1 /* @(#)xxflush.c 8.1 (Berkeley) 6/6/93 */ 2 /* $NetBSD: xxflush.c,v 1.6 2003/08/07 11:17:47 agc Exp $ */ 3 4 /* 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Edward Wang at The University of California, Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 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. 22 * 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 33 * SUCH DAMAGE. 34 */ 35 36 #include "ww.h" 37 #include "xx.h" 38 #include "tt.h" 39 40 void 41 xxflush(int intr) 42 { 43 struct xx *xp, *xq; 44 45 for (xp = xx_head; xp != NULL && !(intr && wwinterrupt()); xp = xq) { 46 switch (xp->cmd) { 47 case xc_move: 48 if (xp->link == 0) 49 (*tt.tt_move)(xp->arg0, xp->arg1); 50 break; 51 case xc_scroll: 52 xxflush_scroll(xp); 53 break; 54 case xc_inschar: 55 (*tt.tt_move)(xp->arg0, xp->arg1); 56 tt.tt_nmodes = xp->arg3; 57 (*tt.tt_inschar)(xp->arg2); 58 break; 59 case xc_insspace: 60 (*tt.tt_move)(xp->arg0, xp->arg1); 61 (*tt.tt_insspace)(xp->arg2); 62 break; 63 case xc_delchar: 64 (*tt.tt_move)(xp->arg0, xp->arg1); 65 (*tt.tt_delchar)(xp->arg2); 66 break; 67 case xc_clear: 68 (*tt.tt_clear)(); 69 break; 70 case xc_clreos: 71 (*tt.tt_move)(xp->arg0, xp->arg1); 72 (*tt.tt_clreos)(); 73 break; 74 case xc_clreol: 75 (*tt.tt_move)(xp->arg0, xp->arg1); 76 (*tt.tt_clreol)(); 77 break; 78 case xc_write: 79 (*tt.tt_move)(xp->arg0, xp->arg1); 80 tt.tt_nmodes = xp->arg3; 81 (*tt.tt_write)(xp->buf, xp->arg2); 82 break; 83 } 84 xq = xp->link; 85 xxfree(xp); 86 } 87 if ((xx_head = xp) == NULL) { 88 xx_tail = 0; 89 xxbufp = xxbuf; 90 } 91 ttflush(); 92 } 93 94 void 95 xxflush_scroll(struct xx *xp) 96 { 97 struct xx *xq; 98 99 top: 100 if (xp->arg0 == 0) 101 return; 102 /* 103 * We handle retain (da and db) by putting the burden on scrolling up, 104 * which is the less common operation. It must ensure that 105 * text is not pushed below the screen, so scrolling down doesn't 106 * have to worry about it. 107 * 108 * Try scrolling region (or scrolling the whole screen) first. 109 * Can we assume "sr" doesn't push text below the screen 110 * so we don't have to worry about retain below? 111 * What about scrolling down with a newline? It probably does 112 * push text above (with da). Scrolling up would then have 113 * to take care of that. 114 * It's easy to be fool proof, but that slows things down. 115 * The current solution is to disallow tt_scroll_up if da or db is true 116 * but cs (scrolling region) is not. Again, we sacrifice scrolling 117 * up in favor of scrolling down. The idea is having scrolling regions 118 * probably means we can scroll (even the whole screen) with impunity. 119 * This lets us work efficiently on simple terminals (use newline 120 * on the bottom to scroll), on any terminal without retain, and 121 * on vt100 style scrolling regions (I think). 122 */ 123 if (xp->arg0 > 0) { 124 if ((xq = xp->link) != NULL && xq->cmd == xc_scroll && 125 xp->arg2 == xq->arg2 && xq->arg0 < 0) { 126 if (xp->arg1 < xq->arg1) { 127 if (xp->arg2 - xp->arg0 <= xq->arg1) { 128 xq->arg0 = xp->arg0; 129 xq->arg1 = xp->arg1; 130 xq->arg2 = xp->arg2; 131 return; 132 } 133 xp->arg2 = xq->arg1 + xp->arg0; 134 xq->arg0 += xp->arg0; 135 xq->arg1 = xp->arg2; 136 if (xq->arg0 > 0) 137 xq->arg1 -= xq->arg0; 138 goto top; 139 } else { 140 if (xp->arg1 - xq->arg0 >= xp->arg2) 141 return; 142 xq->arg2 = xp->arg1 - xq->arg0; 143 xp->arg0 += xq->arg0; 144 xp->arg1 = xq->arg2; 145 if (xp->arg0 < 0) 146 xp->arg1 += xp->arg0; 147 goto top; 148 } 149 } 150 if (xp->arg0 > xp->arg2 - xp->arg1) 151 xp->arg0 = xp->arg2 - xp->arg1; 152 if (tt.tt_scroll_down) { 153 if (tt.tt_scroll_top != xp->arg1 || 154 tt.tt_scroll_bot != xp->arg2 - 1) { 155 if (tt.tt_setscroll == 0) 156 goto down; 157 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1); 158 } 159 tt.tt_scroll_down(xp->arg0); 160 } else { 161 down: 162 (*tt.tt_move)(xp->arg1, 0); 163 (*tt.tt_delline)(xp->arg0); 164 if (xp->arg2 < tt.tt_nrow) { 165 (*tt.tt_move)(xp->arg2 - xp->arg0, 0); 166 (*tt.tt_insline)(xp->arg0); 167 } 168 } 169 } else { 170 xp->arg0 = - xp->arg0; 171 if (xp->arg0 > xp->arg2 - xp->arg1) 172 xp->arg0 = xp->arg2 - xp->arg1; 173 if (tt.tt_scroll_up) { 174 if (tt.tt_scroll_top != xp->arg1 || 175 tt.tt_scroll_bot != xp->arg2 - 1) { 176 if (tt.tt_setscroll == 0) 177 goto up; 178 (*tt.tt_setscroll)(xp->arg1, xp->arg2 - 1); 179 } 180 tt.tt_scroll_up(xp->arg0); 181 } else { 182 up: 183 if (tt.tt_retain || xp->arg2 != tt.tt_nrow) { 184 (*tt.tt_move)(xp->arg2 - xp->arg0, 0); 185 (*tt.tt_delline)(xp->arg0); 186 } 187 (*tt.tt_move)(xp->arg1, 0); 188 (*tt.tt_insline)(xp->arg0); 189 } 190 } 191 } 192