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
  37 #ifndef lint
  38 static char sccsid[] = "@(#)wwscroll.c  8.1 (Berkeley) 6/6/93";
  39 static char rcsid[] =
  40   "$FreeBSD: src/usr.bin/window/wwscroll.c,v 1.1.1.1.14.1 2001/05/17 09:45:01 obrien Exp $";
  41 #endif /* not lint */
  42
  43 #include "ww.h"
  44 #include "tt.h"
  45
  46 wwscroll(w, n)
  47 register struct ww *w;
  48 int n;
  49 {
  50         register dir;
  51         register top;
  52
  53         if (n == 0)
  54                 return;
  55         dir = n < 0 ? -1 : 1;
  56         top = w->ww_b.t - n;
  57         if (top > w->ww_w.t)
  58                 top = w->ww_w.t;
  59         else if (top + w->ww_b.nr < w->ww_w.b)
  60                 top = w->ww_w.b - w->ww_b.nr;
  61         n = abs(top - w->ww_b.t);
  62         if (n < w->ww_i.nr) {
  63                 while (--n >= 0) {
  64                         (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
  65                         w->ww_buf += dir;
  66                         w->ww_b.t -= dir;
  67                         w->ww_b.b -= dir;
  68                 }
  69         } else {
  70                 w->ww_buf -= top - w->ww_b.t;
  71                 w->ww_b.t = top;
  72                 w->ww_b.b = top + w->ww_b.nr;
  73                 wwredrawwin(w);
  74         }
  75 }
  76
  77 /*
  78  * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
  79  * Don't adjust ww_scroll.
  80  * And don't redraw 'leaveit' lines.
  81  */
  82 wwscroll1(w, row1, row2, dir, leaveit)
  83 register struct ww *w;
  84 int row1, row2, dir;
  85 int leaveit;
  86 {
  87         register i;
  88         int row1x, row2x;
  89         int nvis;
  90         int nvismax;
  91         int scrolled = 0;
  92
  93         /*
  94          * See how many lines on the screen are affected.
  95          * And calculate row1x, row2x, and left at the same time.
  96          */
  97         for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
  98                 ;
  99         if (i >= row2)                  /* can't do any fancy stuff */
 100                 goto out;
 101         row1x = i;
 102         for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
 103                 ;
 104         if (i <= row1x)
 105                 goto out;               /* just one line is easy */
 106         row2x = i + 1;
 107
 108         /*
 109          * See how much of this window is visible.
 110          */
 111         nvismax = wwncol * (row2x - row1x);
 112         nvis = 0;
 113         for (i = row1x; i < row2x; i++)
 114                 nvis += w->ww_nvis[i];
 115
 116         /*
 117          * If it's a good idea to scroll and the terminal can, then do it.
 118          */
 119         if (nvis < nvismax / 2)
 120                 goto no_scroll;         /* not worth it */
 121         if ((dir > 0 ? tt.tt_scroll_down == 0 : tt.tt_scroll_up == 0) ||
 122             (tt.tt_scroll_top != row1x || tt.tt_scroll_bot != row2x - 1) &&
 123             tt.tt_setscroll == 0)
 124                 if (tt.tt_delline == 0 || tt.tt_insline == 0)
 125                         goto no_scroll;
 126         xxscroll(dir, row1x, row2x);
 127         scrolled = 1;
 128         /*
 129          * Fix up the old screen.
 130          */
 131         {
 132                 register union ww_char *tmp;
 133                 register union ww_char **cpp, **cqq;
 134
 135                 if (dir > 0) {
 136                         cpp = &wwos[row1x];
 137                         cqq = cpp + 1;
 138                         tmp = *cpp;
 139                         for (i = row2x - row1x; --i > 0;)
 140                                 *cpp++ = *cqq++;
 141                         *cpp = tmp;
 142                 } else {
 143                         cpp = &wwos[row2x];
 144                         cqq = cpp - 1;
 145                         tmp = *cqq;
 146                         for (i = row2x - row1x; --i > 0;)
 147                                 *--cpp = *--cqq;
 148                         *cqq = tmp;
 149                 }
 150                 for (i = wwncol; --i >= 0;)
 151                         tmp++->c_w = ' ';
 152         }
 153
 154 no_scroll:
 155         /*
 156          * Fix the new screen.
 157          */
 158         if (nvis == nvismax) {
 159                 /*
 160                  * Can shift whole lines.
 161                  */
 162                 if (dir > 0) {
 163                         {
 164                                 register union ww_char *tmp;
 165                                 register union ww_char **cpp, **cqq;
 166
 167                                 cpp = &wwns[row1x];
 168                                 cqq = cpp + 1;
 169                                 tmp = *cpp;
 170                                 for (i = row2x - row1x; --i > 0;)
 171                                         *cpp++ = *cqq++;
 172                                 *cpp = tmp;
 173                         }
 174                         if (scrolled) {
 175                                 register char *p, *q;
 176
 177                                 p = &wwtouched[row1x];
 178                                 q = p + 1;
 179                                 for (i = row2x - row1x; --i > 0;)
 180                                         *p++ = *q++;
 181                                 *p |= WWU_TOUCHED;
 182                         } else {
 183                                 register char *p;
 184
 185                                 p = &wwtouched[row1x];
 186                                 for (i = row2x - row1x; --i >= 0;)
 187                                         *p++ |= WWU_TOUCHED;
 188                         }
 189                         wwredrawwin1(w, row1, row1x, dir);
 190                         wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
 191                 } else {
 192                         {
 193                                 register union ww_char *tmp;
 194                                 register union ww_char **cpp, **cqq;
 195
 196                                 cpp = &wwns[row2x];
 197                                 cqq = cpp - 1;
 198                                 tmp = *cqq;
 199                                 for (i = row2x - row1x; --i > 0;)
 200                                         *--cpp = *--cqq;
 201                                 *cqq = tmp;
 202                         }
 203                         if (scrolled) {
 204                                 register char *p, *q;
 205
 206                                 p = &wwtouched[row2x];
 207                                 q = p - 1;
 208                                 for (i = row2x - row1x; --i > 0;)
 209                                         *--p = *--q;
 210                                 *q |= WWU_TOUCHED;
 211                         } else {
 212                                 register char *p;
 213
 214                                 p = &wwtouched[row1x];
 215                                 for (i = row2x - row1x; --i >= 0;)
 216                                         *p++ |= WWU_TOUCHED;
 217                         }
 218                         wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
 219                         wwredrawwin1(w, row2x, row2, dir);
 220                 }
 221         } else {
 222                 if (scrolled) {
 223                         register char *p;
 224
 225                         p = &wwtouched[row1x];
 226                         for (i = row2x - row1x; --i >= 0;)
 227                                 *p++ |= WWU_TOUCHED;
 228                 }
 229 out:
 230                 if (dir > 0)
 231                         wwredrawwin1(w, row1, row2 - leaveit, dir);
 232                 else
 233                         wwredrawwin1(w, row1 + leaveit, row2, dir);
 234         }
 235         return scrolled;
 236 }