op public repos

Blob

Date:: Mon Jul 12 21:22:47 2021 UTC
Message:: typo + fmt
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 /*
18  * Ncurses UI for telescope.
19  *
20  * Text scrolling
21  * ==============
22  *
23  * ncurses allows you to scroll a window, but when a line goes out of
24  * the visible area it's forgotten.  We keep a list of formatted lines
25  * (``visual lines'') that we know fits in the window, and draw them.
26  *
27  * This means that on every resize we have to clear our list of lines
28  * and re-render everything.  A clever approach would be to do this
29  * ``on-demand'', but it's still missing.
30  *
31  */
32 
33 #include <assert.h>
34 #include <curses.h>
35 #include <event.h>
36 #include <locale.h>
37 #include <signal.h>
38 #include <stdarg.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "minibuffer.h"
44 #include "telescope.h"
45 #include "ui.h"
46 #include "utf8.h"
47 
48 static struct event	stdioev, winchev;
49 
50 static void		 restore_curs_x(struct buffer *);
51 
52 static struct vline	*nth_line(struct buffer*, size_t);
53 static int		 readkey(void);
54 static void		 dispatch_stdio(int, short, void*);
55 static void		 handle_clear_echoarea(int, short, void*);
56 static void		 handle_resize(int, short, void*);
57 static void		 handle_resize_nodelay(int, short, void*);
58 static int		 wrap_page(struct buffer*, int);
59 static void		 print_vline(int, int, WINDOW*, struct vline*);
60 static void		 redraw_tabline(void);
61 static void		 redraw_window(WINDOW*, int, int, struct buffer*);
62 static void		 redraw_help(void);
63 static void		 redraw_body(struct tab*);
64 static void		 redraw_modeline(struct tab*);
65 static void		 redraw_minibuffer(void);
66 static void		 do_redraw_echoarea(void);
67 static void		 do_redraw_minibuffer(void);
68 static void		 place_cursor(int);
69 static void		 redraw_tab(struct tab*);
70 static void		 emit_help_item(char*, void*);
71 static void		 rec_compute_help(struct kmap*, char*, size_t);
72 static void		 recompute_help(void);
73 static void		 update_loading_anim(int, short, void*);
74 static void		 stop_loading_anim(struct tab*);
75 
76 static int		 x_offset;
77 
78 struct thiskey thiskey;
79 
80 static struct event	resizeev;
81 static struct timeval	resize_timer = { 0, 250000 };
82 
83 static WINDOW	*tabline, *body, *modeline, *echoarea;
84 
85 int			 body_lines, body_cols;
86 
87 static WINDOW		*help;
88 static struct buffer	 helpwin;
89 static int		 help_lines, help_cols;
90 
91 static int		 side_window;
92 
93 static struct event	clechoev;
94 static struct timeval	clechoev_timer = { 5, 0 };
95 static struct timeval	loadingev_timer = { 0, 250000 };
96 
97 static uint32_t		 tab_counter;
98 
99 static char	keybuf[64];
100 
101 struct kmap global_map,
102 	minibuffer_map,
103 	*current_map,
104 	*base_map;
105 
106 int in_minibuffer;
107 
108 static inline void
109 update_x_offset(void)
110 {
111 	if (olivetti_mode && fill_column < body_cols)
112 		x_offset = (body_cols - fill_column)/2;
113 	else
114 		x_offset = 0;
115 }
116 
117 void
118 save_excursion(struct excursion *place, struct buffer *buffer)
119 {
120 	place->curs_x = buffer->curs_x;
121 	place->curs_y = buffer->curs_y;
122 	place->line_off = buffer->line_off;
123 	place->current_line = buffer->current_line;
124 	place->cpoff = buffer->cpoff;
125 }
126 
127 void
128 restore_excursion(struct excursion *place, struct buffer *buffer)
129 {
130 	buffer->curs_x = place->curs_x;
131 	buffer->curs_y = place->curs_y;
132 	buffer->line_off = place->line_off;
