2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Edward Wang at The University of California, Berkeley.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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
38 static char sccsid[] = "@(#)wwscroll.c 8.1 (Berkeley) 6/6/93";
45 register struct ww *w;
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);
62 (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
68 w->ww_buf -= top - w->ww_b.t;
70 w->ww_b.b = top + w->ww_b.nr;
76 * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
77 * Don't adjust ww_scroll.
78 * And don't redraw 'leaveit' lines.
80 wwscroll1(w, row1, row2, dir, leaveit)
81 register struct ww *w;
92 * See how many lines on the screen are affected.
93 * And calculate row1x, row2x, and left at the same time.
95 for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
97 if (i >= row2) /* can't do any fancy stuff */
100 for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
103 goto out; /* just one line is easy */
107 * See how much of this window is visible.
109 nvismax = wwncol * (row2x - row1x);
111 for (i = row1x; i < row2x; i++)
112 nvis += w->ww_nvis[i];
115 * If it's a good idea to scroll and the terminal can, then do it.
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)
124 xxscroll(dir, row1x, row2x);
127 * Fix up the old screen.
130 register union ww_char *tmp;
131 register union ww_char **cpp, **cqq;
137 for (i = row2x - row1x; --i > 0;)
144 for (i = row2x - row1x; --i > 0;)
148 for (i = wwncol; --i >= 0;)
154 * Fix the new screen.
156 if (nvis == nvismax) {
158 * Can shift whole lines.
162 register union ww_char *tmp;
163 register union ww_char **cpp, **cqq;
168 for (i = row2x - row1x; --i > 0;)
173 register char *p, *q;
175 p = &wwtouched[row1x];
177 for (i = row2x - row1x; --i > 0;)
183 p = &wwtouched[row1x];
184 for (i = row2x - row1x; --i >= 0;)
187 wwredrawwin1(w, row1, row1x, dir);
188 wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
191 register union ww_char *tmp;
192 register union ww_char **cpp, **cqq;
197 for (i = row2x - row1x; --i > 0;)
202 register char *p, *q;
204 p = &wwtouched[row2x];
206 for (i = row2x - row1x; --i > 0;)
212 p = &wwtouched[row1x];
213 for (i = row2x - row1x; --i >= 0;)
216 wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
217 wwredrawwin1(w, row2x, row2, dir);
223 p = &wwtouched[row1x];
224 for (i = row2x - row1x; --i >= 0;)
229 wwredrawwin1(w, row1, row2 - leaveit, dir);
231 wwredrawwin1(w, row1 + leaveit, row2, dir);