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Date:: Sat Jul 17 21:07:06 2021 UTC
Message:: Farewell, nth_line! You were a good function. Slow and avoidable actually, but a good function indeed.
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2021 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 /*
18  * Ncurses UI for telescope.
19  *
20  * Text scrolling
21  * ==============
22  *
23  * ncurses allows you to scroll a window, but when a line goes out of
24  * the visible area it's forgotten.  We keep a list of formatted lines
25  * (``visual lines'') that we know fits in the window, and draw them.
26  *
27  * This means that on every resize we have to clear our list of lines
28  * and re-render everything.  A clever approach would be to do this
29  * ``on-demand'', but it's still missing.
30  *
31  */
32 
33 #include <assert.h>
34 #include <curses.h>
35 #include <event.h>
36 #include <locale.h>
37 #include <signal.h>
38 #include <stdarg.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "defaults.h"
44 #include "minibuffer.h"
45 #include "telescope.h"
46 #include "ui.h"
47 #include "utf8.h"
48 
49 static struct event	stdioev, winchev;
50 
51 static void		 restore_curs_x(struct buffer *);
52 
53 static struct vline	*nth_line(struct buffer*, size_t);
54 static int		 readkey(void);
55 static void		 dispatch_stdio(int, short, void*);
56 static void		 handle_clear_echoarea(int, short, void*);
57 static void		 handle_resize(int, short, void*);
58 static void		 handle_resize_nodelay(int, short, void*);
59 static void		 rearrange_windows(void);
60 static int		 wrap_page(struct buffer*, int);
61 static void		 line_prefix_and_text(struct vline *, char *, size_t, const char **, const char **);
62 static void		 print_vline(int, int, WINDOW*, struct vline*);
63 static void		 redraw_tabline(void);
64 static void		 redraw_window(WINDOW*, int, int, int, struct buffer*);
65 static void		 redraw_help(void);
66 static void		 redraw_body(struct tab*);
67 static void		 redraw_modeline(struct tab*);
68 static void		 redraw_minibuffer(void);
69 static void		 do_redraw_echoarea(void);
70 static void		 do_redraw_minibuffer(void);
71 static void		 do_redraw_minibuffer_compl(void);
72 static void		 place_cursor(int);
73 static void		 redraw_tab(struct tab*);
74 static void		 emit_help_item(char*, void*);
75 static void		 rec_compute_help(struct kmap*, char*, size_t);
76 static void		 recompute_help(void);
77 static void		 update_loading_anim(int, short, void*);
78 static void		 stop_loading_anim(struct tab*);
79 
80 /*
81  * Used to know when we're finished loading.
82  */
83 static int		 operating;
84 
85 static int		 should_rearrange_windows;
86 static int		 too_small;
87 static int		 x_offset;
88 
89 struct thiskey	 thiskey;
90 struct tab	*current_tab;
91 
92 static struct event	resizeev;
93 static struct timeval	resize_timer = { 0, 250000 };
94 
95 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
96 
97 int			 body_lines, body_cols;
98 
99 static WINDOW		*help;
100 static struct buffer	 helpwin;
101 static int		 help_lines, help_cols;
102 
103 static int		 side_window;
104 
105 static struct event	clechoev;
106 static struct timeval	clechoev_timer = { 5, 0 };
107 static struct timeval	loadingev_timer = { 0, 250000 };
108 
109 static uint32_t		 tab_counter;
110 
111 static char	keybuf[64];
112 
113 struct kmap global_map,
114 	minibuffer_map,
115 	*current_map,
116 	*base_map;
117 
118 int in_minibuffer;
119 
120 static inline void
121 update_x_offset(void)
122 {
123 	if (olivetti_mode && fill_column < body_cols)
124 		x_offset = (body_cols - fill_column)/2;
125 	else
126 		x_offset = 0;
127 }
128 
129 void
130 save_excursion(struct excursion *place, struct buffer *buffer)
131 {
132 	place->curs_x = buffer->curs_x;
133 	place->curs_y = buffer->curs_y;
134 	place->line_off = buffer->line_off;
135 	place->current_line = buffer->current_line;
136 	place->cpoff = buffer->cpoff;
137 }
138 
139 void
140 restore_excursion(struct excursion *place, struct buffer *buffer)
141 {
142 	buffer->curs_x = place->curs_x;
143 	buffer->curs_y = place->curs_y;
144 	buffer->line_off = place->line_off;
145 	buffer->current_line = place->current_line;
146 	buffer->cpoff = place->cpoff;
147 }
148 
149 static void
150 restore_curs_x(struct buffer *buffer)
151 {
152 	struct vline	*vl;
