xref: /freebsd/usr.bin/talk/display.c (revision ea825d02749f382c3f7e17f28247f20a48733eab)
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. 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 #include <wctype.h>
45 #define _XOPEN_SOURCE_EXTENDED
46 #include <curses.h>
47 
48 #include "talk.h"
49 
50 void	display(xwin_t *, wchar_t *);
51 
52 xwin_t	my_win;
53 xwin_t	his_win;
54 WINDOW	*line_win;
55 
56 int	curses_initialized = 0;
57 
58 /*
59  * max HAS to be a function, it is called with
60  * an argument of the form --foo at least once.
61  */
62 int
63 max(int a, int b)
64 {
65 
66 	return (a > b ? a : b);
67 }
68 
69 static cchar_t *
70 makecchar(wchar_t in)
71 {
72 	static cchar_t cc;
73 	wchar_t wc[2];
74 
75 	wc[0] = in;
76 	wc[1] = L'\0';
77 
78 	if (setcchar(&cc, wc, A_NORMAL, 0, NULL) != OK)
79 		p_error("settchar(3) failure");
80 
81 	return (&cc);
82 }
83 
84 /*
85  * Display a symbol on somebody's window, processing some control
86  * characters while we are at it.
87  */
88 void
89 display(xwin_t *win, wchar_t *wc)
90 {
91 
92 	/*
93 	 * Alas, can't use variables in C switch statement.
94 	 * Workaround these 3 cases with goto.
95 	 */
96 	if (*wc == win->kill)
97 		goto kill;
98 	else if (*wc == win->cerase)
99 		goto cerase;
100 	else if (*wc == win->werase)
101 		goto werase;
102 
103 	switch (*wc) {
104 	case L'\n':
105 	case L'\r':
106 		wadd_wch(win->x_win, makecchar(L'\n'));
107 		getyx(win->x_win, win->x_line, win->x_col);
108 		wrefresh(win->x_win);
109 		return;
110 
111 	case 004:
112 		if (win == &my_win) {
113 			/* Ctrl-D clears the screen. */
114 			werase(my_win.x_win);
115 			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
116 			wrefresh(my_win.x_win);
117 			werase(his_win.x_win);
118 			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
119 			wrefresh(his_win.x_win);
120 		}
121 		return;
122 
123 	/* Erase character. */
124 	case 010:	/* BS */
125 	case 0177:	/* DEL */
126 cerase:
127 		wmove(win->x_win, win->x_line, max(--win->x_col, 0));
128 		getyx(win->x_win, win->x_line, win->x_col);
129 		waddch(win->x_win, ' ');
130 		wmove(win->x_win, win->x_line, win->x_col);
131 		getyx(win->x_win, win->x_line, win->x_col);
132 		wrefresh(win->x_win);
133 		return;
134 
135 	case 027:	/* ^W */
136 werase:
137 	    {
138 		/*
139 		 * On word erase search backwards until we find
140 		 * the beginning of a word or the beginning of
141 		 * the line.
142 		 */
143 		int endcol, xcol, c;
144 
145 		endcol = win->x_col;
146 		xcol = endcol - 1;
147 		while (xcol >= 0) {
148 			c = readwin(win->x_win, win->x_line, xcol);
149 			if (c != ' ')
150 				break;
151 			xcol--;
152 		}
153 		while (xcol >= 0) {
154 			c = readwin(win->x_win, win->x_line, xcol);
155 			if (c == ' ')
156 				break;
157 			xcol--;
158 		}
159 		wmove(win->x_win, win->x_line, xcol + 1);
160 		for (int i = xcol + 1; i < endcol; i++)
161 			waddch(win->x_win, ' ');
162 		wmove(win->x_win, win->x_line, xcol + 1);
163 		getyx(win->x_win, win->x_line, win->x_col);
164 		wrefresh(win->x_win);
165 		return;
166 	    }
167 
168 	case 025:	/* ^U */
169 kill:
170 		wmove(win->x_win, win->x_line, 0);
171 		wclrtoeol(win->x_win);
172 		getyx(win->x_win, win->x_line, win->x_col);
173 		wrefresh(win->x_win);
174 		return;
175 
176 	case L'\f':
177 		if (win == &my_win)
178 			wrefresh(curscr);
179 		return;
180 
181 	case L'\7':
182 		write(STDOUT_FILENO, wc, sizeof(*wc));
183 		return;
184 	}
185 
186 
187 	if (iswprint(*wc) || *wc == L'\t')
188 		wadd_wch(win->x_win, makecchar(*wc));
189 	else
190 		beep();
191 
192 	getyx(win->x_win, win->x_line, win->x_col);
193 	wrefresh(win->x_win);
194 }
195 
196 /*
197  * Read the character at the indicated position in win
198  */
199 int
200 readwin(WINDOW *win, int line, int col)
201 {
202 	int oldline, oldcol;
203 	int c;
204 
205 	getyx(win, oldline, oldcol);
206 	wmove(win, line, col);
207 	c = winch(win);
208 	wmove(win, oldline, oldcol);
209 	return (c);
210 }
211