133 	buffer->current_line = place->current_line;
134 	buffer->cpoff = place->cpoff;
135 }
136 
137 static void
138 restore_curs_x(struct buffer *buffer)
139 {
140 	struct vline	*vl;
141 	const char	*prfx;
142 
143 	vl = buffer->current_line;
144 	if (vl == NULL || vl->line == NULL)
145 		buffer->curs_x = buffer->cpoff = 0;
146 	else
147 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
148 
149 	buffer->curs_x += x_offset;
150 
151 	if (vl != NULL) {
152 		prfx = line_prefixes[vl->parent->type].prfx1;
153 		buffer->curs_x += utf8_swidth(prfx);
154 	}
155 }
156 
157 void
158 global_key_unbound(void)
159 {
160 	message("%s is undefined", keybuf);
161 }
162 
163 static struct vline *
164 nth_line(struct buffer *buffer, size_t n)
165 {
166 	struct vline	*vl;
167 	size_t		 i;
168 
169 	i = 0;
170 	TAILQ_FOREACH(vl, &buffer->head, vlines) {
171 		if (i == n)
172 			return vl;
173 		i++;
174 	}
175 
176 	/* unreachable */
177 	abort();
178 }
179 
180 struct tab *
181 current_tab(void)
182 {
183 	struct tab *t;
184 
185 	TAILQ_FOREACH(t, &tabshead, tabs) {
186 		if (t->flags & TAB_CURRENT)
187 			return t;
188 	}
189 
190 	/* unreachable */
191 	abort();
192 }
193 
194 struct buffer *
195 current_buffer(void)
196 {
197 	if (in_minibuffer)
198 		return &ministate.buffer;
199 	return &current_tab()->buffer;
200 }
201 
202 static int
203 readkey(void)
204 {
205 	uint32_t state = 0;
206 
207 	if ((thiskey.key = wgetch(body)) == ERR)
208 		return 0;
209 
210 	thiskey.meta = thiskey.key == 27;
211 	if (thiskey.meta) {
212 		thiskey.key = wgetch(body);
213 		if (thiskey.key == ERR || thiskey.key == 27) {
214 			thiskey.meta = 0;
215 			thiskey.key = 27;
216 		}
217 	}
218 
219 	thiskey.cp = 0;
220 	if ((unsigned int)thiskey.key < UINT8_MAX) {
221 		while (1) {
222 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
223 				break;
224 			if ((thiskey.key = wgetch(body)) == ERR) {
225 				message("Error decoding user input");
226 				return 0;
227 			}
228 		}
229 	}
230 
231 	return 1;
232 }
233 
234 static void
235 dispatch_stdio(int fd, short ev, void *d)
236 {
237 	struct keymap	*k;
238 	const char	*keyname;
239 	char		 tmp[5] = {0};
240 
241 	if (!readkey())
242 		return;
243 
244 	if (keybuf[0] != '\0')
245 		strlcat(keybuf, " ", sizeof(keybuf));
246 	if (thiskey.meta)
247 		strlcat(keybuf, "M-", sizeof(keybuf));
248 	if (thiskey.cp != 0) {
249 		utf8_encode(thiskey.cp, tmp);
250 		strlcat(keybuf, tmp, sizeof(keybuf));
251 	} else {
252 		if ((keyname = unkbd(thiskey.key)) != NULL)
253 			strlcat(keybuf, keyname, sizeof(keybuf));
254 		else {
255 			tmp[0] = thiskey.key;
256 			strlcat(keybuf, tmp, sizeof(keybuf));
257 		}
258 	}
259 
260 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
261 		if (k->meta == thiskey.meta &&
262 		    k->key == thiskey.key) {
263 			if (k->fn == NULL)
264 				current_map = &k->map;
265 			else {
266 				current_map = base_map;
267 				strlcpy(keybuf, "", sizeof(keybuf));
268 				k->fn(current_buffer());
269 			}
270 			goto done;
271 		}
272 	}
273 
274 	if (current_map->unhandled_input != NULL)
275 		current_map->unhandled_input();
276 	else
277 		global_key_unbound();
278 
279 	strlcpy(keybuf, "", sizeof(keybuf));
280 	current_map = base_map;
281 
282 done:
283 	if (side_window)
284 		recompute_help();
285 
286 	redraw_tab(current_tab());
287 }
288 
289 static void
290 handle_clear_echoarea(int fd, short ev, void *d)
291 {
292 	free(ministate.curmesg);
293 	ministate.curmesg = NULL;
294 
295 	redraw_minibuffer();
296 	place_cursor(0);
297 }
