xref: /netbsd-src/usr.bin/talk/display.c (revision ce63d6c20fc4ec8ddc95c84bb229e3c4ecf82b69)
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[] = "@(#)display.c	5.4 (Berkeley) 6/1/90";
36 #endif /* not lint */
37 
38 /*
39  * The window 'manager', initializes curses and handles the actual
40  * displaying of text
41  */
42 #include "talk.h"
43 
44 xwin_t	my_win;
45 xwin_t	his_win;
46 WINDOW	*line_win;
47 
48 int	curses_initialized = 0;
49 
50 /*
51  * max HAS to be a function, it is called with
52  * a argument of the form --foo at least once.
53  */
54 max(a,b)
55 	int a, b;
56 {
57 
58 	return (a > b ? a : b);
59 }
60 
61 /*
62  * Display some text on somebody's window, processing some control
63  * characters while we are at it.
64  */
65 display(win, text, size)
66 	register xwin_t *win;
67 	register char *text;
68 	int size;
69 {
70 	register int i;
71 	char cch;
72 
73 	for (i = 0; i < size; i++) {
74 		if (*text == '\n') {
75 			xscroll(win, 0);
76 			text++;
77 			continue;
78 		}
79 		/* erase character */
80 		if (*text == win->cerase) {
81 			wmove(win->x_win, win->x_line, max(--win->x_col, 0));
82 			getyx(win->x_win, win->x_line, win->x_col);
83 			waddch(win->x_win, ' ');
84 			wmove(win->x_win, win->x_line, win->x_col);
85 			getyx(win->x_win, win->x_line, win->x_col);
86 			text++;
87 			continue;
88 		}
89 		/*
90 		 * On word erase search backwards until we find
91 		 * the beginning of a word or the beginning of
92 		 * the line.
93 		 */
94 		if (*text == win->werase) {
95 			int endcol, xcol, i, c;
96 
97 			endcol = win->x_col;
98 			xcol = endcol - 1;
99 			while (xcol >= 0) {
100 				c = readwin(win->x_win, win->x_line, xcol);
101 				if (c != ' ')
102 					break;
103 				xcol--;
104 			}
105 			while (xcol >= 0) {
106 				c = readwin(win->x_win, win->x_line, xcol);
107 				if (c == ' ')
108 					break;
109 				xcol--;
110 			}
111 			wmove(win->x_win, win->x_line, xcol + 1);
112 			for (i = xcol + 1; i < endcol; i++)
113 				waddch(win->x_win, ' ');
114 			wmove(win->x_win, win->x_line, xcol + 1);
115 			getyx(win->x_win, win->x_line, win->x_col);
116 			continue;
117 		}
118 		/* line kill */
119 		if (*text == win->kill) {
120 			wmove(win->x_win, win->x_line, 0);
121 			wclrtoeol(win->x_win);
122 			getyx(win->x_win, win->x_line, win->x_col);
123 			text++;
124 			continue;
125 		}
126 		if (*text == '\f') {
127 			if (win == &my_win)
128 				wrefresh(curscr);
129 			text++;
130 			continue;
131 		}
132 		if (win->x_col == COLS-1) {
133 			/* check for wraparound */
134 			xscroll(win, 0);
135 		}
136 		if (*text < ' ' && *text != '\t') {
137 			waddch(win->x_win, '^');
138 			getyx(win->x_win, win->x_line, win->x_col);
139 			if (win->x_col == COLS-1) /* check for wraparound */
140 				xscroll(win, 0);
141 			cch = (*text & 63) + 64;
142 			waddch(win->x_win, cch);
143 		} else
144 			waddch(win->x_win, *text);
145 		getyx(win->x_win, win->x_line, win->x_col);
146 		text++;
147 	}
148 	wrefresh(win->x_win);
149 }
150 
151 /*
152  * Read the character at the indicated position in win
153  */
154 readwin(win, line, col)
155 	WINDOW *win;
156 {
157 	int oldline, oldcol;
158 	register int c;
159 
160 	getyx(win, oldline, oldcol);
161 	wmove(win, line, col);
162 	c = winch(win);
163 	wmove(win, oldline, oldcol);
164 	return (c);
165 }
166 
167 /*
168  * Scroll a window, blanking out the line following the current line
169  * so that the current position is obvious
170  */
171 xscroll(win, flag)
172 	register xwin_t *win;
173 	int flag;
174 {
175 
176 	if (flag == -1) {
177 		wmove(win->x_win, 0, 0);
178 		win->x_line = 0;
179 		win->x_col = 0;
180 		return;
181 	}
182 	win->x_line = (win->x_line + 1) % win->x_nlines;
183 	win->x_col = 0;
184 	wmove(win->x_win, win->x_line, win->x_col);
185 	wclrtoeol(win->x_win);
186 	wmove(win->x_win, (win->x_line + 1) % win->x_nlines, win->x_col);
187 	wclrtoeol(win->x_win);
188 	wmove(win->x_win, win->x_line, win->x_col);
189 }
190