usr.bin/window/xxflush.c

   1 /*      @(#)xxflush.c   8.1 (Berkeley) 6/6/93   */
   2 /*      $NetBSD: xxflush.c,v 1.6 2003/08/07 11:17:47 agc Exp $  */
   3
   4 /*
   5  * Copyright (c) 1989, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Edward Wang at The University of California, Berkeley.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "ww.h"
  37 #include "xx.h"
  38 #include "tt.h"
  39
  40 void
  41 xxflush(int intr)
  42 {
  43         struct xx *xp, *xq;
  44
  45         for (xp = xx_head; xp != NULL && !(intr && wwinterrupt()); xp = xq) {
  46                 switch (xp->cmd) {
  47                 case xc_move:
  48                         if (xp->link == 0)
  49                                 (*tt.tt_move)(xp->arg0, xp->arg1);
  50                         break;
  51                 case xc_scroll:
  52                         xxflush_scroll(xp);
  53                         break;
  54                 case xc_inschar:
  55                         (*tt.tt_move)(xp->arg0, xp->arg1);
  56                         tt.tt_nmodes = xp->arg3;
  57                         (*tt.tt_inschar)(xp->arg2);
  58                         break;
  59                 case xc_insspace:
  60                         (*tt.tt_move)(xp->arg0, xp->arg1);
  61                         (*tt.tt_insspace)(xp->arg2);
  62                         break;
  63                 case xc_delchar:
  64                         (*tt.tt_move)(xp->arg0, xp->arg1);
  65                         (*tt.tt_delchar)(xp->arg2);
  66                         break;
  67                 case xc_clear:
  68                         (*tt.tt_clear)();
  69                         break;
  70                 case xc_clreos:
  71                         (*tt.tt_move)(xp->arg0, xp->arg1);
  72                         (*tt.tt_clreos)();
  73                         break;
  74                 case xc_clreol:
  75                         (*tt.tt_move)(xp->arg0, xp->arg1);
  76                         (*tt.tt_clreol)();
  77                         break;
  78                 case xc_write:
  79                         (*tt.tt_move)(xp->arg0, xp->arg1);
  80                         tt.tt_nmodes = xp->arg3;
  81                         (*tt.tt_write)(xp->buf, xp->arg2);
  82                         break;
  83                 }
  84                 xq = xp->link;
  85                 xxfree(xp);
  86         }
  87         if ((xx_head = xp) == NULL) {
  88                 xx_tail = 0;
  89                 xxbufp = xxbuf;
  90         }
  91         ttflush();
  92 }
  93
  94 void
  95 xxflush_scroll(struct xx *xp)
  96 {
  97         struct xx *xq;
  98
  99  top:
 100         if (xp->arg0 == 0)
 101                 return;
 102         /*
 103          * We handle retain (da and db) by putting the burden on scrolling up,
 104          * which is the less common operation.  It must ensure that
 105          * text is not pushed below the screen, so scrolling down doesn't
 106          * have to worry about it.
 107          *
 108          * Try scrolling region (or scrolling the whole screen) first.
 109          * Can we assume "sr" doesn't push text below the screen
 110          * so we don't have to worry about retain below?
 111          * What about scrolling down with a newline?  It probably does
 112          * push text above (with da).  Scrolling up would then have
 113          * to take care of that.
 114          * It's easy to be fool proof, but that slows things down.
 115          * The current solution is to disallow tt_scroll_up if da or db is true
 116          * but cs (scrolling region) is not.  Again, we sacrifice scrolling
 117          * up in favor of scrolling down.  The idea is having scrolling regions
 118          * probably means we can scroll (even the whole screen) with impunity.
 119          * This lets us work efficiently on simple terminals (use newline
 120          * on the bottom to scroll), on any terminal without retain, and
 121          * on vt100 style scrolling regions (I think).
 122          */
 123         if (xp->arg0 > 0) {
 124                 if ((xq = xp->link) != NULL && xq->cmd == xc_scroll &&
 125                     xp->arg2 == xq->arg2 && xq->arg0 < 0) {
 126                         if (xp->arg1 < xq->arg1) {
 127                                 if (xp->arg2 - xp->arg0 <= xq->arg1) {
 128                                         xq->arg0 = xp->arg0;
 129                                         xq->arg1 = xp->arg1;
 130                                         xq->arg2 = xp->arg2;
 131                                         return;
 132                                 }
 133                                 xp->arg2 = xq->arg1 + xp->arg0;
 134                                 xq->arg0 += xp->arg0;
 135                                 xq->arg1 = xp->arg2;
 136                                 if (xq->arg0 > 0)
 137                                         xq->arg1 -= xq->arg0;
 138                                 goto top;
 139                         } else {
 140                                 if (xp->arg1 - xq->arg0 >= xp->arg2)
 141                                         return;
 142                                 xq->arg2 = xp->arg1 - xq->arg0;
 143                                 xp->arg0 += xq->arg0;
 144                                 xp->arg1 = xq->arg2;
 145                                 if (xp->arg0 < 0)
 146                                         xp->arg1 += xp->arg0;
 147                                 goto top;
 148                         }
 149                 }
 150                 if (xp->arg0 > xp->arg2 - xp->arg1)
 151                         xp->arg0 = xp->arg2 - xp->arg1;
 152                 if (tt.tt_scroll_down) {
 153                         if (tt.tt_scroll_top != xp->arg1 ||
 154                             tt.tt_scroll_bot != xp->arg2 - 1) {
 155                                 if (tt.tt_setscroll == 0)
 156                                         goto down;
 157                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 158                         }
 159                         tt.tt_scroll_down(xp->arg0);
 160                 } else {
 161                 down:
 162                         (*tt.tt_move)(xp->arg1, 0);
 163                         (*tt.tt_delline)(xp->arg0);
 164                         if (xp->arg2 < tt.tt_nrow) {
 165                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 166                                 (*tt.tt_insline)(xp->arg0);
 167                         }
 168                 }
 169         } else {
 170                 xp->arg0 = - xp->arg0;
 171                 if (xp->arg0 > xp->arg2 - xp->arg1)
 172                         xp->arg0 = xp->arg2 - xp->arg1;
 173                 if (tt.tt_scroll_up) {
 174                         if (tt.tt_scroll_top != xp->arg1 ||
 175                             tt.tt_scroll_bot != xp->arg2 - 1) {
 176                                 if (tt.tt_setscroll == 0)
 177                                         goto up;
 178                                 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1);
 179                         }
 180                         tt.tt_scroll_up(xp->arg0);
 181                 } else  {
 182                 up:
 183                         if (tt.tt_retain || xp->arg2 != tt.tt_nrow) {
 184                                 (*tt.tt_move)(xp->arg2 - xp->arg0, 0);
 185                                 (*tt.tt_delline)(xp->arg0);
 186                         }
 187                         (*tt.tt_move)(xp->arg1, 0);
 188                         (*tt.tt_insline)(xp->arg0);
 189                 }
 190         }
 191 }