153 	const char	*prfx;
154 
155 	vl = buffer->current_line;
156 	if (vl == NULL || vl->line == NULL)
157 		buffer->curs_x = buffer->cpoff = 0;
158 	else if (vl->parent->data != NULL)
159 		buffer->curs_x = utf8_snwidth(vl->parent->data+1, buffer->cpoff) + 1;
160 	else
161 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
162 
163 	buffer->curs_x += x_offset;
164 
165 	if (vl == NULL)
166 		return;
167 
168 	if (vl->parent->data != NULL)
169 		buffer->curs_x += utf8_swidth_between(vl->parent->line, vl->parent->data);
170 	else {
171 		prfx = line_prefixes[vl->parent->type].prfx1;
172 		buffer->curs_x += utf8_swidth(prfx);
173 	}
174 }
175 
176 void
177 global_key_unbound(void)
178 {
179 	message("%s is undefined", keybuf);
180 }
181 
182 struct buffer *
183 current_buffer(void)
184 {
185 	if (in_minibuffer)
186 		return &ministate.buffer;
187 	return &current_tab->buffer;
188 }
189 
190 static int
191 readkey(void)
192 {
193 	uint32_t state = 0;
194 
195 	if ((thiskey.key = wgetch(body)) == ERR)
196 		return 0;
197 
198 	thiskey.meta = thiskey.key == 27;
199 	if (thiskey.meta) {
200 		thiskey.key = wgetch(body);
201 		if (thiskey.key == ERR || thiskey.key == 27) {
202 			thiskey.meta = 0;
203 			thiskey.key = 27;
204 		}
205 	}
206 
207 	thiskey.cp = 0;
208 	if ((unsigned int)thiskey.key < UINT8_MAX) {
209 		while (1) {
210 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
211 				break;
212 			if ((thiskey.key = wgetch(body)) == ERR) {
213 				message("Error decoding user input");
214 				return 0;
215 			}
216 		}
217 	}
218 
219 	return 1;
220 }
221 
222 static void
223 dispatch_stdio(int fd, short ev, void *d)
224 {
225 	struct keymap	*k;
226 	const char	*keyname;
227 	char		 tmp[5] = {0};
228 
229 	/* TODO: schedule a redraw? */
230 	if (too_small)
231 		return;
232 
233 	if (!readkey())
234 		return;
235 
236 	if (keybuf[0] != '\0')
237 		strlcat(keybuf, " ", sizeof(keybuf));
238 	if (thiskey.meta)
239 		strlcat(keybuf, "M-", sizeof(keybuf));
240 	if (thiskey.cp != 0) {
241 		utf8_encode(thiskey.cp, tmp);
242 		strlcat(keybuf, tmp, sizeof(keybuf));
243 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
244 		strlcat(keybuf, keyname, sizeof(keybuf));
245 	} else {
246 		tmp[0] = thiskey.key;
247 		strlcat(keybuf, tmp, sizeof(keybuf));
248 	}
249 
250 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
251 		if (k->meta == thiskey.meta &&
252 		    k->key == thiskey.key) {
253 			if (k->fn == NULL)
254 				current_map = &k->map;
255 			else {
256 				current_map = base_map;
257 				strlcpy(keybuf, "", sizeof(keybuf));
258 				k->fn(current_buffer());
259 			}
260 			goto done;
261 		}
262 	}
263 
264 	if (current_map->unhandled_input != NULL)
265 		current_map->unhandled_input();
266 	else
267 		global_key_unbound();
268 
269 	strlcpy(keybuf, "", sizeof(keybuf));
270 	current_map = base_map;
271 
272 done:
273 	if (side_window)
274 		recompute_help();
275 
276 	if (should_rearrange_windows)
277 		rearrange_windows();
278 	redraw_tab(current_tab);
279 }
280 
281 static void
282 handle_clear_echoarea(int fd, short ev, void *d)
283 {
284 	free(ministate.curmesg);
285 	ministate.curmesg = NULL;
286 
287 	redraw_minibuffer();
288 	place_cursor(0);
289 }
290 
291 static void
292 handle_resize(int sig, short ev, void *d)
293 {
294 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
295 		event_del(&resizeev);
296 	}
297 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
298 	evtimer_add(&resizeev, &resize_timer);
299 }
300 
301 static void
302 handle_resize_nodelay(int s, short ev, void *d)
303 {
304 	endwin();
305 	refresh();
306 	clear();
307 
308 	rearrange_windows();
309 }
310 
311 static void
312 rearrange_windows(void)
313 {
314 	int		 lines;
315 
316 	should_rearrange_windows = 0;
317 
318 	lines = LINES;
319 
320 	if ((too_small = lines < 15)) {
321 		erase();
322 		printw("Window too small.");
323 		refresh();
324 		return;
325 	}
326 
327 	/* move and resize the windows, in reverse order! */
328 
329 	if (in_minibuffer == MB_COMPREAD) {
330 		mvwin(minibuffer, lines-10, 0);
331 		wresize(minibuffer, 10, COLS);
332 		lines -= 10;
333 
334 		wrap_page(&ministate.compl.buffer, COLS);
335 	}
336 
337 	mvwin(echoarea, --lines, 0);
338 	wresize(echoarea, 1, COLS);
339 
340 	mvwin(modeline, --lines, 0);
341 	wresize(modeline, 1, COLS);
342 
343 	body_lines = --lines;
