window(1): Remove __RCSID & friends.
[dragonfly.git] / 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 }