usr.bin/window/xxflush.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Edward Wang at The University of California, Berkeley.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #ifndef lint
  38 static char sccsid[] = "@(#)xxflush.c   8.1 (Berkeley) 6/6/93";
  39 static char rcsid[] =
  40   "$FreeBSD: src/usr.bin/window/xxflush.c,v 1.1.1.1.14.1 2001/05/17 09:45:02 obrien Exp $";
  41 #endif /* not lint */
  42
  43 #include "ww.h"
  44 #include "xx.h"
  45 #include "tt.h"
  46
  47 xxflush(intr)
  48         register intr;
  49 {
  50         register struct xx *xp, *xq;
  51
  52         for (xp = xx_head; xp != 0 && !(intr && wwinterrupt()); xp = xq) {
  53                 switch (xp->cmd) {
  54                 case xc_move:
  55                         if (xp->link == 0)
  56                                 (*tt.tt_move)(xp->arg0, xp->arg1);
  57                         break;
  58                 case xc_scroll:
  59                         xxflush_scroll(xp);
  60                         break;
  61                 case xc_inschar:
  62                         (*tt.tt_move)(xp->arg0, xp->arg1);
  63                         tt.tt_nmodes = xp->arg3;
  64                         (*tt.tt_inschar)(xp->arg2);
  65                         break;
  66                 case xc_insspace:
  67                         (*tt.tt_move)(xp->arg0, xp->arg1);
  68                         (*tt.tt_insspace)(xp->arg2);
  69                         break;
  70                 case xc_delchar:
  71                         (*tt.tt_move)(xp->arg0, xp->arg1);
  72                         (*tt.tt_delchar)(xp->arg2);
  73                         break;
  74                 case xc_clear:
  75                         (*tt.tt_clear)();
  76                         break;
  77                 case xc_clreos:
  78                         (*tt.tt_move)(xp->arg0, xp->arg1);
  79                         (*tt.tt_clreos)();
  80                         break;
  81                 case xc_clreol:
  82                         (*tt.tt_move)(xp->arg0, xp->arg1);
  83                         (*tt.tt_clreol)();
  84                         break;
  85                 case xc_write:
  86                         (*tt.tt_move)(xp->arg0, xp->arg1);
  87                         tt.tt_nmodes = xp->arg3;
  88                         (*tt.tt_write)(xp->buf, xp->arg2);
  89                         break;
  90                 }
  91                 xq = xp->link;
  92                 xxfree(xp);
  93         }
  94         if ((xx_head = xp) == 0) {
  95                 xx_tail = 0;
  96                 xxbufp = xxbuf;
  97         }
  98         ttflush();
  99 }
 100
 101 xxflush_scroll(xp)
 102         register struct xx *xp;
 103 {
 104         register struct xx *xq;
 105
 106  top:
 107         if (xp->arg0 == 0)
 108                 return;
 109         /*
 110          * We handle retain (da and db) by putting the burden on scrolling up,
 111          * which is the less common operation.  It must ensure that
 112          * text is not pushed below the screen, so scrolling down doesn't
 113          * have to worry about it.
 114          *
 115          * Try scrolling region (or scrolling the whole screen) first.
 116          * Can we assume "sr" doesn't push text below the screen
 117          * so we don't have to worry about retain below?
 118          * What about scrolling down with a newline?  It probably does
 119          * push text above (with da).  Scrolling up would then have
 120          * to take care of that.
 121          * It's easy to be fool proof, but that slows things down.
 122          * The current solution is to disallow tt_scroll_up if da or db is true
 123          * but cs (scrolling region) is not.  Again, we sacrifice scrolling
 124          * up in favor of scrolling down.  The idea is having scrolling regions
 125          * probably means we can scroll (even the whole screen) with impunity.
 126          * This lets us work efficiently on simple terminals (use newline
 127          * on the bottom to scroll), on any terminal without retain, and
 128          * on vt100 style scrolling regions (I think).
 129          */
 130         if (xp->arg0 > 0) {
 131                 if ((xq = xp->link) != 0 && xq->cmd == xc_scroll &&
 132                     xp->arg2 == xq->arg2 && xq->arg0 < 0) {
 133                         if (xp->arg1 < xq->arg1) {
 134                                 if (xp->arg2 - xp->arg0 <= xq->arg1) {
 135                                         xq->arg0 = xp->arg0;
 136                                         xq->arg1 = xp->arg1;
 137                                         xq->arg2 = xp->arg2;
 138                                         return;
 139                                 }
 140                                 xp->arg2 = xq->arg1 + xp->arg0;
 141                                 xq->arg0 += xp->arg0;
 142                                 xq->arg1 = xp->arg2;
 143                                 if (xq->arg0 > 0)
 144                                         xq->arg1 -= xq->arg0;
 145                                 goto top;
 146                         } else {
 147                                 if (xp->arg1 - xq->arg0 >= xp->arg2)
 148                                         return;
 149                                 xq->arg2 = xp->arg1 - xq->arg0;
 150                                 xp->arg0 += xq->arg0;
 151                                 xp->arg1 = xq->arg2;
 152                                 if (xp->arg0 < 0)
 153                                         xp->arg1 += xp->arg0;
 154                                 goto top;
 155                         }
 156                 }
 157                 if (xp->arg0 > xp->arg2 - xp->arg1)
 158                         xp->arg0 = xp->arg2 - xp->arg1;
 159                 if (tt.tt_scroll_down) {
 160                         if (tt.tt_scroll_top != xp->arg1 ||
 161                             tt.tt_scroll_bot != xp->arg2 - 1) {
 162                                 if (tt.tt_setscroll == 0)
 163                                         goto down;
 164                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 165                         }
 166                         tt.tt_scroll_down(xp->arg0);
 167                 } else {
 168                 down:
 169                         (*tt.tt_move)(xp->arg1, 0);
 170                         (*tt.tt_delline)(xp->arg0);
 171                         if (xp->arg2 < tt.tt_nrow) {
 172                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 173                                 (*tt.tt_insline)(xp->arg0);
 174                         }
 175                 }
 176         } else {
 177                 xp->arg0 = - xp->arg0;
 178                 if (xp->arg0 > xp->arg2 - xp->arg1)
 179                         xp->arg0 = xp->arg2 - xp->arg1;
 180                 if (tt.tt_scroll_up) {
 181                         if (tt.tt_scroll_top != xp->arg1 ||
 182                             tt.tt_scroll_bot != xp->arg2 - 1) {
 183                                 if (tt.tt_setscroll == 0)
 184                                         goto up;
 185                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 186                         }
 187                         tt.tt_scroll_up(xp->arg0);
 188                 } else  {
 189                 up:
 190                         if (tt.tt_retain || xp->arg2 != tt.tt_nrow) {
 191                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 192                                 (*tt.tt_delline)(xp->arg0);
 193                         }
 194                         (*tt.tt_move)(xp->arg1, 0);
 195                         (*tt.tt_insline)(xp->arg0);
 196                 }
 197         }
 198 }