344 	body_cols = COLS;
345 
346 	if (side_window) {
347 		help_cols = 0.3 * COLS;
348 		help_lines = lines;
349 		mvwin(help, 1, 0);
350 		wresize(help, help_lines, help_cols);
351 
352 		wrap_page(&helpwin, help_cols);
353 
354 		body_cols = COLS - help_cols - 1;
355 		mvwin(body, 1, help_cols);
356 	} else
357 		mvwin(body, 1, 0);
358 
359 	update_x_offset();
360 	wresize(body, body_lines, body_cols);
361 
362 	wresize(tabline, 1, COLS);
363 
364 	wrap_page(&current_tab->buffer, body_cols);
365 	redraw_tab(current_tab);
366 }
367 
368 static int
369 wrap_page(struct buffer *buffer, int width)
370 {
371 	struct line		*l;
372 	const struct line	*top_orig, *orig;
373 	struct vline		*vl;
374 	int			 pre_width;
375 	const char		*prfx;
376 
377 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
378 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
379 
380 	buffer->top_line = NULL;
381 	buffer->current_line = NULL;
382 
383 	buffer->force_redraw = 1;
384 	buffer->curs_y = 0;
385 	buffer->line_off = 0;
386 
387 	empty_vlist(buffer);
388 
389 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
390 		prfx = line_prefixes[l->type].prfx1;
391 		switch (l->type) {
392 		case LINE_TEXT:
393 		case LINE_LINK:
394 		case LINE_TITLE_1:
395 		case LINE_TITLE_2:
396 		case LINE_TITLE_3:
397 		case LINE_ITEM:
398 		case LINE_QUOTE:
399 		case LINE_PRE_START:
400 		case LINE_PRE_END:
401 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
402 			break;
403 		case LINE_PRE_CONTENT:
404 			if (olivetti_mode)
405 				pre_width = MIN(fill_column, width);
406 			else
407 				pre_width = width;
408 			hardwrap_text(buffer, l, pre_width);
409 			break;
410 		case LINE_COMPL:
411 		case LINE_COMPL_CURRENT:
412 			wrap_one(buffer, prfx, l, width);
413 			break;
414 		}
415 
416 		if (top_orig == l && buffer->top_line == NULL) {
417 			buffer->line_off = buffer->line_max-1;
418 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
419 
420 			while (1) {
421 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
422 				if (vl == NULL || vl->parent != orig)
423 					break;
424 				buffer->top_line = vl;
425 				buffer->line_off--;
426 			}
427 		}
428 
429 		if (orig == l && buffer->current_line == NULL) {
430 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
431 
432 			while (1) {
433 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
434 				if (vl == NULL || vl->parent != orig)
435 					break;
436 				buffer->current_line = vl;
437 			}
438 		}
439 	}
440 
441         if (buffer->current_line == NULL)
442 		buffer->current_line = TAILQ_FIRST(&buffer->head);
443 
444 	if (buffer->top_line == NULL)
445 		buffer->top_line = buffer->current_line;
446 
447 	return 1;
448 }
449 
450 static void
451 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
452     const char **prfx_ret, const char **text_ret)
453 {
454 	int type, i, cont, width;
455 	char *space, *t;
456 
457 	if ((*text_ret = vl->line) == NULL)
458 		*text_ret = "";
459 
460 	cont = vl->flags & L_CONTINUATION;
461 	type = vl->parent->type;
462 	if (!cont)
463 		*prfx_ret = line_prefixes[type].prfx1;
464 	else
465 		*prfx_ret = line_prefixes[type].prfx2;
466 
467 	space = vl->parent->data;
468 	if (!emojify_link || type != LINE_LINK || space == NULL)
469 		return;
470 
471 	if (cont) {
472 		memset(buf, 0, len);
473 		width = utf8_swidth_between(vl->parent->line, space);
474 		for (i = 0; i < width + 1; ++i)
475 			strlcat(buf, " ", len);
476 	} else {
477 		strlcpy(buf, *text_ret, len);
478 		if ((t = strchr(buf, ' ')) != NULL)
479 			*t = '\0';
480 		strlcat(buf, " ", len);
481 
482 		/* skip the emoji */
483                 *text_ret += (space - vl->parent->line) + 1;
484 	}
485 
486 	*prfx_ret = buf;
487 }
488 
489 /*
490  * Core part of the rendering.  It prints a vline starting from the
491  * current cursor position.  Printing a vline consists of skipping
492  * `off' columns (for olivetti-mode), print the correct prefix (which
493  * may be the emoji in case of emojified links-lines), printing the
494  * text itself, filling until width - off and filling off columns
495  * again.
496  */
497 static void
498 print_vline(int off, int width, WINDOW *window, struct vline *vl)
499 {
500 	/*
501 	 * Believe me or not, I've seen emoji ten code points long!
502 	 * That means, to stay large, 4*10 bytes + NUL.
