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Date:: Fri Jul 16 13:46:44 2021 UTC
Message:: typo
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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 
86 static struct event	resizeev;
87 static struct timeval	resize_timer = { 0, 250000 };
88 
89 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
90 
91 int			 body_lines, body_cols;
92 
93 static WINDOW		*help;
94 static struct buffer	 helpwin;
95 static int		 help_lines, help_cols;
96 
97 static int		 side_window;
98 
99 static struct event	clechoev;
100 static struct timeval	clechoev_timer = { 5, 0 };
101 static struct timeval	loadingev_timer = { 0, 250000 };
102 
103 static uint32_t		 tab_counter;
104 
105 static char	keybuf[64];
106 
107 struct kmap global_map,
108 	minibuffer_map,
109 	*current_map,
110 	*base_map;
111 
112 int in_minibuffer;
113 
114 static inline void
115 update_x_offset(void)
116 {
117 	if (olivetti_mode && fill_column < body_cols)
118 		x_offset = (body_cols - fill_column)/2;
119 	else
120 		x_offset = 0;
121 }
122 
123 void
124 save_excursion(struct excursion *place, struct buffer *buffer)
125 {
126 	place->curs_x = buffer->curs_x;
127 	place->curs_y = buffer->curs_y;
128 	place->line_off = buffer->line_off;
129 	place->current_line = buffer->current_line;
130 	place->cpoff = buffer->cpoff;
131 }
132 
133 void
134 restore_excursion(struct excursion *place, struct buffer *buffer)
135 {
136 	buffer->curs_x = place->curs_x;
137 	buffer->curs_y = place->curs_y;
138 	buffer->line_off = place->line_off;
139 	buffer->current_line = place->current_line;
140 	buffer->cpoff = place->cpoff;
141 }
142 
143 static void
144 restore_curs_x(struct buffer *buffer)
145 {
146 	struct vline	*vl;
147 	const char	*prfx;
148 
149 	vl = buffer->current_line;
150 	if (vl == NULL || vl->line == NULL)
151 		buffer->curs_x = buffer->cpoff = 0;
152 	else if (vl->parent->data != NULL)
153 		buffer->curs_x = utf8_snwidth(vl->parent->data+1, buffer->cpoff) + 1;
154 	else
155 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
156 
157 	buffer->curs_x += x_offset;
158 
159 	if (vl != NULL) {
160 		prfx = line_prefixes[vl->parent->type].prfx1;
161 		buffer->curs_x += utf8_swidth(prfx);
162 	}
163 }
164 
165 void
166 global_key_unbound(void)
167 {
168 	message("%s is undefined", keybuf);
169 }
170 
171 static struct vline *
172 nth_line(struct buffer *buffer, size_t n)
173 {
174 	struct vline	*vl;
175 	size_t		 i;
176 
177 	i = 0;
178 	TAILQ_FOREACH(vl, &buffer->head, vlines) {
179 		if (i == n)
180 			return vl;
181 		i++;
182 	}
183 
184 	/* unreachable */
185 	abort();
186 }
187 
188 struct tab *
189 current_tab(void)
190 {
191 	struct tab *t;
192 
193 	TAILQ_FOREACH(t, &tabshead, tabs) {
194 		if (t->flags & TAB_CURRENT)
195 			return t;
196 	}
197 
198 	/* unreachable */
199 	abort();
200 }
201 
202 struct buffer *
203 current_buffer(void)
204 {
205 	if (in_minibuffer)
206 		return &ministate.buffer;
207 	return &current_tab()->buffer;
208 }
209 
210 static int
211 readkey(void)
212 {
213 	uint32_t state = 0;
214 
215 	if ((thiskey.key = wgetch(body)) == ERR)
216 		return 0;
217 
218 	thiskey.meta = thiskey.key == 27;
219 	if (thiskey.meta) {
220 		thiskey.key = wgetch(body);
221 		if (thiskey.key == ERR || thiskey.key == 27) {
222 			thiskey.meta = 0;
223 			thiskey.key = 27;
224 		}
225 	}
226 
227 	thiskey.cp = 0;
228 	if ((unsigned int)thiskey.key < UINT8_MAX) {
229 		while (1) {
230 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
231 				break;
232 			if ((thiskey.key = wgetch(body)) == ERR) {
233 				message("Error decoding user input");
234 				return 0;
235 			}
236 		}
237 	}
238 
239 	return 1;
240 }
241 
242 static void
243 dispatch_stdio(int fd, short ev, void *d)
244 {
245 	struct keymap	*k;
246 	const char	*keyname;
247 	char		 tmp[5] = {0};
248 
249 	/* TODO: schedule a redraw? */
