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Date:: Wed Jul 14 13:32:17 2021 UTC
Message:: wrap long line
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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 int		 wrap_page(struct buffer*, int);
60 static void		 print_vline(int, int, WINDOW*, struct vline*);
61 static void		 redraw_tabline(void);
62 static void		 redraw_window(WINDOW*, int, int, struct buffer*);
63 static void		 redraw_help(void);
64 static void		 redraw_body(struct tab*);
65 static void		 redraw_modeline(struct tab*);
66 static void		 redraw_minibuffer(void);
67 static void		 do_redraw_echoarea(void);
68 static void		 do_redraw_minibuffer(void);
69 static void		 do_redraw_minibuffer_compl(void);
70 static void		 place_cursor(int);
71 static void		 redraw_tab(struct tab*);
72 static void		 emit_help_item(char*, void*);
73 static void		 rec_compute_help(struct kmap*, char*, size_t);
74 static void		 recompute_help(void);
75 static void		 update_loading_anim(int, short, void*);
76 static void		 stop_loading_anim(struct tab*);
77 
78 static int		 too_small;
79 static int		 x_offset;
80 
81 struct thiskey thiskey;
82 
83 static struct event	resizeev;
84 static struct timeval	resize_timer = { 0, 250000 };
85 
86 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
87 
88 int			 body_lines, body_cols;
89 
90 static WINDOW		*help;
91 static struct buffer	 helpwin;
92 static int		 help_lines, help_cols;
93 
94 static int		 side_window;
95 
96 static struct event	clechoev;
97 static struct timeval	clechoev_timer = { 5, 0 };
98 static struct timeval	loadingev_timer = { 0, 250000 };
99 
100 static uint32_t		 tab_counter;
101 
102 static char	keybuf[64];
103 
104 struct kmap global_map,
105 	minibuffer_map,
106 	*current_map,
107 	*base_map;
108 
109 int in_minibuffer;
110 
111 static inline void
112 update_x_offset(void)
113 {
114 	if (olivetti_mode && fill_column < body_cols)
115 		x_offset = (body_cols - fill_column)/2;
116 	else
117 		x_offset = 0;
118 }
119 
120 void
121 save_excursion(struct excursion *place, struct buffer *buffer)
122 {
123 	place->curs_x = buffer->curs_x;
124 	place->curs_y = buffer->curs_y;
125 	place->line_off = buffer->line_off;
126 	place->current_line = buffer->current_line;
127 	place->cpoff = buffer->cpoff;
128 }
129 
130 void
131 restore_excursion(struct excursion *place, struct buffer *buffer)
132 {
133 	buffer->curs_x = place->curs_x;
134 	buffer->curs_y = place->curs_y;
135 	buffer->line_off = place->line_off;
136 	buffer->current_line = place->current_line;
137 	buffer->cpoff = place->cpoff;
138 }
139 
140 static void
141 restore_curs_x(struct buffer *buffer)
142 {
143 	struct vline	*vl;
144 	const char	*prfx;
145 
146 	vl = buffer->current_line;
147 	if (vl == NULL || vl->line == NULL)
148 		buffer->curs_x = buffer->cpoff = 0;
149 	else
150 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
151 
152 	buffer->curs_x += x_offset;
153 
154 	if (vl != NULL) {
155 		prfx = line_prefixes[vl->parent->type].prfx1;
156 		buffer->curs_x += utf8_swidth(prfx);
157 	}
158 }
159 
160 void
161 global_key_unbound(void)
162 {
163 	message("%s is undefined", keybuf);
164 }
165 
166 static struct vline *
167 nth_line(struct buffer *buffer, size_t n)
168 {
169 	struct vline	*vl;
170 	size_t		 i;
171 
172 	i = 0;
173 	TAILQ_FOREACH(vl, &buffer->head, vlines) {
174 		if (i == n)
175 			return vl;
176 		i++;
177 	}
178 
179 	/* unreachable */
180 	abort();
181 }
182 
183 struct tab *
184 current_tab(void)
185 {
186 	struct tab *t;
187 
188 	TAILQ_FOREACH(t, &tabshead, tabs) {
189 		if (t->flags & TAB_CURRENT)
190 			return t;
191 	}
192 
193 	/* unreachable */
194 	abort();
195 }
196 
197 struct buffer *
198 current_buffer(void)
