usr.bin/window/wwscroll.c

   1 /*      $NetBSD: wwscroll.c,v 1.6 2002/06/14 01:07:01 wiz Exp $ */
   2
   3 /*
   4  * Copyright (c) 1983, 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. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 #ifndef lint
  37 #if 0
  38 static char sccsid[] = "@(#)wwscroll.c  8.1 (Berkeley) 6/6/93";
  39 #else
  40 __RCSID("$NetBSD: wwscroll.c,v 1.6 2002/06/14 01:07:01 wiz Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include <stdlib.h>
  45
  46 #include "ww.h"
  47 #include "tt.h"
  48 #include "xx.h"
  49
  50 void
  51 wwscroll(struct ww *w, int n)
  52 {
  53         int dir;
  54         int top;
  55
  56         if (n == 0)
  57                 return;
  58         dir = n < 0 ? -1 : 1;
  59         top = w->ww_b.t - n;
  60         if (top > w->ww_w.t)
  61                 top = w->ww_w.t;
  62         else if (top + w->ww_b.nr < w->ww_w.b)
  63                 top = w->ww_w.b - w->ww_b.nr;
  64         n = abs(top - w->ww_b.t);
  65         if (n < w->ww_i.nr) {
  66                 while (--n >= 0) {
  67                         (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
  68                         w->ww_buf += dir;
  69                         w->ww_b.t -= dir;
  70                         w->ww_b.b -= dir;
  71                 }
  72         } else {
  73                 w->ww_buf -= top - w->ww_b.t;
  74                 w->ww_b.t = top;
  75                 w->ww_b.b = top + w->ww_b.nr;
  76                 wwredrawwin(w);
  77         }
  78 }
  79
  80 /*
  81  * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
  82  * Don't adjust ww_scroll.
  83  * And don't redraw 'leaveit' lines.
  84  */
  85 int
  86 wwscroll1(struct ww *w, int row1, int row2, int dir, int leaveit)
  87 {
  88         int i;
  89         int row1x, row2x;
  90         int nvis;
  91         int nvismax;
  92         int scrolled = 0;
  93
  94         /*
  95          * See how many lines on the screen are affected.
  96          * And calculate row1x, row2x, and left at the same time.
  97          */
  98         for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
  99                 ;
 100         if (i >= row2)                  /* can't do any fancy stuff */
 101                 goto out;
 102         row1x = i;
 103         for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
 104                 ;
 105         if (i <= row1x)
 106                 goto out;               /* just one line is easy */
 107         row2x = i + 1;
 108
 109         /*
 110          * See how much of this window is visible.
 111          */
 112         nvismax = wwncol * (row2x - row1x);
 113         nvis = 0;
 114         for (i = row1x; i < row2x; i++)
 115                 nvis += w->ww_nvis[i];
 116
 117         /*
 118          * If it's a good idea to scroll and the terminal can, then do it.
 119          */
 120         if (nvis < nvismax / 2)
 121                 goto no_scroll;         /* not worth it */
 122         if ((dir > 0 ? tt.tt_scroll_down == 0 : tt.tt_scroll_up == 0) ||
 123             ((tt.tt_scroll_top != row1x || tt.tt_scroll_bot != row2x - 1) &&
 124             tt.tt_setscroll == 0))
 125                 if (tt.tt_delline == 0 || tt.tt_insline == 0)
 126                         goto no_scroll;
 127         xxscroll(dir, row1x, row2x);
 128         scrolled = 1;
 129         /*
 130          * Fix up the old screen.
 131          */
 132         {
 133                 union ww_char *tmp;
 134                 union ww_char **cpp, **cqq;
 135
 136                 if (dir > 0) {
 137                         cpp = &wwos[row1x];
 138                         cqq = cpp + 1;
 139                         tmp = *cpp;
 140                         for (i = row2x - row1x; --i > 0;)
 141                                 *cpp++ = *cqq++;
 142                         *cpp = tmp;
 143                 } else {
 144                         cpp = &wwos[row2x];
 145                         cqq = cpp - 1;
 146                         tmp = *cqq;
 147                         for (i = row2x - row1x; --i > 0;)
 148                                 *--cpp = *--cqq;
 149                         *cqq = tmp;
 150                 }
 151                 for (i = wwncol; --i >= 0;)
 152                         tmp++->c_w = ' ';
 153         }
 154
 155 no_scroll:
 156         /*
 157          * Fix the new screen.
 158          */
 159         if (nvis == nvismax) {
 160                 /*
 161                  * Can shift whole lines.
 162                  */
 163                 if (dir > 0) {
 164                         {
 165                                 union ww_char *tmp;
 166                                 union ww_char **cpp, **cqq;
 167
 168                                 cpp = &wwns[row1x];
 169                                 cqq = cpp + 1;
 170                                 tmp = *cpp;
 171                                 for (i = row2x - row1x; --i > 0;)
 172                                         *cpp++ = *cqq++;
 173                                 *cpp = tmp;
 174                         }
 175                         if (scrolled) {
 176                                 char *p, *q;
 177
 178                                 p = &wwtouched[row1x];
 179                                 q = p + 1;
 180                                 for (i = row2x - row1x; --i > 0;)
 181                                         *p++ = *q++;
 182                                 *p |= WWU_TOUCHED;
 183                         } else {
 184                                 char *p;
 185
 186                                 p = &wwtouched[row1x];
 187                                 for (i = row2x - row1x; --i >= 0;)
 188                                         *p++ |= WWU_TOUCHED;
 189                         }
 190                         wwredrawwin1(w, row1, row1x, dir);
 191                         wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
 192                 } else {
 193                         {
 194                                 union ww_char *tmp;
 195                                 union ww_char **cpp, **cqq;
 196
 197                                 cpp = &wwns[row2x];
 198                                 cqq = cpp - 1;
 199                                 tmp = *cqq;
 200                                 for (i = row2x - row1x; --i > 0;)
 201                                         *--cpp = *--cqq;
 202                                 *cqq = tmp;
 203                         }
 204                         if (scrolled) {
 205                                 char *p, *q;
 206
 207                                 p = &wwtouched[row2x];
 208                                 q = p - 1;
 209                                 for (i = row2x - row1x; --i > 0;)
 210                                         *--p = *--q;
 211                                 *q |= WWU_TOUCHED;
 212                         } else {
 213                                 char *p;
 214
 215                                 p = &wwtouched[row1x];
 216                                 for (i = row2x - row1x; --i >= 0;)
 217                                         *p++ |= WWU_TOUCHED;
 218                         }
 219                         wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
 220                         wwredrawwin1(w, row2x, row2, dir);
 221                 }
 222         } else {
 223                 if (scrolled) {
 224                         char *p;
 225
 226                         p = &wwtouched[row1x];
 227                         for (i = row2x - row1x; --i >= 0;)
 228                                 *p++ |= WWU_TOUCHED;
 229                 }
 230 out:
 231                 if (dir > 0)
 232                         wwredrawwin1(w, row1, row2 - leaveit, dir);
 233                 else
 234                         wwredrawwin1(w, row1 + leaveit, row2, dir);
 235         }
 236         return scrolled;
 237 }