298 
299 static void
300 handle_resize(int sig, short ev, void *d)
301 {
302 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
303 		event_del(&resizeev);
304 	}
305 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
306 	evtimer_add(&resizeev, &resize_timer);
307 }
308 
309 static void
310 handle_resize_nodelay(int s, short ev, void *d)
311 {
312 	struct tab	*tab;
313 
314 	endwin();
315 	refresh();
316 	clear();
317 
318 	/* move and resize the windows, in reverse order! */
319 
320 	mvwin(echoarea, LINES-1, 0);
321 	wresize(echoarea, 1, COLS);
322 
323 	mvwin(modeline, LINES-2, 0);
324 	wresize(modeline, 1, COLS);
325 
326 	body_lines = LINES-3;
327 	body_cols = COLS;
328 
329 	if (side_window) {
330 		help_cols = 0.3 * COLS;
331 		help_lines = LINES-3;
332 		mvwin(help, 1, 0);
333 		wresize(help, help_lines, help_cols);
334 
335 		wrap_page(&helpwin, help_cols);
336 
337 		body_cols = COLS - help_cols - 1;
338 		mvwin(body, 1, help_cols);
339 	} else
340 		mvwin(body, 1, 0);
341 
342 	update_x_offset();
343 	wresize(body, body_lines, body_cols);
344 
345 	wresize(tabline, 1, COLS);
346 
347 	tab = current_tab();
348 
349 	wrap_page(&tab->buffer, body_cols);
350 	redraw_tab(tab);
351 }
352 
353 static int
354 wrap_page(struct buffer *buffer, int width)
355 {
356 	struct line		*l;
357 	const struct line	*top_orig, *orig;
358 	struct vline		*vl;
359 	int			 pre_width;
360 	const char		*prfx;
361 
362 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
363 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
364 
365 	buffer->top_line = NULL;
366 	buffer->current_line = NULL;
367 
368 	buffer->force_redraw = 1;
369 	buffer->curs_y = 0;
370 	buffer->line_off = 0;
371 
372 	empty_vlist(buffer);
373 
374 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
375 		prfx = line_prefixes[l->type].prfx1;
376 		switch (l->type) {
377 		case LINE_TEXT:
378 		case LINE_LINK:
379 		case LINE_TITLE_1:
380 		case LINE_TITLE_2:
381 		case LINE_TITLE_3:
382 		case LINE_ITEM:
383 		case LINE_QUOTE:
384 		case LINE_PRE_START:
385 		case LINE_PRE_END:
386 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
387 			break;
388 		case LINE_PRE_CONTENT:
389 			if (olivetti_mode)
390 				pre_width = MIN(fill_column, width);
391 			else
392 				pre_width = width;
393 			hardwrap_text(buffer, l, pre_width);
394 			break;
395 		}
396 
397 		if (top_orig == l && buffer->top_line == NULL) {
398 			buffer->line_off = buffer->line_max-1;
399 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
400 
401 			while (1) {
402 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
403 				if (vl == NULL || vl->parent != orig)
404 					break;
405 				buffer->top_line = vl;
406 				buffer->line_off--;
407 			}
408 		}
409 
410 		if (orig == l && buffer->current_line == NULL) {
411 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
412 
413 			while (1) {
414 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
415 				if (vl == NULL || vl->parent != orig)
416 					break;
417 				buffer->current_line = vl;
418 			}
419 		}
420 	}
421 
422         if (buffer->current_line == NULL)
423 		buffer->current_line = TAILQ_FIRST(&buffer->head);
424 
425 	if (buffer->top_line == NULL)
426 		buffer->top_line = buffer->current_line;
427 
428 	return 1;
429 }
430 
431 static void
432 print_vline(int off, int width, WINDOW *window, struct vline *vl)
433 {
434 	const char *text;
435 	const char *prfx;
436 	struct line_face *f;
437 	int i, left, x, y;
438 
439 	f = &line_faces[vl->parent->type];
440 
441 	/* unused, set by getyx */
