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Date:: Sat Jul 17 17:00:34 2021 UTC
Message:: keep track of the current tab and restore it after startup
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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 static int		 should_rearrange_windows;
81 static int		 too_small;
82 static int		 x_offset;
83 
84 struct thiskey	 thiskey;
85 struct tab	*current_tab;
86 
87 static struct event	resizeev;
88 static struct timeval	resize_timer = { 0, 250000 };
89 
90 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
91 
92 int			 body_lines, body_cols;
93 
94 static WINDOW		*help;
95 static struct buffer	 helpwin;
96 static int		 help_lines, help_cols;
97 
98 static int		 side_window;
99 
100 static struct event	clechoev;
101 static struct timeval	clechoev_timer = { 5, 0 };
102 static struct timeval	loadingev_timer = { 0, 250000 };
103 
104 static uint32_t		 tab_counter;
105 
106 static char	keybuf[64];
107 
108 struct kmap global_map,
109 	minibuffer_map,
110 	*current_map,
111 	*base_map;
112 
113 int in_minibuffer;
114 
115 static inline void
116 update_x_offset(void)
117 {
118 	if (olivetti_mode && fill_column < body_cols)
119 		x_offset = (body_cols - fill_column)/2;
120 	else
121 		x_offset = 0;
122 }
123 
124 void
125 save_excursion(struct excursion *place, struct buffer *buffer)
126 {
127 	place->curs_x = buffer->curs_x;
128 	place->curs_y = buffer->curs_y;
129 	place->line_off = buffer->line_off;
130 	place->current_line = buffer->current_line;
131 	place->cpoff = buffer->cpoff;
132 }
133 
134 void
135 restore_excursion(struct excursion *place, struct buffer *buffer)
136 {
137 	buffer->curs_x = place->curs_x;
138 	buffer->curs_y = place->curs_y;
139 	buffer->line_off = place->line_off;
140 	buffer->current_line = place->current_line;
141 	buffer->cpoff = place->cpoff;
142 }
143 
144 static void
145 restore_curs_x(struct buffer *buffer)
146 {
147 	struct vline	*vl;
148 	const char	*prfx;
149 
150 	vl = buffer->current_line;
151 	if (vl == NULL || vl->line == NULL)
152 		buffer->curs_x = buffer->cpoff = 0;
153 	else if (vl->parent->data != NULL)
154 		buffer->curs_x = utf8_snwidth(vl->parent->data+1, buffer->cpoff) + 1;
155 	else
156 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
157 
158 	buffer->curs_x += x_offset;
159 
160 	if (vl != NULL) {
161 		prfx = line_prefixes[vl->parent->type].prfx1;
162 		buffer->curs_x += utf8_swidth(prfx);
163 	}
164 }
165 
166 void
167 global_key_unbound(void)
168 {
169 	message("%s is undefined", keybuf);
170 }
171 
172 static struct vline *
173 nth_line(struct buffer *buffer, size_t n)
174 {
175 	struct vline	*vl;
176 	size_t		 i;
177 
178 	i = 0;
179 	TAILQ_FOREACH(vl, &buffer->head, vlines) {
180 		if (i == n)
181 			return vl;
182 		i++;
183 	}
184 
185 	/* unreachable */
186 	abort();
187 }
188 
189 struct buffer *
190 current_buffer(void)
191 {
192 	if (in_minibuffer)
193 		return &ministate.buffer;
194 	return &current_tab->buffer;
195 }
196 
197 static int
198 readkey(void)
199 {
200 	uint32_t state = 0;
201 
202 	if ((thiskey.key = wgetch(body)) == ERR)
203 		return 0;
204 
205 	thiskey.meta = thiskey.key == 27;
206 	if (thiskey.meta) {
207 		thiskey.key = wgetch(body);
208 		if (thiskey.key == ERR || thiskey.key == 27) {
209 			thiskey.meta = 0;
210 			thiskey.key = 27;
211 		}
212 	}
213 
214 	thiskey.cp = 0;
215 	if ((unsigned int)thiskey.key < UINT8_MAX) {
216 		while (1) {
217 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
218 				break;
219 			if ((thiskey.key = wgetch(body)) == ERR) {
220 				message("Error decoding user input");
