1 /*
2  * Copyright (c) 2020 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "star-platinum.h"
18 
19 #include <err.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include <unistd.h>
23 
24 #include <X11/XKBlib.h>
25 #include <X11/Xutil.h>
26 
27 #ifndef __OpenBSD__
28 # define pledge(a, b) 0
29 #endif
30 
31 extern FILE *yyin;
32 char *fname;
33 
34 extern int yylineno;
35 int yyparse(void);
36 
37 struct group *config;
38 int goterror = 0;
39 
40 Display *d;
41 
42 int ignored_modifiers[] = {
43 	0, 			/* no modifiers */
44 	LockMask,		/* caps lock */
45 	Mod2Mask,		/* num lock */
46 	Mod3Mask,		/* scroll lock */
47 	Mod5Mask,		/* ? */
48 };
49 
50 #define IGNORE_MODIFIERS (LockMask | Mod2Mask | Mod3Mask | Mod5Mask)
51 
52 void
53 yyerror(const char *e)
54 {
55 	goterror = 1;
56 	fprintf(stderr, "%s:%d %s\n", fname, yylineno, e);
57 }
58 
59 char *
60 find_config()
61 {
62 	char *home, *xdg, *t;
63 	int free_xdg = 0;
64 
65 	home = getenv("HOME");
66 	xdg = getenv("XDG_CONFIG_HOME");
67 
68 	if (home == NULL && xdg == NULL)
69 		return NULL;
70 
71 	/* file in home directory >>>>>> XDG shit */
72 	if (home != NULL) {
73 		if (asprintf(&t, "%s/.star-platinum.conf", home) == -1)
74 			return NULL;
75 		if (access(t, R_OK) == 0)
76 			return t;
77 
78 		free(t);
79 		/* continue to search */
80 	}
81 
82 	/* sanitize XDG_CONFIG_HOME */
83 	if (xdg == NULL) {
84 		free_xdg = 1;
85 		if (asprintf(&xdg, "%s/.config", home) == -1)
86 			return NULL;
87 	}
88 
89 	if (asprintf(&t, "%s/star-platinum.conf", xdg) == -1)
90 		goto err;
91 
92 	if (access(t, R_OK) == 0)
93 		return t;
94 	free(t);
95 
96 err:
97 	if (free_xdg)
98 		free(xdg);
99 
100 	return NULL;
101 }
102 
103 int
104 main(int argc, char **argv)
105 {
106 	int status = 0, dump_config = 0, conftest = 0, ch;
107 	struct group *g;
108 	struct rule *r;
109 	XEvent e;
110 	Window root;
111 
112 	fname = NULL;
113 	while ((ch = getopt(argc, argv, "c:dn")) != -1) {
114 		switch (ch) {
115 		case 'c':
116 			free(fname);
117 			if ((fname = strdup(optarg)) == NULL)
118 				err(1, "strdup");
119 			break;
120 
121 		case 'd':
122 			dump_config = 1;
123 			break;
124 
125 		case 'n':
126 			conftest = 1;
127 			break;
128 
129 		default:
130 			fprintf(stderr, "USAGE: %s [-dn] [-c conf]\n", *argv);
131 			return 1;
132 		}
133 	}
134 
135 	if (fname == NULL) {
136 		if ((fname = find_config()) == NULL)
137 			errx(1, "can't find a configuration file");
138 	}
139 
140 	if ((yyin = fopen(fname, "r")) == NULL)
141 		err(1, "cannot open %s", fname);
142 	yyparse();
143 	fclose(yyin);
144 
145 	free(fname);
146 	fname = NULL;
147 
148 	if (goterror)
149                 return 1;
150 
151 	if (dump_config)
152 		printgroup(config);
153 
154 	if (conftest) {
155 		recfree_group(config);
156 		return 0;
157 	}
158 
159 	if ((d = XOpenDisplay(NULL)) == NULL) {
160 		recfree_group(config);
161 		return 1;
162 	}
163 
164 	root = DefaultRootWindow(d);
165 
166 	/* grab all the keys */
167 	for (g = config; g != NULL; g = g->next)
168 		for (r = g->rules; r != NULL; r = r->next)
169 			grabkey(r->key);
170 
171 	XSelectInput(d, root, KeyPressMask);
172 	XFlush(d);
173 
174 	pledge("stdio", "");
175 
176 	while (1) {
177 		XNextEvent(d, &e);
178 		switch (e.type) {
179 		case KeyRelease:
180 		case KeyPress:
181 			process_event(config, (XKeyEvent*)&e);
182 			break;
183 
184 		default:
185 			printf("Unknown event %d\n", e.type);
186 			break;
187 		}
188 	}
189 
190 	XCloseDisplay(d);
191 	recfree_group(config);
192 	return status;
193 }
194 
195 
196 /* xlib */
197 
198 /* TODO: it should grab ALL POSSIBLE COMBINATIONS of `ignored_modifiers`! */