199 {
200 	if (in_minibuffer)
201 		return &ministate.buffer;
202 	return &current_tab()->buffer;
203 }
204 
205 static int
206 readkey(void)
207 {
208 	uint32_t state = 0;
209 
210 	if ((thiskey.key = wgetch(body)) == ERR)
211 		return 0;
212 
213 	thiskey.meta = thiskey.key == 27;
214 	if (thiskey.meta) {
215 		thiskey.key = wgetch(body);
216 		if (thiskey.key == ERR || thiskey.key == 27) {
217 			thiskey.meta = 0;
218 			thiskey.key = 27;
219 		}
220 	}
221 
222 	thiskey.cp = 0;
223 	if ((unsigned int)thiskey.key < UINT8_MAX) {
224 		while (1) {
225 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
226 				break;
227 			if ((thiskey.key = wgetch(body)) == ERR) {
228 				message("Error decoding user input");
229 				return 0;
230 			}
231 		}
232 	}
233 
234 	return 1;
235 }
236 
237 static void
238 dispatch_stdio(int fd, short ev, void *d)
239 {
240 	struct keymap	*k;
241 	const char	*keyname;
242 	char		 tmp[5] = {0};
243 
244 	/* TODO: schedule a redraw? */
245 	if (too_small)
246 		return;
247 
248 	if (!readkey())
249 		return;
250 
251 	if (keybuf[0] != '\0')
252 		strlcat(keybuf, " ", sizeof(keybuf));
253 	if (thiskey.meta)
254 		strlcat(keybuf, "M-", sizeof(keybuf));
255 	if (thiskey.cp != 0) {
256 		utf8_encode(thiskey.cp, tmp);
257 		strlcat(keybuf, tmp, sizeof(keybuf));
258 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
259 		strlcat(keybuf, keyname, sizeof(keybuf));
260 	} else {
261 		tmp[0] = thiskey.key;
262 		strlcat(keybuf, tmp, sizeof(keybuf));
263 	}
264 
265 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
266 		if (k->meta == thiskey.meta &&
267 		    k->key == thiskey.key) {
268 			if (k->fn == NULL)
269 				current_map = &k->map;
270 			else {
271 				current_map = base_map;
272 				strlcpy(keybuf, "", sizeof(keybuf));
273 				k->fn(current_buffer());
274 			}
275 			goto done;
276 		}
277 	}
278 
279 	if (current_map->unhandled_input != NULL)
280 		current_map->unhandled_input();
281 	else
282 		global_key_unbound();
283 
284 	strlcpy(keybuf, "", sizeof(keybuf));
285 	current_map = base_map;
286 
287 done:
288 	if (side_window)
289 		recompute_help();
290 
291 	redraw_tab(current_tab());
292 }
293 
294 static void
295 handle_clear_echoarea(int fd, short ev, void *d)
296 {
297 	free(ministate.curmesg);
298 	ministate.curmesg = NULL;
299 
300 	redraw_minibuffer();
301 	place_cursor(0);
302 }
303 
304 static void
305 handle_resize(int sig, short ev, void *d)
306 {
307 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
308 		event_del(&resizeev);
309 	}
310 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
311 	evtimer_add(&resizeev, &resize_timer);
312 }
313 
314 static void
315 handle_resize_nodelay(int s, short ev, void *d)
316 {
317 	struct tab	*tab;
318 	int		 lines;
319 
320 	endwin();
321 	refresh();
322 	clear();
323 
324 	lines = LINES;
325 
326 	if ((too_small = lines < 15)) {
327 		erase();
328 		printw("Window too small.");
329 		refresh();
330 		return;
331 	}
332 
333 	/* move and resize the windows, in reverse order! */
334 
335 	if (in_minibuffer == MB_COMPREAD) {
336 		mvwin(minibuffer, lines-10, 0);
337 		wresize(minibuffer, 10, COLS);
338 		lines -= 10;
339 
340 		wrap_page(&ministate.compl.buffer, COLS);
341 	}
342 
343 	mvwin(echoarea, --lines, 0);
344 	wresize(echoarea, 1, COLS);
345 
346 	mvwin(modeline, --lines, 0);
347 	wresize(modeline, 1, COLS);
348 
349 	body_lines = --lines;
350 	body_cols = COLS;
351 
352 	if (side_window) {
353 		help_cols = 0.3 * COLS;
354 		help_lines = lines;
355 		mvwin(help, 1, 0);
356 		wresize(help, help_lines, help_cols);
357 
358 		wrap_page(&helpwin, help_cols);
359 
360 		body_cols = COLS - help_cols - 1;
361 		mvwin(body, 1, help_cols);
362 	} else