221 				return 0;
222 			}
223 		}
224 	}
225 
226 	return 1;
227 }
228 
229 static void
230 dispatch_stdio(int fd, short ev, void *d)
231 {
232 	struct keymap	*k;
233 	const char	*keyname;
234 	char		 tmp[5] = {0};
235 
236 	/* TODO: schedule a redraw? */
237 	if (too_small)
238 		return;
239 
240 	if (!readkey())
241 		return;
242 
243 	if (keybuf[0] != '\0')
244 		strlcat(keybuf, " ", sizeof(keybuf));
245 	if (thiskey.meta)
246 		strlcat(keybuf, "M-", sizeof(keybuf));
247 	if (thiskey.cp != 0) {
248 		utf8_encode(thiskey.cp, tmp);
249 		strlcat(keybuf, tmp, sizeof(keybuf));
250 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
251 		strlcat(keybuf, keyname, sizeof(keybuf));
252 	} else {
253 		tmp[0] = thiskey.key;
254 		strlcat(keybuf, tmp, sizeof(keybuf));
255 	}
256 
257 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
258 		if (k->meta == thiskey.meta &&
259 		    k->key == thiskey.key) {
260 			if (k->fn == NULL)
261 				current_map = &k->map;
262 			else {
263 				current_map = base_map;
264 				strlcpy(keybuf, "", sizeof(keybuf));
265 				k->fn(current_buffer());
266 			}
267 			goto done;
268 		}
269 	}
270 
271 	if (current_map->unhandled_input != NULL)
272 		current_map->unhandled_input();
273 	else
274 		global_key_unbound();
275 
276 	strlcpy(keybuf, "", sizeof(keybuf));
277 	current_map = base_map;
278 
279 done:
280 	if (side_window)
281 		recompute_help();
282 
283 	if (should_rearrange_windows)
284 		rearrange_windows();
285 	redraw_tab(current_tab);
286 }
287 
288 static void
289 handle_clear_echoarea(int fd, short ev, void *d)
290 {
291 	free(ministate.curmesg);
292 	ministate.curmesg = NULL;
293 
294 	redraw_minibuffer();
295 	place_cursor(0);
296 }
297 
298 static void
299 handle_resize(int sig, short ev, void *d)
300 {
301 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
302 		event_del(&resizeev);
303 	}
304 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
305 	evtimer_add(&resizeev, &resize_timer);
306 }
307 
308 static void
309 handle_resize_nodelay(int s, short ev, void *d)
310 {
311 	endwin();
312 	refresh();
313 	clear();
314 
315 	rearrange_windows();
316 }
317 
318 static void
319 rearrange_windows(void)
320 {
321 	int		 lines;
322 
323 	should_rearrange_windows = 0;
324 
325 	lines = LINES;
326 
327 	if ((too_small = lines < 15)) {
328 		erase();
329 		printw("Window too small.");
330 		refresh();
331 		return;
332 	}
333 
334 	/* move and resize the windows, in reverse order! */
335 
336 	if (in_minibuffer == MB_COMPREAD) {
337 		mvwin(minibuffer, lines-10, 0);
338 		wresize(minibuffer, 10, COLS);
339 		lines -= 10;
340 
341 		wrap_page(&ministate.compl.buffer, COLS);
342 	}
343 
344 	mvwin(echoarea, --lines, 0);
345 	wresize(echoarea, 1, COLS);
346 
347 	mvwin(modeline, --lines, 0);
348 	wresize(modeline, 1, COLS);
349 
350 	body_lines = --lines;
351 	body_cols = COLS;
352 
353 	if (side_window) {
354 		help_cols = 0.3 * COLS;
355 		help_lines = lines;
356 		mvwin(help, 1, 0);
357 		wresize(help, help_lines, help_cols);
358 
359 		wrap_page(&helpwin, help_cols);
360 
361 		body_cols = COLS - help_cols - 1;
362 		mvwin(body, 1, help_cols);
363 	} else
364 		mvwin(body, 1, 0);
365 
366 	update_x_offset();
367 	wresize(body, body_lines, body_cols);
368 
369 	wresize(tabline, 1, COLS);
370 
371 	wrap_page(&current_tab->buffer, body_cols);
372 	redraw_tab(current_tab);
373 }
374 
375 static int
376 wrap_page(struct buffer *buffer, int width)
377 {
378 	struct line		*l;
379 	const struct line	*top_orig, *orig;
380 	struct vline		*vl;
381 	int			 pre_width;
382 	const char		*prfx;