442 	(void)y;
443 
444 	if (!vl->flags)
445 		prfx = line_prefixes[vl->parent->type].prfx1;
446 	else
447 		prfx = line_prefixes[vl->parent->type].prfx2;
448 
449 	text = vl->line;
450 	if (text == NULL)
451 		text = "";
452 
453 	wattr_on(window, body_face.left, NULL);
454 	for (i = 0; i < off; i++)
455 		waddch(window, ' ');
456 	wattr_off(window, body_face.left, NULL);
457 
458 	wattr_on(window, f->prefix, NULL);
459 	wprintw(window, "%s", prfx);
460 	wattr_off(window, f->prefix, NULL);
461 
462 	wattr_on(window, f->text, NULL);
463 	wprintw(window, "%s", text);
464 	wattr_off(window, f->text, NULL);
465 
466 	getyx(window, y, x);
467 
468 	left = width - x;
469 
470 	wattr_on(window, f->trail, NULL);
471 	for (i = 0; i < left - off; ++i)
472 		waddch(window, ' ');
473 	wattr_off(window, f->trail, NULL);
474 
475 	wattr_on(window, body_face.right, NULL);
476 	for (i = 0; i < off; i++)
477 		waddch(window, ' ');
478 	wattr_off(window, body_face.right, NULL);
479 
480 }
481 
482 static void
483 redraw_tabline(void)
484 {
485 	struct tab	*tab;
486 	size_t		 toskip, ots, tabwidth, space, x;
487 	int		 current, y, truncated;
488 	const char	*title;
489 	char		 buf[25];
490 
491 	x = 0;
492 
493 	/* unused, but setted by a getyx */
494 	(void)y;
495 
496 	tabwidth = sizeof(buf)+1;
497 	space = COLS-2;
498 
499 	toskip = 0;
500 	TAILQ_FOREACH(tab, &tabshead, tabs) {
501 		toskip++;
502 		if (tab->flags & TAB_CURRENT)
503 			break;
504 	}
505 
506 	if (toskip * tabwidth < space)
507 		toskip = 0;
508 	else {
509 		ots = toskip;
510 		toskip--;
511                 while (toskip != 0 &&
512 		    (ots - toskip+1) * tabwidth < space)
513 			toskip--;
514 	}
515 
516 	werase(tabline);
517 	wattr_on(tabline, tab_face.background, NULL);
518 	wprintw(tabline, toskip == 0 ? " " : "<");
519 	wattr_off(tabline, tab_face.background, NULL);
520 
521 	truncated = 0;
522 	TAILQ_FOREACH(tab, &tabshead, tabs) {
523 		if (truncated)
524 			break;
525 		if (toskip != 0) {
526 			toskip--;
527 			continue;
528 		}
529 
530 		getyx(tabline, y, x);
531 		if (x + sizeof(buf)+2 >= (size_t)COLS)
532 			truncated = 1;
533 
534 		current = tab->flags & TAB_CURRENT;
535 
536 		if (*(title = tab->buffer.page.title) == '\0')
537 			title = tab->hist_cur->h;
538 
539 		if (tab->flags & TAB_URGENT)
540 			strlcpy(buf, "!", sizeof(buf));
541 		else
542 			strlcpy(buf, " ", sizeof(buf));
543 
544                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
545 			/* truncation happens */
546 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
547 		} else {
548 			/* pad with spaces */
549 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
550 				/* nop */ ;
551 		}
552 
553 		if (current)
554 			wattr_on(tabline, tab_face.current, NULL);
555 		else
556 			wattr_on(tabline, tab_face.tab, NULL);
557 
558 		wprintw(tabline, "%s", buf);
559 		if (TAILQ_NEXT(tab, tabs) != NULL)
560 			wprintw(tabline, " ");
561 
562 		if (current)
563 			wattr_off(tabline, tab_face.current, NULL);
564 		else
565 			wattr_off(tabline, tab_face.tab, NULL);
566 	}
567 
568 	wattr_on(tabline, tab_face.background, NULL);
569 	for (; x < (size_t)COLS; ++x)
570 		waddch(tabline, ' ');
571 	if (truncated)
572 		mvwprintw(tabline, 0, COLS-1, ">");
573 	wattr_off(tabline, tab_face.background, NULL);
574 }
575 
576 /*
577  * Compute the first visible line around vl.  Try to search forward
578  * until the end of the buffer; if a visible line is not found, search
579  * backward.  Return NULL if no viable line was found.
