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