383 
384 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
385 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
386 
387 	buffer->top_line = NULL;
388 	buffer->current_line = NULL;
389 
390 	buffer->force_redraw = 1;
391 	buffer->curs_y = 0;
392 	buffer->line_off = 0;
393 
394 	empty_vlist(buffer);
395 
396 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
397 		prfx = line_prefixes[l->type].prfx1;
398 		switch (l->type) {
399 		case LINE_TEXT:
400 		case LINE_LINK:
401 		case LINE_TITLE_1:
402 		case LINE_TITLE_2:
403 		case LINE_TITLE_3:
404 		case LINE_ITEM:
405 		case LINE_QUOTE:
406 		case LINE_PRE_START:
407 		case LINE_PRE_END:
408 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
409 			break;
410 		case LINE_PRE_CONTENT:
411 			if (olivetti_mode)
412 				pre_width = MIN(fill_column, width);
413 			else
414 				pre_width = width;
415 			hardwrap_text(buffer, l, pre_width);
416 			break;
417 		case LINE_COMPL:
418 		case LINE_COMPL_CURRENT:
419 			wrap_one(buffer, prfx, l, width);
420 			break;
421 		}
422 
423 		if (top_orig == l && buffer->top_line == NULL) {
424 			buffer->line_off = buffer->line_max-1;
425 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
426 
427 			while (1) {
428 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
429 				if (vl == NULL || vl->parent != orig)
430 					break;
431 				buffer->top_line = vl;
432 				buffer->line_off--;
433 			}
434 		}
435 
436 		if (orig == l && buffer->current_line == NULL) {
437 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
438 
439 			while (1) {
440 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
441 				if (vl == NULL || vl->parent != orig)
442 					break;
443 				buffer->current_line = vl;
444 			}
445 		}
446 	}
447 
448         if (buffer->current_line == NULL)
449 		buffer->current_line = TAILQ_FIRST(&buffer->head);
450 
451 	if (buffer->top_line == NULL)
452 		buffer->top_line = buffer->current_line;
453 
454 	return 1;
455 }
456 
457 static void
458 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
459     const char **prfx_ret, const char **text_ret)
460 {
461 	int type, i, cont, width;
462 	char *space, *t;
463 
464 	if ((*text_ret = vl->line) == NULL)
465 		*text_ret = "";
466 
467 	cont = vl->flags & L_CONTINUATION;
468 	type = vl->parent->type;
469 	if (!cont)
470 		*prfx_ret = line_prefixes[type].prfx1;
471 	else
472 		*prfx_ret = line_prefixes[type].prfx2;
473 
474 	space = vl->parent->data;
475 	if (!emojify_link || type != LINE_LINK || space == NULL)
476 		return;
477 
478 	if (cont) {
479 		memset(buf, 0, len);
480 		width = utf8_swidth_between(vl->parent->line, space);
481 		for (i = 0; i < width + 1; ++i)
482 			strlcat(buf, " ", len);
483 	} else {
484 		strlcpy(buf, *text_ret, len);
485 		if ((t = strchr(buf, ' ')) != NULL)
486 			*t = '\0';
487 		strlcat(buf, " ", len);
488 
489 		/* skip the emoji */
490                 *text_ret += (space - vl->parent->line) + 1;
491 	}
492 
493 	*prfx_ret = buf;
494 }
495 
496 /*
497  * Core part of the rendering.  It prints a vline starting from the
498  * current cursor position.  Printing a vline consists of skipping
499  * `off' columns (for olivetti-mode), print the correct prefix (which
500  * may be the emoji in case of emojified links-lines), printing the
501  * text itself, filling until width - off and filling off columns
502  * again.
503  */
504 static void
505 print_vline(int off, int width, WINDOW *window, struct vline *vl)
506 {
507 	/*
508 	 * Believe me or not, I've seen emoji ten code points long!
509 	 * That means, to stay large, 4*10 bytes + NUL.