580  */
581 static inline struct vline *
582 adjust_line(struct vline *vl, struct buffer *buffer)
583 {
584 	struct vline *t;
585 
586 	if (!(vl->parent->flags & L_HIDDEN))
587 		return vl;
588 
589 	/* search forward */
590 	for (t = vl;
591 	     t != NULL && t->parent->flags & L_HIDDEN;
592 	     t = TAILQ_NEXT(t, vlines))
593 		;		/* nop */
594 
595 	if (t != NULL)
596 		return t;
597 
598 	/* search backward */
599 	for (t = vl;
600 	     t != NULL && t->parent->flags & L_HIDDEN;
601 	     t = TAILQ_PREV(t, vhead, vlines))
602 		;		/* nop */
603 
604 	return t;
605 }
606 
607 static void
608 redraw_window(WINDOW *win, int height, int width, struct buffer *buffer)
609 {
610         struct vline	*vl;
611 	int		 l, onscreen;
612 
613 	restore_curs_x(buffer);
614 
615 	/*
616 	 * TODO: ignoring buffer->force_update and always
617 	 * re-rendering.  In theory we can recompute the y position
618 	 * without a re-render, and optimize here.  It's not the only
619 	 * optimisation possible here, wscrl wolud also be an
620 	 * interesting one.
621 	 */
622 
623 again:
624 	werase(win);
625 	buffer->curs_y = 0;
626 
627 	if (TAILQ_EMPTY(&buffer->head))
628 		goto end;
629 
630 	buffer->top_line = adjust_line(buffer->top_line, buffer);
631 	if (buffer->top_line == NULL)
632 		goto end;
633 
634 	buffer->current_line = adjust_line(buffer->current_line, buffer);
635 
636 	l = 0;
637 	onscreen = 0;
638 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
639 		if (vl->parent->flags & L_HIDDEN)
640 			continue;
641 
642 		wmove(win, l, 0);
643 		print_vline(x_offset, width, win, vl);
644 
645 		if (vl == buffer->current_line)
646 			onscreen = 1;
647 
648 		if (!onscreen)
649 			buffer->curs_y++;
650 
651 		l++;
652 		if (l == height)
653 			break;
654 	}
655 
656 	if (!onscreen) {
657 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
658 			if (vl == buffer->current_line)
659 				break;
660 			if (vl->parent->flags & L_HIDDEN)
661 				continue;
662 			buffer->line_off++;
663 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
664 		}
665 
666 		goto again;
667 	}
668 
669 	buffer->last_line_off = buffer->line_off;
670 	buffer->force_redraw = 0;
671 end:
672 	wmove(win, buffer->curs_y, buffer->curs_x);
673 }
674 
675 static void
676 redraw_help(void)
677 {
678 	redraw_window(help, help_lines, help_cols, &helpwin);
679 }
680 
681 static void
682 redraw_body(struct tab *tab)
683 {
684 	static struct tab *last_tab;
685 
686 	if (last_tab != tab)
687 		tab->buffer.force_redraw =1;
688 	last_tab = tab;
689 
690 	redraw_window(body, body_lines, body_cols, &tab->buffer);
691 }
692 
693 static inline char
694 trust_status_char(enum trust_state ts)
695 {
696 	switch (ts) {
697 	case TS_UNKNOWN:	return 'u';
698 	case TS_UNTRUSTED:	return '!';
699 	case TS_TEMP_TRUSTED:	return '!';
700 	case TS_TRUSTED:	return 'v';
701 	case TS_VERIFIED:	return 'V';
702 	default:		return 'X';
703 	}
704 }
705 
706 static void
707 redraw_modeline(struct tab *tab)
708 {
709 	double		 pct;
710 	int		 x, y, max_x, max_y;
711 	const char	*mode = tab->buffer.page.name;
712 	const char	*spin = "-\\|/";
713 
714 	werase(modeline);
715 	wattr_on(modeline, modeline_face.background, NULL);
716 	wmove(modeline, 0, 0);
717 
718 	wprintw(modeline, "-%c%c %s ",
719 	    spin[tab->loading_anim_step],
720 	    trust_status_char(tab->trust),
721 	    mode == NULL ? "(none)" : mode);
722 
723 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0 / tab->buffer.line_max;
724 
725 	if (tab->buffer.line_max <= (size_t)body_lines)
726                 wprintw(modeline, "All ");
727 	else if (tab->buffer.line_off == 0)
728                 wprintw(modeline, "Top ");
