).  Eventually, we clear the screen
* (or its open mode equivalent) and redraw.
*/
vshow(addr, top)
       line *addr, *top;
{
#ifndef CBREAK
       register bool fried = 0;
#endif
       register int cnt = addr - dot;
       register int i = vcline + cnt;
       short oldhold = hold;

       if (state != HARDOPEN && state != ONEOPEN && i >= 0 && i < vcnt) {
               dot = addr;
               getDOT();
               vcline = i;
               return;
       }
       if (state != VISUAL) {
               dot = addr;
               vopen(dot, WBOT);
               return;
       }
       if (top == 0) {
               vcontext(addr, '.');
               return;
       }
       dot = top;
#ifndef CBREAK
       if (vcookit(2))
               fried++, vcook();
#endif
       oldhold = hold;
       hold |= HOLDAT;
       vclear();
       vreset(0);
       vredraw(WTOP);
       /* error if vcline >= vcnt ! */
       vcline = addr - top;
       dot = addr;
       getDOT();
       hold = oldhold;
       vsync(LASTLINE);
#ifndef CBREAK
       if (fried)
               flusho(), vraw();
#endif
}

/*
* reset the state.
* If inecho then leave us at the beginning of the echo
* area;  we are called this way in the middle of a :e escape
* from visual, e.g.
*/
vreset(inecho)
       bool inecho;
{

       vcnt = vcline = 0;
       WTOP = basWTOP;
       WLINES = basWLINES;
       if (inecho)
               splitw = 1, vgoto(WECHO, 0);
}

/*
* Starting from which line preceding tp uses almost (but not more
* than) cnt physical lines?
*/
line *
vback(tp, cnt)
       register int cnt;
       register line *tp;
{
       register int d;

       if (cnt > 0)
               for (; tp > one; tp--) {
                       getline(tp[-1]);
                       d = vdepth();
                       if (d > cnt)
                               break;
                       cnt -= d;
               }
       return (tp);
}

/*
* How much scrolling will it take to roll cnt lines starting at tp?
*/
vfit(tp, cnt)
       register line *tp;
       int cnt;
{
       register int j;

       j = 0;
       while (cnt > 0) {
               cnt--;
               getline(tp[cnt]);
               j += vdepth();
       }
       if (tp > dot)
               j -= WBOT - LASTLINE;
       return (j);
}

/*
* Roll cnt lines onto the screen.
*/
vroll(cnt)
       register int cnt;
{
#ifndef CBREAK
       register bool fried = 0;
#endif
       short oldhold = hold;

#ifdef ADEBUG
       if (trace)
               tfixnl(), fprintf(trace, "vroll(%d)\n", cnt);
#endif
       if (state != VISUAL)
               hold |= HOLDAT|HOLDROL;
       if (WBOT == WECHO) {
               vcnt = 0;
               if (state == ONEOPEN)
                       vup1();
       }
#ifndef CBREAK
       if (vcookit(cnt))
               fried++, vcook();
#endif
       for (; cnt > 0 && Peekkey != ATTN; cnt--) {
               dot++, vcline++;
               vopen(dot, LASTLINE);
               vscrap();
       }
       hold = oldhold;
       if (state == HARDOPEN)
               sethard();
       vsyncCL();
#ifndef CBREAK
       if (fried)
               flusho(), vraw();
#endif
}

/*
* Roll backwards (scroll up).
*/
vrollR(cnt)
       register int cnt;
{
       register bool fried = 0;
       short oldhold = hold;

#ifdef ADEBUG
       if (trace)
               tfixnl(), fprintf(trace, "vrollR(%d), dot=%d\n", cnt, lineDOT());
#endif
#ifndef CBREAK
       if (vcookit(cnt))
               fried++, vcook();
#endif
       if (WBOT == WECHO)
               vcnt = 0;
       heldech = 0;
       hold |= HOLDAT|HOLDECH;
       for (; cnt > 0 && Peekkey != ATTN; cnt--) {
               dot--;
               vopen(dot, WTOP);
               vscrap();
       }
       hold = oldhold;
       if (heldech)
               vclrech(0);
       vsync(LINE(vcnt-1));
#ifndef CBREAK
       if (fried)
               flusho(), vraw();
#endif
}

/*
* Go into cooked mode (allow interrupts) during
* a scroll if we are at less than 1200 baud and not
* a 'vi' command, of if we are in a 'vi' command and the
* scroll is more than 2 full screens.
*
* BUG:         An interrupt during a scroll in this way
*              dumps to command mode.
*/
vcookit(cnt)
       register int cnt;
{

       return (cnt > 1 && (ospeed < B1200 && !initev || cnt > LINES * 2));
}

/*
* Determine displayed depth of current line.
*/
vdepth()
{
       register int d;

       d = (column(NOSTR) + WCOLS - 1 + (Putchar == listchar) + IN) / WCOLS;
#ifdef ADEBUG
       if (trace)
               tfixnl(), fprintf(trace, "vdepth returns %d\n", d == 0 ? 1 : d);
#endif
       return (d == 0 ? 1 : d);
}

/*
* Move onto a new line, with cursor at position curs.
*/
vnline(curs)
       char *curs;
{

       if (curs)
               wcursor = curs;
       else if (vmoving)
               wcursor = vfindcol(vmovcol);
       else
               wcursor = vskipwh(linebuf);
       cursor = linebuf;
       vmove();
}