510 	 */
511 	char emojibuf[41] = {0};
512 	const char *text, *prfx;
513 	struct line_face *f;
514 	int i, left, x, y;
515 
516 	f = &line_faces[vl->parent->type];
517 
518 	/* unused, set by getyx */
519 	(void)y;
520 
521 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
522 
523 	wattr_on(window, body_face.left, NULL);
524 	for (i = 0; i < off; i++)
525 		waddch(window, ' ');
526 	wattr_off(window, body_face.left, NULL);
527 
528 	wattr_on(window, f->prefix, NULL);
529 	wprintw(window, "%s", prfx);
530 	wattr_off(window, f->prefix, NULL);
531 
532 	wattr_on(window, f->text, NULL);
533 	wprintw(window, "%s", text);
534 	wattr_off(window, f->text, NULL);
535 
536 	getyx(window, y, x);
537 
538 	left = width - x;
539 
540 	wattr_on(window, f->trail, NULL);
541 	for (i = 0; i < left - off; ++i)
542 		waddch(window, ' ');
543 	wattr_off(window, f->trail, NULL);
544 
545 	wattr_on(window, body_face.right, NULL);
546 	for (i = 0; i < off; i++)
547 		waddch(window, ' ');
548 	wattr_off(window, body_face.right, NULL);
549 
550 }
551 
552 static void
553 redraw_tabline(void)
554 {
555 	struct tab	*tab;
556 	size_t		 toskip, ots, tabwidth, space, x;
557 	int		 current, y, truncated, pair;
558 	const char	*title;
559 	char		 buf[25];
560 
561 	x = 0;
562 
563 	/* unused, but setted by a getyx */
564 	(void)y;
565 
566 	tabwidth = sizeof(buf)+1;
567 	space = COLS-2;
568 
569 	toskip = 0;
570 	TAILQ_FOREACH(tab, &tabshead, tabs) {
571 		toskip++;
572 		if (tab == current_tab)
573 			break;
574 	}
575 
576 	if (toskip * tabwidth < space)
577 		toskip = 0;
578 	else {
579 		ots = toskip;
580 		toskip--;
581                 while (toskip != 0 &&
582 		    (ots - toskip+1) * tabwidth < space)
583 			toskip--;
584 	}
585 
586 	werase(tabline);
587 	wattr_on(tabline, tab_face.background, NULL);
588 	wprintw(tabline, toskip == 0 ? " " : "<");
589 	wattr_off(tabline, tab_face.background, NULL);
590 
591 	truncated = 0;
592 	TAILQ_FOREACH(tab, &tabshead, tabs) {
593 		if (truncated)
594 			break;
595 		if (toskip != 0) {
596 			toskip--;
597 			continue;
598 		}
599 
600 		getyx(tabline, y, x);
601 		if (x + sizeof(buf)+2 >= (size_t)COLS)
602 			truncated = 1;
603 
604 		current = tab == current_tab;
605 
606 		if (*(title = tab->buffer.page.title) == '\0')
607 			title = tab->hist_cur->h;
608 
609 		if (tab->flags & TAB_URGENT)
610 			strlcpy(buf, "!", sizeof(buf));
611 		else
612 			strlcpy(buf, " ", sizeof(buf));
613 
614                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
615 			/* truncation happens */
616 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
617 		} else {
618 			/* pad with spaces */
619 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
620 				/* nop */ ;
621 		}
622 
623 		pair = current ? tab_face.current : tab_face.tab;
624 		wattr_on(tabline, pair, NULL);
625 		wprintw(tabline, "%s", buf);
626 		wattr_off(tabline, pair, NULL);
627 
628 		wattr_on(tabline, tab_face.background, NULL);
629 		if (TAILQ_NEXT(tab, tabs) != NULL)
630 			wprintw(tabline, "│");
631 		wattr_off(tabline, tab_face.background, NULL);
632 	}
633 
634 	wattr_on(tabline, tab_face.background, NULL);
635 	for (; x < (size_t)COLS; ++x)
636 		waddch(tabline, ' ');
637 	if (truncated)
638 		mvwprintw(tabline, 0, COLS-1, ">");
639 	wattr_off(tabline, tab_face.background, NULL);
640 }
641 
642 /*
643  * Compute the first visible line around vl.  Try to search forward
644  * until the end of the buffer; if a visible line is not found, search
645  * backward.  Return NULL if no viable line was found.
646  */
647 struct vline *
648 adjust_line(struct vline *vl, struct buffer *buffer)
649 {
650 	struct vline *t;
651 
652 	if (vl == NULL)
653 		return NULL;
654 
655 	if (!(vl->parent->flags & L_HIDDEN))
656 		return vl;
657 
658 	/* search forward */
659 	for (t = vl;
660 	     t != NULL && t->parent->flags & L_HIDDEN;
661 	     t = TAILQ_NEXT(t, vlines))
662 		;		/* nop */
663 
664 	if (t != NULL)
665 		return t;
666 
667 	/* search backward */
668 	for (t = vl;
669 	     t != NULL && t->parent->flags & L_HIDDEN;
670 	     t = TAILQ_PREV(t, vhead, vlines))
671 		;		/* nop */
672 
673 	return t;
674 }
675 
676 static void
677 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
678 {
679         struct vline	*vl;
680 	int		 l, onscreen;
681 
682 	restore_curs_x(buffer);
683 
684 	/*
685 	 * TODO: ignoring buffer->force_update and always
686 	 * re-rendering.  In theory we can recompute the y position
687 	 * without a re-render, and optimize here.  It's not the only
688 	 * optimisation possible here, wscrl wolud also be an
689 	 * interesting one.