729 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
730 		wprintw(modeline, "Bottom ");
731 	else
732 		wprintw(modeline, "%.0f%% ", pct);
733 
734 	wprintw(modeline, "%d/%d %s ",
735 	    tab->buffer.line_off + tab->buffer.curs_y,
736 	    tab->buffer.line_max,
737 	    tab->hist_cur->h);
738 
739 	getyx(modeline, y, x);
740 	getmaxyx(modeline, max_y, max_x);
741 
742 	(void)y;
743 	(void)max_y;
744 
745 	for (; x < max_x; ++x)
746 		waddstr(modeline, "-");
747 
748 	wattr_off(modeline, modeline_face.background, NULL);
749 }
750 
751 static void
752 redraw_minibuffer(void)
753 {
754 	wattr_on(echoarea, minibuffer_face.background, NULL);
755 	werase(echoarea);
756 
757 	if (in_minibuffer)
758 		do_redraw_minibuffer();
759 	else
760 		do_redraw_echoarea();
761 
762 	wattr_off(echoarea, minibuffer_face.background, NULL);
763 }
764 
765 static void
766 do_redraw_echoarea(void)
767 {
768 	struct tab *tab;
769 
770 	if (ministate.curmesg != NULL)
771                 wprintw(echoarea, "%s", ministate.curmesg);
772 	else if (*keybuf != '\0')
773 		waddstr(echoarea, keybuf);
774 	else {
775 		/* If nothing else, show the URL at point */
776 		tab = current_tab();
777 		if (tab->buffer.current_line != NULL &&
778 		    tab->buffer.current_line->parent->type == LINE_LINK)
779 			waddstr(echoarea, tab->buffer.current_line->parent->alt);
780 	}
781 }
782 
783 static void
784 do_redraw_minibuffer(void)
785 {
786 	size_t		 off_y, off_x = 0;
787 	const char	*start, *c;
788 
789 	/* unused, set by getyx */
790 	(void)off_y;
791 
792 	mvwprintw(echoarea, 0, 0, "%s", ministate.prompt);
793 	if (ministate.hist_cur != NULL)
794 		wprintw(echoarea, "(%zu/%zu) ",
795 		    ministate.hist_off + 1,
796 		    ministate.history->len);
797 
798 	getyx(echoarea, off_y, off_x);
799 
800 	start = ministate.hist_cur != NULL
801 		? ministate.hist_cur->h
802 		: ministate.buf;
803 	c = utf8_nth(ministate.buffer.current_line->line,
804 	    ministate.buffer.cpoff);
805 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
806 		start = utf8_next_cp(start);
807 	}
808 
809 	waddstr(echoarea, start);
810 
811 	if (ministate.curmesg != NULL)
812 		wprintw(echoarea, " [%s]", ministate.curmesg);
813 
814 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
815 }
816 
817 /*
818  * Place the cursor in the right ncurses window.  If soft is 1, use
819  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
820  * wrefresh.
821  */
822 static void
823 place_cursor(int soft)
824 {
825 	int (*touch)(WINDOW *);
826 
827 	if (soft)
828 		touch = wnoutrefresh;
829 	else
830 		touch = wrefresh;
831 
832 	if (in_minibuffer) {
833 		touch(body);
834 		touch(echoarea);
835 	} else {
836 		touch(echoarea);
837 		touch(body);
838 	}
839 }
840 
841 static void
842 redraw_tab(struct tab *tab)
843 {
844 	if (side_window) {
845 		redraw_help();
846 		wnoutrefresh(help);
847 	}
848 
849 	redraw_tabline();
850 	redraw_body(tab);
851 	redraw_modeline(tab);
852 	redraw_minibuffer();
853 
854 	wnoutrefresh(tabline);
855 	wnoutrefresh(modeline);
856 
857 	place_cursor(1);
858 
859 	doupdate();
860 }
861 
862 static void
863 emit_help_item(char *prfx, void *fn)
864 {
865 	struct line	*l;
866 	struct cmd	*cmd;
867 
868 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
869 		if (fn == cmd->fn)
870 			break;
871 	}
872 	assert(cmd != NULL);
873 
874 	if ((l = calloc(1, sizeof(*l))) == NULL)
875 		abort();
876 
877 	l->type = LINE_TEXT;
878 	l->alt = NULL;
879 
880 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
881 
882 	if (TAILQ_EMPTY(&helpwin.page.head))
883 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
884 	else
885 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
886 }
887 
888 static void
