1 /* @(#)wwscroll.c 8.1 (Berkeley) 6/6/93 */
2 /* $NetBSD: wwscroll.c,v 1.7 2003/08/07 11:17:44 agc Exp $ */
5 * Copyright (c) 1983, 1993
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
9 * Edward Wang at The University of California, Berkeley.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
43 wwscroll(struct ww *w, int n)
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);
59 (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
65 w->ww_buf -= top - w->ww_b.t;
67 w->ww_b.b = top + w->ww_b.nr;
73 * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
74 * Don't adjust ww_scroll.
75 * And don't redraw 'leaveit' lines.
78 wwscroll1(struct ww *w, int row1, int row2, int dir, int leaveit)
87 * See how many lines on the screen are affected.
88 * And calculate row1x, row2x, and left at the same time.
90 for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
92 if (i >= row2) /* can't do any fancy stuff */
95 for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
98 goto out; /* just one line is easy */
102 * See how much of this window is visible.
104 nvismax = wwncol * (row2x - row1x);
106 for (i = row1x; i < row2x; i++)
107 nvis += w->ww_nvis[i];
110 * If it's a good idea to scroll and the terminal can, then do it.
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)
119 xxscroll(dir, row1x, row2x);
122 * Fix up the old screen.
126 union ww_char **cpp, **cqq;
132 for (i = row2x - row1x; --i > 0;)
139 for (i = row2x - row1x; --i > 0;)
143 for (i = wwncol; --i >= 0;)
149 * Fix the new screen.
151 if (nvis == nvismax) {
153 * Can shift whole lines.
158 union ww_char **cpp, **cqq;
163 for (i = row2x - row1x; --i > 0;)
170 p = &wwtouched[row1x];
172 for (i = row2x - row1x; --i > 0;)
178 p = &wwtouched[row1x];
179 for (i = row2x - row1x; --i >= 0;)
182 wwredrawwin1(w, row1, row1x, dir);
183 wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
187 union ww_char **cpp, **cqq;
192 for (i = row2x - row1x; --i > 0;)
199 p = &wwtouched[row2x];
201 for (i = row2x - row1x; --i > 0;)
207 p = &wwtouched[row1x];
208 for (i = row2x - row1x; --i >= 0;)
211 wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
212 wwredrawwin1(w, row2x, row2, dir);
218 p = &wwtouched[row1x];
219 for (i = row2x - row1x; --i >= 0;)
224 wwredrawwin1(w, row1, row2 - leaveit, dir);
226 wwredrawwin1(w, row1 + leaveit, row2, dir);