363 		mvwin(body, 1, 0);
364 
365 	update_x_offset();
366 	wresize(body, body_lines, body_cols);
367 
368 	wresize(tabline, 1, COLS);
369 
370 	tab = current_tab();
371 
372 	wrap_page(&tab->buffer, body_cols);
373 	redraw_tab(tab);
374 }
375 
376 static int
377 wrap_page(struct buffer *buffer, int width)
378 {
379 	struct line		*l;
380 	const struct line	*top_orig, *orig;
381 	struct vline		*vl;
382 	int			 pre_width;
383 	const char		*prfx;
384 
385 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
386 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
387 
388 	buffer->top_line = NULL;
389 	buffer->current_line = NULL;
390 
391 	buffer->force_redraw = 1;
392 	buffer->curs_y = 0;
393 	buffer->line_off = 0;
394 
395 	empty_vlist(buffer);
396 
397 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
398 		prfx = line_prefixes[l->type].prfx1;
399 		switch (l->type) {
400 		case LINE_TEXT:
401 		case LINE_LINK:
402 		case LINE_TITLE_1:
403 		case LINE_TITLE_2:
404 		case LINE_TITLE_3:
405 		case LINE_ITEM:
406 		case LINE_QUOTE:
407 		case LINE_PRE_START:
408 		case LINE_PRE_END:
409 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
410 			break;
411 		case LINE_PRE_CONTENT:
412 			if (olivetti_mode)
413 				pre_width = MIN(fill_column, width);
414 			else
415 				pre_width = width;
416 			hardwrap_text(buffer, l, pre_width);
417 			break;
418 		case LINE_COMPL:
419 		case LINE_COMPL_CURRENT:
420 			/*
421 			 * TODO: should be width, but will break the
422 			 * rendering.  Fix when unlocking completions
423 			 * buffer from olivetti-mode.
424 			 */
425 			wrap_one(buffer, prfx, l, MIN(fill_column, width));
426 		}
427 
428 		if (top_orig == l && buffer->top_line == NULL) {
429 			buffer->line_off = buffer->line_max-1;
430 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
431 
432 			while (1) {
433 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
434 				if (vl == NULL || vl->parent != orig)
435 					break;
436 				buffer->top_line = vl;
437 				buffer->line_off--;
438 			}
439 		}
440 
441 		if (orig == l && buffer->current_line == NULL) {
442 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
443 
444 			while (1) {
445 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
446 				if (vl == NULL || vl->parent != orig)
447 					break;
448 				buffer->current_line = vl;
449 			}
450 		}
451 	}
452 
453         if (buffer->current_line == NULL)
454 		buffer->current_line = TAILQ_FIRST(&buffer->head);
455 
456 	if (buffer->top_line == NULL)
457 		buffer->top_line = buffer->current_line;
458 
459 	return 1;
460 }
461 
462 static void
463 print_vline(int off, int width, WINDOW *window, struct vline *vl)
464 {
465 	const char *text;
466 	const char *prfx;
467 	struct line_face *f;
468 	int i, left, x, y;
469 
470 	f = &line_faces[vl->parent->type];
471 
472 	/* unused, set by getyx */
473 	(void)y;
474 
475 	if (!vl->flags)
476 		prfx = line_prefixes[vl->parent->type].prfx1;
477 	else
478 		prfx = line_prefixes[vl->parent->type].prfx2;
479 
480 	text = vl->line;
481 	if (text == NULL)
482 		text = "";
483 
484 	wattr_on(window, body_face.left, NULL);
485 	for (i = 0; i < off; i++)
486 		waddch(window, ' ');
487 	wattr_off(window, body_face.left, NULL);
488 
489 	wattr_on(window, f->prefix, NULL);
490 	wprintw(window, "%s", prfx);
491 	wattr_off(window, f->prefix, NULL);
492 
493 	wattr_on(window, f->text, NULL);
494 	wprintw(window, "%s", text);
495 	wattr_off(window, f->text, NULL);
496 
497 	getyx(window, y, x);
498 
499 	left = width - x;
500 
501 	wattr_on(window, f->trail, NULL);
502 	for (i = 0; i < left - off; ++i)
503 		waddch(window, ' ');
504 	wattr_off(window, f->trail, NULL);
505 
506 	wattr_on(window, body_face.right, NULL);
