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