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  * @(#)xxflush.c        8.1 (Berkeley) 6/6/93
  37  * $FreeBSD: src/usr.bin/window/xxflush.c,v 1.1.1.1.14.1 2001/05/17 09:45:02 obrien Exp $
  38  * $DragonFly: src/usr.bin/window/xxflush.c,v 1.2 2003/06/17 06:29:34 dillon Exp $
  39  */
  40
  41 #include "ww.h"
  42 #include "xx.h"
  43 #include "tt.h"
  44
  45 xxflush(intr)
  46         register intr;
  47 {
  48         register struct xx *xp, *xq;
  49
  50         for (xp = xx_head; xp != 0 && !(intr && wwinterrupt()); xp = xq) {
  51                 switch (xp->cmd) {
  52                 case xc_move:
  53                         if (xp->link == 0)
  54                                 (*tt.tt_move)(xp->arg0, xp->arg1);
  55                         break;
  56                 case xc_scroll:
  57                         xxflush_scroll(xp);
  58                         break;
  59                 case xc_inschar:
  60                         (*tt.tt_move)(xp->arg0, xp->arg1);
  61                         tt.tt_nmodes = xp->arg3;
  62                         (*tt.tt_inschar)(xp->arg2);
  63                         break;
  64                 case xc_insspace:
  65                         (*tt.tt_move)(xp->arg0, xp->arg1);
  66                         (*tt.tt_insspace)(xp->arg2);
  67                         break;
  68                 case xc_delchar:
  69                         (*tt.tt_move)(xp->arg0, xp->arg1);
  70                         (*tt.tt_delchar)(xp->arg2);
  71                         break;
  72                 case xc_clear:
  73                         (*tt.tt_clear)();
  74                         break;
  75                 case xc_clreos:
  76                         (*tt.tt_move)(xp->arg0, xp->arg1);
  77                         (*tt.tt_clreos)();
  78                         break;
  79                 case xc_clreol:
  80                         (*tt.tt_move)(xp->arg0, xp->arg1);
  81                         (*tt.tt_clreol)();
  82                         break;
  83                 case xc_write:
  84                         (*tt.tt_move)(xp->arg0, xp->arg1);
  85                         tt.tt_nmodes = xp->arg3;
  86                         (*tt.tt_write)(xp->buf, xp->arg2);
  87                         break;
  88                 }
  89                 xq = xp->link;
  90                 xxfree(xp);
  91         }
  92         if ((xx_head = xp) == 0) {
  93                 xx_tail = 0;
  94                 xxbufp = xxbuf;
  95         }
  96         ttflush();
  97 }
  98
  99 xxflush_scroll(xp)
 100         register struct xx *xp;
 101 {
 102         register struct xx *xq;
 103
 104  top:
 105         if (xp->arg0 == 0)
 106                 return;
 107         /*
 108          * We handle retain (da and db) by putting the burden on scrolling up,
 109          * which is the less common operation.  It must ensure that
 110          * text is not pushed below the screen, so scrolling down doesn't
 111          * have to worry about it.
 112          *
 113          * Try scrolling region (or scrolling the whole screen) first.
 114          * Can we assume "sr" doesn't push text below the screen
 115          * so we don't have to worry about retain below?
 116          * What about scrolling down with a newline?  It probably does
 117          * push text above (with da).  Scrolling up would then have
 118          * to take care of that.
 119          * It's easy to be fool proof, but that slows things down.
 120          * The current solution is to disallow tt_scroll_up if da or db is true
 121          * but cs (scrolling region) is not.  Again, we sacrifice scrolling
 122          * up in favor of scrolling down.  The idea is having scrolling regions
 123          * probably means we can scroll (even the whole screen) with impunity.
 124          * This lets us work efficiently on simple terminals (use newline
 125          * on the bottom to scroll), on any terminal without retain, and
 126          * on vt100 style scrolling regions (I think).
 127          */
 128         if (xp->arg0 > 0) {
 129                 if ((xq = xp->link) != 0 && xq->cmd == xc_scroll &&
 130                     xp->arg2 == xq->arg2 && xq->arg0 < 0) {
 131                         if (xp->arg1 < xq->arg1) {
 132                                 if (xp->arg2 - xp->arg0 <= xq->arg1) {
 133                                         xq->arg0 = xp->arg0;
 134                                         xq->arg1 = xp->arg1;
 135                                         xq->arg2 = xp->arg2;
 136                                         return;
 137                                 }
 138                                 xp->arg2 = xq->arg1 + xp->arg0;
 139                                 xq->arg0 += xp->arg0;
 140                                 xq->arg1 = xp->arg2;
 141                                 if (xq->arg0 > 0)
 142                                         xq->arg1 -= xq->arg0;
 143                                 goto top;
 144                         } else {
 145                                 if (xp->arg1 - xq->arg0 >= xp->arg2)
 146                                         return;
 147                                 xq->arg2 = xp->arg1 - xq->arg0;
 148                                 xp->arg0 += xq->arg0;
 149                                 xp->arg1 = xq->arg2;
 150                                 if (xp->arg0 < 0)
 151                                         xp->arg1 += xp->arg0;
 152                                 goto top;
 153                         }
 154                 }
 155                 if (xp->arg0 > xp->arg2 - xp->arg1)
 156                         xp->arg0 = xp->arg2 - xp->arg1;
 157                 if (tt.tt_scroll_down) {
 158                         if (tt.tt_scroll_top != xp->arg1 ||
 159                             tt.tt_scroll_bot != xp->arg2 - 1) {
 160                                 if (tt.tt_setscroll == 0)
 161                                         goto down;
 162                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 163                         }
 164                         tt.tt_scroll_down(xp->arg0);
 165                 } else {
 166                 down:
 167                         (*tt.tt_move)(xp->arg1, 0);
 168                         (*tt.tt_delline)(xp->arg0);
 169                         if (xp->arg2 < tt.tt_nrow) {
 170                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 171                                 (*tt.tt_insline)(xp->arg0);
 172                         }
 173                 }
 174         } else {
 175                 xp->arg0 = - xp->arg0;
 176                 if (xp->arg0 > xp->arg2 - xp->arg1)
 177                         xp->arg0 = xp->arg2 - xp->arg1;
 178                 if (tt.tt_scroll_up) {
 179                         if (tt.tt_scroll_top != xp->arg1 ||
 180                             tt.tt_scroll_bot != xp->arg2 - 1) {
 181                                 if (tt.tt_setscroll == 0)
 182                                         goto up;
 183                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 184                         }
 185                         tt.tt_scroll_up(xp->arg0);
 186                 } else  {
 187                 up:
 188                         if (tt.tt_retain || xp->arg2 != tt.tt_nrow) {
 189                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 190                                 (*tt.tt_delline)(xp->arg0);
 191                         }
 192                         (*tt.tt_move)(xp->arg1, 0);
 193                         (*tt.tt_insline)(xp->arg0);
 194                 }
 195         }
 196 }