690 	 */
691 
692 again:
693 	werase(win);
694 	buffer->curs_y = 0;
695 
696 	if (TAILQ_EMPTY(&buffer->head))
697 		goto end;
698 
699 	if (buffer->top_line == NULL)
700 		buffer->top_line = TAILQ_FIRST(&buffer->head);
701 
702 	buffer->top_line = adjust_line(buffer->top_line, buffer);
703 	if (buffer->top_line == NULL)
704 		goto end;
705 
706 	buffer->current_line = adjust_line(buffer->current_line, buffer);
707 
708 	l = 0;
709 	onscreen = 0;
710 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
711 		if (vl->parent->flags & L_HIDDEN)
712 			continue;
713 
714 		wmove(win, l, 0);
715 		print_vline(off, width, win, vl);
716 
717 		if (vl == buffer->current_line)
718 			onscreen = 1;
719 
720 		if (!onscreen)
721 			buffer->curs_y++;
722 
723 		l++;
724 		if (l == height)
725 			break;
726 	}
727 
728 	if (!onscreen) {
729 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
730 			if (vl == buffer->current_line)
731 				break;
732 			if (vl->parent->flags & L_HIDDEN)
733 				continue;
734 			buffer->line_off++;
735 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
736 		}
737 
738 		if (vl != NULL)
739 			goto again;
740 	}
741 
742 	buffer->last_line_off = buffer->line_off;
743 	buffer->force_redraw = 0;
744 end:
745 	wmove(win, buffer->curs_y, buffer->curs_x);
746 }
747 
748 static void
749 redraw_help(void)
750 {
751 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
752 }
753 
754 static void
755 redraw_body(struct tab *tab)
756 {
757 	static struct tab *last_tab;
758 
759 	if (last_tab != tab)
760 		tab->buffer.force_redraw =1;
761 	last_tab = tab;
762 
763 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
764 }
765 
766 static inline char
767 trust_status_char(enum trust_state ts)
768 {
769 	switch (ts) {
770 	case TS_UNKNOWN:	return 'u';
771 	case TS_UNTRUSTED:	return '!';
772 	case TS_TEMP_TRUSTED:	return '!';
773 	case TS_TRUSTED:	return 'v';
774 	case TS_VERIFIED:	return 'V';
775 	default:		return 'X';
776 	}
777 }
778 
779 static void
780 redraw_modeline(struct tab *tab)
781 {
782 	double		 pct;
783 	int		 x, y, max_x, max_y;
784 	const char	*mode = tab->buffer.page.name;
785 	const char	*spin = "-\\|/";
786 
787 	werase(modeline);
788 	wattr_on(modeline, modeline_face.background, NULL);
789 	wmove(modeline, 0, 0);
790 
791 	wprintw(modeline, "-%c%c %s ",
792 	    spin[tab->loading_anim_step],
793 	    trust_status_char(tab->trust),
794 	    mode == NULL ? "(none)" : mode);
795 
796 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0
797 		/ tab->buffer.line_max;
798 
799 	if (tab->buffer.line_max <= (size_t)body_lines)
800                 wprintw(modeline, "All ");
801 	else if (tab->buffer.line_off == 0)
802                 wprintw(modeline, "Top ");
803 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
804 		wprintw(modeline, "Bottom ");
805 	else
806 		wprintw(modeline, "%.0f%% ", pct);
807 
808 	wprintw(modeline, "%d/%d %s ",
809 	    tab->buffer.line_off + tab->buffer.curs_y,
810 	    tab->buffer.line_max,
811 	    tab->hist_cur->h);
812 
813 	getyx(modeline, y, x);
814 	getmaxyx(modeline, max_y, max_x);
815 
816 	(void)y;
817 	(void)max_y;
818 
819 	for (; x < max_x; ++x)
820 		waddstr(modeline, "-");
821 
822 	wattr_off(modeline, modeline_face.background, NULL);
823 }
824 
825 static void
826 redraw_minibuffer(void)
827 {
828 	wattr_on(echoarea, minibuffer_face.background, NULL);
829 	werase(echoarea);
830 
831 	if (in_minibuffer)
832 		do_redraw_minibuffer();
833 	else
834 		do_redraw_echoarea();
835 
836 	if (in_minibuffer == MB_COMPREAD)
837 		do_redraw_minibuffer_compl();
838 
839 	wattr_off(echoarea, minibuffer_face.background, NULL);
840 }
841 
842 static void
843 do_redraw_echoarea(void)
844 {
845 	struct vline *vl;
846 
847 	if (ministate.curmesg != NULL)
848                 wprintw(echoarea, "%s", ministate.curmesg);
849 	else if (*keybuf != '\0')
850 		waddstr(echoarea, keybuf);
851 	else {
852 		/* If nothing else, show the URL at point */
853 		vl = current_tab->buffer.current_line;
854 		if (vl != NULL && vl->parent->type == LINE_LINK)
855 			waddstr(echoarea, vl->parent->alt);
856 	}
857 }
858 
859 static void
860 do_redraw_minibuffer(void)
861 {