250 	if (too_small)
251 		return;
252 
253 	if (!readkey())
254 		return;
255 
256 	if (keybuf[0] != '\0')
257 		strlcat(keybuf, " ", sizeof(keybuf));
258 	if (thiskey.meta)
259 		strlcat(keybuf, "M-", sizeof(keybuf));
260 	if (thiskey.cp != 0) {
261 		utf8_encode(thiskey.cp, tmp);
262 		strlcat(keybuf, tmp, sizeof(keybuf));
263 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
264 		strlcat(keybuf, keyname, sizeof(keybuf));
265 	} else {
266 		tmp[0] = thiskey.key;
267 		strlcat(keybuf, tmp, sizeof(keybuf));
268 	}
269 
270 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
271 		if (k->meta == thiskey.meta &&
272 		    k->key == thiskey.key) {
273 			if (k->fn == NULL)
274 				current_map = &k->map;
275 			else {
276 				current_map = base_map;
277 				strlcpy(keybuf, "", sizeof(keybuf));
278 				k->fn(current_buffer());
279 			}
280 			goto done;
281 		}
282 	}
283 
284 	if (current_map->unhandled_input != NULL)
285 		current_map->unhandled_input();
286 	else
287 		global_key_unbound();
288 
289 	strlcpy(keybuf, "", sizeof(keybuf));
290 	current_map = base_map;
291 
292 done:
293 	if (side_window)
294 		recompute_help();
295 
296 	if (should_rearrange_windows)
297 		rearrange_windows();
298 	redraw_tab(current_tab());
299 }
300 
301 static void
302 handle_clear_echoarea(int fd, short ev, void *d)
303 {
304 	free(ministate.curmesg);
305 	ministate.curmesg = NULL;
306 
307 	redraw_minibuffer();
308 	place_cursor(0);
309 }
310 
311 static void
312 handle_resize(int sig, short ev, void *d)
313 {
314 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
315 		event_del(&resizeev);
316 	}
317 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
318 	evtimer_add(&resizeev, &resize_timer);
319 }
320 
321 static void
322 handle_resize_nodelay(int s, short ev, void *d)
323 {
324 	endwin();
325 	refresh();
326 	clear();
327 
328 	rearrange_windows();
329 }
330 
331 static void
332 rearrange_windows(void)
333 {
334 	struct tab	*tab;
335 	int		 lines;
336 
337 	should_rearrange_windows = 0;
338 
339 	lines = LINES;
340 
341 	if ((too_small = lines < 15)) {
342 		erase();
343 		printw("Window too small.");
344 		refresh();
345 		return;
346 	}
347 
348 	/* move and resize the windows, in reverse order! */
349 
350 	if (in_minibuffer == MB_COMPREAD) {
351 		mvwin(minibuffer, lines-10, 0);
352 		wresize(minibuffer, 10, COLS);
353 		lines -= 10;
354 
355 		wrap_page(&ministate.compl.buffer, COLS);
356 	}
357 
358 	mvwin(echoarea, --lines, 0);
359 	wresize(echoarea, 1, COLS);
360 
361 	mvwin(modeline, --lines, 0);
362 	wresize(modeline, 1, COLS);
363 
364 	body_lines = --lines;
365 	body_cols = COLS;
366 
367 	if (side_window) {
368 		help_cols = 0.3 * COLS;
369 		help_lines = lines;
370 		mvwin(help, 1, 0);
371 		wresize(help, help_lines, help_cols);
372 
373 		wrap_page(&helpwin, help_cols);
374 
375 		body_cols = COLS - help_cols - 1;
376 		mvwin(body, 1, help_cols);
377 	} else
378 		mvwin(body, 1, 0);
379 
380 	update_x_offset();
381 	wresize(body, body_lines, body_cols);
382 
383 	wresize(tabline, 1, COLS);
384 
385 	tab = current_tab();
386 
387 	wrap_page(&tab->buffer, body_cols);
388 	redraw_tab(tab);
389 }
390 
391 static int
392 wrap_page(struct buffer *buffer, int width)
393 {
394 	struct line		*l;
395 	const struct line	*top_orig, *orig;
396 	struct vline		*vl;
397 	int			 pre_width;
398 	const char		*prfx;
399 
400 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
401 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
402 
403 	buffer->top_line = NULL;
404 	buffer->current_line = NULL;
405 
406 	buffer->force_redraw = 1;
407 	buffer->curs_y = 0;
408 	buffer->line_off = 0;
409 
410 	empty_vlist(buffer);
411 
412 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
413 		prfx = line_prefixes[l->type].prfx1;
414 		switch (l->type) {
415 		case LINE_TEXT:
416 		case LINE_LINK:
417 		case LINE_TITLE_1:
418 		case LINE_TITLE_2:
419 		case LINE_TITLE_3:
420 		case LINE_ITEM:
421 		case LINE_QUOTE:
422 		case LINE_PRE_START:
423 		case LINE_PRE_END:
424 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
425 			break;
426 		case LINE_PRE_CONTENT:
427 			if (olivetti_mode)
428 				pre_width = MIN(fill_column, width);
429 			else
430 				pre_width = width;
431 			hardwrap_text(buffer, l, pre_width);
432 			break;
433 		case LINE_COMPL:
434 		case LINE_COMPL_CURRENT:
435 			wrap_one(buffer, prfx, l, width);
436 			break;
437 		}
438 
439 		if (top_orig == l && buffer->top_line == NULL) {
440 			buffer->line_off = buffer->line_max-1;
441 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
442 
443 			while (1) {
444 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
445 				if (vl == NULL || vl->parent != orig)
446 					break;
447 				buffer->top_line = vl;
448 				buffer->line_off--;
449 			}
450 		}
451 
452 		if (orig == l && buffer->current_line == NULL) {
453 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
454 
455 			while (1) {
456 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
457 				if (vl == NULL || vl->parent != orig)
458 					break;
459 				buffer->current_line = vl;
460 			}
461 		}
462 	}
463 
464         if (buffer->current_line == NULL)
465 		buffer->current_line = TAILQ_FIRST(&buffer->head);
466 
467 	if (buffer->top_line == NULL)
468 		buffer->top_line = buffer->current_line;
469 
470 	return 1;
471 }
472 
473 static void
474 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
475     const char **prfx_ret, const char **text_ret)
476 {
477 	int type, i, cont, width;
478 	char *space, *t;
479 
480 	if ((*text_ret = vl->line) == NULL)
481 		*text_ret = "";
482 
483 	cont = vl->flags & L_CONTINUATION;
484 	type = vl->parent->type;
485 	if (!cont)
486 		*prfx_ret = line_prefixes[type].prfx1;
487 	else
488 		*prfx_ret = line_prefixes[type].prfx2;
489 
490 	space = vl->parent->data;
491 	if (!emojify_link || type != LINE_LINK || space == NULL)
492 		return;
493 
494 	if (cont) {
495 		memset(buf, 0, len);
496 		width = utf8_swidth_between(vl->parent->line, space);
497 		for (i = 0; i < width + 1; ++i)
498 			strlcat(buf, " ", len);
499 	} else {
500 		strlcpy(buf, *text_ret, len);
501 		if ((t = strchr(buf, ' ')) != NULL)
502 			*t = '\0';
503 		strlcat(buf, " ", len);
504 
505 		/* skip the emoji */
506                 *text_ret += (space - vl->parent->line) + 1;
507 	}
508 
509 	*prfx_ret = buf;
510 }
511 
512 /*
513  * Core part of the rendering.  It prints a vline starting from the
514  * current cursor position.  Printing a vline consists of skipping
515  * `off' columns (for olivetti-mode), print the correct prefix (which
516  * may be the emoji in case of emojified links-lines), printing the
517  * text itself, filling until width - off and filling off columns
518  * again.
519  */
520 static void
521 print_vline(int off, int width, WINDOW *window, struct vline *vl)
522 {
523 	/*
524 	 * Believe me or not, I've seen emoji ten code points long!
525 	 * That means, to stay large, 4*10 bytes + NUL.
526 	 */
527 	char emojibuf[41] = {0};
528 	const char *text, *prfx;
529 	struct line_face *f;
530 	int i, left, x, y;
531 
532 	f = &line_faces[vl->parent->type];
533 
534 	/* unused, set by getyx */
535 	(void)y;
536 
537 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
538 
539 	wattr_on(window, body_face.left, NULL);
540 	for (i = 0; i < off; i++)
541 		waddch(window, ' ');
542 	wattr_off(window, body_face.left, NULL);
543 
544 	wattr_on(window, f->prefix, NULL);
545 	wprintw(window, "%s", prfx);
546 	wattr_off(window, f->prefix, NULL);
547 
548 	wattr_on(window, f->text, NULL);
549 	wprintw(window, "%s", text);
550 	wattr_off(window, f->text, NULL);
551 
552 	getyx(window, y, x);
553 
554 	left = width - x;
555 
556 	wattr_on(window, f->trail, NULL);
