xref: /freebsd/usr.bin/talk/display.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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 
48 #include "talk.h"
49 
50 xwin_t	my_win;
51 xwin_t	his_win;
52 WINDOW	*line_win;
53 
54 int	curses_initialized = 0;
55 
56 /*
57  * max HAS to be a function, it is called with
58  * an argument of the form --foo at least once.
59  */
60 int
61 max(int a, int b)
62 {
63 
64 	return (a > b ? a : b);
65 }
66 
67 /*
68  * Display some text on somebody's window, processing some control
69  * characters while we are at it.
70  */
71 void
72 display(xwin_t *win, char *text, int size)
73 {
74 	int i;
75 	char cch;
76 
77 	for (i = 0; i < size; i++) {
78 		if (*text == '\n' || *text == '\r') {
79 			waddch(win->x_win, '\n');
80 			getyx(win->x_win, win->x_line, win->x_col);
81 			text++;
82 			continue;
83 		}
84 		if (*text == 004 && win == &my_win) {
85 			/* control-D clears the screen */
86 			werase(my_win.x_win);
87 			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
88 			wrefresh(my_win.x_win);
89 			werase(his_win.x_win);
90 			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
91 			wrefresh(his_win.x_win);
92 			text++;
93 			continue;
94 		}
95 
96 		/* erase character */
97 		if (   *text == win->cerase
98 		    || *text == 010     /* BS */
99 		    || *text == 0177    /* DEL */
100 		   ) {
101 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
102 			getyx(win->x_win, win->x_line, win->x_col);
103 			waddch(win->x_win, ' ');
104 			wmove(win->x_win, win->x_line, win->x_col);
105 			getyx(win->x_win, win->x_line, win->x_col);
106 			text++;
107 			continue;
108 		}
109 		/*
110 		 * On word erase search backwards until we find
111 		 * the beginning of a word or the beginning of
112 		 * the line.
113 		 */
114 		if (   *text == win->werase
115 		    || *text == 027     /* ^W */
116 		   ) {
117 			int endcol, xcol, ii, c;
118 
119 			endcol = win->x_col;
120 			xcol = endcol - 1;
121 			while (xcol >= 0) {
122 				c = readwin(win->x_win, win->x_line, xcol);
123 				if (c != ' ')
124 					break;
125 				xcol--;
126 			}
127 			while (xcol >= 0) {
128 				c = readwin(win->x_win, win->x_line, xcol);
129 				if (c == ' ')
130 					break;
131 				xcol--;
132 			}
133 			wmove(win->x_win, win->x_line, xcol + 1);
134 			for (ii = xcol + 1; ii < endcol; ii++)
135 				waddch(win->x_win, ' ');
136 			wmove(win->x_win, win->x_line, xcol + 1);
137 			getyx(win->x_win, win->x_line, win->x_col);
138 			text++;
139 			continue;
140 		}
141 		/* line kill */
142 		if (   *text == win->kill
143 		    || *text == 025     /* ^U */
144 		   ) {
145 			wmove(win->x_win, win->x_line, 0);
146 			wclrtoeol(win->x_win);
147 			getyx(win->x_win, win->x_line, win->x_col);
148 			text++;
149 			continue;
150 		}
151 		if (*text == '\f') {
152 			if (win == &my_win)
153 				wrefresh(curscr);
154 			text++;
155 			continue;
156 		}
157 		if (*text == '\7') {
158 			write(STDOUT_FILENO, text, 1);
159 			text++;
160 			continue;
161 		}
162 		if (!isprint((unsigned char)*text) && *text != '\t') {
163 			waddch(win->x_win, '^');
164 			getyx(win->x_win, win->x_line, win->x_col);
165 			cch = (*text & 63) + 64;
166 			waddch(win->x_win, cch);
167 		} else
168 			waddch(win->x_win, (unsigned char)*text);
169 		getyx(win->x_win, win->x_line, win->x_col);
170 		text++;
171 	}
172 	wrefresh(win->x_win);
173 }
174 
175 /*
176  * Read the character at the indicated position in win
177  */
178 int
179 readwin(WINDOW *win, int line, int col)
180 {
181 	int oldline, oldcol;
182 	int c;
183 
184 	getyx(win, oldline, oldcol);
185 	wmove(win, line, col);
186 	c = winch(win);
187 	wmove(win, oldline, oldcol);
188 	return (c);
189 }
190