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 * @(#)wwscroll.c 8.1 (Berkeley) 6/6/93 37 * $FreeBSD: src/usr.bin/window/wwscroll.c,v 1.1.1.1.14.1 2001/05/17 09:45:01 obrien Exp $ 38 * $DragonFly: src/usr.bin/window/wwscroll.c,v 1.2 2003/06/17 04:29:34 dillon Exp $ 39 */ 40 41 #include "ww.h" 42 #include "tt.h" 43 44 wwscroll(w, n) 45 register struct ww *w; 46 int n; 47 { 48 register dir; 49 register top; 50 51 if (n == 0) 52 return; 53 dir = n < 0 ? -1 : 1; 54 top = w->ww_b.t - n; 55 if (top > w->ww_w.t) 56 top = w->ww_w.t; 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); 60 if (n < w->ww_i.nr) { 61 while (--n >= 0) { 62 (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0); 63 w->ww_buf += dir; 64 w->ww_b.t -= dir; 65 w->ww_b.b -= dir; 66 } 67 } else { 68 w->ww_buf -= top - w->ww_b.t; 69 w->ww_b.t = top; 70 w->ww_b.b = top + w->ww_b.nr; 71 wwredrawwin(w); 72 } 73 } 74 75 /* 76 * Scroll one line, between 'row1' and 'row2', in direction 'dir'. 77 * Don't adjust ww_scroll. 78 * And don't redraw 'leaveit' lines. 79 */ 80 wwscroll1(w, row1, row2, dir, leaveit) 81 register struct ww *w; 82 int row1, row2, dir; 83 int leaveit; 84 { 85 register i; 86 int row1x, row2x; 87 int nvis; 88 int nvismax; 89 int scrolled = 0; 90 91 /* 92 * See how many lines on the screen are affected. 93 * And calculate row1x, row2x, and left at the same time. 94 */ 95 for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++) 96 ; 97 if (i >= row2) /* can't do any fancy stuff */ 98 goto out; 99 row1x = i; 100 for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--) 101 ; 102 if (i <= row1x) 103 goto out; /* just one line is easy */ 104 row2x = i + 1; 105 106 /* 107 * See how much of this window is visible. 108 */ 109 nvismax = wwncol * (row2x - row1x); 110 nvis = 0; 111 for (i = row1x; i < row2x; i++) 112 nvis += w->ww_nvis[i]; 113 114 /* 115 * If it's a good idea to scroll and the terminal can, then do it. 116 */ 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) 123 goto no_scroll; 124 xxscroll(dir, row1x, row2x); 125 scrolled = 1; 126 /* 127 * Fix up the old screen. 128 */ 129 { 130 register union ww_char *tmp; 131 register union ww_char **cpp, **cqq; 132 133 if (dir > 0) { 134 cpp = &wwos[row1x]; 135 cqq = cpp + 1; 136 tmp = *cpp; 137 for (i = row2x - row1x; --i > 0;) 138 *cpp++ = *cqq++; 139 *cpp = tmp; 140 } else { 141 cpp = &wwos[row2x]; 142 cqq = cpp - 1; 143 tmp = *cqq; 144 for (i = row2x - row1x; --i > 0;) 145 *--cpp = *--cqq; 146 *cqq = tmp; 147 } 148 for (i = wwncol; --i >= 0;) 149 tmp++->c_w = ' '; 150 } 151 152 no_scroll: 153 /* 154 * Fix the new screen. 155 */ 156 if (nvis == nvismax) { 157 /* 158 * Can shift whole lines. 159 */ 160 if (dir > 0) { 161 { 162 register union ww_char *tmp; 163 register union ww_char **cpp, **cqq; 164 165 cpp = &wwns[row1x]; 166 cqq = cpp + 1; 167 tmp = *cpp; 168 for (i = row2x - row1x; --i > 0;) 169 *cpp++ = *cqq++; 170 *cpp = tmp; 171 } 172 if (scrolled) { 173 register char *p, *q; 174 175 p = &wwtouched[row1x]; 176 q = p + 1; 177 for (i = row2x - row1x; --i > 0;) 178 *p++ = *q++; 179 *p |= WWU_TOUCHED; 180 } else { 181 register char *p; 182 183 p = &wwtouched[row1x]; 184 for (i = row2x - row1x; --i >= 0;) 185 *p++ |= WWU_TOUCHED; 186 } 187 wwredrawwin1(w, row1, row1x, dir); 188 wwredrawwin1(w, row2x - 1, row2 - leaveit, dir); 189 } else { 190 { 191 register union ww_char *tmp; 192 register union ww_char **cpp, **cqq; 193 194 cpp = &wwns[row2x]; 195 cqq = cpp - 1; 196 tmp = *cqq; 197 for (i = row2x - row1x; --i > 0;) 198 *--cpp = *--cqq; 199 *cqq = tmp; 200 } 201 if (scrolled) { 202 register char *p, *q; 203 204 p = &wwtouched[row2x]; 205 q = p - 1; 206 for (i = row2x - row1x; --i > 0;) 207 *--p = *--q; 208 *q |= WWU_TOUCHED; 209 } else { 210 register char *p; 211 212 p = &wwtouched[row1x]; 213 for (i = row2x - row1x; --i >= 0;) 214 *p++ |= WWU_TOUCHED; 215 } 216 wwredrawwin1(w, row1 + leaveit, row1x + 1, dir); 217 wwredrawwin1(w, row2x, row2, dir); 218 } 219 } else { 220 if (scrolled) { 221 register char *p; 222 223 p = &wwtouched[row1x]; 224 for (i = row2x - row1x; --i >= 0;) 225 *p++ |= WWU_TOUCHED; 226 } 227 out: 228 if (dir > 0) 229 wwredrawwin1(w, row1, row2 - leaveit, dir); 230 else 231 wwredrawwin1(w, row1 + leaveit, row2, dir); 232 } 233 return scrolled; 234 } 235