vi/v_z.c

   1 /*-
   2  * Copyright (c) 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * %sccs.include.redist.c%
   6  */
   7
   8 #ifndef lint
   9 static char sccsid[] = "$Id: v_z.c,v 8.8 1993/12/02 15:19:30 bostic Exp $ (Berkeley) $Date: 1993/12/02 15:19:30 $";
  10 #endif /* not lint */
  11
  12 #include <sys/types.h>
  13
  14 #include "vi.h"
  15 #include "vcmd.h"
  16
  17 /*
  18  * v_z -- [count]z[count][-.+^<CR>]
  19  *      Move the screen.
  20  */
  21 int
  22 v_z(sp, ep, vp, fm, tm, rp)
  23         SCR *sp;
  24         EXF *ep;
  25         VICMDARG *vp;
  26         MARK *fm, *tm, *rp;
  27 {
  28         recno_t last, lno;
  29         u_int value;
  30
  31         /*
  32          * The first count is the line to use.  If the value doesn't
  33          * exist, use the last line.
  34          */
  35         if (F_ISSET(vp, VC_C1SET)) {
  36                 lno = vp->count;
  37                 if (file_lline(sp, ep, &last))
  38                         return (1);
  39                 if (lno > last)
  40                         lno = last;
  41         } else
  42                 lno = fm->lno;
  43
  44         /* Set return cursor values. */
  45         rp->lno = lno;
  46         rp->cno = fm->cno;
  47
  48         /*
  49          * The second count is the displayed window size, i.e. the 'z'
  50          * command is another way to get artificially small windows.
  51          *
  52          * !!!
  53          * A window size of 0 was historically allowed, and simply ignored.
  54          * Also, this could be much more simply done by modifying the value
  55          * of the O_WINDOW option, but that's not how it worked historically.
  56          */
  57         if (F_ISSET(vp, VC_C2SET) &&
  58             vp->count2 != 0 && sp->s_rrel(sp, vp->count2))
  59                 return (1);
  60
  61         switch (vp->character) {
  62         case '-':               /* Put the line at the bottom. */
  63                 if (sp->s_fill(sp, ep, lno, P_BOTTOM))
  64                         return (1);
  65                 break;
  66         case '.':               /* Put the line in the middle. */
  67                 if (sp->s_fill(sp, ep, lno, P_MIDDLE))
  68                         return (1);
  69                 break;
  70         default:                /* Put the line at the top for <cr>. */
  71                 value = term_key_val(sp, vp->character);
  72                 if (value != K_CR && value != K_NL) {
  73                         msgq(sp, M_ERR, "usage: %s.", vp->kp->usage);
  74                         return (1);
  75                 }
  76                 /* FALLTHROUGH */
  77         case '+':               /* Put the line at the top. */
  78                 if (sp->s_fill(sp, ep, lno, P_TOP))
  79                         return (1);
  80                 break;
  81         case '^':               /* Print the screen before the z- screen. */
  82                 /*
  83                  * !!!
  84                  * Historic practice isn't real clear on this one.  It seems
  85                  * that the command "70z^" is the same as ":70<cr>z-z^" with
  86                  * an off-by-one difference.  So, until I find documentation
  87                  * to the contrary, the z^ command in this implementation
  88                  * displays the screen immediately before the current one.
  89                  * Fill the screen with the selected line at the bottom, then,
  90                  * scroll the screen down a page, and move to the middle line
  91                  * of the screen.  Historic vi moved the cursor to some random
  92                  * place in the screen, as far as I can tell.
  93                  */
  94                 if (sp->s_fill(sp, ep, lno, P_BOTTOM))
  95                         return (1);
  96                 if (sp->s_down(sp, ep, rp, sp->t_maxrows - 1, 1))
  97                         return (1);
  98                 if (sp->s_position(sp, ep, rp, 0, P_MIDDLE))
  99                         return (1);
 100                 break;
 101         }
 102
 103         /* If the map changes, have to redraw the entire screen. */
 104         F_SET(sp, S_REDRAW);
 105
 106         return (0);
 107 }