xref: /minix3/lib/libcurses/tstp.c (revision 58a2b0008e28f606a7f7f5faaeaba4faac57a1ea)
1 /*	$NetBSD: tstp.c,v 1.38 2010/02/03 15:34:40 roy Exp $	*/
2 
3 /*
4  * Copyright (c) 1981, 1993, 1994
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 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)tstp.c	8.3 (Berkeley) 5/4/94";
36 #else
37 __RCSID("$NetBSD: tstp.c,v 1.38 2010/02/03 15:34:40 roy Exp $");
38 #endif
39 #endif				/* not lint */
40 
41 #ifndef TCSASOFT
42 #define TCSASOFT 0
43 #endif
44 
45 #include <sys/ioctl.h>
46 
47 #include <errno.h>
48 #include <signal.h>
49 #include <termios.h>
50 #include <unistd.h>
51 
52 #include "curses.h"
53 #include "curses_private.h"
54 
55 static int tstp_set = 0;
56 static int winch_set = 0;
57 
58 static void (*otstpfn)
59 __P((int)) = SIG_DFL;
60 
61 static struct sigaction	owsa;
62 
63 /*
64  * stop_signal_handler --
65  *	Handle stop signals.
66  */
67 void
68 __stop_signal_handler(/*ARGSUSED*/int signo)
69 {
70 	sigset_t oset, set;
71 
72 	/*
73 	 * Block window change and timer signals.  The latter is because
74 	 * applications use timers to decide when to repaint the screen.
75 	 */
76 	(void) sigemptyset(&set);
77 	(void) sigaddset(&set, SIGALRM);
78 	(void) sigaddset(&set, SIGWINCH);
79 	(void) sigprocmask(SIG_BLOCK, &set, &oset);
80 
81 	/*
82 	 * End the window, which also resets the terminal state to the
83 	 * original modes.
84 	 */
85 	__stopwin();
86 
87 	/* Unblock SIGTSTP. */
88 	(void) sigemptyset(&set);
89 	(void) sigaddset(&set, SIGTSTP);
90 	(void) sigprocmask(SIG_UNBLOCK, &set, NULL);
91 
92 	/* Stop ourselves. */
93 	(void) kill(0, SIGTSTP);
94 
95 	/* Time passes ... */
96 
97 	/* restart things */
98 	__restartwin();
99 
100 	/* Reset the signals. */
101 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
102 }
103 
104 /*
105  * Set the TSTP handler.
106  */
107 void
108 __set_stophandler(void)
109 {
110 #ifdef DEBUG
111 	__CTRACE(__CTRACE_MISC, "__set_stophandler: %d\n", tstp_set);
112 #endif
113 	if (!tstp_set) {
114 		otstpfn = signal(SIGTSTP, __stop_signal_handler);
115 		tstp_set = 1;
116 	}
117 }
118 
119 /*
120  * Restore the TSTP handler.
121  */
122 void
123 __restore_stophandler(void)
124 {
125 #ifdef DEBUG
126 	__CTRACE(__CTRACE_MISC, "__restore_stophandler: %d\n", tstp_set);
127 #endif
128 	if (tstp_set) {
129 		(void) signal(SIGTSTP, otstpfn);
130 		tstp_set = 0;
131 	}
132 }
133 
134 /*
135  * winch_signal_handler --
136  *	Handle winch signals by pushing KEY_RESIZE into the input stream.
137  */
138 void
139 __winch_signal_handler(/*ARGSUSED*/int signo)
140 {
141 	struct winsize win;
142 
143 	if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
144 	    win.ws_row != 0 && win.ws_col != 0) {
145 		LINES = win.ws_row;
146 		COLS = win.ws_col;
147 	}
148 	/*
149 	 * If there was a previous handler, call that,
150 	 * otherwise tell getch() to send KEY_RESIZE.
151 	 */
152 	if (owsa.sa_handler !=  NULL)
153 		owsa.sa_handler(signo);
154 	else
155 		_cursesi_screen->resized = 1;
156 }
157 
158 /*
159  * Set the WINCH handler.
160  */
161 void
162 __set_winchhandler(void)
163 {
164 #ifdef DEBUG
165 	__CTRACE(__CTRACE_MISC, "__set_winchhandler: %d\n", winch_set);
166 #endif
167 	if (!winch_set) {
168 		struct sigaction sa;
169 
170 		sa.sa_handler = __winch_signal_handler;
171 		sa.sa_flags = 0;
172 		sigemptyset(&sa.sa_mask);
173 		sigaction(SIGWINCH, &sa, &owsa);
174 		winch_set = 1;
175 #ifdef DEBUG
176 		__CTRACE(__CTRACE_MISC,
177 		    "__set_winchhandler: owsa.sa_handler=%p\n",
178 		    owsa.sa_handler);
179 #endif
180 	}
181 }
182 
183 /*
184  * Restore the WINCH handler.
185  */
186 void
187 __restore_winchhandler(void)
188 {
189 #ifdef DEBUG
190 	__CTRACE(__CTRACE_MISC, "__restore_winchhandler: %d\n", winch_set);
191 #endif
192 	if (winch_set > 0) {
193 		struct sigaction cwsa;
194 
195 		sigaction(SIGWINCH, NULL, &cwsa);
196 		if (cwsa.sa_handler == owsa.sa_handler) {
197 			sigaction(SIGWINCH, &owsa, NULL);
198 			winch_set = 0;
199 		} else {
200 			/*
201 			 * We're now using the programs WINCH handler,
202 			 * so don't restore the previous one.
