1 /*
2  * Window system protocol server.
3  * Use select and a single proc and single stack
4  * to avoid aggravating the X11 library, which is
5  * subtle and quick to anger.
6  */
7 
8 // #define SHOWEVENT
9 
10 #include <u.h>
11 #include <sys/select.h>
12 #include <errno.h>
13 #ifdef SHOWEVENT
14 #include <stdio.h>
15 #endif
16 #include "x11-inc.h"
17 
18 #include <libc.h>
19 #include <draw.h>
20 #include <memdraw.h>
21 #include <memlayer.h>
22 #include <keyboard.h>
23 #include <mouse.h>
24 #include <cursor.h>
25 #include <drawfcall.h>
26 #include "x11-memdraw.h"
27 #include "devdraw.h"
28 
29 #undef time
30 
31 #define MouseMask (\
32 	ButtonPressMask|\
33 	ButtonReleaseMask|\
34 	PointerMotionMask|\
35 	Button1MotionMask|\
36 	Button2MotionMask|\
37 	Button3MotionMask)
38 
39 #define Mask MouseMask|ExposureMask|StructureNotifyMask|KeyPressMask|EnterWindowMask|LeaveWindowMask
40 
41 typedef struct Kbdbuf Kbdbuf;
42 typedef struct Mousebuf Mousebuf;
43 typedef struct Fdbuf Fdbuf;
44 typedef struct Tagbuf Tagbuf;
45 
46 struct Kbdbuf
47 {
48 	Rune r[32];
49 	int ri;
50 	int wi;
51 	int stall;
52 };
53 
54 struct Mousebuf
55 {
56 	Mouse m[32];
57 	int ri;
58 	int wi;
59 	int stall;
60 	int resized;
61 };
62 
63 struct Tagbuf
64 {
65 	int t[32];
66 	int ri;
67 	int wi;
68 };
69 
70 struct Fdbuf
71 {
72 	uchar buf[2*MAXWMSG];
73 	uchar *rp;
74 	uchar *wp;
75 	uchar *ep;
76 };
77 
78 Kbdbuf kbd;
79 Mousebuf mouse;
80 Fdbuf fdin;
81 Fdbuf fdout;
82 Tagbuf kbdtags;
83 Tagbuf mousetags;
84 
85 void fdslide(Fdbuf*);
86 void runmsg(Wsysmsg*);
87 void replymsg(Wsysmsg*);
88 void runxevent(XEvent*);
89 void matchkbd(void);
90 void matchmouse(void);
91 int fdnoblock(int);
92 
93 int chatty;
94 int drawsleep;
95 int fullscreen;
96 
97 Rectangle windowrect;
98 Rectangle screenrect;
99 
100 void
101 usage(void)
102 {
103 	fprint(2, "usage: devdraw (don't run directly)\n");
104 	exits("usage");
105 }
106 
107 void
108 bell(void *v, char *msg)
109 {
110 	if(strcmp(msg, "alarm") == 0)
111 		drawsleep = drawsleep ? 0 : 1000;
112 	noted(NCONT);
113 }
114 
115 void
116 main(int argc, char **argv)
117 {
118 	int n, top, firstx;
119 	fd_set rd, wr, xx;
120 	Wsysmsg m;
121 	XEvent event;
122 
123 	/*
124 	 * Move the protocol off stdin/stdout so that
125 	 * any inadvertent prints don't screw things up.
126 	 */
127 	dup(0, 3);
128 	dup(1, 4);
129 	close(0);
130 	close(1);
131 	open("/dev/null", OREAD);
132 	open("/dev/null", OWRITE);
133 
134 	/* reopens stdout if debugging */
135 	runxevent(0);
136 
137 	fmtinstall('W', drawfcallfmt);
138 
139 	ARGBEGIN{
140 	case 'D':
141 		chatty++;
142 		break;
143 	default:
144 		usage();
145 	}ARGEND
146 
147 	/*
148 	 * Ignore arguments.  They're only for good ps -a listings.
