xref: /freebsd/usr.bin/talk/display.c (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
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("$FreeBSD$");
37 
38 #ifndef lint
39 static 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 
51 xwin_t	my_win;
52 xwin_t	his_win;
53 WINDOW	*line_win;
54 
55 int	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  */
61 int
62 max(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  */
72 void
73 display(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  */
179 int
180 readwin(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