862 	size_t		 off_y, off_x = 0;
863 	const char	*start, *c;
864 
865 	/* unused, set by getyx */
866 	(void)off_y;
867 
868 	wmove(echoarea, 0, 0);
869 
870 	if (in_minibuffer == MB_COMPREAD)
871 		wprintw(echoarea, "(%2d) ",
872 		    ministate.compl.buffer.line_max);
873 
874 	wprintw(echoarea, "%s", ministate.prompt);
875 	if (ministate.hist_cur != NULL)
876 		wprintw(echoarea, "(%zu/%zu) ",
877 		    ministate.hist_off + 1,
878 		    ministate.history->len);
879 
880 	getyx(echoarea, off_y, off_x);
881 
882 	start = ministate.hist_cur != NULL
883 		? ministate.hist_cur->h
884 		: ministate.buf;
885 	c = utf8_nth(ministate.buffer.current_line->line,
886 	    ministate.buffer.cpoff);
887 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
888 		start = utf8_next_cp(start);
889 	}
890 
891 	waddstr(echoarea, start);
892 
893 	if (ministate.curmesg != NULL)
894 		wprintw(echoarea, " [%s]", ministate.curmesg);
895 
896 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
897 }
898 
899 static void
900 do_redraw_minibuffer_compl(void)
901 {
902 	redraw_window(minibuffer, 0, 10, body_cols,
903 	    &ministate.compl.buffer);
904 }
905 
906 /*
907  * Place the cursor in the right ncurses window.  If soft is 1, use
908  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
909  * wrefresh.
910  */
911 static void
912 place_cursor(int soft)
913 {
914 	int (*touch)(WINDOW *);
915 
916 	if (soft)
917 		touch = wnoutrefresh;
918 	else
919 		touch = wrefresh;
920 
921 	if (in_minibuffer) {
922 		touch(body);
923 		touch(echoarea);
924 	} else {
925 		touch(echoarea);
926 		touch(body);
927 	}
928 }
929 
930 static void
931 redraw_tab(struct tab *tab)
932 {
933 	if (too_small)
934 		return;
935 
936 	if (side_window) {
937 		redraw_help();
938 		wnoutrefresh(help);
939 	}
940 
941 	redraw_tabline();
942 	redraw_body(tab);
943 	redraw_modeline(tab);
944 	redraw_minibuffer();
945 
946 	wnoutrefresh(tabline);
947 	wnoutrefresh(modeline);
948 
949 	if (in_minibuffer == MB_COMPREAD)
950 		wnoutrefresh(minibuffer);
951 
952 	place_cursor(1);
953 
954 	doupdate();
955 }
956 
957 static void
958 emit_help_item(char *prfx, void *fn)
959 {
960 	struct line	*l;
961 	struct cmd	*cmd;
962 
963 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
964 		if (fn == cmd->fn)
965 			break;
966 	}
967 	assert(cmd != NULL);
968 
969 	if ((l = calloc(1, sizeof(*l))) == NULL)
970 		abort();
971 
972 	l->type = LINE_TEXT;
973 	l->alt = NULL;
974 
975 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
976 
977 	if (TAILQ_EMPTY(&helpwin.page.head))
978 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
979 	else
980 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
981 }
982 
983 static void
984 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
985 {
986 	struct keymap	*k;
987 	char		 p[32];
988 	const char	*kn;
989 
990 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
991 		strlcpy(p, prfx, sizeof(p));
992 		if (*p != '\0')
993 			strlcat(p, " ", sizeof(p));
994 		if (k->meta)
995 			strlcat(p, "M-", sizeof(p));
996 		if ((kn = unkbd(k->key)) != NULL)
997 			strlcat(p, kn, sizeof(p));
998 		else
999 			strlcat(p, keyname(k->key), sizeof(p));
1000 
1001 		if (k->fn == NULL)
1002 			rec_compute_help(&k->map, p, sizeof(p));
1003 		else
1004 			emit_help_item(p, k->fn);
1005 	}
1006 }
1007 
1008 static void
1009 recompute_help(void)
1010 {
1011 	char	p[32] = { 0 };
1012 
1013 	empty_vlist(&helpwin);
1014 	empty_linelist(&helpwin);
1015 	rec_compute_help(current_map, p, sizeof(p));
1016 	wrap_page(&helpwin, help_cols);
1017 }
1018 
1019 void
1020 vmessage(const char *fmt, va_list ap)
1021 {
1022 	if (evtimer_pending(&clechoev, NULL))
1023 		evtimer_del(&clechoev);
1024 
1025 	free(ministate.curmesg);
1026 	ministate.curmesg = NULL;
1027 
1028 	if (fmt != NULL) {
1029 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1030 		evtimer_add(&clechoev, &clechoev_timer);
1031 
1032 		/* TODO: what to do if the allocation fails here? */
1033 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
1034 			ministate.curmesg = NULL;
1035 	}
1036 
1037 	redraw_minibuffer();
1038         place_cursor(0);
1039 }
1040 
1041 void
1042 message(const char *fmt, ...)
