display.c revision 200418 
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35
36__FBSDID("$FreeBSD: head/usr.bin/talk/display.c 200418 2009-12-11 23:23:57Z delphij $");
37
38#ifndef lint
39static const char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
40#endif
41
42/*
43 * The window 'manager', initializes curses and handles the actual
44 * displaying of text
45 */
46#include <ctype.h>
47#include <unistd.h>
48
49#include "talk.h"
50
51xwin_t	my_win;
52xwin_t	his_win;
53WINDOW	*line_win;
54
55int	curses_initialized = 0;
56
57/*
58 * max HAS to be a function, it is called with
59 * an argument of the form --foo at least once.
60 */
61int
62max(int a, int b)
63{
64
65	return (a > b ? a : b);
66}
67
68/*
69 * Display some text on somebody's window, processing some control
70 * characters while we are at it.
71 */
72void
73display(xwin_t *win, char *text, int size)
74{
75	int i;
76	char cch;
77
78	for (i = 0; i < size; i++) {
79		if (*text == '\n' || *text == '\r') {
80			waddch(win->x_win, '\n');
81			getyx(win->x_win, win->x_line, win->x_col);
82			text++;
83			continue;
84		}
85		if (*text == 004 && win == &my_win) {
86			/* control-D clears the screen */
87			werase(my_win.x_win);
88			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
89			wrefresh(my_win.x_win);
90			werase(his_win.x_win);
91			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
92			wrefresh(his_win.x_win);
93			text++;
94			continue;
95		}
96
97		/* erase character */
98		if (   *text == win->cerase
99		    || *text == 010     /* BS */
100		    || *text == 0177    /* DEL */
101		   ) {
102			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
103			getyx(win->x_win, win->x_line, win->x_col);
104			waddch(win->x_win, ' ');
105			wmove(win->x_win, win->x_line, win->x_col);
106			getyx(win->x_win, win->x_line, win->x_col);
107			text++;
108			continue;
109		}
110		/*
111		 * On word erase search backwards until we find
112		 * the beginning of a word or the beginning of
113		 * the line.
114		 */
115		if (   *text == win->werase
116		    || *text == 027     /* ^W */
117		   ) {
118			int endcol, xcol, ii, c;
119
120			endcol = win->x_col;
121			xcol = endcol - 1;
122			while (xcol >= 0) {
123				c = readwin(win->x_win, win->x_line, xcol);
124				if (c != ' ')
125					break;
126				xcol--;
127			}
128			while (xcol >= 0) {
129				c = readwin(win->x_win, win->x_line, xcol);
130				if (c == ' ')
131					break;
132				xcol--;
133			}
134			wmove(win->x_win, win->x_line, xcol + 1);
135			for (ii = xcol + 1; ii < endcol; ii++)
136				waddch(win->x_win, ' ');
137			wmove(win->x_win, win->x_line, xcol + 1);
138			getyx(win->x_win, win->x_line, win->x_col);
139			text++;
140			continue;
141		}
142		/* line kill */
143		if (   *text == win->kill
144		    || *text == 025     /* ^U */
145		   ) {
146			wmove(win->x_win, win->x_line, 0);
147			wclrtoeol(win->x_win);
148			getyx(win->x_win, win->x_line, win->x_col);
149			text++;
150			continue;
151		}
152		if (*text == '\f') {
153			if (win == &my_win)
154				wrefresh(curscr);
155			text++;
156			continue;
157		}
158		if (*text == '\7') {
159			write(STDOUT_FILENO, text, 1);
160			text++;
161			continue;
162		}
163		if (!isprint((unsigned char)*text) && *text != '\t') {
164			waddch(win->x_win, '^');
165			getyx(win->x_win, win->x_line, win->x_col);
166			cch = (*text & 63) + 64;
167			waddch(win->x_win, cch);
168		} else
169			waddch(win->x_win, (unsigned char)*text);
170		getyx(win->x_win, win->x_line, win->x_col);
171		text++;
172	}
173	wrefresh(win->x_win);
174}
175
176/*
177 * Read the character at the indicated position in win
178 */
179int
180readwin(WINDOW *win, int line, int col)
181{
182	int oldline, oldcol;
183	int c;
184
185	getyx(win, oldline, oldcol);
186	wmove(win, line, col);
187	c = winch(win);
188	wmove(win, oldline, oldcol);
189	return (c);
190}
191