503 	 */
504 	char emojibuf[41] = {0};
505 	const char *text, *prfx;
506 	struct line_face *f;
507 	int i, left, x, y;
508 
509 	f = &line_faces[vl->parent->type];
510 
511 	/* unused, set by getyx */
512 	(void)y;
513 
514 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
515 
516 	wattr_on(window, body_face.left, NULL);
517 	for (i = 0; i < off; i++)
518 		waddch(window, ' ');
519 	wattr_off(window, body_face.left, NULL);
520 
521 	wattr_on(window, f->prefix, NULL);
522 	wprintw(window, "%s", prfx);
523 	wattr_off(window, f->prefix, NULL);
524 
525 	wattr_on(window, f->text, NULL);
526 	wprintw(window, "%s", text);
527 	wattr_off(window, f->text, NULL);
528 
529 	getyx(window, y, x);
530 
531 	left = width - x;
532 
533 	wattr_on(window, f->trail, NULL);
534 	for (i = 0; i < left - off; ++i)
535 		waddch(window, ' ');
536 	wattr_off(window, f->trail, NULL);
537 
538 	wattr_on(window, body_face.right, NULL);
539 	for (i = 0; i < off; i++)
540 		waddch(window, ' ');
541 	wattr_off(window, body_face.right, NULL);
542 
543 }
544 
545 static void
546 redraw_tabline(void)
547 {
548 	struct tab	*tab;
549 	size_t		 toskip, ots, tabwidth, space, x;
550 	int		 current, y, truncated, pair;
551 	const char	*title;
552 	char		 buf[25];
553 
554 	x = 0;
555 
556 	/* unused, but setted by a getyx */
557 	(void)y;
558 
559 	tabwidth = sizeof(buf)+1;
560 	space = COLS-2;
561 
562 	toskip = 0;
563 	TAILQ_FOREACH(tab, &tabshead, tabs) {
564 		toskip++;
565 		if (tab == current_tab)
566 			break;
567 	}
568 
569 	if (toskip * tabwidth < space)
570 		toskip = 0;
571 	else {
572 		ots = toskip;
573 		toskip--;
574                 while (toskip != 0 &&
575 		    (ots - toskip+1) * tabwidth < space)
576 			toskip--;
577 	}
578 
579 	werase(tabline);
580 	wattr_on(tabline, tab_face.background, NULL);
581 	wprintw(tabline, toskip == 0 ? " " : "<");
582 	wattr_off(tabline, tab_face.background, NULL);
583 
584 	truncated = 0;
585 	TAILQ_FOREACH(tab, &tabshead, tabs) {
586 		if (truncated)
587 			break;
588 		if (toskip != 0) {
589 			toskip--;
590 			continue;
591 		}
592 
593 		getyx(tabline, y, x);
594 		if (x + sizeof(buf)+2 >= (size_t)COLS)
595 			truncated = 1;
596 
597 		current = tab == current_tab;
598 
599 		if (*(title = tab->buffer.page.title) == '\0')
600 			title = tab->hist_cur->h;
601 
602 		if (tab->flags & TAB_URGENT)
603 			strlcpy(buf, "!", sizeof(buf));
604 		else
605 			strlcpy(buf, " ", sizeof(buf));
606 
607                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
608 			/* truncation happens */
609 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
610 		} else {
611 			/* pad with spaces */
612 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
613 				/* nop */ ;
614 		}
615 
616 		pair = current ? tab_face.current : tab_face.tab;
617 		wattr_on(tabline, pair, NULL);
618 		wprintw(tabline, "%s", buf);
619 		wattr_off(tabline, pair, NULL);
620 
621 		wattr_on(tabline, tab_face.background, NULL);
622 		if (TAILQ_NEXT(tab, tabs) != NULL)
623 			wprintw(tabline, "│");
624 		wattr_off(tabline, tab_face.background, NULL);
625 	}
626 
627 	wattr_on(tabline, tab_face.background, NULL);
628 	for (; x < (size_t)COLS; ++x)
629 		waddch(tabline, ' ');
630 	if (truncated)
631 		mvwprintw(tabline, 0, COLS-1, ">");
632 	wattr_off(tabline, tab_face.background, NULL);
633 }
634 
635 /*
636  * Compute the first visible line around vl.  Try to search forward
637  * until the end of the buffer; if a visible line is not found, search
638  * backward.  Return NULL if no viable line was found.
639  */
640 struct vline *
641 adjust_line(struct vline *vl, struct buffer *buffer)
642 {
643 	struct vline *t;
644 
645 	if (vl == NULL)
646 		return NULL;
647 
648 	if (!(vl->parent->flags & L_HIDDEN))
649 		return vl;
650 
651 	/* search forward */
652 	for (t = vl;
653 	     t != NULL && t->parent->flags & L_HIDDEN;
654 	     t = TAILQ_NEXT(t, vlines))
655 		;		/* nop */
656 
657 	if (t != NULL)
658 		return t;
659 
660 	/* search backward */
661 	for (t = vl;
662 	     t != NULL && t->parent->flags & L_HIDDEN;
663 	     t = TAILQ_PREV(t, vhead, vlines))
664 		;		/* nop */
665 
666 	return t;
667 }
668 
669 static void
670 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
671 {
672         struct vline	*vl;
673 	int		 l, onscreen;
674 
675 	restore_curs_x(buffer);
676 
677 	/*
678 	 * TODO: ignoring buffer->force_update and always
679 	 * re-rendering.  In theory we can recompute the y position
680 	 * without a re-render, and optimize here.  It's not the only
681 	 * optimisation possible here, wscrl wolud also be an
682 	 * interesting one.