1043 {
1044 	va_list ap;
1045 
1046 	va_start(ap, fmt);
1047 	vmessage(fmt, ap);
1048 	va_end(ap);
1049 }
1050 
1051 void
1052 start_loading_anim(struct tab *tab)
1053 {
1054 	if (tab->loading_anim)
1055 		return;
1056 	tab->loading_anim = 1;
1057 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1058 	evtimer_add(&tab->loadingev, &loadingev_timer);
1059 }
1060 
1061 static void
1062 update_loading_anim(int fd, short ev, void *d)
1063 {
1064 	struct tab	*tab = d;
1065 
1066 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1067 
1068 	if (tab == current_tab) {
1069 		redraw_modeline(tab);
1070 		wrefresh(modeline);
1071 		wrefresh(body);
1072 		if (in_minibuffer)
1073 			wrefresh(echoarea);
1074 	}
1075 
1076 	evtimer_add(&tab->loadingev, &loadingev_timer);
1077 }
1078 
1079 static void
1080 stop_loading_anim(struct tab *tab)
1081 {
1082 	if (!tab->loading_anim)
1083 		return;
1084 	evtimer_del(&tab->loadingev);
1085 	tab->loading_anim = 0;
1086 	tab->loading_anim_step = 0;
1087 
1088 	if (tab != current_tab)
1089 		return;
1090 
1091 	redraw_modeline(tab);
1092 
1093 	wrefresh(modeline);
1094 	wrefresh(body);
1095 	if (in_minibuffer)
1096 		wrefresh(echoarea);
1097 }
1098 
1099 void
1100 load_url_in_tab(struct tab *tab, const char *url)
1101 {
1102 	message("Loading %s...", url);
1103 	start_loading_anim(tab);
1104 	load_url(tab, url);
1105 
1106 	tab->buffer.curs_x = 0;
1107 	tab->buffer.curs_y = 0;
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 
1118 unsigned int
1119 tab_new_id(void)
1120 {
1121 	return tab_counter++;
1122 }
1123 
1124 struct tab *
1125 new_tab(const char *url)
1126 {
1127 	struct tab	*tab;
1128 
1129 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1130 		event_loopbreak();
1131 		return NULL;
1132 	}
1133 	tab->fd = -1;
1134 
1135 	TAILQ_INIT(&tab->hist.head);
1136 
1137 	TAILQ_INIT(&tab->buffer.head);
1138 
1139 	tab->id = tab_new_id();
1140 	switch_to_tab(tab);
1141 
1142 	if (TAILQ_EMPTY(&tabshead))
1143 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1144 	else
1145 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1146 
1147 	load_url_in_tab(tab, url);
1148 	return tab;
1149 }
1150 
1151 int
1152 ui_print_colors(void)
1153 {
1154 	int colors = 0, pairs = 0, can_change = 0;
1155 	int columns = 16, lines, color, i, j;
1156 
1157 	initscr();
1158 	if (has_colors()) {
1159 		start_color();
1160 		use_default_colors();
1161 
1162 		colors = COLORS;
1163 		pairs = COLOR_PAIRS;
1164 		can_change = can_change_color();
1165 	}
1166 	endwin();
1167 
1168 	printf("Term info:\n");
1169 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1170 	    getenv("TERM"), colors, pairs, can_change);
1171 	printf("\n");
1172 
1173 	if (colors == 0) {
1174 		printf("No color support\n");
1175 		return 0;
1176 	}
1177 
1178 	printf("Available colors:\n\n");
1179 	lines = (colors - 1) / columns + 1;
1180 	color = 0;
1181 	for (i = 0; i < lines; ++i) {
1182 		for (j = 0; j < columns; ++j, ++color) {
1183 			printf("\033[0;38;5;%dm %03d", color, color);
1184 		}
1185 		printf("\n");
1186 	}
1187 
1188 	printf("\033[0m");
1189 	fflush(stdout);
1190 	return 0;
1191 }
1192 
1193 int
1194 ui_init()
1195 {
1196 	setlocale(LC_ALL, "");
1197 
1198 	TAILQ_INIT(&eecmd_history.head);
1199 	TAILQ_INIT(&ir_history.head);
1200 	TAILQ_INIT(&lu_history.head);
1201 
1202 	ministate.line.type = LINE_TEXT;
1203 	ministate.vline.parent = &ministate.line;
1204 	ministate.buffer.current_line = &ministate.vline;
1205 
1206 	/* initialize help window */
1207 	TAILQ_INIT(&helpwin.head);
1208 
1209 	base_map = &global_map;
1210 	current_map = &global_map;
1211 
1212 	initscr();
1213 
1214 	if (enable_colors) {
1215 		if (has_colors()) {