557 	for (i = 0; i < left - off; ++i)
558 		waddch(window, ' ');
559 	wattr_off(window, f->trail, NULL);
560 
561 	wattr_on(window, body_face.right, NULL);
562 	for (i = 0; i < off; i++)
563 		waddch(window, ' ');
564 	wattr_off(window, body_face.right, NULL);
565 
566 }
567 
568 static void
569 redraw_tabline(void)
570 {
571 	struct tab	*tab;
572 	size_t		 toskip, ots, tabwidth, space, x;
573 	int		 current, y, truncated;
574 	const char	*title;
575 	char		 buf[25];
576 
577 	x = 0;
578 
579 	/* unused, but setted by a getyx */
580 	(void)y;
581 
582 	tabwidth = sizeof(buf)+1;
583 	space = COLS-2;
584 
585 	toskip = 0;
586 	TAILQ_FOREACH(tab, &tabshead, tabs) {
587 		toskip++;
588 		if (tab->flags & TAB_CURRENT)
589 			break;
590 	}
591 
592 	if (toskip * tabwidth < space)
593 		toskip = 0;
594 	else {
595 		ots = toskip;
596 		toskip--;
597                 while (toskip != 0 &&
598 		    (ots - toskip+1) * tabwidth < space)
599 			toskip--;
600 	}
601 
602 	werase(tabline);
603 	wattr_on(tabline, tab_face.background, NULL);
604 	wprintw(tabline, toskip == 0 ? " " : "<");
605 	wattr_off(tabline, tab_face.background, NULL);
606 
607 	truncated = 0;
608 	TAILQ_FOREACH(tab, &tabshead, tabs) {
609 		if (truncated)
610 			break;
611 		if (toskip != 0) {
612 			toskip--;
613 			continue;
614 		}
615 
616 		getyx(tabline, y, x);
617 		if (x + sizeof(buf)+2 >= (size_t)COLS)
618 			truncated = 1;
619 
620 		current = tab->flags & TAB_CURRENT;
621 
622 		if (*(title = tab->buffer.page.title) == '\0')
623 			title = tab->hist_cur->h;
624 
625 		if (tab->flags & TAB_URGENT)
626 			strlcpy(buf, "!", sizeof(buf));
627 		else
628 			strlcpy(buf, " ", sizeof(buf));
629 
630                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
631 			/* truncation happens */
632 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
633 		} else {
634 			/* pad with spaces */
635 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
636 				/* nop */ ;
637 		}
638 
639 		if (current)
640 			wattr_on(tabline, tab_face.current, NULL);
641 		else
642 			wattr_on(tabline, tab_face.tab, NULL);
643 
644 		wprintw(tabline, "%s", buf);
645 		if (TAILQ_NEXT(tab, tabs) != NULL)
646 			wprintw(tabline, " ");
647 
648 		if (current)
649 			wattr_off(tabline, tab_face.current, NULL);
650 		else
651 			wattr_off(tabline, tab_face.tab, NULL);
652 	}
653 
654 	wattr_on(tabline, tab_face.background, NULL);
655 	for (; x < (size_t)COLS; ++x)
656 		waddch(tabline, ' ');
657 	if (truncated)
658 		mvwprintw(tabline, 0, COLS-1, ">");
659 	wattr_off(tabline, tab_face.background, NULL);
660 }
661 
662 /*
663  * Compute the first visible line around vl.  Try to search forward
664  * until the end of the buffer; if a visible line is not found, search
665  * backward.  Return NULL if no viable line was found.
666  */
667 struct vline *
668 adjust_line(struct vline *vl, struct buffer *buffer)
669 {
670 	struct vline *t;
671 
672 	if (vl == NULL)
673 		return NULL;
674 
675 	if (!(vl->parent->flags & L_HIDDEN))
676 		return vl;
677 
678 	/* search forward */
679 	for (t = vl;
680 	     t != NULL && t->parent->flags & L_HIDDEN;
681 	     t = TAILQ_NEXT(t, vlines))
682 		;		/* nop */
683 
684 	if (t != NULL)
685 		return t;
686 
687 	/* search backward */
688 	for (t = vl;
689 	     t != NULL && t->parent->flags & L_HIDDEN;
690 	     t = TAILQ_PREV(t, vhead, vlines))
691 		;		/* nop */
692 
693 	return t;
694 }
695 
696 static void
697 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
698 {
699         struct vline	*vl;
700 	int		 l, onscreen;
701 
702 	restore_curs_x(buffer);
703 
704 	/*
705 	 * TODO: ignoring buffer->force_update and always
706 	 * re-rendering.  In theory we can recompute the y position
707 	 * without a re-render, and optimize here.  It's not the only
708 	 * optimisation possible here, wscrl wolud also be an
709 	 * interesting one.