683 	 */
684 
685 again:
686 	werase(win);
687 	buffer->curs_y = 0;
688 
689 	if (TAILQ_EMPTY(&buffer->head))
690 		goto end;
691 
692 	if (buffer->top_line == NULL)
693 		buffer->top_line = TAILQ_FIRST(&buffer->head);
694 
695 	buffer->top_line = adjust_line(buffer->top_line, buffer);
696 	if (buffer->top_line == NULL)
697 		goto end;
698 
699 	buffer->current_line = adjust_line(buffer->current_line, buffer);
700 
701 	l = 0;
702 	onscreen = 0;
703 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
704 		if (vl->parent->flags & L_HIDDEN)
705 			continue;
706 
707 		wmove(win, l, 0);
708 		print_vline(off, width, win, vl);
709 
710 		if (vl == buffer->current_line)
711 			onscreen = 1;
712 
713 		if (!onscreen)
714 			buffer->curs_y++;
715 
716 		l++;
717 		if (l == height)
718 			break;
719 	}
720 
721 	if (!onscreen) {
722 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
723 			if (vl == buffer->current_line)
724 				break;
725 			if (vl->parent->flags & L_HIDDEN)
726 				continue;
727 			buffer->line_off++;
728 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
729 		}
730 
731 		if (vl != NULL)
732 			goto again;
733 	}
734 
735 	buffer->last_line_off = buffer->line_off;
736 	buffer->force_redraw = 0;
737 end:
738 	wmove(win, buffer->curs_y, buffer->curs_x);
739 }
740 
741 static void
742 redraw_help(void)
743 {
744 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
745 }
746 
747 static void
748 redraw_body(struct tab *tab)
749 {
750 	static struct tab *last_tab;
751 
752 	if (last_tab != tab)
753 		tab->buffer.force_redraw =1;
754 	last_tab = tab;
755 
756 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
757 }
758 
759 static inline char
760 trust_status_char(enum trust_state ts)
761 {
762 	switch (ts) {
763 	case TS_UNKNOWN:	return 'u';
764 	case TS_UNTRUSTED:	return '!';
765 	case TS_TEMP_TRUSTED:	return '!';
766 	case TS_TRUSTED:	return 'v';
767 	case TS_VERIFIED:	return 'V';
768 	default:		return 'X';
769 	}
770 }
771 
772 static void
773 redraw_modeline(struct tab *tab)
774 {
775 	double		 pct;
776 	int		 x, y, max_x, max_y;
777 	const char	*mode = tab->buffer.page.name;
778 	const char	*spin = "-\\|/";
779 
780 	werase(modeline);
781 	wattr_on(modeline, modeline_face.background, NULL);
782 	wmove(modeline, 0, 0);
783 
784 	wprintw(modeline, "-%c%c %s ",
785 	    spin[tab->loading_anim_step],
786 	    trust_status_char(tab->trust),
787 	    mode == NULL ? "(none)" : mode);
788 
789 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0
790 		/ tab->buffer.line_max;
791 
792 	if (tab->buffer.line_max <= (size_t)body_lines)
793                 wprintw(modeline, "All ");
794 	else if (tab->buffer.line_off == 0)
795                 wprintw(modeline, "Top ");
796 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
797 		wprintw(modeline, "Bottom ");
798 	else
799 		wprintw(modeline, "%.0f%% ", pct);
800 
801 	wprintw(modeline, "%d/%d %s ",
802 	    tab->buffer.line_off + tab->buffer.curs_y,
803 	    tab->buffer.line_max,
804 	    tab->hist_cur->h);
805 
806 	getyx(modeline, y, x);
807 	getmaxyx(modeline, max_y, max_x);
808 
809 	(void)y;
810 	(void)max_y;
811 
812 	for (; x < max_x; ++x)
813 		waddstr(modeline, "-");
814 
815 	wattr_off(modeline, modeline_face.background, NULL);
816 }
817 
818 static void
819 redraw_minibuffer(void)
820 {
821 	wattr_on(echoarea, minibuffer_face.background, NULL);
822 	werase(echoarea);
823 
824 	if (in_minibuffer)
825 		do_redraw_minibuffer();
826 	else
827 		do_redraw_echoarea();
828 
829 	if (in_minibuffer == MB_COMPREAD)
830 		do_redraw_minibuffer_compl();
831 
832 	wattr_off(echoarea, minibuffer_face.background, NULL);
833 }
834 
835 static void
836 do_redraw_echoarea(void)
837 {
838 	struct vline *vl;
839 
840 	if (ministate.curmesg != NULL)
841                 wprintw(echoarea, "%s", ministate.curmesg);
842 	else if (*keybuf != '\0')
843 		waddstr(echoarea, keybuf);
844 	else {
845 		/* If nothing else, show the URL at point */
846 		vl = current_tab->buffer.current_line;
847 		if (vl != NULL && vl->parent->type == LINE_LINK)
848 			waddstr(echoarea, vl->parent->alt);
849 	}
850 }
851 
852 static void
853 do_redraw_minibuffer(void)
854 {
855 	size_t		 off_y, off_x = 0;
856 	const char	*start, *c;
857 