1216 			start_color();
1217 			use_default_colors();
1218 		} else
1219 			enable_colors = 0;
1220 	}
1221 
1222 	config_apply_style();
1223 
1224 	raw();
1225 	noecho();
1226 	nonl();
1227 	intrflush(stdscr, FALSE);
1228 
1229 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1230 		return 0;
1231 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1232 		return 0;
1233 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1234 		return 0;
1235 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1236 		return 0;
1237 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1238 		return 0;
1239 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1240 		return 0;
1241 
1242 	body_lines = LINES-3;
1243 	body_cols = COLS;
1244 
1245 	wbkgd(body, body_face.body);
1246 	wbkgd(echoarea, minibuffer_face.background);
1247 
1248 	update_x_offset();
1249 
1250 	keypad(body, TRUE);
1251 	scrollok(body, FALSE);
1252 
1253 	/* non-blocking input */
1254 	wtimeout(body, 0);
1255 
1256 	mvwprintw(body, 0, 0, "");
1257 
1258 	/*
1259 	 * Dummy so libevent2 won't complain that no event_base is set
1260 	 * when checking event_pending for the first time
1261 	 */
1262 	evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1263 	evtimer_add(&clechoev, &clechoev_timer);
1264 	evtimer_set(&resizeev, handle_resize, NULL);
1265 	evtimer_add(&resizeev, &resize_timer);
1266 
1267 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1268 	event_add(&stdioev, NULL);
1269 
1270 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1271 	signal_add(&winchev, NULL);
1272 
1273 	return 1;
1274 }
1275 
1276 void
1277 ui_refresh(void)
1278 {
1279 	redraw_tab(current_tab);
1280 }
1281 
1282 void
1283 ui_on_tab_loaded(struct tab *tab)
1284 {
1285 	stop_loading_anim(tab);
1286 	message("Loaded %s", tab->hist_cur->h);
1287 
1288 	redraw_tabline();
1289 	wrefresh(tabline);
1290 	place_cursor(0);
1291 }
1292 
1293 void
1294 ui_on_tab_refresh(struct tab *tab)
1295 {
1296 	wrap_page(&tab->buffer, body_cols);
1297 	if (tab == current_tab)
1298 		redraw_tab(tab);
1299 	else
1300 		tab->flags |= TAB_URGENT;
1301 }
1302 
1303 const char *
1304 ui_keyname(int k)
1305 {
1306 	return keyname(k);
1307 }
1308 
1309 void
1310 ui_toggle_side_window(void)
1311 {
1312 	side_window = !side_window;
1313 	if (side_window)
1314 		recompute_help();
1315 
1316 	/*
1317 	 * ugly hack, but otherwise the window doesn't get updated
1318 	 * until I call rearrange_windows a second time (e.g. via
1319 	 * C-l).  I will be happy to know why something like this is
1320 	 * needed.
1321 	 */
1322 	rearrange_windows();
1323 	rearrange_windows();
1324 }
1325 
1326 void
1327 ui_schedule_redraw(void)
1328 {
1329 	should_rearrange_windows = 1;
1330 }
1331 
1332 void
1333 ui_require_input(struct tab *tab, int hide)
1334 {
1335 	/* TODO: hard-switching to another tab is ugly */
1336 	switch_to_tab(tab);
1337 
1338 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1339 	    &ir_history, NULL, NULL);
1340 	strlcpy(ministate.prompt, "Input required: ",
1341 	    sizeof(ministate.prompt));
1342 	redraw_tab(tab);
1343 }
1344 
1345 void
1346 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1347     struct tab *data)
1348 {
1349 	yornp(prompt, fn, data);
1350 	redraw_tab(current_tab);
1351 }
1352 
1353 void
1354 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1355     struct tab *data)
1356 {
1357 	completing_read(prompt, fn, data);
1358 	redraw_tab(current_tab);
1359 }
1360 
1361 void
1362 ui_suspend(void)
1363 {
1364 	endwin();
1365 
1366 	kill(getpid(), SIGSTOP);
1367 
1368 	refresh();
1369 	clear();
1370 	rearrange_windows();
1371 }
1372 
1373 void
1374 ui_end(void)
1375 {
1376 	endwin();
1377 }