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