xref: /netbsd-src/usr.bin/talk/display.c (revision 0b9f50897e9a9c6709320fafb4c3787fddcc0a45)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * 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 #ifndef lint
35 /*static char sccsid[] = "from: @(#)display.c	5.4 (Berkeley) 6/1/90";*/
36 static char rcsid[] = "$Id: display.c,v 1.2 1993/08/01 18:07:53 mycroft Exp $";
37 #endif /* not lint */
38 
39 /*
40  * The window 'manager', initializes curses and handles the actual
41  * displaying of text
42  */
43 #include "talk.h"
44 
45 xwin_t	my_win;
46 xwin_t	his_win;
47 WINDOW	*line_win;
48 
49 int	curses_initialized = 0;
50 
51 /*
52  * max HAS to be a function, it is called with
53  * a argument of the form --foo at least once.
54  */
55 max(a,b)
56 	int a, b;
57 {
58 
59 	return (a > b ? a : b);
60 }
61 
62 /*
63  * Display some text on somebody's window, processing some control
64  * characters while we are at it.
65  */
66 display(win, text, size)
67 	register xwin_t *win;
68 	register char *text;
69 	int size;
70 {
71 	register 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, i, 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 (i = xcol + 1; i < endcol; i++)
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 			continue;
118 		}
119 		/* line kill */
120 		if (*text == win->kill) {
121 			wmove(win->x_win, win->x_line, 0);
122 			wclrtoeol(win->x_win);
123 			getyx(win->x_win, win->x_line, win->x_col);
124 			text++;
125 			continue;
126 		}
127 		if (*text == '\f') {
128 			if (win == &my_win)
129 				wrefresh(curscr);
130 			text++;
131 			continue;
132 		}
133 		if (win->x_col == COLS-1) {
134 			/* check for wraparound */
135 			xscroll(win, 0);
136 		}
137 		if (*text < ' ' && *text != '\t') {
138 			waddch(win->x_win, '^');
139 			getyx(win->x_win, win->x_line, win->x_col);
140 			if (win->x_col == COLS-1) /* check for wraparound */
141 				xscroll(win, 0);
142 			cch = (*text & 63) + 64;
143 			waddch(win->x_win, cch);
144 		} else
145 			waddch(win->x_win, *text);
146 		getyx(win->x_win, win->x_line, win->x_col);
147 		text++;
148 	}
149 	wrefresh(win->x_win);
150 }
151 
152 /*
153  * Read the character at the indicated position in win
154  */
155 readwin(win, line, col)
156 	WINDOW *win;
157 {
158 	int oldline, oldcol;
159 	register int c;
160 
161 	getyx(win, oldline, oldcol);
162 	wmove(win, line, col);
163 	c = winch(win);
164 	wmove(win, oldline, oldcol);
165 	return (c);
166 }
167 
168 /*
169  * Scroll a window, blanking out the line following the current line
170  * so that the current position is obvious
171  */
172 xscroll(win, flag)
173 	register xwin_t *win;
174 	int flag;
175 {
176 
177 	if (flag == -1) {
178 		wmove(win->x_win, 0, 0);
179 		win->x_line = 0;
180 		win->x_col = 0;
181 		return;
182 	}
183 	win->x_line = (win->x_line + 1) % win->x_nlines;
184 	win->x_col = 0;
185 	wmove(win->x_win, win->x_line, win->x_col);
186 	wclrtoeol(win->x_win);
187 	wmove(win->x_win, (win->x_line + 1) % win->x_nlines, win->x_col);
188 	wclrtoeol(win->x_win);
189 	wmove(win->x_win, win->x_line, win->x_col);
190 }
191