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
xxflush(int intr)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
xxflush_scroll(struct xx * xp)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