149 	 */
150 	
151 	notify(bell);
152 
153 	fdin.rp = fdin.wp = fdin.buf;
154 	fdin.ep = fdin.buf+sizeof fdin.buf;
155 	
156 	fdout.rp = fdout.wp = fdout.buf;
157 	fdout.ep = fdout.buf+sizeof fdout.buf;
158 
159 	fdnoblock(3);
160 	fdnoblock(4);
161 
162 	firstx = 1;
163 	_x.fd = -1;
164 	for(;;){
165 		/* set up file descriptors */
166 		FD_ZERO(&rd);
167 		FD_ZERO(&wr);
168 		FD_ZERO(&xx);
169 		/*
170 		 * Don't read unless there's room *and* we haven't
171 		 * already filled the output buffer too much.
172 		 */
173 		if(fdout.wp < fdout.buf+MAXWMSG && fdin.wp < fdin.ep)
174 			FD_SET(3, &rd);
175 		if(fdout.wp > fdout.rp)
176 			FD_SET(4, &wr);
177 		FD_SET(3, &xx);
178 		FD_SET(4, &xx);
179 		top = 4;
180 		if(_x.fd >= 0){
181 			if(firstx){
182 				firstx = 0;
183 				XSelectInput(_x.display, _x.drawable, Mask);
184 			}
185 			FD_SET(_x.fd, &rd);
186 			FD_SET(_x.fd, &xx);
187 			XFlush(_x.display);
188 			if(_x.fd > top)
189 				top = _x.fd;
190 		}
191 
192 		if(chatty)
193 			fprint(2, "select %d...\n", top+1);
194 		/* wait for something to happen */
195 	    again:
196 		if(select(top+1, &rd, &wr, &xx, NULL) < 0){
197 			if(errno == EINTR)
198 				goto again;
199 			if(chatty)
200 				fprint(2, "select failure\n");
201 			exits(0);
202 		}
203 		if(chatty)
204 			fprint(2, "got select...\n");
205 
206 		{
207 			/* read what we can */
208 			n = 1;
209 			while(fdin.wp < fdin.ep && (n = read(3, fdin.wp, fdin.ep-fdin.wp)) > 0)
210 				fdin.wp += n;
211 			if(n == 0){
212 				if(chatty)
213 					fprint(2, "eof\n");
214 				exits(0);
215 			}
216 			if(n < 0 && errno != EAGAIN)
217 				sysfatal("reading wsys msg: %r");
218 
219 			/* pick off messages one by one */
220 			while((n = convM2W(fdin.rp, fdin.wp-fdin.rp, &m)) > 0){
221 				/* fprint(2, "<- %W\n", &m); */
222 				runmsg(&m);
223 				fdin.rp += n;
224 			}
225 			
226 			/* slide data to beginning of buf */
227 			fdslide(&fdin);
228 		}
229 		{
230 			/* write what we can */
231 			n = 1;
232 			while(fdout.rp < fdout.wp && (n = write(4, fdout.rp, fdout.wp-fdout.rp)) > 0)
233 				fdout.rp += n;
234 			if(n == 0)
235 				sysfatal("short write writing wsys");
236 			if(n < 0 && errno != EAGAIN)
237 				sysfatal("writing wsys msg: %r");
238 
239 			/* slide data to beginning of buf */
240 			fdslide(&fdout);
241 		}
242 		{
243 			/*
244 			 * Read an X message if we can.
245 			 * (XPending actually calls select to make sure
246 			 * the display's fd is readable and then reads
247 			 * in any waiting data before declaring whether
248 			 * there are events on the queue.)
249 			 */
250 			while(XPending(_x.display)){
251 				XNextEvent(_x.display, &event);
252 				runxevent(&event);
253 			}
254 		}
255 	}
256 }
257 
258 int
259 fdnoblock(int fd)
260 {
261 	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL)|O_NONBLOCK);
262 }
263 
264 void
265 fdslide(Fdbuf *fb)
266 {
267 	int n;
268 
269 	n = fb->wp - fb->rp;
270 	if(n > 0)
271 		memmove(fb->buf, fb->rp, n);
272 	fb->rp = fb->buf;
273 	fb->wp = fb->rp+n;
274 }
275 
276 void
277 replyerror(Wsysmsg *m)
278 {
279 	char err[256];
280 	
281 	rerrstr(err, sizeof err);
282 	m->type = Rerror;
283 	m->error = err;
284 	replymsg(m);
285 }
286 
287 
288 
289 /* 
290  * Handle a single wsysmsg. 