710 	 */
711 
712 again:
713 	werase(win);
714 	buffer->curs_y = 0;
715 
716 	if (TAILQ_EMPTY(&buffer->head))
717 		goto end;
718 
719 	if (buffer->top_line == NULL)
720 		buffer->top_line = TAILQ_FIRST(&buffer->head);
721 
722 	buffer->top_line = adjust_line(buffer->top_line, buffer);
723 	if (buffer->top_line == NULL)
724 		goto end;
725 
726 	buffer->current_line = adjust_line(buffer->current_line, buffer);
727 
728 	l = 0;
729 	onscreen = 0;
730 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
731 		if (vl->parent->flags & L_HIDDEN)
732 			continue;
733 
734 		wmove(win, l, 0);
735 		print_vline(off, width, win, vl);
736 
737 		if (vl == buffer->current_line)
738 			onscreen = 1;
739 
740 		if (!onscreen)
741 			buffer->curs_y++;
742 
743 		l++;
744 		if (l == height)
745 			break;
746 	}
747 
748 	if (!onscreen) {
749 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
750 			if (vl == buffer->current_line)
751 				break;
752 			if (vl->parent->flags & L_HIDDEN)
753 				continue;
754 			buffer->line_off++;
755 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
756 		}
757 
758 		if (vl != NULL)
759 			goto again;
760 	}
761 
762 	buffer->last_line_off = buffer->line_off;
763 	buffer->force_redraw = 0;
764 end:
765 	wmove(win, buffer->curs_y, buffer->curs_x);
766 }
767 
768 static void
769 redraw_help(void)
770 {
771 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
772 }
773 
774 static void
775 redraw_body(struct tab *tab)
776 {
777 	static struct tab *last_tab;
778 
779 	if (last_tab != tab)
780 		tab->buffer.force_redraw =1;
781 	last_tab = tab;
782 
783 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
784 }
785 
786 static inline char
787 trust_status_char(enum trust_state ts)
788 {
789 	switch (ts) {
790 	case TS_UNKNOWN:	return 'u';
791 	case TS_UNTRUSTED:	return '!';
792 	case TS_TEMP_TRUSTED:	return '!';
793 	case TS_TRUSTED:	return 'v';
794 	case TS_VERIFIED:	return 'V';
795 	default:		return 'X';
796 	}
797 }
798 
799 static void
800 redraw_modeline(struct tab *tab)
801 {
802 	double		 pct;
803 	int		 x, y, max_x, max_y;
804 	const char	*mode = tab->buffer.page.name;
805 	const char	*spin = "-\\|/";
806 
807 	werase(modeline);
808 	wattr_on(modeline, modeline_face.background, NULL);
809 	wmove(modeline, 0, 0);
810 
811 	wprintw(modeline, "-%c%c %s ",
812 	    spin[tab->loading_anim_step],
813 	    trust_status_char(tab->trust),
814 	    mode == NULL ? "(none)" : mode);
815 
816 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0
817 		/ tab->buffer.line_max;
818 
819 	if (tab->buffer.line_max <= (size_t)body_lines)
820                 wprintw(modeline, "All ");
821 	else if (tab->buffer.line_off == 0)
822                 wprintw(modeline, "Top ");
823 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
824 		wprintw(modeline, "Bottom ");
825 	else
826 		wprintw(modeline, "%.0f%% ", pct);
827 
828 	wprintw(modeline, "%d/%d %s ",
829 	    tab->buffer.line_off + tab->buffer.curs_y,
830 	    tab->buffer.line_max,
831 	    tab->hist_cur->h);
832 
833 	getyx(modeline, y, x);
834 	getmaxyx(modeline, max_y, max_x);
835 
836 	(void)y;
837 	(void)max_y;
838 
839 	for (; x < max_x; ++x)
840 		waddstr(modeline, "-");
841 
842 	wattr_off(modeline, modeline_face.background, NULL);
843 }
844 
845 static void
846 redraw_minibuffer(void)
847 {
848 	wattr_on(echoarea, minibuffer_face.background, NULL);
849 	werase(echoarea);
850 
851 	if (in_minibuffer)
852 		do_redraw_minibuffer();
853 	else
854 		do_redraw_echoarea();
855 
856 	if (in_minibuffer == MB_COMPREAD)
857 		do_redraw_minibuffer_compl();
858 
859 	wattr_off(echoarea, minibuffer_face.background, NULL);
860 }
861 
862 static void
863 do_redraw_echoarea(void)
864 {
865 	struct tab *tab;
866 
867 	if (ministate.curmesg != NULL)
868                 wprintw(echoarea, "%s", ministate.curmesg);
869 	else if (*keybuf != '\0')
870 		waddstr(echoarea, keybuf);
871 	else {
872 		/* If nothing else, show the URL at point */
873 		tab = current_tab();
874 		if (tab->buffer.current_line != NULL &&
875 		    tab->buffer.current_line->parent->type == LINE_LINK)
876 			waddstr(echoarea,
877 			    tab->buffer.current_line->parent->alt);
878 	}
879 }
880 
881 static void
882 do_redraw_minibuffer(void)
883 {
884 	size_t		 off_y, off_x = 0;
885 	const char	*start, *c;
886 
887 	/* unused, set by getyx */
888 	(void)off_y;
889 
890 	wmove(echoarea, 0, 0);
891 
892 	if (in_minibuffer == MB_COMPREAD)
893 		wprintw(echoarea, "(%2d) ",
894 		    ministate.compl.buffer.line_max);
895 
896 	wprintw(echoarea, "%s", ministate.prompt);
897 	if (ministate.hist_cur != NULL)
898 		wprintw(echoarea, "(%zu/%zu) ",
899 		    ministate.hist_off + 1,
900 		    ministate.history->len);
901 
902 	getyx(echoarea, off_y, off_x);
903 
904 	start = ministate.hist_cur != NULL
905 		? ministate.hist_cur->h
906 		: ministate.buf;
907 	c = utf8_nth(ministate.buffer.current_line->line,
908 	    ministate.buffer.cpoff);
909 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
910 		start = utf8_next_cp(start);
911 	}
912 
913 	waddstr(echoarea, start);
914 
915 	if (ministate.curmesg != NULL)
916 		wprintw(echoarea, " [%s]", ministate.curmesg);
917 
918 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
919 }
920 
921 static void
922 do_redraw_minibuffer_compl(void)
923 {
924 	redraw_window(minibuffer, 0, 10, body_cols,
925 	    &ministate.compl.buffer);
926 }
927 
928 /*
929  * Place the cursor in the right ncurses window.  If soft is 1, use
930  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
931  * wrefresh.