199 void
200 grabkey(struct key k)
201 {
202 	static size_t len = sizeof(ignored_modifiers)/sizeof(int);
203 	size_t i;
204 	Window root;
205 
206 	root = DefaultRootWindow(d);
207 
208 	/* printf("Grabbing "); printkey(k); printf("\n"); */
209 	for (i = 0; i < len; ++i) {
210                 XGrabKey(d, XKeysymToKeycode(d, k.key),
211 		    k.modifier | ignored_modifiers[i],
212 		    root, False, GrabModeAsync, GrabModeAsync);
213 	}
214 }
215 
216 KeySym
217 keycode_to_keysym(unsigned int kc)
218 {
219 	/* group 0 (?). shift level is 0 because we don't want it*/
220 	return XkbKeycodeToKeysym(d, kc, 0, 0);
221 }
222 
223 Window
224 focused_window()
225 {
226 	Window w;
227 	int revert_to;
228 
229 	/* one can use (at least) three way to obtain the current
230 	 * focused window using xlib:
231 	 *
232 	 * - XQueryTree : you traverse tre tree until you find the
233 	 *     window
234 	 *
235 	 * - looking at _NET_ACTIVE_WINDOW in the root window, but
236 	 *    depedns on the window manager to set it
237 	 *
238 	 * - using XGetInputFocus
239 	 *
240 	 * I don't know the pro/cons of these, but XGetInputFocus
241 	 * seems the easiest.
242 	 */
243 	XGetInputFocus(d, &w, &revert_to);
244 	return w;
245 }
246 
247 void
248 send_fake(Window w, struct key k, int pressed)
249 {
250 	XKeyEvent e;
251 
252 	e.type = pressed ? KeyPress : KeyRelease;
253 
254 	e.display = d;
255 	e.window = w;
256 	e.root = DefaultRootWindow(d);
257 	e.subwindow = None;
258 	e.time = CurrentTime;
259 
260 	/* TODO: fix these */
261 	e.x = 1;
262 	e.y = 1;
263 	e.x_root = 1;
264 	e.y_root = 1;
265 
266 	e.same_screen = True;
267 	e.keycode = XKeysymToKeycode(d, k.key);
268 	e.state = k.modifier;
269 
270 	XSendEvent(d, w, True, KeyPressMask, (XEvent*)&e);
271 	XFlush(d);
272 }
273 
274 int
275 window_match_class(Window w, const char *class)
276 {
277 	XClassHint ch;
278 	int matched;
279 
280         if (!XGetClassHint(d, w, &ch)) {
281 		fprintf(stderr, "XGetClassHint failed\n");
282 		return 0;
283 	}
284 
285 	matched = !strcmp(ch.res_class, class);
286 
287 	XFree(ch.res_name);
288 	XFree(ch.res_class);
289 
290 	return matched;
291 }
292 
293 
294 /* action */
295 
296 void
297 do_action(struct action a, Window focused, int pressed)
298 {
299 	switch (a.type) {
300 	case AFAKE:
301 		send_fake(focused, a.send_key, pressed);
302 		break;
303 
304 	case ASPECIAL:
305 		switch (a.special) {
306 		case ATOGGLE:
307 		case AACTIVATE:
308 		case ADEACTIVATE:
309 			printf("TODO\n");
310 			break;
311 
312 		case AIGNORE:
313 			break;
314 
315 		default:
316 			/* unreachable */
317 			abort();
318 		}
319                 break;
320 
321 	default:
322 		/* unreachable */
323 		abort();
324 	}
325 }
326 
327 
328 /* match */
329 
330 struct match *
331 new_match(int prop, char *s)
332 {
333 	struct match *m;
334 
335 	if ((m = calloc(1, sizeof(*m))) == NULL)
336 		err(1, "calloc");
337 	m->prop = prop;
338 	m->str = s;
339 	return m;
340 }
341 
342 void
343 recfree_match(struct match *m)
344 {
345 	struct match *mt;
346 
347 	if (m == NULL)
348 		return;
349 
350 	mt = m->next;
351 	free(m->str);
352 	free(m);
353 	recfree_match(mt);
354 }
355 
356 int
357 match_window(struct match *m, Window w)
358 {
359         switch (m->prop) {
360 	case MCLASS:
361 		return window_match_class(w, m->str);
362 		break;
363 
364 	default:
365 		/* unreachable */
366 		abort();
367 	}
368 }
369 
370 
371 /* rule */
372 
373 struct rule *
374 new_rule(struct key k, struct action a)
375 {
376 	struct rule *r;
377 
378 	if ((r = calloc(1, sizeof(*r))) == NULL)
379 		err(1, "calloc");
