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 37 #ifndef lint 38 static char sccsid[] = "@(#)wwscroll.c 8.1 (Berkeley) 6/6/93"; 39 static char rcsid[] = 40 "$FreeBSD: src/usr.bin/window/wwscroll.c,v 1.1.1.1.14.1 2001/05/17 09:45:01 obrien Exp $"; 41 #endif /* not lint */ 42 43 #include "ww.h" 44 #include "tt.h" 45 46 wwscroll(w, n) 47 register struct ww *w; 48 int n; 49 { 50 register dir; 51 register top; 52 53 if (n == 0) 54 return; 55 dir = n < 0 ? -1 : 1; 56 top = w->ww_b.t - n; 57 if (top > w->ww_w.t) 58 top = w->ww_w.t; 59 else if (top + w->ww_b.nr < w->ww_w.b) 60 top = w->ww_w.b - w->ww_b.nr; 61 n = abs(top - w->ww_b.t); 62 if (n < w->ww_i.nr) { 63 while (--n >= 0) { 64 (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0); 65 w->ww_buf += dir; 66 w->ww_b.t -= dir; 67 w->ww_b.b -= dir; 68 } 69 } else { 70 w->ww_buf -= top - w->ww_b.t; 71 w->ww_b.t = top; 72 w->ww_b.b = top + w->ww_b.nr; 73 wwredrawwin(w); 74 } 75 } 76 77 /* 78 * Scroll one line, between 'row1' and 'row2', in direction 'dir'. 79 * Don't adjust ww_scroll. 80 * And don't redraw 'leaveit' lines. 81 */ 82 wwscroll1(w, row1, row2, dir, leaveit) 83 register struct ww *w; 84 int row1, row2, dir; 85 int leaveit; 86 { 87 register i; 88 int row1x, row2x; 89 int nvis; 90 int nvismax; 91 int scrolled = 0; 92 93 /* 94 * See how many lines on the screen are affected. 95 * And calculate row1x, row2x, and left at the same time. 96 */ 97 for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++) 98 ; 99 if (i >= row2) /* can't do any fancy stuff */ 100 goto out; 101 row1x = i; 102 for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--) 103 ; 104 if (i <= row1x) 105 goto out; /* just one line is easy */ 106 row2x = i + 1; 107 108 /* 109 * See how much of this window is visible. 110 */ 111 nvismax = wwncol * (row2x - row1x); 112 nvis = 0; 113 for (i = row1x; i < row2x; i++) 114 nvis += w->ww_nvis[i]; 115 116 /* 117 * If it's a good idea to scroll and the terminal can, then do it. 118 */ 119 if (nvis < nvismax / 2) 120 goto no_scroll; /* not worth it */ 121 if ((dir > 0 ? tt.tt_scroll_down == 0 : tt.tt_scroll_up == 0) || 122 (tt.tt_scroll_top != row1x || tt.tt_scroll_bot != row2x - 1) && 123 tt.tt_setscroll == 0) 124 if (tt.tt_delline == 0 || tt.tt_insline == 0) 125 goto no_scroll; 126 xxscroll(dir, row1x, row2x); 127 scrolled = 1; 128 /* 129 * Fix up the old screen. 130 */ 131 { 132 register union ww_char *tmp; 133 register union ww_char **cpp, **cqq; 134 135 if (dir > 0) { 136 cpp = &wwos[row1x]; 137 cqq = cpp + 1; 138 tmp = *cpp; 139 for (i = row2x - row1x; --i > 0;) 140 *cpp++ = *cqq++; 141 *cpp = tmp; 142 } else { 143 cpp = &wwos[row2x]; 144 cqq = cpp - 1; 145 tmp = *cqq; 146 for (i = row2x - row1x; --i > 0;) 147 *--cpp = *--cqq; 148 *cqq = tmp; 149 } 150 for (i = wwncol; --i >= 0;) 151 tmp++->c_w = ' '; 152 } 153 154 no_scroll: 155 /* 156 * Fix the new screen. 157 */ 158 if (nvis == nvismax) { 159 /* 160 * Can shift whole lines. 161 */ 162 if (dir > 0) { 163 { 164 register union ww_char *tmp; 165 register union ww_char **cpp, **cqq; 166 167 cpp = &wwns[row1x]; 168 cqq = cpp + 1; 169 tmp = *cpp; 170 for (i = row2x - row1x; --i > 0;) 171 *cpp++ = *cqq++; 172 *cpp = tmp; 173 } 174 if (scrolled) { 175 register char *p, *q; 176 177 p = &wwtouched[row1x]; 178 q = p + 1; 179 for (i = row2x - row1x; --i > 0;) 180 *p++ = *q++; 181 *p |= WWU_TOUCHED; 182 } else { 183 register char *p; 184 185 p = &wwtouched[row1x]; 186 for (i = row2x - row1x; --i >= 0;) 187 *p++ |= WWU_TOUCHED; 188 } 189 wwredrawwin1(w, row1, row1x, dir); 190 wwredrawwin1(w, row2x - 1, row2 - leaveit, dir); 191 } else { 192 { 193 register union ww_char *tmp; 194 register union ww_char **cpp, **cqq; 195 196 cpp = &wwns[row2x]; 197 cqq = cpp - 1; 198 tmp = *cqq; 199 for (i = row2x - row1x; --i > 0;) 200 *--cpp = *--cqq; 201 *cqq = tmp; 202 } 203 if (scrolled) { 204 register char *p, *q; 205 206 p = &wwtouched[row2x]; 207 q = p - 1; 208 for (i = row2x - row1x; --i > 0;) 209 *--p = *--q; 210 *q |= WWU_TOUCHED; 211 } else { 212 register char *p; 213 214 p = &wwtouched[row1x]; 215 for (i = row2x - row1x; --i >= 0;) 216 *p++ |= WWU_TOUCHED; 217 } 218 wwredrawwin1(w, row1 + leaveit, row1x + 1, dir); 219 wwredrawwin1(w, row2x, row2, dir); 220 } 221 } else { 222 if (scrolled) { 223 register char *p; 224 225 p = &wwtouched[row1x]; 226 for (i = row2x - row1x; --i >= 0;) 227 *p++ |= WWU_TOUCHED; 228 } 229 out: 230 if (dir > 0) 231 wwredrawwin1(w, row1, row2 - leaveit, dir); 232 else 233 wwredrawwin1(w, row1 + leaveit, row2, dir); 234 } 235 return scrolled; 236 } 237