932  */
933 static void
934 place_cursor(int soft)
935 {
936 	int (*touch)(WINDOW *);
937 
938 	if (soft)
939 		touch = wnoutrefresh;
940 	else
941 		touch = wrefresh;
942 
943 	if (in_minibuffer) {
944 		touch(body);
945 		touch(echoarea);
946 	} else {
947 		touch(echoarea);
948 		touch(body);
949 	}
950 }
951 
952 static void
953 redraw_tab(struct tab *tab)
954 {
955 	if (too_small)
956 		return;
957 
958 	if (side_window) {
959 		redraw_help();
960 		wnoutrefresh(help);
961 	}
962 
963 	redraw_tabline();
964 	redraw_body(tab);
965 	redraw_modeline(tab);
966 	redraw_minibuffer();
967 
968 	wnoutrefresh(tabline);
969 	wnoutrefresh(modeline);
970 
971 	if (in_minibuffer == MB_COMPREAD)
972 		wnoutrefresh(minibuffer);
973 
974 	place_cursor(1);
975 
976 	doupdate();
977 }
978 
979 static void
980 emit_help_item(char *prfx, void *fn)
981 {
982 	struct line	*l;
983 	struct cmd	*cmd;
984 
985 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
986 		if (fn == cmd->fn)
987 			break;
988 	}
989 	assert(cmd != NULL);
990 
991 	if ((l = calloc(1, sizeof(*l))) == NULL)
992 		abort();
993 
994 	l->type = LINE_TEXT;
995 	l->alt = NULL;
996 
997 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
998 
999 	if (TAILQ_EMPTY(&helpwin.page.head))
1000 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
1001 	else
1002 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
1003 }
1004 
1005 static void
1006 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
1007 {
1008 	struct keymap	*k;
1009 	char		 p[32];
1010 	const char	*kn;
1011 
1012 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
1013 		strlcpy(p, prfx, sizeof(p));
1014 		if (*p != '\0')
1015 			strlcat(p, " ", sizeof(p));
1016 		if (k->meta)
1017 			strlcat(p, "M-", sizeof(p));
1018 		if ((kn = unkbd(k->key)) != NULL)
1019 			strlcat(p, kn, sizeof(p));
1020 		else
1021 			strlcat(p, keyname(k->key), sizeof(p));
1022 
1023 		if (k->fn == NULL)
1024 			rec_compute_help(&k->map, p, sizeof(p));
1025 		else
1026 			emit_help_item(p, k->fn);
1027 	}
1028 }
1029 
1030 static void
1031 recompute_help(void)
1032 {
1033 	char	p[32] = { 0 };
1034 
1035 	empty_vlist(&helpwin);
1036 	empty_linelist(&helpwin);
1037 	rec_compute_help(current_map, p, sizeof(p));
1038 	wrap_page(&helpwin, help_cols);
1039 }
1040 
1041 void
1042 vmessage(const char *fmt, va_list ap)
1043 {
1044 	if (evtimer_pending(&clechoev, NULL))
1045 		evtimer_del(&clechoev);
1046 
1047 	free(ministate.curmesg);
1048 	ministate.curmesg = NULL;
1049 
1050 	if (fmt != NULL) {
1051 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1052 		evtimer_add(&clechoev, &clechoev_timer);
1053 
1054 		/* TODO: what to do if the allocation fails here? */
1055 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
1056 			ministate.curmesg = NULL;
1057 	}
1058 
1059 	redraw_minibuffer();
1060         place_cursor(0);
1061 }
1062 
1063 void
1064 message(const char *fmt, ...)