291  * Might queue for later (kbd, mouse read)
292  */
293 void
294 runmsg(Wsysmsg *m)
295 {
296 	uchar buf[65536];
297 	int n;
298 	Memimage *i;
299 	
300 	switch(m->type){
301 	case Tinit:
302 		memimageinit();
303 		i = _xattach(m->label, m->winsize);
304 		_initdisplaymemimage(i);
305 		replymsg(m);
306 		break;
307 
308 	case Trdmouse:
309 		mousetags.t[mousetags.wi++] = m->tag;
310 		if(mousetags.wi == nelem(mousetags.t))
311 			mousetags.wi = 0;
312 		if(mousetags.wi == mousetags.ri)
313 			sysfatal("too many queued mouse reads");
314 		/* fprint(2, "mouse unstall\n"); */
315 		mouse.stall = 0;
316 		matchmouse();
317 		break;
318 
319 	case Trdkbd:
320 		kbdtags.t[kbdtags.wi++] = m->tag;
321 		if(kbdtags.wi == nelem(kbdtags.t))
322 			kbdtags.wi = 0;
323 		if(kbdtags.wi == kbdtags.ri)
324 			sysfatal("too many queued keyboard reads");
325 		kbd.stall = 0;
326 		matchkbd();
327 		break;
328 
329 	case Tmoveto:
330 		_xmoveto(m->mouse.xy);
331 		replymsg(m);
332 		break;
333 
334 	case Tcursor:
335 		if(m->arrowcursor)
336 			_xsetcursor(nil);
337 		else
338 			_xsetcursor(&m->cursor);
339 		replymsg(m);
340 		break;
341 			
342 	case Tbouncemouse:
343 		_xbouncemouse(&m->mouse);
344 		replymsg(m);
345 		break;
346 
347 	case Tlabel:
348 		_xsetlabel(m->label);
349 		replymsg(m);
350 		break;
351 
352 	case Trdsnarf:
353 		m->snarf = _xgetsnarf();
354 		replymsg(m);
355 		free(m->snarf);
356 		break;
357 
358 	case Twrsnarf:
359 		_xputsnarf(m->snarf);
360 		replymsg(m);
361 		break;
362 
363 	case Trddraw:
364 		n = m->count;
365 		if(n > sizeof buf)
366 			n = sizeof buf;
367 		n = _drawmsgread(buf, n);
368 		if(n < 0)
369 			replyerror(m);
370 		else{
371 			m->count = n;
372 			m->data = buf;
373 			replymsg(m);
374 		}
375 		break;
376 
377 	case Twrdraw:
378 		if(_drawmsgwrite(m->data, m->count) < 0)
379 			replyerror(m);
380 		else
381 			replymsg(m);
382 		break;
383 	
384 	case Ttop:
385 		_xtopwindow();
386 		replymsg(m);
387 		break;
388 	
389 	case Tresize:
390 		_xresizewindow(m->rect);
391 		replymsg(m);
392 		break;
393 	}
394 }
395 
396 /*
397  * Reply to m.
398  */
399 void
400 replymsg(Wsysmsg *m)
401 {
402 	int n;
403 
404 	/* T -> R msg */
405 	if(m->type%2 == 0)
406 		m->type++;
407 		
408 	/* fprint(2, "-> %W\n", m); */
409 	/* copy to output buffer */
410 	n = sizeW2M(m);
411 	if(fdout.wp+n > fdout.ep)
412 		sysfatal("out of space for reply message");
413 	convW2M(m, fdout.wp, n);
414 	fdout.wp += n;
415 }
416 
417 /*
418  * Match queued kbd reads with queued kbd characters.
