xref: /freebsd/usr.bin/talk/display.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 
34 __FBSDID("$FreeBSD$");
35 
36 #ifndef lint
37 static const char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
38 #endif
39 
40 /*
41  * The window 'manager', initializes curses and handles the actual
42  * displaying of text
43  */
44 #include <ctype.h>
45 #include <unistd.h>
46 #include <wctype.h>
47 #define _XOPEN_SOURCE_EXTENDED
48 #include <curses.h>
49 
50 #include "talk.h"
51 
52 void	display(xwin_t *, wchar_t *);
53 
54 xwin_t	my_win;
55 xwin_t	his_win;
56 WINDOW	*line_win;
57 
58 int	curses_initialized = 0;
59 
60 /*
61  * max HAS to be a function, it is called with
62  * an argument of the form --foo at least once.
63  */
64 int
65 max(int a, int b)
66 {
67 
68 	return (a > b ? a : b);
69 }
70 
71 static cchar_t *
72 makecchar(wchar_t in)
73 {
74 	static cchar_t cc;
75 	wchar_t wc[2];
76 
77 	wc[0] = in;
78 	wc[1] = L'\0';
79 
80 	if (setcchar(&cc, wc, A_NORMAL, 0, NULL) != OK)
81 		p_error("settchar(3) failure");
82 
83 	return (&cc);
84 }
85 
86 /*
87  * Display a symbol on somebody's window, processing some control
88  * characters while we are at it.
89  */
90 void
91 display(xwin_t *win, wchar_t *wc)
92 {
93 
94 	/*
95 	 * Alas, can't use variables in C switch statement.
96 	 * Workaround these 3 cases with goto.
97 	 */
98 	if (*wc == win->kill)
99 		goto kill;
100 	else if (*wc == win->cerase)
101 		goto cerase;
102 	else if (*wc == win->werase)
103 		goto werase;
104 
105 	switch (*wc) {
106 	case L'\n':
107 	case L'\r':
108 		wadd_wch(win->x_win, makecchar(L'\n'));
109 		getyx(win->x_win, win->x_line, win->x_col);
110 		wrefresh(win->x_win);
111 		return;
112 
113 	case 004:
114 		if (win == &my_win) {
115 			/* Ctrl-D clears the screen. */
116 			werase(my_win.x_win);
117 			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
118 			wrefresh(my_win.x_win);
119 			werase(his_win.x_win);
120 			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
121 			wrefresh(his_win.x_win);
122 		}
123 		return;
124 
125 	/* Erase character. */
126 	case 010:	/* BS */
127 	case 0177:	/* DEL */
128 cerase:
129 		wmove(win->x_win, win->x_line, max(--win->x_col, 0));
130 		getyx(win->x_win, win->x_line, win->x_col);
131 		waddch(win->x_win, ' ');
132 		wmove(win->x_win, win->x_line, win->x_col);
133 		getyx(win->x_win, win->x_line, win->x_col);
134 		wrefresh(win->x_win);
135 		return;
136 
137 	case 027:	/* ^W */
138 werase:
139 	    {
140 		/*
141 		 * On word erase search backwards until we find
142 		 * the beginning of a word or the beginning of
143 		 * the line.
144 		 */
145 		int endcol, xcol, c;
146 
147 		endcol = win->x_col;
148 		xcol = endcol - 1;
149 		while (xcol >= 0) {
150 			c = readwin(win->x_win, win->x_line, xcol);
151 			if (c != ' ')
152 				break;
153 			xcol--;
154 		}
155 		while (xcol >= 0) {
156 			c = readwin(win->x_win, win->x_line, xcol);
157 			if (c == ' ')
158 				break;
159 			xcol--;
160 		}
161 		wmove(win->x_win, win->x_line, xcol + 1);
162 		for (int i = xcol + 1; i < endcol; i++)
163 			waddch(win->x_win, ' ');
164 		wmove(win->x_win, win->x_line, xcol + 1);
165 		getyx(win->x_win, win->x_line, win->x_col);
166 		wrefresh(win->x_win);
167 		return;
168 	    }
169 
170 	case 025:	/* ^U */
171 kill:
172 		wmove(win->x_win, win->x_line, 0);
173 		wclrtoeol(win->x_win);
174 		getyx(win->x_win, win->x_line, win->x_col);
175 		wrefresh(win->x_win);
176 		return;
177 
178 	case L'\f':
179 		if (win == &my_win)
180 			wrefresh(curscr);
181 		return;
182 
183 	case L'\7':
184 		write(STDOUT_FILENO, wc, sizeof(*wc));
185 		return;
186 	}
187 
188 
189 	if (iswprint(*wc) || *wc == L'\t')
190 		wadd_wch(win->x_win, makecchar(*wc));
191 	else
192 		beep();
193 
194 	getyx(win->x_win, win->x_line, win->x_col);
195 	wrefresh(win->x_win);
196 }
197 
198 /*
199  * Read the character at the indicated position in win
200  */
201 int
202 readwin(WINDOW *win, int line, int col)
203 {
204 	int oldline, oldcol;
205 	int c;
206 
207 	getyx(win, oldline, oldcol);
208 	wmove(win, line, col);
209 	c = winch(win);
210 	wmove(win, oldline, oldcol);
211 	return (c);
212 }
213