507 	for (i = 0; i < off; i++)
508 		waddch(window, ' ');
509 	wattr_off(window, body_face.right, NULL);
510 
511 }
512 
513 static void
514 redraw_tabline(void)
515 {
516 	struct tab	*tab;
517 	size_t		 toskip, ots, tabwidth, space, x;
518 	int		 current, y, truncated;
519 	const char	*title;
520 	char		 buf[25];
521 
522 	x = 0;
523 
524 	/* unused, but setted by a getyx */
525 	(void)y;
526 
527 	tabwidth = sizeof(buf)+1;
528 	space = COLS-2;
529 
530 	toskip = 0;
531 	TAILQ_FOREACH(tab, &tabshead, tabs) {
532 		toskip++;
533 		if (tab->flags & TAB_CURRENT)
534 			break;
535 	}
536 
537 	if (toskip * tabwidth < space)
538 		toskip = 0;
539 	else {
540 		ots = toskip;
541 		toskip--;
542                 while (toskip != 0 &&
543 		    (ots - toskip+1) * tabwidth < space)
544 			toskip--;
545 	}
546 
547 	werase(tabline);
548 	wattr_on(tabline, tab_face.background, NULL);
549 	wprintw(tabline, toskip == 0 ? " " : "<");
550 	wattr_off(tabline, tab_face.background, NULL);
551 
552 	truncated = 0;
553 	TAILQ_FOREACH(tab, &tabshead, tabs) {
554 		if (truncated)
555 			break;
556 		if (toskip != 0) {
557 			toskip--;
558 			continue;
559 		}
560 
561 		getyx(tabline, y, x);
562 		if (x + sizeof(buf)+2 >= (size_t)COLS)
563 			truncated = 1;
564 
565 		current = tab->flags & TAB_CURRENT;
566 
567 		if (*(title = tab->buffer.page.title) == '\0')
568 			title = tab->hist_cur->h;
569 
570 		if (tab->flags & TAB_URGENT)
571 			strlcpy(buf, "!", sizeof(buf));
572 		else
573 			strlcpy(buf, " ", sizeof(buf));
574 
575                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
576 			/* truncation happens */
577 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
578 		} else {
579 			/* pad with spaces */
580 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
581 				/* nop */ ;
582 		}
583 
584 		if (current)
585 			wattr_on(tabline, tab_face.current, NULL);
586 		else
587 			wattr_on(tabline, tab_face.tab, NULL);
588 
589 		wprintw(tabline, "%s", buf);
590 		if (TAILQ_NEXT(tab, tabs) != NULL)
591 			wprintw(tabline, " ");
592 
593 		if (current)
594 			wattr_off(tabline, tab_face.current, NULL);
595 		else
596 			wattr_off(tabline, tab_face.tab, NULL);
597 	}
598 
599 	wattr_on(tabline, tab_face.background, NULL);
600 	for (; x < (size_t)COLS; ++x)
601 		waddch(tabline, ' ');
602 	if (truncated)
603 		mvwprintw(tabline, 0, COLS-1, ">");
604 	wattr_off(tabline, tab_face.background, NULL);
605 }
606 
607 /*
608  * Compute the first visible line around vl.  Try to search forward
609  * until the end of the buffer; if a visible line is not found, search
610  * backward.  Return NULL if no viable line was found.
611  */
612 struct vline *
613 adjust_line(struct vline *vl, struct buffer *buffer)
614 {
615 	struct vline *t;
616 
617 	if (vl == NULL)
618 		return NULL;
619 
620 	if (!(vl->parent->flags & L_HIDDEN))
621 		return vl;
622 
623 	/* search forward */
624 	for (t = vl;
625 	     t != NULL && t->parent->flags & L_HIDDEN;
626 	     t = TAILQ_NEXT(t, vlines))
627 		;		/* nop */
628 
629 	if (t != NULL)
630 		return t;
631 
632 	/* search backward */
633 	for (t = vl;
634 	     t != NULL && t->parent->flags & L_HIDDEN;
635 	     t = TAILQ_PREV(t, vhead, vlines))
636 		;		/* nop */
637 
638 	return t;
639 }
640 
641 static void
642 redraw_window(WINDOW *win, int height, int width, struct buffer *buffer)
643 {
644         struct vline	*vl;
645 	int		 l, onscreen;
646 
647 	restore_curs_x(buffer);
648 
649 	/*
650 	 * TODO: ignoring buffer->force_update and always
651 	 * re-rendering.  In theory we can recompute the y position
652 	 * without a re-render, and optimize here.  It's not the only
653 	 * optimisation possible here, wscrl wolud also be an
654 	 * interesting one.
