window/xxflush.c

   1 /*      $NetBSD: xxflush.c,v 1.4 1997/11/21 08:38:05 lukem Exp $        */
   2
   3 /*
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Edward Wang at The University of California, Berkeley.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include <sys/cdefs.h>
  40 #ifndef lint
  41 #if 0
  42 static char sccsid[] = "@(#)xxflush.c   8.1 (Berkeley) 6/6/93";
  43 #else
  44 __RCSID("$NetBSD: xxflush.c,v 1.4 1997/11/21 08:38:05 lukem Exp $");
  45 #endif
  46 #endif /* not lint */
  47
  48 #include "ww.h"
  49 #include "xx.h"
  50 #include "tt.h"
  51
  52 void
  53 xxflush(intr)
  54         int intr;
  55 {
  56         struct xx *xp, *xq;
  57
  58         for (xp = xx_head; xp != 0 && !(intr && wwinterrupt()); xp = xq) {
  59                 switch (xp->cmd) {
  60                 case xc_move:
  61                         if (xp->link == 0)
  62                                 (*tt.tt_move)(xp->arg0, xp->arg1);
  63                         break;
  64                 case xc_scroll:
  65                         xxflush_scroll(xp);
  66                         break;
  67                 case xc_inschar:
  68                         (*tt.tt_move)(xp->arg0, xp->arg1);
  69                         tt.tt_nmodes = xp->arg3;
  70                         (*tt.tt_inschar)(xp->arg2);
  71                         break;
  72                 case xc_insspace:
  73                         (*tt.tt_move)(xp->arg0, xp->arg1);
  74                         (*tt.tt_insspace)(xp->arg2);
  75                         break;
  76                 case xc_delchar:
  77                         (*tt.tt_move)(xp->arg0, xp->arg1);
  78                         (*tt.tt_delchar)(xp->arg2);
  79                         break;
  80                 case xc_clear:
  81                         (*tt.tt_clear)();
  82                         break;
  83                 case xc_clreos:
  84                         (*tt.tt_move)(xp->arg0, xp->arg1);
  85                         (*tt.tt_clreos)();
  86                         break;
  87                 case xc_clreol:
  88                         (*tt.tt_move)(xp->arg0, xp->arg1);
  89                         (*tt.tt_clreol)();
  90                         break;
  91                 case xc_write:
  92                         (*tt.tt_move)(xp->arg0, xp->arg1);
  93                         tt.tt_nmodes = xp->arg3;
  94                         (*tt.tt_write)(xp->buf, xp->arg2);
  95                         break;
  96                 }
  97                 xq = xp->link;
  98                 xxfree(xp);
  99         }
 100         if ((xx_head = xp) == 0) {
 101                 xx_tail = 0;
 102                 xxbufp = xxbuf;
 103         }
 104         ttflush();
 105 }
 106
 107 void
 108 xxflush_scroll(xp)
 109         struct xx *xp;
 110 {
 111         struct xx *xq;
 112
 113  top:
 114         if (xp->arg0 == 0)
 115                 return;
 116         /*
 117          * We handle retain (da and db) by putting the burden on scrolling up,
 118          * which is the less common operation.  It must ensure that
 119          * text is not pushed below the screen, so scrolling down doesn't
 120          * have to worry about it.
 121          *
 122          * Try scrolling region (or scrolling the whole screen) first.
 123          * Can we assume "sr" doesn't push text below the screen
 124          * so we don't have to worry about retain below?
 125          * What about scrolling down with a newline?  It probably does
 126          * push text above (with da).  Scrolling up would then have
 127          * to take care of that.
 128          * It's easy to be fool proof, but that slows things down.
 129          * The current solution is to disallow tt_scroll_up if da or db is true
 130          * but cs (scrolling region) is not.  Again, we sacrifice scrolling
 131          * up in favor of scrolling down.  The idea is having scrolling regions
 132          * probably means we can scroll (even the whole screen) with impunity.
 133          * This lets us work efficiently on simple terminals (use newline
 134          * on the bottom to scroll), on any terminal without retain, and
 135          * on vt100 style scrolling regions (I think).
 136          */
 137         if (xp->arg0 > 0) {
 138                 if ((xq = xp->link) != 0 && xq->cmd == xc_scroll &&
 139                     xp->arg2 == xq->arg2 && xq->arg0 < 0) {
 140                         if (xp->arg1 < xq->arg1) {
 141                                 if (xp->arg2 - xp->arg0 <= xq->arg1) {
 142                                         xq->arg0 = xp->arg0;
 143                                         xq->arg1 = xp->arg1;
 144                                         xq->arg2 = xp->arg2;
 145                                         return;
 146                                 }
 147                                 xp->arg2 = xq->arg1 + xp->arg0;
 148                                 xq->arg0 += xp->arg0;
 149                                 xq->arg1 = xp->arg2;
 150                                 if (xq->arg0 > 0)
 151                                         xq->arg1 -= xq->arg0;
 152                                 goto top;
 153                         } else {
 154                                 if (xp->arg1 - xq->arg0 >= xp->arg2)
 155                                         return;
 156                                 xq->arg2 = xp->arg1 - xq->arg0;
 157                                 xp->arg0 += xq->arg0;
 158                                 xp->arg1 = xq->arg2;
 159                                 if (xp->arg0 < 0)
 160                                         xp->arg1 += xp->arg0;
 161                                 goto top;
 162                         }
 163                 }
 164                 if (xp->arg0 > xp->arg2 - xp->arg1)
 165                         xp->arg0 = xp->arg2 - xp->arg1;
 166                 if (tt.tt_scroll_down) {
 167                         if (tt.tt_scroll_top != xp->arg1 ||
 168                             tt.tt_scroll_bot != xp->arg2 - 1) {
 169                                 if (tt.tt_setscroll == 0)
 170                                         goto down;
 171                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 172                         }
 173                         tt.tt_scroll_down(xp->arg0);
 174                 } else {
 175                 down:
 176                         (*tt.tt_move)(xp->arg1, 0);
 177                         (*tt.tt_delline)(xp->arg0);
 178                         if (xp->arg2 < tt.tt_nrow) {
 179                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 180                                 (*tt.tt_insline)(xp->arg0);
 181                         }
 182                 }
 183         } else {
 184                 xp->arg0 = - xp->arg0;
 185                 if (xp->arg0 > xp->arg2 - xp->arg1)
 186                         xp->arg0 = xp->arg2 - xp->arg1;
 187                 if (tt.tt_scroll_up) {
 188                         if (tt.tt_scroll_top != xp->arg1 ||
 189                             tt.tt_scroll_bot != xp->arg2 - 1) {
 190                                 if (tt.tt_setscroll == 0)
 191                                         goto up;
 192                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 193                         }
 194                         tt.tt_scroll_up(xp->arg0);
 195                 } else  {
 196                 up:
 197                         if (tt.tt_retain || xp->arg2 != tt.tt_nrow) {
 198                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 199                                 (*tt.tt_delline)(xp->arg0);
 200                         }
 201                         (*tt.tt_move)(xp->arg1, 0);
 202                         (*tt.tt_insline)(xp->arg0);
 203                 }
 204         }
 205 }