usr.bin/window/wwscroll.c

   1 /*      @(#)wwscroll.c  8.1 (Berkeley) 6/6/93   */
   2 /*      $NetBSD: wwscroll.c,v 1.7 2003/08/07 11:17:44 agc Exp $ */
   3
   4 /*
   5  * Copyright (c) 1983, 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 <stdlib.h>
  37
  38 #include "ww.h"
  39 #include "tt.h"
  40 #include "xx.h"
  41
  42 void
  43 wwscroll(struct ww *w, int n)
  44 {
  45         int dir;
  46         int top;
  47
  48         if (n == 0)
  49                 return;
  50         dir = n < 0 ? -1 : 1;
  51         top = w->ww_b.t - n;
  52         if (top > w->ww_w.t)
  53                 top = w->ww_w.t;
  54         else if (top + w->ww_b.nr < w->ww_w.b)
  55                 top = w->ww_w.b - w->ww_b.nr;
  56         n = abs(top - w->ww_b.t);
  57         if (n < w->ww_i.nr) {
  58                 while (--n >= 0) {
  59                         (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
  60                         w->ww_buf += dir;
  61                         w->ww_b.t -= dir;
  62                         w->ww_b.b -= dir;
  63                 }
  64         } else {
  65                 w->ww_buf -= top - w->ww_b.t;
  66                 w->ww_b.t = top;
  67                 w->ww_b.b = top + w->ww_b.nr;
  68                 wwredrawwin(w);
  69         }
  70 }
  71
  72 /*
  73  * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
  74  * Don't adjust ww_scroll.
  75  * And don't redraw 'leaveit' lines.
  76  */
  77 int
  78 wwscroll1(struct ww *w, int row1, int row2, int dir, int leaveit)
  79 {
  80         int i;
  81         int row1x, row2x;
  82         int nvis;
  83         int nvismax;
  84         int scrolled = 0;
  85
  86         /*
  87          * See how many lines on the screen are affected.
  88          * And calculate row1x, row2x, and left at the same time.
  89          */
  90         for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
  91                 ;
  92         if (i >= row2)                  /* can't do any fancy stuff */
  93                 goto out;
  94         row1x = i;
  95         for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
  96                 ;
  97         if (i <= row1x)
  98                 goto out;               /* just one line is easy */
  99         row2x = i + 1;
 100
 101         /*
 102          * See how much of this window is visible.
 103          */
 104         nvismax = wwncol * (row2x - row1x);
 105         nvis = 0;
 106         for (i = row1x; i < row2x; i++)
 107                 nvis += w->ww_nvis[i];
 108
 109         /*
 110          * If it's a good idea to scroll and the terminal can, then do it.
 111          */
 112         if (nvis < nvismax / 2)
 113                 goto no_scroll;         /* not worth it */
 114         if ((dir > 0 ? tt.tt_scroll_down == 0 : tt.tt_scroll_up == 0) ||
 115             ((tt.tt_scroll_top != row1x || tt.tt_scroll_bot != row2x - 1) &&
 116             tt.tt_setscroll == 0))
 117                 if (tt.tt_delline == 0 || tt.tt_insline == 0)
 118                         goto no_scroll;
 119         xxscroll(dir, row1x, row2x);
 120         scrolled = 1;
 121         /*
 122          * Fix up the old screen.
 123          */
 124         {
 125                 union ww_char *tmp;
 126                 union ww_char **cpp, **cqq;
 127
 128                 if (dir > 0) {
 129                         cpp = &wwos[row1x];
 130                         cqq = cpp + 1;
 131                         tmp = *cpp;
 132                         for (i = row2x - row1x; --i > 0;)
 133                                 *cpp++ = *cqq++;
 134                         *cpp = tmp;
 135                 } else {
 136                         cpp = &wwos[row2x];
 137                         cqq = cpp - 1;
 138                         tmp = *cqq;
 139                         for (i = row2x - row1x; --i > 0;)
 140                                 *--cpp = *--cqq;
 141                         *cqq = tmp;
 142                 }
 143                 for (i = wwncol; --i >= 0;)
 144                         tmp++->c_w = ' ';
 145         }
 146
 147 no_scroll:
 148         /*
 149          * Fix the new screen.
 150          */
 151         if (nvis == nvismax) {
 152                 /*
 153                  * Can shift whole lines.
 154                  */
 155                 if (dir > 0) {
 156                         {
 157                                 union ww_char *tmp;
 158                                 union ww_char **cpp, **cqq;
 159
 160                                 cpp = &wwns[row1x];
 161                                 cqq = cpp + 1;
 162                                 tmp = *cpp;
 163                                 for (i = row2x - row1x; --i > 0;)
 164                                         *cpp++ = *cqq++;
 165                                 *cpp = tmp;
 166                         }
 167                         if (scrolled) {
 168                                 char *p, *q;
 169
 170                                 p = &wwtouched[row1x];
 171                                 q = p + 1;
 172                                 for (i = row2x - row1x; --i > 0;)
 173                                         *p++ = *q++;
 174                                 *p |= WWU_TOUCHED;
 175                         } else {
 176                                 char *p;
 177
 178                                 p = &wwtouched[row1x];
 179                                 for (i = row2x - row1x; --i >= 0;)
 180                                         *p++ |= WWU_TOUCHED;
 181                         }
 182                         wwredrawwin1(w, row1, row1x, dir);
 183                         wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
 184                 } else {
 185                         {
 186                                 union ww_char *tmp;
 187                                 union ww_char **cpp, **cqq;
 188
 189                                 cpp = &wwns[row2x];
 190                                 cqq = cpp - 1;
 191                                 tmp = *cqq;
 192                                 for (i = row2x - row1x; --i > 0;)
 193                                         *--cpp = *--cqq;
 194                                 *cqq = tmp;
 195                         }
 196                         if (scrolled) {
 197                                 char *p, *q;
 198
 199                                 p = &wwtouched[row2x];
 200                                 q = p - 1;
 201                                 for (i = row2x - row1x; --i > 0;)
 202                                         *--p = *--q;
 203                                 *q |= WWU_TOUCHED;
 204                         } else {
 205                                 char *p;
 206
 207                                 p = &wwtouched[row1x];
 208                                 for (i = row2x - row1x; --i >= 0;)
 209                                         *p++ |= WWU_TOUCHED;
 210                         }
 211                         wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
 212                         wwredrawwin1(w, row2x, row2, dir);
 213                 }
 214         } else {
 215                 if (scrolled) {
 216                         char *p;
 217
 218                         p = &wwtouched[row1x];
 219                         for (i = row2x - row1x; --i >= 0;)
 220                                 *p++ |= WWU_TOUCHED;
 221                 }
 222 out:
 223                 if (dir > 0)
 224                         wwredrawwin1(w, row1, row2 - leaveit, dir);
 225                 else
 226                         wwredrawwin1(w, row1 + leaveit, row2, dir);
 227         }
 228         return scrolled;
 229 }