655 	 */
656 
657 again:
658 	werase(win);
659 	buffer->curs_y = 0;
660 
661 	if (TAILQ_EMPTY(&buffer->head))
662 		goto end;
663 
664 	if (buffer->top_line == NULL)
665 		buffer->top_line = TAILQ_FIRST(&buffer->head);
666 
667 	buffer->top_line = adjust_line(buffer->top_line, buffer);
668 	if (buffer->top_line == NULL)
669 		goto end;
670 
671 	buffer->current_line = adjust_line(buffer->current_line, buffer);
672 
673 	l = 0;
674 	onscreen = 0;
675 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
676 		if (vl->parent->flags & L_HIDDEN)
677 			continue;
678 
679 		wmove(win, l, 0);
680 		print_vline(x_offset, width, win, vl);
681 
682 		if (vl == buffer->current_line)
683 			onscreen = 1;
684 
685 		if (!onscreen)
686 			buffer->curs_y++;
687 
688 		l++;
689 		if (l == height)
690 			break;
691 	}
692 
693 	if (!onscreen) {
694 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
695 			if (vl == buffer->current_line)
696 				break;
697 			if (vl->parent->flags & L_HIDDEN)
698 				continue;
699 			buffer->line_off++;
700 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
701 		}
702 
703 		if (vl != NULL)
704 			goto again;
705 	}
706 
707 	buffer->last_line_off = buffer->line_off;
708 	buffer->force_redraw = 0;
709 end:
710 	wmove(win, buffer->curs_y, buffer->curs_x);
711 }
712 
713 static void
714 redraw_help(void)
715 {
716 	redraw_window(help, help_lines, help_cols, &helpwin);
717 }
718 
719 static void
720 redraw_body(struct tab *tab)
721 {
722 	static struct tab *last_tab;
723 
724 	if (last_tab != tab)
725 		tab->buffer.force_redraw =1;
726 	last_tab = tab;
727 
728 	redraw_window(body, body_lines, body_cols, &tab->buffer);
729 }
730 
731 static inline char
732 trust_status_char(enum trust_state ts)
733 {
734 	switch (ts) {
735 	case TS_UNKNOWN:	return 'u';
736 	case TS_UNTRUSTED:	return '!';
737 	case TS_TEMP_TRUSTED:	return '!';
738 	case TS_TRUSTED:	return 'v';
739 	case TS_VERIFIED:	return 'V';
740 	default:		return 'X';
741 	}
742 }
743 
744 static void
745 redraw_modeline(struct tab *tab)
746 {
747 	double		 pct;
748 	int		 x, y, max_x, max_y;
749 	const char	*mode = tab->buffer.page.name;
750 	const char	*spin = "-\\|/";
751 
752 	werase(modeline);
753 	wattr_on(modeline, modeline_face.background, NULL);
754 	wmove(modeline, 0, 0);
755 
756 	wprintw(modeline, "-%c%c %s ",
757 	    spin[tab->loading_anim_step],
758 	    trust_status_char(tab->trust),
759 	    mode == NULL ? "(none)" : mode);
760 
761 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0
762 		/ tab->buffer.line_max;
763 
764 	if (tab->buffer.line_max <= (size_t)body_lines)
765                 wprintw(modeline, "All ");
766 	else if (tab->buffer.line_off == 0)
767                 wprintw(modeline, "Top ");
768 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
769 		wprintw(modeline, "Bottom ");
770 	else
771 		wprintw(modeline, "%.0f%% ", pct);
772 
773 	wprintw(modeline, "%d/%d %s ",
774 	    tab->buffer.line_off + tab->buffer.curs_y,
775 	    tab->buffer.line_max,
776 	    tab->hist_cur->h);
777 
778 	getyx(modeline, y, x);
779 	getmaxyx(modeline, max_y, max_x);
780 
781 	(void)y;
782 	(void)max_y;
783 
784 	for (; x < max_x; ++x)
785 		waddstr(modeline, "-");
786 
787 	wattr_off(modeline, modeline_face.background, NULL);
788 }
789 
790 static void
791 redraw_minibuffer(void)
792 {
793 	wattr_on(echoarea, minibuffer_face.background, NULL);
794 	werase(echoarea);
795 
796 	if (in_minibuffer)
797 		do_redraw_minibuffer();
798 	else
799 		do_redraw_echoarea();
800 
801 	if (in_minibuffer == MB_COMPREAD)
802 		do_redraw_minibuffer_compl();
803 
804 	wattr_off(echoarea, minibuffer_face.background, NULL);
805 }
806 
807 static void
808 do_redraw_echoarea(void)
809 {
810 	struct tab *tab;
811 
812 	if (ministate.curmesg != NULL)
813                 wprintw(echoarea, "%s", ministate.curmesg);
814 	else if (*keybuf != '\0')
815 		waddstr(echoarea, keybuf);
816 	else {
817 		/* If nothing else, show the URL at point */
818 		tab = current_tab();
819 		if (tab->buffer.current_line != NULL &&
820 		    tab->buffer.current_line->parent->type == LINE_LINK)
