xref: /freebsd/usr.bin/talk/display.c (revision cc16dea626cf2fc80cde667ac4798065108e596c)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 
32 __FBSDID("$FreeBSD$");
33 
34 #ifndef lint
35 static const char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
36 #endif
37 
38 /*
39  * The window 'manager', initializes curses and handles the actual
40  * displaying of text
41  */
42 #include <ctype.h>
43 #include <unistd.h>
44 
45 #include "talk.h"
46 
47 xwin_t	my_win;
48 xwin_t	his_win;
49 WINDOW	*line_win;
50 
51 int	curses_initialized = 0;
52 
53 /*
54  * max HAS to be a function, it is called with
55  * an argument of the form --foo at least once.
56  */
57 int
58 max(int a, int b)
59 {
60 
61 	return (a > b ? a : b);
62 }
63 
64 /*
65  * Display some text on somebody's window, processing some control
66  * characters while we are at it.
67  */
68 void
69 display(xwin_t *win, char *text, int size)
70 {
71 	int i;
72 	char cch;
73 
74 	for (i = 0; i < size; i++) {
75 		if (*text == '\n' || *text == '\r') {
76 			waddch(win->x_win, '\n');
77 			getyx(win->x_win, win->x_line, win->x_col);
78 			text++;
79 			continue;
80 		}
81 		if (*text == 004 && win == &my_win) {
82 			/* control-D clears the screen */
83 			werase(my_win.x_win);
84 			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
85 			wrefresh(my_win.x_win);
86 			werase(his_win.x_win);
87 			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
88 			wrefresh(his_win.x_win);
89 			text++;
90 			continue;
91 		}
92 
93 		/* erase character */
94 		if (   *text == win->cerase
95 		    || *text == 010     /* BS */
96 		    || *text == 0177    /* DEL */
97 		   ) {
98 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
99 			getyx(win->x_win, win->x_line, win->x_col);
100 			waddch(win->x_win, ' ');
101 			wmove(win->x_win, win->x_line, win->x_col);
102 			getyx(win->x_win, win->x_line, win->x_col);
103 			text++;
104 			continue;
105 		}
106 		/*
107 		 * On word erase search backwards until we find
108 		 * the beginning of a word or the beginning of
109 		 * the line.
110 		 */
111 		if (   *text == win->werase
112 		    || *text == 027     /* ^W */
113 		   ) {
114 			int endcol, xcol, ii, c;
115 
116 			endcol = win->x_col;
117 			xcol = endcol - 1;
118 			while (xcol >= 0) {
119 				c = readwin(win->x_win, win->x_line, xcol);
120 				if (c != ' ')
121 					break;
122 				xcol--;
123 			}
124 			while (xcol >= 0) {
125 				c = readwin(win->x_win, win->x_line, xcol);
126 				if (c == ' ')
127 					break;
128 				xcol--;
129 			}
130 			wmove(win->x_win, win->x_line, xcol + 1);
131 			for (ii = xcol + 1; ii < endcol; ii++)
132 				waddch(win->x_win, ' ');
133 			wmove(win->x_win, win->x_line, xcol + 1);
134 			getyx(win->x_win, win->x_line, win->x_col);
135 			text++;
136 			continue;
137 		}
138 		/* line kill */
139 		if (   *text == win->kill
140 		    || *text == 025     /* ^U */
141 		   ) {
142 			wmove(win->x_win, win->x_line, 0);
143 			wclrtoeol(win->x_win);
144 			getyx(win->x_win, win->x_line, win->x_col);
145 			text++;
146 			continue;
147 		}
148 		if (*text == '\f') {
149 			if (win == &my_win)
150 				wrefresh(curscr);
151 			text++;
152 			continue;
153 		}
154 		if (*text == '\7') {
155 			write(STDOUT_FILENO, text, 1);
156 			text++;
157 			continue;
158 		}
159 		if (!isprint((unsigned char)*text) && *text != '\t') {
160 			waddch(win->x_win, '^');
161 			getyx(win->x_win, win->x_line, win->x_col);
162 			cch = (*text & 63) + 64;
163 			waddch(win->x_win, cch);
164 		} else
165 			waddch(win->x_win, (unsigned char)*text);
166 		getyx(win->x_win, win->x_line, win->x_col);
167 		text++;
168 	}
169 	wrefresh(win->x_win);
170 }
171 
172 /*
173  * Read the character at the indicated position in win
174  */
175 int
176 readwin(WINDOW *win, int line, int col)
177 {
178 	int oldline, oldcol;
179 	int c;
180 
181 	getyx(win, oldline, oldcol);
182 	wmove(win, line, col);
183 	c = winch(win);
184 	wmove(win, oldline, oldcol);
185 	return (c);
186 }
187