1065 {
1066 	va_list ap;
1067 
1068 	va_start(ap, fmt);
1069 	vmessage(fmt, ap);
1070 	va_end(ap);
1071 }
1072 
1073 void
1074 start_loading_anim(struct tab *tab)
1075 {
1076 	if (tab->loading_anim)
1077 		return;
1078 	tab->loading_anim = 1;
1079 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1080 	evtimer_add(&tab->loadingev, &loadingev_timer);
1081 }
1082 
1083 static void
1084 update_loading_anim(int fd, short ev, void *d)
1085 {
1086 	struct tab	*tab = d;
1087 
1088 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1089 
1090 	if (tab->flags & TAB_CURRENT) {
1091 		redraw_modeline(tab);
1092 		wrefresh(modeline);
1093 		wrefresh(body);
1094 		if (in_minibuffer)
1095 			wrefresh(echoarea);
1096 	}
1097 
1098 	evtimer_add(&tab->loadingev, &loadingev_timer);
1099 }
1100 
1101 static void
1102 stop_loading_anim(struct tab *tab)
1103 {
1104 	if (!tab->loading_anim)
1105 		return;
1106 	evtimer_del(&tab->loadingev);
1107 	tab->loading_anim = 0;
1108 	tab->loading_anim_step = 0;
1109 
1110 	if (!(tab->flags & TAB_CURRENT))
1111 		return;
1112 
1113 	redraw_modeline(tab);
1114 
1115 	wrefresh(modeline);
1116 	wrefresh(body);
1117 	if (in_minibuffer)
1118 		wrefresh(echoarea);
1119 }
1120 
1121 void
1122 load_url_in_tab(struct tab *tab, const char *url)
1123 {
1124 	message("Loading %s...", url);
1125 	start_loading_anim(tab);
1126 	load_url(tab, url);
1127 
1128 	tab->buffer.curs_x = 0;
1129 	tab->buffer.curs_y = 0;
1130 	redraw_tab(tab);
1131 }
1132 
1133 void
1134 switch_to_tab(struct tab *tab)
1135 {
1136 	struct tab	*t;
1137 
1138 	TAILQ_FOREACH(t, &tabshead, tabs) {
1139 		t->flags &= ~TAB_CURRENT;
1140 	}
1141 
1142 	tab->flags |= TAB_CURRENT;
1143 	tab->flags &= ~TAB_URGENT;
1144 }
1145 
1146 unsigned int
1147 tab_new_id(void)
1148 {
1149 	return tab_counter++;
1150 }
1151 
1152 struct tab *
1153 new_tab(const char *url)
1154 {
1155 	struct tab	*tab;
1156 
1157 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1158 		event_loopbreak();
1159 		return NULL;
1160 	}
1161 	tab->fd = -1;
1162 
1163 	TAILQ_INIT(&tab->hist.head);
1164 
1165 	TAILQ_INIT(&tab->buffer.head);
1166 
1167 	tab->id = tab_new_id();
1168 	switch_to_tab(tab);
1169 
1170 	if (TAILQ_EMPTY(&tabshead))
1171 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1172 	else
1173 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1174 
1175 	load_url_in_tab(tab, url);
1176 	return tab;
1177 }
1178 
1179 int
1180 ui_print_colors(void)
1181 {
1182 	int colors = 0, pairs = 0, can_change = 0;
1183 	int columns = 16, lines, color, i, j;
1184 
1185 	initscr();
1186 	if (has_colors()) {
1187 		start_color();
1188 		use_default_colors();
1189 
1190 		colors = COLORS;
1191 		pairs = COLOR_PAIRS;
1192 		can_change = can_change_color();
1193 	}
1194 	endwin();
1195 
1196 	printf("Term info:\n");
1197 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1198 	    getenv("TERM"), colors, pairs, can_change);
1199 	printf("\n");
1200 
1201 	if (colors == 0) {
1202 		printf("No color support\n");
1203 		return 0;
1204 	}
1205 
1206 	printf("Available colors:\n\n");
1207 	lines = (colors - 1) / columns + 1;
1208 	color = 0;
1209 	for (i = 0; i < lines; ++i) {
1210 		for (j = 0; j < columns; ++j, ++color) {
1211 			printf("\033[0;38;5;%dm %03d", color, color);
1212 		}
1213 		printf("\n");
1214 	}
1215 
1216 	printf("\033[0m");
1217 	fflush(stdout);
1218 	return 0;
1219 }
1220 
1221 int
1222 ui_init()
1223 {
1224 	setlocale(LC_ALL, "");
1225 
1226 	TAILQ_INIT(&eecmd_history.head);
1227 	TAILQ_INIT(&ir_history.head);
1228 	TAILQ_INIT(&lu_history.head);
1229 
1230 	ministate.line.type = LINE_TEXT;
1231 	ministate.vline.parent = &ministate.line;
1232 	ministate.buffer.current_line = &ministate.vline;
1233 
1234 	/* initialize help window */
1235 	TAILQ_INIT(&helpwin.head);