380 	memcpy(&r->key, &k, sizeof(k));
381 	memcpy(&r->action, &a, sizeof(a));
382 	return r;
383 }
384 
385 void
386 recfree_rule(struct rule *r)
387 {
388 	struct rule *rt;
389 
390 	if (r == NULL)
391 		return;
392 
393 	rt = r->next;
394 	free(r);
395 	recfree_rule(rt);
396 }
397 
398 int
399 rule_matched(struct rule *r, struct key k)
400 {
401 	unsigned int m;
402 
403 	m = k.modifier;
404 	m &= ~IGNORE_MODIFIERS; /* clear ignored modifiers */
405 
406 	return r->key.modifier == m
407 		&& r->key.key == k.key;
408 }
409 
410 
411 /* group */
412 
413 struct group *
414 new_group(struct match *matches, struct rule *rules)
415 {
416 	struct group *g;
417 
418 	if ((g = calloc(1, sizeof(*g))) == NULL)
419 		err(1, "calloc");
420 	g->matches = matches;
421 	g->rules = rules;
422 	return g;
423 }
424 
425 void
426 recfree_group(struct group *g)
427 {
428 	struct group *gt;
429 
430 	if (g == NULL)
431 		return;
432 
433 	gt = g->next;
434 	recfree_match(g->matches);
435 	recfree_rule(g->rules);
436 	free(g);
437 	recfree_group(gt);
438 }
439 
440 void
441 process_event(struct group *g, XKeyEvent *e)
442 {
443 	Window focused;
444 	struct rule *r;
445 	struct key pressed = {
446 		.modifier = e->state,
447 		.key = keycode_to_keysym(e->keycode),
448 	};
449 
450 	focused = focused_window();
451 
452 	for (; g != NULL; g = g->next) {
453 		if (!group_match(g, focused))
454 			continue;
455 
456 		for (r = g->rules; r != NULL; r = r->next) {
457 			if (rule_matched(r, pressed)) {
458                                 do_action(r->action, focused, e->type == KeyPress);
459 				return;
460 			}
461 		}
462 	}
463 
464 	send_fake(focused, pressed, e->type == KeyPress);
465 }
466 
467 int
468 group_match(struct group *g, Window w)
469 {
470 	struct match *m;
471 
472 	for (m = g->matches; m != NULL; m = m->next)
473 		if (match_window(m, w))
474 			return 1;
475 	return 0;
476 }
477 
478 
479 /* debug/dump stuff */
480 
481 void
482 printkey(struct key k)
483 {
484 	if (k.modifier & ControlMask)
485 		printf("C-");
486 	if (k.modifier & ShiftMask)
487 		printf("S-");
488 	if (k.modifier & Mod1Mask)
489 		printf("M-");
490 	if (k.modifier & Mod4Mask)
491 		printf("s-");
492 
493 	printf("%s", XKeysymToString(k.key));
494 }
495 
496 void
497 printaction(struct action a)
498 {
499 	if (a.type == ASPECIAL) {
500 		switch (a.special) {
501 		case ATOGGLE: printf("toggle"); break;
502 		case AACTIVATE: printf("activate"); break;
503 		case ADEACTIVATE: printf("deactivate"); break;
504 		case AIGNORE: printf("ignore"); break;
505 		}
506 	} else {
507 		printf("send key ");
508 		printkey(a.send_key);
509 	}
510 }
511 
512 void
513 printmatch(struct match *m)
514 {
515 	if (m == NULL) {
516 		printf("(null)");
517 		return;
518 	}
519 	printf("match ");
520 	switch (m->prop) {
521 	case MCLASS:
522 		printf("class");
523 		break;
524 	default:
525 		abort();
526 	}
527 	printf(" %s", m->str);
528 
529 	if (m->next == NULL)
530 		printf("\n");
531 	else {
532 		printf(" ; ");
533 		printmatch(m->next);
534 	}
535 }
536 
537 void
538 printrule(struct rule *r)
539 {
540 	if (r == NULL) {
541 		printf("(null)");
542 		return;
543 	}
544 	printf("on ");
545 	printkey(r->key);
546 	printf(" do ");
547 	printaction(r->action);
548 	printf("\n");
549 
550 	if (r->next != NULL)
551 		printrule(r->next);
552 }
553 
554 void
555 printgroup(struct group *g)
556 {
557 	if (g == NULL) {
558 		printf("(null)");
559 		return;
560 	}
561 	printmatch(g->matches);
562 	printf("\n");
563 	printrule(g->rules);
564 	printf("\n\n");
565 
566 	if (g->next != NULL)
567 		printgroup(g->next);
568 }