889 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
890 {
891 	struct keymap	*k;
892 	char		 p[32];
893 	const char	*kn;
894 
895 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
896 		strlcpy(p, prfx, sizeof(p));
897 		if (*p != '\0')
898 			strlcat(p, " ", sizeof(p));
899 		if (k->meta)
900 			strlcat(p, "M-", sizeof(p));
901 		if ((kn = unkbd(k->key)) != NULL)
902 			strlcat(p, kn, sizeof(p));
903 		else
904 			strlcat(p, keyname(k->key), sizeof(p));
905 
906 		if (k->fn == NULL)
907 			rec_compute_help(&k->map, p, sizeof(p));
908 		else
909 			emit_help_item(p, k->fn);
910 	}
911 }
912 
913 static void
914 recompute_help(void)
915 {
916 	char	p[32] = { 0 };
917 
918 	empty_vlist(&helpwin);
919 	empty_linelist(&helpwin);
920 	rec_compute_help(current_map, p, sizeof(p));
921 	wrap_page(&helpwin, help_cols);
922 }
923 
924 void
925 vmessage(const char *fmt, va_list ap)
926 {
927 	if (evtimer_pending(&clechoev, NULL))
928 		evtimer_del(&clechoev);
929 
930 	free(ministate.curmesg);
931 	ministate.curmesg = NULL;
932 
933 	if (fmt != NULL) {
934 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
935 		evtimer_add(&clechoev, &clechoev_timer);
936 
937 		/* TODO: what to do if the allocation fails here? */
938 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
939 			ministate.curmesg = NULL;
940 	}
941 
942 	redraw_minibuffer();
943         place_cursor(0);
944 }
945 
946 void
947 message(const char *fmt, ...)
948 {
949 	va_list ap;
950 
951 	va_start(ap, fmt);
952 	vmessage(fmt, ap);
953 	va_end(ap);
954 }
955 
956 void
957 start_loading_anim(struct tab *tab)
958 {
959 	if (tab->loading_anim)
960 		return;
961 	tab->loading_anim = 1;
962 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
963 	evtimer_add(&tab->loadingev, &loadingev_timer);
964 }
965 
966 static void
967 update_loading_anim(int fd, short ev, void *d)
968 {
969 	struct tab	*tab = d;
970 
971 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
972 
973 	if (tab->flags & TAB_CURRENT) {
974 		redraw_modeline(tab);
975 		wrefresh(modeline);
976 		wrefresh(body);
977 		if (in_minibuffer)
978 			wrefresh(echoarea);
979 	}
980 
981 	evtimer_add(&tab->loadingev, &loadingev_timer);
982 }
983 
984 static void
985 stop_loading_anim(struct tab *tab)
986 {
987 	if (!tab->loading_anim)
988 		return;
989 	evtimer_del(&tab->loadingev);
990 	tab->loading_anim = 0;
991 	tab->loading_anim_step = 0;
992 
993 	if (!(tab->flags & TAB_CURRENT))
994 		return;
995 
996 	redraw_modeline(tab);
997 
998 	wrefresh(modeline);
999 	wrefresh(body);
1000 	if (in_minibuffer)
1001 		wrefresh(echoarea);
1002 }
1003 
1004 void
1005 load_url_in_tab(struct tab *tab, const char *url)
1006 {
1007 	message("Loading %s...", url);
1008 	start_loading_anim(tab);
1009 	load_url(tab, url);
1010 
1011 	tab->buffer.curs_x = 0;
1012 	tab->buffer.curs_y = 0;
1013 	redraw_tab(tab);
1014 }
1015 
1016 void
1017 switch_to_tab(struct tab *tab)
1018 {
1019 	struct tab	*t;
1020 
1021 	TAILQ_FOREACH(t, &tabshead, tabs) {
1022 		t->flags &= ~TAB_CURRENT;
1023 	}
1024 
1025 	tab->flags |= TAB_CURRENT;
1026 	tab->flags &= ~TAB_URGENT;
1027 }
1028 
1029 unsigned int
1030 tab_new_id(void)
1031 {
1032 	return tab_counter++;
1033 }
1034 
1035 struct tab *
1036 new_tab(const char *url)
1037 {
1038 	struct tab	*tab;
1039 
1040 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1041 		event_loopbreak();
1042 		return NULL;
1043 	}
1044 	tab->fd = -1;
1045 
1046 	TAILQ_INIT(&tab->hist.head);
1047 
1048 	TAILQ_INIT(&tab->buffer.head);
1049 
1050 	tab->id = tab_new_id();
1051 	switch_to_tab(tab);
1052 
1053 	if (TAILQ_EMPTY(&tabshead))
1054 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1055 	else