858 	/* unused, set by getyx */
859 	(void)off_y;
860 
861 	wmove(echoarea, 0, 0);
862 
863 	if (in_minibuffer == MB_COMPREAD)
864 		wprintw(echoarea, "(%2d) ",
865 		    ministate.compl.buffer.line_max);
866 
867 	wprintw(echoarea, "%s", ministate.prompt);
868 	if (ministate.hist_cur != NULL)
869 		wprintw(echoarea, "(%zu/%zu) ",
870 		    ministate.hist_off + 1,
871 		    ministate.history->len);
872 
873 	getyx(echoarea, off_y, off_x);
874 
875 	start = ministate.hist_cur != NULL
876 		? ministate.hist_cur->h
877 		: ministate.buf;
878 	c = utf8_nth(ministate.buffer.current_line->line,
879 	    ministate.buffer.cpoff);
880 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
881 		start = utf8_next_cp(start);
882 	}
883 
884 	waddstr(echoarea, start);
885 
886 	if (ministate.curmesg != NULL)
887 		wprintw(echoarea, " [%s]", ministate.curmesg);
888 
889 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
890 }
891 
892 static void
893 do_redraw_minibuffer_compl(void)
894 {
895 	redraw_window(minibuffer, 0, 10, body_cols,
896 	    &ministate.compl.buffer);
897 }
898 
899 /*
900  * Place the cursor in the right ncurses window.  If soft is 1, use
901  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
902  * wrefresh.
903  */
904 static void
905 place_cursor(int soft)
906 {
907 	int (*touch)(WINDOW *);
908 
909 	if (soft)
910 		touch = wnoutrefresh;
911 	else
912 		touch = wrefresh;
913 
914 	if (in_minibuffer) {
915 		touch(body);
916 		touch(echoarea);
917 	} else {
918 		touch(echoarea);
919 		touch(body);
920 	}
921 }
922 
923 static void
924 redraw_tab(struct tab *tab)
925 {
926 	if (too_small)
927 		return;
928 
929 	if (side_window) {
930 		redraw_help();
931 		wnoutrefresh(help);
932 	}
933 
934 	redraw_tabline();
935 	redraw_body(tab);
936 	redraw_modeline(tab);
937 	redraw_minibuffer();
938 
939 	wnoutrefresh(tabline);
940 	wnoutrefresh(modeline);
941 
942 	if (in_minibuffer == MB_COMPREAD)
943 		wnoutrefresh(minibuffer);
944 
945 	place_cursor(1);
946 
947 	doupdate();
948 
949 	if (set_title)
950 		dprintf(1, "\033]0;%s - Telescope\a",
951 		    current_tab->buffer.page.title);
952 }
953 
954 static void
955 emit_help_item(char *prfx, void *fn)
956 {
957 	struct line	*l;
958 	struct cmd	*cmd;
959 
960 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
961 		if (fn == cmd->fn)
962 			break;
963 	}
964 	assert(cmd != NULL);
965 
966 	if ((l = calloc(1, sizeof(*l))) == NULL)
967 		abort();
968 
969 	l->type = LINE_TEXT;
970 	l->alt = NULL;
971 
972 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
973 
974 	if (TAILQ_EMPTY(&helpwin.page.head))
975 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
976 	else
977 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
978 }
979 
980 static void
981 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
982 {
983 	struct keymap	*k;
984 	char		 p[32];
985 	const char	*kn;
986 
987 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
988 		strlcpy(p, prfx, sizeof(p));
989 		if (*p != '\0')
990 			strlcat(p, " ", sizeof(p));
991 		if (k->meta)
992 			strlcat(p, "M-", sizeof(p));
993 		if ((kn = unkbd(k->key)) != NULL)
994 			strlcat(p, kn, sizeof(p));
995 		else
996 			strlcat(p, keyname(k->key), sizeof(p));
997 
998 		if (k->fn == NULL)
999 			rec_compute_help(&k->map, p, sizeof(p));
1000 		else
1001 			emit_help_item(p, k->fn);
1002 	}
1003 }
1004 
1005 static void
1006 recompute_help(void)
1007 {
1008 	char	p[32] = { 0 };
1009 
1010 	empty_vlist(&helpwin);
1011 	empty_linelist(&helpwin);
1012 	rec_compute_help(current_map, p, sizeof(p));
1013 	wrap_page(&helpwin, help_cols);
1014 }
1015 
1016 void
1017 vmessage(const char *fmt, va_list ap)
1018 {
1019 	if (evtimer_pending(&clechoev, NULL))
1020 		evtimer_del(&clechoev);
1021 
1022 	free(ministate.curmesg);
1023 	ministate.curmesg = NULL;
1024 
1025 	if (fmt != NULL) {
1026 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1027 		evtimer_add(&clechoev, &clechoev_timer);
1028 
1029 		/* TODO: what to do if the allocation fails here? */
1030 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
1031 			ministate.curmesg = NULL;
1032 	}
1033 
1034 	redraw_minibuffer();
1035         place_cursor(0);
1036 }
1037 
1038 void
1039 message(const char *fmt, ...)