203 			 */
204 			winch_set = -1;
205 #ifdef DEBUG
206 			__CTRACE(__CTRACE_MISC, "cwsa.sa_handler = %p\n",
207 			    cwsa.sa_handler);
208 #endif
209 		}
210 	}
211 }
212 
213 /* To allow both SIGTSTP and endwin() to come back nicely, we provide
214    the following routines. */
215 
216 int
217 __stopwin(void)
218 {
219 #ifdef DEBUG
220 	__CTRACE(__CTRACE_MISC, "__stopwin\n");
221 #endif
222 	if (_cursesi_screen->endwin)
223 		return OK;
224 
225 	/* Get the current terminal state (which the user may have changed). */
226 	(void) tcgetattr(fileno(_cursesi_screen->infd),
227 			 &_cursesi_screen->save_termios);
228 
229 	__restore_stophandler();
230 	__restore_winchhandler();
231 
232 	if (curscr != NULL) {
233 		__unsetattr(0);
234 		__mvcur((int) curscr->cury, (int) curscr->curx,
235 		    (int) curscr->maxy - 1, 0, 0);
236 	}
237 
238 	if (meta_off != NULL)
239 		(void) tputs(meta_off, 0, __cputchar);
240 
241 	if ((curscr != NULL) && (curscr->flags & __KEYPAD))
242 		(void) tputs(keypad_local, 0, __cputchar);
243 	(void) tputs(cursor_normal, 0, __cputchar);
244 	(void) tputs(exit_ca_mode, 0, __cputchar);
245 	(void) fflush(_cursesi_screen->outfd);
246 	(void) setvbuf(_cursesi_screen->outfd, NULL, _IOLBF, (size_t) 0);
247 
248 	_cursesi_screen->endwin = 1;
249 
250 	return (tcsetattr(fileno(_cursesi_screen->infd),
251 			  __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
252 			  &_cursesi_screen->orig_termios) ? ERR : OK);
253 }
254 
255 
256 void
257 __restartwin(void)
258 {
259 	struct winsize win;
260 	int nlines, ncols;
261 
262 #ifdef DEBUG
263 	__CTRACE(__CTRACE_MISC, "__restartwin\n");
264 #endif
265 	if (!_cursesi_screen->endwin)
266 		return;
267 
268 	/* Reset the curses SIGTSTP and SIGWINCH signal handlers. */
269 	__set_stophandler();
270 	__set_winchhandler();
271 
272 	/*
273 	 * Check to see if the window size has changed.
274 	 * If the application didn't update LINES and COLS,
275 	 * set the * resized flag to tell getch() to push KEY_RESIZE.
276 	 * Update curscr (which also updates __virtscr) and stdscr
277 	 * to match the new size.
278 	 */
279 	if (ioctl(fileno(_cursesi_screen->outfd), TIOCGWINSZ, &win) != -1 &&
280 	    win.ws_row != 0 && win.ws_col != 0) {
281 		if (win.ws_row != LINES) {
282 			LINES = win.ws_row;
283 			_cursesi_screen->resized = 1;
284 		}
285 		if (win.ws_col != COLS) {
286 			COLS = win.ws_col;
287 			_cursesi_screen->resized = 1;
288 		}
289 	}
290 	/*
291 	 * We need to make local copies of LINES and COLS, otherwise we
292 	 * could lose if they are changed between wresize() calls.
293 	 */
294 	nlines = LINES;
295 	ncols = COLS;
296 	if (curscr->maxy != nlines || curscr->maxx != ncols)
297 		wresize(curscr, nlines, ncols);
298 	if (stdscr->maxy != nlines || stdscr->maxx != ncols)
299 		wresize(stdscr, nlines, ncols);
300 
301 	/* save the new "default" terminal state */
302 	(void) tcgetattr(fileno(_cursesi_screen->infd),
303 			 &_cursesi_screen->orig_termios);
304 
305 	/* Reset the terminal state to the mode just before we stopped. */
306 	(void) tcsetattr(fileno(_cursesi_screen->infd),
307 			 __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
308 			 &_cursesi_screen->save_termios);
309 
310 	/* Restore colours */
311 	__restore_colors();
312 
313 	/* Reset meta */
314 	__restore_meta_state();
315 
316 	/* Restart the screen. */
317 	__startwin(_cursesi_screen);
318 
319 	/* Reset cursor visibility */
320 	__restore_cursor_vis();
321 
322 	/* Repaint the screen. */
323 	wrefresh(curscr);
324 }
325 
326 int
327 def_prog_mode(void)
328 {
329 	if (_cursesi_screen->endwin)
330 		return ERR;
331 
332 	return (tcgetattr(fileno(_cursesi_screen->infd),
333 			  &_cursesi_screen->save_termios) ? ERR : OK);
334 }
335 
336 int
337 reset_prog_mode(void)
338 {
339 
340 	return tcsetattr(fileno(_cursesi_screen->infd),
341 			 __tcaction ? TCSASOFT | TCSADRAIN : TCSADRAIN,
342 			 &_cursesi_screen->save_termios) ? ERR : OK;
343 }
344 
345 int
346 def_shell_mode(void)
347 {
348 	return (tcgetattr(fileno(_cursesi_screen->infd),
349 			  &_cursesi_screen->orig_termios) ? ERR : OK);
350 }
351 
352 int
353 reset_shell_mode(void)
354 {
355 	return (__stopwin());
356 }
357