1056 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1057 
1058 	load_url_in_tab(tab, url);
1059 	return tab;
1060 }
1061 
1062 int
1063 ui_init()
1064 {
1065 	setlocale(LC_ALL, "");
1066 
1067 	TAILQ_INIT(&eecmd_history.head);
1068 	TAILQ_INIT(&ir_history.head);
1069 	TAILQ_INIT(&lu_history.head);
1070 
1071 	ministate.line.type = LINE_TEXT;
1072 	ministate.vline.parent = &ministate.line;
1073 	ministate.buffer.current_line = &ministate.vline;
1074 
1075 	/* initialize help window */
1076 	TAILQ_INIT(&helpwin.head);
1077 
1078 	base_map = &global_map;
1079 	current_map = &global_map;
1080 
1081 	initscr();
1082 
1083 	if (enable_colors) {
1084 		if (has_colors()) {
1085 			start_color();
1086 			use_default_colors();
1087 		} else
1088 			enable_colors = 0;
1089 	}
1090 
1091 	config_apply_style();
1092 
1093 	raw();
1094 	noecho();
1095 	nonl();
1096 	intrflush(stdscr, FALSE);
1097 
1098 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1099 		return 0;
1100 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1101 		return 0;
1102 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1103 		return 0;
1104 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1105 		return 0;
1106 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1107 		return 0;
1108 
1109 	body_lines = LINES-3;
1110 	body_cols = COLS;
1111 
1112 	wbkgd(body, body_face.body);
1113 	wbkgd(echoarea, minibuffer_face.background);
1114 
1115 	update_x_offset();
1116 
1117 	keypad(body, TRUE);
1118 	scrollok(body, FALSE);
1119 
1120 	/* non-blocking input */
1121 	wtimeout(body, 0);
1122 
1123 	mvwprintw(body, 0, 0, "");
1124 
1125 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1126 	event_add(&stdioev, NULL);
1127 
1128 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1129 	signal_add(&winchev, NULL);
1130 
1131 	return 1;
1132 }
1133 
1134 void
1135 ui_on_tab_loaded(struct tab *tab)
1136 {
1137 	stop_loading_anim(tab);
1138 	message("Loaded %s", tab->hist_cur->h);
1139 
1140 	redraw_tabline();
1141 	wrefresh(tabline);
1142 	place_cursor(0);
1143 }
1144 
1145 void
1146 ui_on_tab_refresh(struct tab *tab)
1147 {
1148 	wrap_page(&tab->buffer, body_cols);
1149 	if (tab->flags & TAB_CURRENT)
1150 		redraw_tab(tab);
1151 	else
1152 		tab->flags |= TAB_URGENT;
1153 }
1154 
1155 const char *
1156 ui_keyname(int k)
1157 {
1158 	return keyname(k);
1159 }
1160 
1161 void
1162 ui_toggle_side_window(void)
1163 {
1164 	side_window = !side_window;
1165 	if (side_window)
1166 		recompute_help();
1167 
1168 	/*
1169 	 * ugly hack, but otherwise the window doesn't get updated
1170 	 * until I call handle_resize a second time (i.e. C-l).  I
1171 	 * will be happy to know why something like this is needed.
1172 	 */
1173 	handle_resize_nodelay(0, 0, NULL);
1174 	handle_resize_nodelay(0, 0, NULL);
1175 }
1176 
1177 void
1178 ui_schedule_redraw(void)
1179 {
1180 	handle_resize_nodelay(0, 0, NULL);
1181 }
1182 
1183 void
1184 ui_require_input(struct tab *tab, int hide)
1185 {
1186 	/* TODO: hard-switching to another tab is ugly */
1187 	switch_to_tab(tab);
1188 
1189 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1190 	    &ir_history);
1191 	strlcpy(ministate.prompt, "Input required: ",
1192 	    sizeof(ministate.prompt));
1193 	redraw_tab(tab);
1194 }
1195 
1196 void
1197 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1198     struct tab *data)
1199 {
1200 	yornp(prompt, fn, data);
1201 	redraw_tab(current_tab());
1202 }
1203 
1204 void
1205 ui_read(const char *prompt, void (*fn)(const char*, unsigned int),
1206     unsigned int data)
1207 {
1208 	completing_read(prompt, fn, data);
1209 	redraw_tab(current_tab());
1210 }
1211 
1212 void
1213 ui_end(void)
1214 {
1215 	endwin();
1216 }