821 			waddstr(echoarea, tab->buffer.current_line->parent->alt);
822 	}
823 }
824 
825 static void
826 do_redraw_minibuffer(void)
827 {
828 	size_t		 off_y, off_x = 0;
829 	const char	*start, *c;
830 
831 	/* unused, set by getyx */
832 	(void)off_y;
833 
834 	mvwprintw(echoarea, 0, 0, "%s", ministate.prompt);
835 	if (ministate.hist_cur != NULL)
836 		wprintw(echoarea, "(%zu/%zu) ",
837 		    ministate.hist_off + 1,
838 		    ministate.history->len);
839 
840 	getyx(echoarea, off_y, off_x);
841 
842 	start = ministate.hist_cur != NULL
843 		? ministate.hist_cur->h
844 		: ministate.buf;
845 	c = utf8_nth(ministate.buffer.current_line->line,
846 	    ministate.buffer.cpoff);
847 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
848 		start = utf8_next_cp(start);
849 	}
850 
851 	waddstr(echoarea, start);
852 
853 	if (ministate.curmesg != NULL)
854 		wprintw(echoarea, " [%s]", ministate.curmesg);
855 
856 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
857 }
858 
859 static void
860 do_redraw_minibuffer_compl(void)
861 {
862 	redraw_window(minibuffer, 10, body_cols,
863 	    &ministate.compl.buffer);
864 }
865 
866 /*
867  * Place the cursor in the right ncurses window.  If soft is 1, use
868  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
869  * wrefresh.
870  */
871 static void
872 place_cursor(int soft)
873 {
874 	int (*touch)(WINDOW *);
875 
876 	if (soft)
877 		touch = wnoutrefresh;
878 	else
879 		touch = wrefresh;
880 
881 	if (in_minibuffer) {
882 		touch(body);
883 		touch(echoarea);
884 	} else {
885 		touch(echoarea);
886 		touch(body);
887 	}
888 }
889 
890 static void
891 redraw_tab(struct tab *tab)
892 {
893 	if (too_small)
894 		return;
895 
896 	if (side_window) {
897 		redraw_help();
898 		wnoutrefresh(help);
899 	}
900 
901 	redraw_tabline();
902 	redraw_body(tab);
903 	redraw_modeline(tab);
904 	redraw_minibuffer();
905 
906 	wnoutrefresh(tabline);
907 	wnoutrefresh(modeline);
908 
909 	if (in_minibuffer == MB_COMPREAD)
910 		wnoutrefresh(minibuffer);
911 
912 	place_cursor(1);
913 
914 	doupdate();
915 }
916 
917 static void
918 emit_help_item(char *prfx, void *fn)
919 {
920 	struct line	*l;
921 	struct cmd	*cmd;
922 
923 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
924 		if (fn == cmd->fn)
925 			break;
926 	}
927 	assert(cmd != NULL);
928 
929 	if ((l = calloc(1, sizeof(*l))) == NULL)
930 		abort();
931 
932 	l->type = LINE_TEXT;
933 	l->alt = NULL;
934 
935 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
936 
937 	if (TAILQ_EMPTY(&helpwin.page.head))
938 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
939 	else
940 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
941 }
942 
943 static void
944 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
945 {
946 	struct keymap	*k;
947 	char		 p[32];
948 	const char	*kn;
949 
950 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
951 		strlcpy(p, prfx, sizeof(p));
952 		if (*p != '\0')
953 			strlcat(p, " ", sizeof(p));
954 		if (k->meta)
955 			strlcat(p, "M-", sizeof(p));
956 		if ((kn = unkbd(k->key)) != NULL)
957 			strlcat(p, kn, sizeof(p));
958 		else
959 			strlcat(p, keyname(k->key), sizeof(p));
960 
961 		if (k->fn == NULL)
962 			rec_compute_help(&k->map, p, sizeof(p));
963 		else
964 			emit_help_item(p, k->fn);
965 	}
966 }
967 
968 static void
969 recompute_help(void)
970 {
971 	char	p[32] = { 0 };
972 
973 	empty_vlist(&helpwin);
974 	empty_linelist(&helpwin);
975 	rec_compute_help(current_map, p, sizeof(p));
976 	wrap_page(&helpwin, help_cols);
977 }
978 
979 void
980 vmessage(const char *fmt, va_list ap)
981 {
982 	if (evtimer_pending(&clechoev, NULL))
983 		evtimer_del(&clechoev);
984 
985 	free(ministate.curmesg);
986 	ministate.curmesg = NULL;
987 
988 	if (fmt != NULL) {
989 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
990 		evtimer_add(&clechoev, &clechoev_timer);
991 
992 		/* TODO: what to do if the allocation fails here? */
993 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
994 			ministate.curmesg = NULL;
995 	}
996 
997 	redraw_minibuffer();
998         place_cursor(0);
999 }
1000 
1001 void
1002 message(const char *fmt, ...)