1236 
1237 	base_map = &global_map;
1238 	current_map = &global_map;
1239 
1240 	initscr();
1241 
1242 	if (enable_colors) {
1243 		if (has_colors()) {
1244 			start_color();
1245 			use_default_colors();
1246 		} else
1247 			enable_colors = 0;
1248 	}
1249 
1250 	config_apply_style();
1251 
1252 	raw();
1253 	noecho();
1254 	nonl();
1255 	intrflush(stdscr, FALSE);
1256 
1257 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1258 		return 0;
1259 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1260 		return 0;
1261 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1262 		return 0;
1263 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1264 		return 0;
1265 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1266 		return 0;
1267 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1268 		return 0;
1269 
1270 	body_lines = LINES-3;
1271 	body_cols = COLS;
1272 
1273 	wbkgd(body, body_face.body);
1274 	wbkgd(echoarea, minibuffer_face.background);
1275 
1276 	update_x_offset();
1277 
1278 	keypad(body, TRUE);
1279 	scrollok(body, FALSE);
1280 
1281 	/* non-blocking input */
1282 	wtimeout(body, 0);
1283 
1284 	mvwprintw(body, 0, 0, "");
1285 
1286 	/*
1287 	 * Dummy so libevent2 won't complain that no event_base is set
1288 	 * when checking event_pending for the first time
1289 	 */
1290 	evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1291 	evtimer_add(&clechoev, &clechoev_timer);
1292 	evtimer_set(&resizeev, handle_resize, NULL);
1293 	evtimer_add(&resizeev, &resize_timer);
1294 
1295 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1296 	event_add(&stdioev, NULL);
1297 
1298 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1299 	signal_add(&winchev, NULL);
1300 
1301 	return 1;
1302 }
1303 
1304 void
1305 ui_on_tab_loaded(struct tab *tab)
1306 {
1307 	stop_loading_anim(tab);
1308 	message("Loaded %s", tab->hist_cur->h);
1309 
1310 	redraw_tabline();
1311 	wrefresh(tabline);
1312 	place_cursor(0);
1313 }
1314 
1315 void
1316 ui_on_tab_refresh(struct tab *tab)
1317 {
1318 	wrap_page(&tab->buffer, body_cols);
1319 	if (tab->flags & TAB_CURRENT)
1320 		redraw_tab(tab);
1321 	else
1322 		tab->flags |= TAB_URGENT;
1323 }
1324 
1325 const char *
1326 ui_keyname(int k)
1327 {
1328 	return keyname(k);
1329 }
1330 
1331 void
1332 ui_toggle_side_window(void)
1333 {
1334 	side_window = !side_window;
1335 	if (side_window)
1336 		recompute_help();
1337 
1338 	/*
1339 	 * ugly hack, but otherwise the window doesn't get updated
1340 	 * until I call rearrange_windows a second time (e.g. via
1341 	 * C-l).  I will be happy to know why something like this is
1342 	 * needed.
1343 	 */
1344 	rearrange_windows();
1345 	rearrange_windows();
1346 }
1347 
1348 void
1349 ui_schedule_redraw(void)
1350 {
1351 	should_rearrange_windows = 1;
1352 }
1353 
1354 void
1355 ui_require_input(struct tab *tab, int hide)
1356 {
1357 	/* TODO: hard-switching to another tab is ugly */
1358 	switch_to_tab(tab);
1359 
1360 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1361 	    &ir_history, NULL, NULL);
1362 	strlcpy(ministate.prompt, "Input required: ",
1363 	    sizeof(ministate.prompt));
1364 	redraw_tab(tab);
1365 }
1366 
1367 void
1368 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1369     struct tab *data)
1370 {
1371 	yornp(prompt, fn, data);
1372 	redraw_tab(current_tab());
1373 }
1374 
1375 void
1376 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1377     struct tab *data)
1378 {
1379 	completing_read(prompt, fn, data);
1380 	redraw_tab(current_tab());
1381 }
1382 
1383 void
1384 ui_suspend(void)
1385 {
1386 	endwin();
1387 
1388 	kill(getpid(), SIGSTOP);
1389 
1390 	refresh();
1391 	clear();
1392 	rearrange_windows();
1393 }
1394 
1395 void
1396 ui_end(void)
1397 {
1398 	endwin();
1399 }