usr.bin/window/wwscroll.c

   1 /*
   2  * Copyright (c) 1983, 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  * @(#)wwscroll.c       8.1 (Berkeley) 6/6/93
  37  * $FreeBSD: src/usr.bin/window/wwscroll.c,v 1.1.1.1.14.1 2001/05/17 09:45:01 obrien Exp $
  38  * $DragonFly: src/usr.bin/window/wwscroll.c,v 1.2 2003/06/17 04:29:34 dillon Exp $
  39  */
  40
  41 #include "ww.h"
  42 #include "tt.h"
  43
  44 wwscroll(w, n)
  45 register struct ww *w;
  46 int n;
  47 {
  48         register dir;
  49         register top;
  50
  51         if (n == 0)
  52                 return;
  53         dir = n < 0 ? -1 : 1;
  54         top = w->ww_b.t - n;
  55         if (top > w->ww_w.t)
  56                 top = w->ww_w.t;
  57         else if (top + w->ww_b.nr < w->ww_w.b)
  58                 top = w->ww_w.b - w->ww_b.nr;
  59         n = abs(top - w->ww_b.t);
  60         if (n < w->ww_i.nr) {
  61                 while (--n >= 0) {
  62                         (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
  63                         w->ww_buf += dir;
  64                         w->ww_b.t -= dir;
  65                         w->ww_b.b -= dir;
  66                 }
  67         } else {
  68                 w->ww_buf -= top - w->ww_b.t;
  69                 w->ww_b.t = top;
  70                 w->ww_b.b = top + w->ww_b.nr;
  71                 wwredrawwin(w);
  72         }
  73 }
  74
  75 /*
  76  * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
  77  * Don't adjust ww_scroll.
  78  * And don't redraw 'leaveit' lines.
  79  */
  80 wwscroll1(w, row1, row2, dir, leaveit)
  81 register struct ww *w;
  82 int row1, row2, dir;
  83 int leaveit;
  84 {
  85         register i;
  86         int row1x, row2x;
  87         int nvis;
  88         int nvismax;
  89         int scrolled = 0;
  90
  91         /*
  92          * See how many lines on the screen are affected.
  93          * And calculate row1x, row2x, and left at the same time.
  94          */
  95         for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
  96                 ;
  97         if (i >= row2)                  /* can't do any fancy stuff */
  98                 goto out;
  99         row1x = i;
 100         for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
 101                 ;
 102         if (i <= row1x)
 103                 goto out;               /* just one line is easy */
 104         row2x = i + 1;
 105
 106         /*
 107          * See how much of this window is visible.
 108          */
 109         nvismax = wwncol * (row2x - row1x);
 110         nvis = 0;
 111         for (i = row1x; i < row2x; i++)
 112                 nvis += w->ww_nvis[i];
 113
 114         /*
 115          * If it's a good idea to scroll and the terminal can, then do it.
 116          */
 117         if (nvis < nvismax / 2)
 118                 goto no_scroll;         /* not worth it */
 119         if ((dir > 0 ? tt.tt_scroll_down == 0 : tt.tt_scroll_up == 0) ||
 120             (tt.tt_scroll_top != row1x || tt.tt_scroll_bot != row2x - 1) &&
 121             tt.tt_setscroll == 0)
 122                 if (tt.tt_delline == 0 || tt.tt_insline == 0)
 123                         goto no_scroll;
 124         xxscroll(dir, row1x, row2x);
 125         scrolled = 1;
 126         /*
 127          * Fix up the old screen.
 128          */
 129         {
 130                 register union ww_char *tmp;
 131                 register union ww_char **cpp, **cqq;
 132
 133                 if (dir > 0) {
 134                         cpp = &wwos[row1x];
 135                         cqq = cpp + 1;
 136                         tmp = *cpp;
 137                         for (i = row2x - row1x; --i > 0;)
 138                                 *cpp++ = *cqq++;
 139                         *cpp = tmp;
 140                 } else {
 141                         cpp = &wwos[row2x];
 142                         cqq = cpp - 1;
 143                         tmp = *cqq;
 144                         for (i = row2x - row1x; --i > 0;)
 145                                 *--cpp = *--cqq;
 146                         *cqq = tmp;
 147                 }
 148                 for (i = wwncol; --i >= 0;)
 149                         tmp++->c_w = ' ';
 150         }
 151
 152 no_scroll:
 153         /*
 154          * Fix the new screen.
 155          */
 156         if (nvis == nvismax) {
 157                 /*
 158                  * Can shift whole lines.
 159                  */
 160                 if (dir > 0) {
 161                         {
 162                                 register union ww_char *tmp;
 163                                 register union ww_char **cpp, **cqq;
 164
 165                                 cpp = &wwns[row1x];
 166                                 cqq = cpp + 1;
 167                                 tmp = *cpp;
 168                                 for (i = row2x - row1x; --i > 0;)
 169                                         *cpp++ = *cqq++;
 170                                 *cpp = tmp;
 171                         }
 172                         if (scrolled) {
 173                                 register char *p, *q;
 174
 175                                 p = &wwtouched[row1x];
 176                                 q = p + 1;
 177                                 for (i = row2x - row1x; --i > 0;)
 178                                         *p++ = *q++;
 179                                 *p |= WWU_TOUCHED;
 180                         } else {
 181                                 register char *p;
 182
 183                                 p = &wwtouched[row1x];
 184                                 for (i = row2x - row1x; --i >= 0;)
 185                                         *p++ |= WWU_TOUCHED;
 186                         }
 187                         wwredrawwin1(w, row1, row1x, dir);
 188                         wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
 189                 } else {
 190                         {
 191                                 register union ww_char *tmp;
 192                                 register union ww_char **cpp, **cqq;
 193
 194                                 cpp = &wwns[row2x];
 195                                 cqq = cpp - 1;
 196                                 tmp = *cqq;
 197                                 for (i = row2x - row1x; --i > 0;)
 198                                         *--cpp = *--cqq;
 199                                 *cqq = tmp;
 200                         }
 201                         if (scrolled) {
 202                                 register char *p, *q;
 203
 204                                 p = &wwtouched[row2x];
 205                                 q = p - 1;
 206                                 for (i = row2x - row1x; --i > 0;)
 207                                         *--p = *--q;
 208                                 *q |= WWU_TOUCHED;
 209                         } else {
 210                                 register char *p;
 211
 212                                 p = &wwtouched[row1x];
 213                                 for (i = row2x - row1x; --i >= 0;)
 214                                         *p++ |= WWU_TOUCHED;
 215                         }
 216                         wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
 217                         wwredrawwin1(w, row2x, row2, dir);
 218                 }
 219         } else {
 220                 if (scrolled) {
 221                         register char *p;
 222
 223                         p = &wwtouched[row1x];
 224                         for (i = row2x - row1x; --i >= 0;)
 225                                 *p++ |= WWU_TOUCHED;
 226                 }
 227 out:
 228                 if (dir > 0)
 229                         wwredrawwin1(w, row1, row2 - leaveit, dir);
 230                 else
 231                         wwredrawwin1(w, row1 + leaveit, row2, dir);
 232         }
 233         return scrolled;
 234 }