1003 {
1004 	va_list ap;
1005 
1006 	va_start(ap, fmt);
1007 	vmessage(fmt, ap);
1008 	va_end(ap);
1009 }
1010 
1011 void
1012 start_loading_anim(struct tab *tab)
1013 {
1014 	if (tab->loading_anim)
1015 		return;
1016 	tab->loading_anim = 1;
1017 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1018 	evtimer_add(&tab->loadingev, &loadingev_timer);
1019 }
1020 
1021 static void
1022 update_loading_anim(int fd, short ev, void *d)
1023 {
1024 	struct tab	*tab = d;
1025 
1026 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1027 
1028 	if (tab->flags & TAB_CURRENT) {
1029 		redraw_modeline(tab);
1030 		wrefresh(modeline);
1031 		wrefresh(body);
1032 		if (in_minibuffer)
1033 			wrefresh(echoarea);
1034 	}
1035 
1036 	evtimer_add(&tab->loadingev, &loadingev_timer);
1037 }
1038 
1039 static void
1040 stop_loading_anim(struct tab *tab)
1041 {
1042 	if (!tab->loading_anim)
1043 		return;
1044 	evtimer_del(&tab->loadingev);
1045 	tab->loading_anim = 0;
1046 	tab->loading_anim_step = 0;
1047 
1048 	if (!(tab->flags & TAB_CURRENT))
1049 		return;
1050 
1051 	redraw_modeline(tab);
1052 
1053 	wrefresh(modeline);
1054 	wrefresh(body);
1055 	if (in_minibuffer)
1056 		wrefresh(echoarea);
1057 }
1058 
1059 void
1060 load_url_in_tab(struct tab *tab, const char *url)
1061 {
1062 	message("Loading %s...", url);
1063 	start_loading_anim(tab);
1064 	load_url(tab, url);
1065 
1066 	tab->buffer.curs_x = 0;
1067 	tab->buffer.curs_y = 0;
1068 	redraw_tab(tab);
1069 }
1070 
1071 void
1072 switch_to_tab(struct tab *tab)
1073 {
1074 	struct tab	*t;
1075 
1076 	TAILQ_FOREACH(t, &tabshead, tabs) {
1077 		t->flags &= ~TAB_CURRENT;
1078 	}
1079 
1080 	tab->flags |= TAB_CURRENT;
1081 	tab->flags &= ~TAB_URGENT;
1082 }
1083 
1084 unsigned int
1085 tab_new_id(void)
1086 {
1087 	return tab_counter++;
1088 }
1089 
1090 struct tab *
1091 new_tab(const char *url)
1092 {
1093 	struct tab	*tab;
1094 
1095 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1096 		event_loopbreak();
1097 		return NULL;
1098 	}
1099 	tab->fd = -1;
1100 
1101 	TAILQ_INIT(&tab->hist.head);
1102 
1103 	TAILQ_INIT(&tab->buffer.head);
1104 
1105 	tab->id = tab_new_id();
1106 	switch_to_tab(tab);
1107 
1108 	if (TAILQ_EMPTY(&tabshead))
1109 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1110 	else
1111 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1112 
1113 	load_url_in_tab(tab, url);
1114 	return tab;
1115 }
1116 
1117 int
1118 ui_init()
1119 {
1120 	setlocale(LC_ALL, "");
1121 
1122 	TAILQ_INIT(&eecmd_history.head);
1123 	TAILQ_INIT(&ir_history.head);
1124 	TAILQ_INIT(&lu_history.head);
1125 
1126 	ministate.line.type = LINE_TEXT;
1127 	ministate.vline.parent = &ministate.line;
1128 	ministate.buffer.current_line = &ministate.vline;
1129 
1130 	/* initialize help window */
1131 	TAILQ_INIT(&helpwin.head);
1132 
1133 	base_map = &global_map;
1134 	current_map = &global_map;
1135 
1136 	initscr();
1137 
1138 	if (enable_colors) {
1139 		if (has_colors()) {
1140 			start_color();
1141 			use_default_colors();
1142 		} else
1143 			enable_colors = 0;
1144 	}
1145 
1146 	config_apply_style();
1147 
1148 	raw();
1149 	noecho();