1040 {
1041 	va_list ap;
1042 
1043 	va_start(ap, fmt);
1044 	vmessage(fmt, ap);
1045 	va_end(ap);
1046 }
1047 
1048 void
1049 start_loading_anim(struct tab *tab)
1050 {
1051 	if (tab->loading_anim)
1052 		return;
1053 	tab->loading_anim = 1;
1054 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1055 	evtimer_add(&tab->loadingev, &loadingev_timer);
1056 }
1057 
1058 static void
1059 update_loading_anim(int fd, short ev, void *d)
1060 {
1061 	struct tab	*tab = d;
1062 
1063 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1064 
1065 	if (tab == current_tab) {
1066 		redraw_modeline(tab);
1067 		wrefresh(modeline);
1068 		wrefresh(body);
1069 		if (in_minibuffer)
1070 			wrefresh(echoarea);
1071 	}
1072 
1073 	evtimer_add(&tab->loadingev, &loadingev_timer);
1074 }
1075 
1076 static void
1077 stop_loading_anim(struct tab *tab)
1078 {
1079 	if (!tab->loading_anim)
1080 		return;
1081 	evtimer_del(&tab->loadingev);
1082 	tab->loading_anim = 0;
1083 	tab->loading_anim_step = 0;
1084 
1085 	if (tab != current_tab)
1086 		return;
1087 
1088 	redraw_modeline(tab);
1089 
1090 	wrefresh(modeline);
1091 	wrefresh(body);
1092 	if (in_minibuffer)
1093 		wrefresh(echoarea);
1094 }
1095 
1096 void
1097 load_url_in_tab(struct tab *tab, const char *url)
1098 {
1099 	if (!operating) {
1100 		load_url(tab, url);
1101 		return;
1102 	}
1103 
1104 	message("Loading %s...", url);
1105 	start_loading_anim(tab);
1106 	load_url(tab, url);
1107 
1108 	redraw_tab(tab);
1109 }
1110 
1111 void
1112 switch_to_tab(struct tab *tab)
1113 {
1114 	current_tab = tab;
1115 	tab->flags &= ~TAB_URGENT;
1116 
1117 	if (operating && tab->flags & TAB_LAZY)
1118 		load_url_in_tab(tab, tab->hist_cur->h);
1119 }
1120 
1121 unsigned int
1122 tab_new_id(void)
1123 {
1124 	return tab_counter++;
1125 }
1126 
1127 struct tab *
1128 new_tab(const char *url)
1129 {
1130 	struct tab	*tab;
1131 
1132 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1133 		event_loopbreak();
1134 		return NULL;
1135 	}
1136 	tab->fd = -1;
1137 
1138 	TAILQ_INIT(&tab->hist.head);
1139 
1140 	TAILQ_INIT(&tab->buffer.head);
1141 
1142 	tab->id = tab_new_id();
1143 	if (!operating)
1144 		tab->flags |= TAB_LAZY;
1145 	switch_to_tab(tab);
1146 
1147 	if (TAILQ_EMPTY(&tabshead))
1148 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1149 	else
1150 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1151 
1152 	load_url_in_tab(tab, url);
1153 	return tab;
1154 }
1155 
1156 int
1157 ui_print_colors(void)
1158 {
1159 	int colors = 0, pairs = 0, can_change = 0;
1160 	int columns = 16, lines, color, i, j;
1161 
1162 	initscr();
1163 	if (has_colors()) {
1164 		start_color();
1165 		use_default_colors();
1166 
1167 		colors = COLORS;
1168 		pairs = COLOR_PAIRS;
1169 		can_change = can_change_color();
1170 	}
1171 	endwin();
1172 
1173 	printf("Term info:\n");
1174 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1175 	    getenv("TERM"), colors, pairs, can_change);
1176 	printf("\n");
1177 
1178 	if (colors == 0) {
1179 		printf("No color support\n");
1180 		return 0;
1181 	}
1182 
1183 	printf("Available colors:\n\n");
1184 	lines = (colors - 1) / columns + 1;
1185 	color = 0;
1186 	for (i = 0; i < lines; ++i) {
1187 		for (j = 0; j < columns; ++j, ++color) {
1188 			printf("\033[0;38;5;%dm %03d", color, color);
1189 		}
1190 		printf("\n");
1191 	}
1192 
1193 	printf("\033[0m");
1194 	fflush(stdout);
1195 	return 0;
1196 }
1197 
1198 int
1199 ui_init()
1200 {
1201 	setlocale(LC_ALL, "");
1202 
1203 	TAILQ_INIT(&eecmd_history.head);
1204 	TAILQ_INIT(&ir_history.head);
1205 	TAILQ_INIT(&lu_history.head);
1206 
1207 	ministate.line.type = LINE_TEXT;
1208 	ministate.vline.parent = &ministate.line;
1209 	ministate.buffer.current_line = &ministate.vline;
1210 
1211 	/* initialize help window */
1212 	TAILQ_INIT(&helpwin.head);
1213 
1214 	base_map = &global_map;
1215 	current_map = &global_map;
