xref: /netbsd-src/usr.bin/talk/display.c (revision a536ee5124e62c9a0051a252f7833dc8f50f44c9)
1 /*	$NetBSD: display.c,v 1.9 2011/09/06 18:32:03 joerg Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
36 #endif
37 __RCSID("$NetBSD: display.c,v 1.9 2011/09/06 18:32:03 joerg Exp $");
38 #endif /* not lint */
39 
40 /*
41  * The window 'manager', initializes curses and handles the actual
42  * displaying of text
43  */
44 #include "talk.h"
45 #include <ctype.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  * a 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') {
76 			xscroll(win, 0);
77 			text++;
78 			continue;
79 		}
80 		/* erase character */
81 		if (*text == win->cerase) {
82 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
83 			getyx(win->x_win, win->x_line, win->x_col);
84 			waddch(win->x_win, ' ');
85 			wmove(win->x_win, win->x_line, win->x_col);
86 			getyx(win->x_win, win->x_line, win->x_col);
87 			text++;
88 			continue;
89 		}
90 		/*
91 		 * On word erase search backwards until we find
92 		 * the beginning of a word or the beginning of
93 		 * the line.
94 		 */
95 		if (*text == win->werase) {
96 			int endcol, xcol, j, c;
97 
98 			endcol = win->x_col;
99 			xcol = endcol - 1;
100 			while (xcol >= 0) {
101 				c = readwin(win->x_win, win->x_line, xcol);
102 				if (c != ' ')
103 					break;
104 				xcol--;
105 			}
106 			while (xcol >= 0) {
107 				c = readwin(win->x_win, win->x_line, xcol);
108 				if (c == ' ')
109 					break;
110 				xcol--;
111 			}
112 			wmove(win->x_win, win->x_line, xcol + 1);
113 			for (j = xcol + 1; j < endcol; j++)
114 				waddch(win->x_win, ' ');
115 			wmove(win->x_win, win->x_line, xcol + 1);
116 			getyx(win->x_win, win->x_line, win->x_col);
117 			text++;
118 			continue;
119 		}
120 		/* line kill */
121 		if (*text == win->kill) {
122 			wmove(win->x_win, win->x_line, 0);
123 			wclrtoeol(win->x_win);
124 			getyx(win->x_win, win->x_line, win->x_col);
125 			text++;
126 			continue;
127 		}
128 		if (*text == '\f') {
129 			if (win == &my_win)
130 				wrefresh(curscr);
131 			text++;
132 			continue;
133 		}
134 		if (*text == '\07') {
135 			beep();
136 			text++;
137 			continue;
138 		}
139 		if (win->x_col == COLS-1) {
140 			/* check for wraparound */
141 			xscroll(win, 0);
142 		}
143 		if ( !isprint((u_char)*text) && *text != '\t') {
144 			waddch(win->x_win, '^');
145 			getyx(win->x_win, win->x_line, win->x_col);
146 			if (win->x_col == COLS-1) /* check for wraparound */
147 				xscroll(win, 0);
148 			cch = (*text & 63) + 64;
149 			waddch(win->x_win, cch);
150 		} else
151 			waddch(win->x_win, *text);
152 		getyx(win->x_win, win->x_line, win->x_col);
153 		text++;
154 	}
155 	wrefresh(win->x_win);
156 }
157 
158 /*
159  * Read the character at the indicated position in win
160  */
161 int
162 readwin(WINDOW *win, int line, int col)
163 {
164 	int oldline, oldcol;
165 	int c;
166 
167 	getyx(win, oldline, oldcol);
168 	wmove(win, line, col);
169 	c = winch(win);
170 	wmove(win, oldline, oldcol);
171 	return (c);
172 }
173 
174 /*
175  * Scroll a window, blanking out the line following the current line
176  * so that the current position is obvious
177  */
178 void
179 xscroll(xwin_t *win, int flag)
180 {
181 
182 	if (flag == -1) {
183 		wmove(win->x_win, 0, 0);
184 		win->x_line = 0;
185 		win->x_col = 0;
186 		return;
187 	}
188 	win->x_line = (win->x_line + 1) % win->x_nlines;
189 	win->x_col = 0;
190 	wmove(win->x_win, win->x_line, win->x_col);
191 	wclrtoeol(win->x_win);
192 	wmove(win->x_win, (win->x_line + 1) % win->x_nlines, win->x_col);
193 	wclrtoeol(win->x_win);
194 	wmove(win->x_win, win->x_line, win->x_col);
195 }
196