1150 	nonl();
1151 	intrflush(stdscr, FALSE);
1152 
1153 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1154 		return 0;
1155 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1156 		return 0;
1157 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1158 		return 0;
1159 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1160 		return 0;
1161 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1162 		return 0;
1163 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1164 		return 0;
1165 
1166 	body_lines = LINES-3;
1167 	body_cols = COLS;
1168 
1169 	wbkgd(body, body_face.body);
1170 	wbkgd(echoarea, minibuffer_face.background);
1171 
1172 	update_x_offset();
1173 
1174 	keypad(body, TRUE);
1175 	scrollok(body, FALSE);
1176 
1177 	/* non-blocking input */
1178 	wtimeout(body, 0);
1179 
1180 	mvwprintw(body, 0, 0, "");
1181 
1182 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1183 	event_add(&stdioev, NULL);
1184 
1185 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1186 	signal_add(&winchev, NULL);
1187 
1188 	return 1;
1189 }
1190 
1191 void
1192 ui_on_tab_loaded(struct tab *tab)
1193 {
1194 	stop_loading_anim(tab);
1195 	message("Loaded %s", tab->hist_cur->h);
1196 
1197 	redraw_tabline();
1198 	wrefresh(tabline);
1199 	place_cursor(0);
1200 }
1201 
1202 void
1203 ui_on_tab_refresh(struct tab *tab)
1204 {
1205 	wrap_page(&tab->buffer, body_cols);
1206 	if (tab->flags & TAB_CURRENT)
1207 		redraw_tab(tab);
1208 	else
1209 		tab->flags |= TAB_URGENT;
1210 }
1211 
1212 const char *
1213 ui_keyname(int k)
1214 {
1215 	return keyname(k);
1216 }
1217 
1218 void
1219 ui_toggle_side_window(void)
1220 {
1221 	side_window = !side_window;
1222 	if (side_window)
1223 		recompute_help();
1224 
1225 	/*
1226 	 * ugly hack, but otherwise the window doesn't get updated
1227 	 * until I call handle_resize a second time (i.e. C-l).  I
1228 	 * will be happy to know why something like this is needed.
1229 	 */
1230 	handle_resize_nodelay(0, 0, NULL);
1231 	handle_resize_nodelay(0, 0, NULL);
1232 }
1233 
1234 void
1235 ui_schedule_redraw(void)
1236 {
1237 	struct timeval tv = {0, 0};
1238 
1239 	if (event_pending(&resizeev, EV_TIMEOUT, NULL))
1240 		event_del(&resizeev);
1241 
1242 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
1243 	evtimer_add(&resizeev, &tv);
1244 }
1245 
1246 void
1247 ui_require_input(struct tab *tab, int hide)
1248 {
1249 	/* TODO: hard-switching to another tab is ugly */
1250 	switch_to_tab(tab);
1251 
1252 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1253 	    &ir_history, NULL, NULL);
1254 	strlcpy(ministate.prompt, "Input required: ",
1255 	    sizeof(ministate.prompt));
1256 	redraw_tab(tab);
1257 }
1258 
1259 void
1260 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1261     struct tab *data)
1262 {
1263 	yornp(prompt, fn, data);
1264 	redraw_tab(current_tab());
1265 }
1266 
1267 void
1268 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1269     struct tab *data)
1270 {
1271 	completing_read(prompt, fn, data);
1272 	redraw_tab(current_tab());
1273 }
1274 
1275 void
1276 ui_end(void)
1277 {
1278 	endwin();
1279 }