1216 
1217 	initscr();
1218 
1219 	if (enable_colors) {
1220 		if (has_colors()) {
1221 			start_color();
1222 			use_default_colors();
1223 		} else
1224 			enable_colors = 0;
1225 	}
1226 
1227 	config_apply_style();
1228 
1229 	raw();
1230 	noecho();
1231 	nonl();
1232 	intrflush(stdscr, FALSE);
1233 
1234 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1235 		return 0;
1236 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1237 		return 0;
1238 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1239 		return 0;
1240 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1241 		return 0;
1242 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1243 		return 0;
1244 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1245 		return 0;
1246 
1247 	body_lines = LINES-3;
1248 	body_cols = COLS;
1249 
1250 	wbkgd(body, body_face.body);
1251 	wbkgd(echoarea, minibuffer_face.background);
1252 
1253 	update_x_offset();
1254 
1255 	keypad(body, TRUE);
1256 	scrollok(body, FALSE);
1257 
1258 	/* non-blocking input */
1259 	wtimeout(body, 0);
1260 
1261 	mvwprintw(body, 0, 0, "");
1262 
1263 	/*
1264 	 * Dummy so libevent2 won't complain that no event_base is set
1265 	 * when checking event_pending for the first time
1266 	 */
1267 	evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1268 	evtimer_add(&clechoev, &clechoev_timer);
1269 	evtimer_set(&resizeev, handle_resize, NULL);
1270 	evtimer_add(&resizeev, &resize_timer);
1271 
1272 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1273 	event_add(&stdioev, NULL);
1274 
1275 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1276 	signal_add(&winchev, NULL);
1277 
1278 	return 1;
1279 }
1280 
1281 void
1282 ui_main_loop(void)
1283 {
1284 	operating = 1;
1285 	switch_to_tab(current_tab);
1286 	redraw_tab(current_tab);
1287 
1288 	event_dispatch();
1289 }
1290 
1291 void
1292 ui_on_tab_loaded(struct tab *tab)
1293 {
1294 	stop_loading_anim(tab);
1295 	message("Loaded %s", tab->hist_cur->h);
1296 
1297 	redraw_tabline();
1298 	wrefresh(tabline);
1299 	place_cursor(0);
1300 }
1301 
1302 void
1303 ui_on_tab_refresh(struct tab *tab)
1304 {
1305 	wrap_page(&tab->buffer, body_cols);
1306 	if (tab == current_tab)
1307 		redraw_tab(tab);
1308 	else
1309 		tab->flags |= TAB_URGENT;
1310 }
1311 
1312 const char *
1313 ui_keyname(int k)
1314 {
1315 	return keyname(k);
1316 }
1317 
1318 void
1319 ui_toggle_side_window(void)
1320 {
1321 	side_window = !side_window;
1322 	if (side_window)
1323 		recompute_help();
1324 
1325 	/*
1326 	 * ugly hack, but otherwise the window doesn't get updated
1327 	 * until I call rearrange_windows a second time (e.g. via
1328 	 * C-l).  I will be happy to know why something like this is
1329 	 * needed.
1330 	 */
1331 	rearrange_windows();
1332 	rearrange_windows();
1333 }
1334 
1335 void
1336 ui_schedule_redraw(void)
1337 {
1338 	should_rearrange_windows = 1;
1339 }
1340 
1341 void
1342 ui_require_input(struct tab *tab, int hide)
1343 {
1344 	/* TODO: hard-switching to another tab is ugly */
1345 	switch_to_tab(tab);
1346 
1347 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1348 	    &ir_history, NULL, NULL);
1349 	strlcpy(ministate.prompt, "Input required: ",
1350 	    sizeof(ministate.prompt));
1351 	redraw_tab(tab);
1352 }
1353 
1354 void
1355 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1356     struct tab *data)
1357 {
1358 	yornp(prompt, fn, data);
1359 	redraw_tab(current_tab);
1360 }
1361 
1362 void
1363 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1364     struct tab *data)
1365 {
1366 	completing_read(prompt, fn, data);
1367 	redraw_tab(current_tab);
1368 }
1369 
1370 void
1371 ui_suspend(void)
1372 {
1373 	endwin();
1374 
1375 	kill(getpid(), SIGSTOP);
1376 
1377 	refresh();
1378 	clear();
1379 	rearrange_windows();
1380 }
1381 
1382 void
1383 ui_end(void)
1384 {
1385 	endwin();
1386 }