xref: /freebsd/usr.bin/talk/display.c (revision 315ee00f)
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 
33 #ifndef lint
34 static const char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
35 #endif
36 
37 /*
38  * The window 'manager', initializes curses and handles the actual
39  * displaying of text
40  */
41 #include <ctype.h>
42 #include <unistd.h>
43 #include <wctype.h>
44 #define _XOPEN_SOURCE_EXTENDED
45 #include <curses.h>
46 
47 #include "talk.h"
48 
49 void	display(xwin_t *, wchar_t *);
50 
51 xwin_t	my_win;
52 xwin_t	his_win;
53 WINDOW	*line_win;
54 
55 int	curses_initialized = 0;
56 
57 /*
58  * max HAS to be a function, it is called with
59  * an argument of the form --foo at least once.
60  */
61 int
62 max(int a, int b)
63 {
64 
65 	return (a > b ? a : b);
66 }
67 
68 static cchar_t *
69 makecchar(wchar_t in)
70 {
71 	static cchar_t cc;
72 	wchar_t wc[2];
73 
74 	wc[0] = in;
75 	wc[1] = L'\0';
76 
77 	if (setcchar(&cc, wc, A_NORMAL, 0, NULL) != OK)
78 		p_error("settchar(3) failure");
79 
80 	return (&cc);
81 }
82 
83 /*
84  * Display a symbol on somebody's window, processing some control
85  * characters while we are at it.
86  */
87 void
88 display(xwin_t *win, wchar_t *wc)
89 {
90 
91 	/*
92 	 * Alas, can't use variables in C switch statement.
93 	 * Workaround these 3 cases with goto.
94 	 */
95 	if (*wc == win->kill)
96 		goto kill;
97 	else if (*wc == win->cerase)
98 		goto cerase;
99 	else if (*wc == win->werase)
100 		goto werase;
101 
102 	switch (*wc) {
103 	case L'\n':
104 	case L'\r':
105 		wadd_wch(win->x_win, makecchar(L'\n'));
106 		getyx(win->x_win, win->x_line, win->x_col);
107 		wrefresh(win->x_win);
108 		return;
109 
110 	case 004:
111 		if (win == &my_win) {
112 			/* Ctrl-D clears the screen. */
113 			werase(my_win.x_win);
114 			getyx(my_win.x_win, my_win.x_line, my_win.x_col);
115 			wrefresh(my_win.x_win);
116 			werase(his_win.x_win);
117 			getyx(his_win.x_win, his_win.x_line, his_win.x_col);
118 			wrefresh(his_win.x_win);
119 		}
120 		return;
121 
122 	/* Erase character. */
123 	case 010:	/* BS */
124 	case 0177:	/* DEL */
125 cerase:
126 		wmove(win->x_win, win->x_line, max(--win->x_col, 0));
127 		getyx(win->x_win, win->x_line, win->x_col);
128 		waddch(win->x_win, ' ');
129 		wmove(win->x_win, win->x_line, win->x_col);
130 		getyx(win->x_win, win->x_line, win->x_col);
131 		wrefresh(win->x_win);
132 		return;
133 
134 	case 027:	/* ^W */
135 werase:
136 	    {
137 		/*
138 		 * On word erase search backwards until we find
139 		 * the beginning of a word or the beginning of
140 		 * the line.
141 		 */
142 		int endcol, xcol, c;
143 
144 		endcol = win->x_col;
145 		xcol = endcol - 1;
146 		while (xcol >= 0) {
147 			c = readwin(win->x_win, win->x_line, xcol);
148 			if (c != ' ')
149 				break;
150 			xcol--;
151 		}
152 		while (xcol >= 0) {
153 			c = readwin(win->x_win, win->x_line, xcol);
154 			if (c == ' ')
155 				break;
156 			xcol--;
157 		}
158 		wmove(win->x_win, win->x_line, xcol + 1);
159 		for (int i = xcol + 1; i < endcol; i++)
160 			waddch(win->x_win, ' ');
161 		wmove(win->x_win, win->x_line, xcol + 1);
162 		getyx(win->x_win, win->x_line, win->x_col);
163 		wrefresh(win->x_win);
164 		return;
165 	    }
166 
167 	case 025:	/* ^U */
168 kill:
169 		wmove(win->x_win, win->x_line, 0);
170 		wclrtoeol(win->x_win);
171 		getyx(win->x_win, win->x_line, win->x_col);
172 		wrefresh(win->x_win);
173 		return;
174 
175 	case L'\f':
176 		if (win == &my_win)
177 			wrefresh(curscr);
178 		return;
179 
180 	case L'\7':
181 		write(STDOUT_FILENO, wc, sizeof(*wc));
182 		return;
183 	}
184 
185 
186 	if (iswprint(*wc) || *wc == L'\t')
187 		wadd_wch(win->x_win, makecchar(*wc));
188 	else
189 		beep();
190 
191 	getyx(win->x_win, win->x_line, win->x_col);
192 	wrefresh(win->x_win);
193 }
194 
195 /*
196  * Read the character at the indicated position in win
197  */
198 int
199 readwin(WINDOW *win, int line, int col)
200 {
201 	int oldline, oldcol;
202 	int c;
203 
204 	getyx(win, oldline, oldcol);
205 	wmove(win, line, col);
206 	c = winch(win);
207 	wmove(win, oldline, oldcol);
208 	return (c);
209 }
210