xref: /freebsd/usr.bin/talk/display.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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(a,b)
62 	int a, 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(win, text, size)
74 	xwin_t *win;
75 	char *text;
76 	int size;
77 {
78 	int i;
79 	char cch;
80 
81 	for (i = 0; i < size; i++) {
82 		if (*text == '\n' || *text == '\r') {
83 			waddch(win->x_win, '\n');
84 			getyx(win->x_win, win->x_line, win->x_col);
85 			text++;
86 			continue;
87 		}
88 		if (*text == 004 && win == &my_win) {
89 			/* control-D clears the screen */
90 			werase(my_win.x_win);
91 			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
92 			wrefresh(my_win.x_win);
93 			werase(his_win.x_win);
94 			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
95 			wrefresh(his_win.x_win);
96 			text++;
97 			continue;
98 		}
99 
100 		/* erase character */
101 		if (   *text == win->cerase
102 		    || *text == 010     /* BS */
103 		    || *text == 0177    /* DEL */
104 		   ) {
105 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
106 			getyx(win->x_win, win->x_line, win->x_col);
107 			waddch(win->x_win, ' ');
108 			wmove(win->x_win, win->x_line, win->x_col);
109 			getyx(win->x_win, win->x_line, win->x_col);
110 			text++;
111 			continue;
112 		}
113 		/*
114 		 * On word erase search backwards until we find
115 		 * the beginning of a word or the beginning of
116 		 * the line.
117 		 */
118 		if (   *text == win->werase
119 		    || *text == 027     /* ^W */
120 		   ) {
121 			int endcol, xcol, ii, c;
122 
123 			endcol = win->x_col;
124 			xcol = endcol - 1;
125 			while (xcol >= 0) {
126 				c = readwin(win->x_win, win->x_line, xcol);
127 				if (c != ' ')
128 					break;
129 				xcol--;
130 			}
131 			while (xcol >= 0) {
132 				c = readwin(win->x_win, win->x_line, xcol);
133 				if (c == ' ')
134 					break;
135 				xcol--;
136 			}
137 			wmove(win->x_win, win->x_line, xcol + 1);
138 			for (ii = xcol + 1; ii < endcol; ii++)
139 				waddch(win->x_win, ' ');
140 			wmove(win->x_win, win->x_line, xcol + 1);
141 			getyx(win->x_win, win->x_line, win->x_col);
142 			text++;
143 			continue;
144 		}
145 		/* line kill */
146 		if (   *text == win->kill
147 		    || *text == 025     /* ^U */
148 		   ) {
149 			wmove(win->x_win, win->x_line, 0);
150 			wclrtoeol(win->x_win);
151 			getyx(win->x_win, win->x_line, win->x_col);
152 			text++;
153 			continue;
154 		}
155 		if (*text == '\f') {
156 			if (win == &my_win)
157 				wrefresh(curscr);
158 			text++;
159 			continue;
160 		}
161 		if (*text == '\7') {
162 			write(STDOUT_FILENO, text, 1);
163 			text++;
164 			continue;
165 		}
166 		if (!isprint((unsigned char)*text) && *text != '\t') {
167 			waddch(win->x_win, '^');
168 			getyx(win->x_win, win->x_line, win->x_col);
169 			cch = (*text & 63) + 64;
170 			waddch(win->x_win, cch);
171 		} else
172 			waddch(win->x_win, (unsigned char)*text);
173 		getyx(win->x_win, win->x_line, win->x_col);
174 		text++;
175 	}
176 	wrefresh(win->x_win);
177 }
178 
179 /*
180  * Read the character at the indicated position in win
181  */
182 int
183 readwin(win, line, col)
184 	WINDOW *win;
185 	int line;
186 	int col;
187 {
188 	int oldline, oldcol;
189 	int c;
190 
191 	getyx(win, oldline, oldcol);
192 	wmove(win, line, col);
193 	c = winch(win);
194 	wmove(win, oldline, oldcol);
195 	return (c);
196 }
197