419  */
420 void
421 matchkbd(void)
422 {
423 	Wsysmsg m;
424 	
425 	if(kbd.stall)
426 		return;
427 	while(kbd.ri != kbd.wi && kbdtags.ri != kbdtags.wi){
428 		m.type = Rrdkbd;
429 		m.tag = kbdtags.t[kbdtags.ri++];
430 		if(kbdtags.ri == nelem(kbdtags.t))
431 			kbdtags.ri = 0;
432 		m.rune = kbd.r[kbd.ri++];
433 		if(kbd.ri == nelem(kbd.r))
434 			kbd.ri = 0;
435 		replymsg(&m);
436 	}
437 }
438 
439 /*
440  * Match queued mouse reads with queued mouse events.
441  */
442 void
443 matchmouse(void)
444 {
445 	Wsysmsg m;
446 	
447 	while(mouse.ri != mouse.wi && mousetags.ri != mousetags.wi){
448 		m.type = Rrdmouse;
449 		m.tag = mousetags.t[mousetags.ri++];
450 		if(mousetags.ri == nelem(mousetags.t))
451 			mousetags.ri = 0;
452 		m.mouse = mouse.m[mouse.ri];
453 		m.resized = mouse.resized;
454 		/*
455 		if(m.resized)
456 			fprint(2, "sending resize\n");
457 		*/
458 		mouse.resized = 0;
459 		mouse.ri++;
460 		if(mouse.ri == nelem(mouse.m))
461 			mouse.ri = 0;
462 		replymsg(&m);
463 	}
464 }
465 
466 /*
467  * Handle an incoming X event.
468  */
469 void
470 runxevent(XEvent *xev)
471 {
472 	int c;
473 	KeySym k;
474 	static Mouse m;
475 
476 #ifdef SHOWEVENT
477 	static int first = 1;
478 	if(first){
479 		dup(create("/tmp/devdraw.out", OWRITE, 0666), 1);
480 		setbuf(stdout, 0);
481 		first = 0;
482 	}
483 #endif
484 
485 	if(xev == 0)
486 		return;
487 
488 #ifdef SHOWEVENT
489 	print("\n");
490 	ShowEvent(xev);
491 #endif
492 
493 	switch(xev->type){
494 	case Expose:
495 		_xexpose(xev);
496 		break;
497 	
498 	case DestroyNotify:
499 		if(_xdestroy(xev))
500 			exits(0);
501 		break;
502 
503 	case ConfigureNotify:
504 		if(_xconfigure(xev)){
505 			mouse.resized = 1;
506 			_xreplacescreenimage();
507 			goto addmouse;
508 		}
509 		break;
510 
511 	case ButtonPress:
512 	case ButtonRelease:
513 	case MotionNotify:
514 		if(mouse.stall)
515 			return;
516 		if(_xtoplan9mouse(xev, &m) < 0)
517 			return;
518 	addmouse:
519 		mouse.m[mouse.wi] = m;
520 		mouse.wi++;
521 		if(mouse.wi == nelem(mouse.m))
522 			mouse.wi = 0;
523 		if(mouse.wi == mouse.ri){
524 			mouse.stall = 1;
525 			mouse.ri = 0;
526 			mouse.wi = 1;
527 			mouse.m[0] = m;
528 			/* fprint(2, "mouse stall\n"); */
529 		}
530 		matchmouse();
531 		break;
532 	
533 	case KeyPress:
534 		if(kbd.stall)
535 			return;
536 		XLookupString((XKeyEvent*)xev, NULL, 0, &k, NULL);
537 		if(k == XK_F11){
538 			fullscreen = !fullscreen;
539 			_xmovewindow(fullscreen ? screenrect : windowrect);
540 			return;
541 		}
542 		if((c = _xtoplan9kbd(xev)) < 0)
543 			return;
544 		kbd.r[kbd.wi++] = c;
545 		if(kbd.wi == nelem(kbd.r))
546 			kbd.wi = 0;
547 		if(kbd.ri == kbd.wi)
548 			kbd.stall = 1;
549 		matchkbd();
550 		break;
551 	
552 	case SelectionRequest:
553 		_xselect(xev);
554 		break;
555 	}
556 }
557