1/* $NetBSD: wwscroll.c,v 1.6 2002/06/14 01:07:01 wiz Exp $ */ 2 3/* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Edward Wang at The University of California, Berkeley. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <sys/cdefs.h> 36#ifndef lint 37#if 0 38static char sccsid[] = "@(#)wwscroll.c 8.1 (Berkeley) 6/6/93"; 39#else 40__RCSID("$NetBSD: wwscroll.c,v 1.6 2002/06/14 01:07:01 wiz Exp $"); 41#endif 42#endif /* not lint */ 43 44#include <stdlib.h> 45 46#include "ww.h" 47#include "tt.h" 48#include "xx.h" 49 50void 51wwscroll(struct ww *w, int n) 52{ 53 int dir; 54 int top; 55 56 if (n == 0) 57 return; 58 dir = n < 0 ? -1 : 1; 59 top = w->ww_b.t - n; 60 if (top > w->ww_w.t) 61 top = w->ww_w.t; 62 else if (top + w->ww_b.nr < w->ww_w.b) 63 top = w->ww_w.b - w->ww_b.nr; 64 n = abs(top - w->ww_b.t); 65 if (n < w->ww_i.nr) { 66 while (--n >= 0) { 67 (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0); 68 w->ww_buf += dir; 69 w->ww_b.t -= dir; 70 w->ww_b.b -= dir; 71 } 72 } else { 73 w->ww_buf -= top - w->ww_b.t; 74 w->ww_b.t = top; 75 w->ww_b.b = top + w->ww_b.nr; 76 wwredrawwin(w); 77 } 78} 79 80/* 81 * Scroll one line, between 'row1' and 'row2', in direction 'dir'. 82 * Don't adjust ww_scroll. 83 * And don't redraw 'leaveit' lines. 84 */ 85int 86wwscroll1(struct ww *w, int row1, int row2, int dir, int leaveit) 87{ 88 int i; 89 int row1x, row2x; 90 int nvis; 91 int nvismax; 92 int scrolled = 0; 93 94 /* 95 * See how many lines on the screen are affected. 96 * And calculate row1x, row2x, and left at the same time. 97 */ 98 for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++) 99 ; 100 if (i >= row2) /* can't do any fancy stuff */ 101 goto out; 102 row1x = i; 103 for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--) 104 ; 105 if (i <= row1x) 106 goto out; /* just one line is easy */ 107 row2x = i + 1; 108 109 /* 110 * See how much of this window is visible. 111 */ 112 nvismax = wwncol * (row2x - row1x); 113 nvis = 0; 114 for (i = row1x; i < row2x; i++) 115 nvis += w->ww_nvis[i]; 116 117 /* 118 * If it's a good idea to scroll and the terminal can, then do it. 119 */ 120 if (nvis < nvismax / 2) 121 goto no_scroll; /* not worth it */ 122 if ((dir > 0 ? tt.tt_scroll_down == 0 : tt.tt_scroll_up == 0) || 123 ((tt.tt_scroll_top != row1x || tt.tt_scroll_bot != row2x - 1) && 124 tt.tt_setscroll == 0)) 125 if (tt.tt_delline == 0 || tt.tt_insline == 0) 126 goto no_scroll; 127 xxscroll(dir, row1x, row2x); 128 scrolled = 1; 129 /* 130 * Fix up the old screen. 131 */ 132 { 133 union ww_char *tmp; 134 union ww_char **cpp, **cqq; 135 136 if (dir > 0) { 137 cpp = &wwos[row1x]; 138 cqq = cpp + 1; 139 tmp = *cpp; 140 for (i = row2x - row1x; --i > 0;) 141 *cpp++ = *cqq++; 142 *cpp = tmp; 143 } else { 144 cpp = &wwos[row2x]; 145 cqq = cpp - 1; 146 tmp = *cqq; 147 for (i = row2x - row1x; --i > 0;) 148 *--cpp = *--cqq; 149 *cqq = tmp; 150 } 151 for (i = wwncol; --i >= 0;) 152 tmp++->c_w = ' '; 153 } 154 155no_scroll: 156 /* 157 * Fix the new screen. 158 */ 159 if (nvis == nvismax) { 160 /* 161 * Can shift whole lines. 162 */ 163 if (dir > 0) { 164 { 165 union ww_char *tmp; 166 union ww_char **cpp, **cqq; 167 168 cpp = &wwns[row1x]; 169 cqq = cpp + 1; 170 tmp = *cpp; 171 for (i = row2x - row1x; --i > 0;) 172 *cpp++ = *cqq++; 173 *cpp = tmp; 174 } 175 if (scrolled) { 176 char *p, *q; 177 178 p = &wwtouched[row1x]; 179 q = p + 1; 180 for (i = row2x - row1x; --i > 0;) 181 *p++ = *q++; 182 *p |= WWU_TOUCHED; 183 } else { 184 char *p; 185 186 p = &wwtouched[row1x]; 187 for (i = row2x - row1x; --i >= 0;) 188 *p++ |= WWU_TOUCHED; 189 } 190 wwredrawwin1(w, row1, row1x, dir); 191 wwredrawwin1(w, row2x - 1, row2 - leaveit, dir); 192 } else { 193 { 194 union ww_char *tmp; 195 union ww_char **cpp, **cqq; 196 197 cpp = &wwns[row2x]; 198 cqq = cpp - 1; 199 tmp = *cqq; 200 for (i = row2x - row1x; --i > 0;) 201 *--cpp = *--cqq; 202 *cqq = tmp; 203 } 204 if (scrolled) { 205 char *p, *q; 206 207 p = &wwtouched[row2x]; 208 q = p - 1; 209 for (i = row2x - row1x; --i > 0;) 210 *--p = *--q; 211 *q |= WWU_TOUCHED; 212 } else { 213 char *p; 214 215 p = &wwtouched[row1x]; 216 for (i = row2x - row1x; --i >= 0;) 217 *p++ |= WWU_TOUCHED; 218 } 219 wwredrawwin1(w, row1 + leaveit, row1x + 1, dir); 220 wwredrawwin1(w, row2x, row2, dir); 221 } 222 } else { 223 if (scrolled) { 224 char *p; 225 226 p = &wwtouched[row1x]; 227 for (i = row2x - row1x; --i >= 0;) 228 *p++ |= WWU_TOUCHED; 229 } 230out: 231 if (dir > 0) 232 wwredrawwin1(w, row1, row2 - leaveit, dir); 233 else 234 wwredrawwin1(w, row1 + leaveit, row2, dir); 235 } 236 return scrolled; 237} 238