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 "compat.h"
34 
35 #include <assert.h>
36 #include <curses.h>
37 #include <locale.h>
38 #include <signal.h>
39 #include <stdarg.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "defaults.h"
45 #include "minibuffer.h"
46 #include "session.h"
47 #include "telescope.h"
48 #include "ui.h"
49 #include "utf8.h"
50 
51 static struct event	stdioev, winchev;
52 
53 static void		 restore_curs_x(struct buffer *);
54 
55 static int		 readkey(void);
56 static void		 dispatch_stdio(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 void		 line_prefix_and_text(struct vline *, char *, size_t, const char **, const char **);
61 static void		 print_vline(int, int, WINDOW*, struct vline*);
62 static void		 redraw_tabline(void);
63 static void		 redraw_window(WINDOW*, int, int, int, struct buffer*);
64 static void		 redraw_download(void);
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		 update_loading_anim(int, short, void*);
75 static void		 stop_loading_anim(struct tab*);
76 
77 static int		 should_rearrange_windows;
78 static int		 show_tab_bar;
79 static int		 too_small;
80 static int		 x_offset;
81 
82 struct thiskey	 thiskey;
83 struct tab	*current_tab;
84 
85 static struct event	resizeev;
86 static struct timeval	resize_timer = { 0, 250000 };
87 
88 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
89 
90 int			 body_lines, body_cols;
91 
92 static WINDOW		*help;
93 /* not static so we can see them from help.c */
94 struct buffer		 helpwin;
95 int			 help_lines, help_cols;
96 
97 static WINDOW		*download;
98 /* not static so we can see them from download.c */
99 struct buffer		 downloadwin;
100 int			 download_lines;
101 int			 download_cols;
102 
103 static int		 side_window;
104 static int		 in_side_window;
105 
106 static struct timeval	loadingev_timer = { 0, 250000 };
107 
108 static char	keybuf[64];
109 
110 /* XXX: don't forget to init these in main() */
111 struct kmap global_map,
112 	minibuffer_map,
113 	*current_map,
114 	*base_map;
115 
116 static inline void
117 update_x_offset(void)
118 {
119 	if (olivetti_mode && fill_column < body_cols)
120 		x_offset = (body_cols - fill_column)/2;
121 	else
122 		x_offset = 0;
123 }
124 
125 void
126 save_excursion(struct excursion *place, struct buffer *buffer)
127 {
128 	place->curs_x = buffer->curs_x;
129 	place->curs_y = buffer->curs_y;
130 	place->line_off = buffer->line_off;
131 	place->top_line = buffer->top_line;
132 	place->current_line = buffer->current_line;
133 	place->cpoff = buffer->cpoff;
134 }
135 
136 void
137 restore_excursion(struct excursion *place, struct buffer *buffer)
138 {
139 	buffer->curs_x = place->curs_x;
140 	buffer->curs_y = place->curs_y;
141 	buffer->line_off = place->line_off;
142 	buffer->top_line = place->top_line;
143 	buffer->current_line = place->current_line;
144 	buffer->cpoff = place->cpoff;
145 }
146 
147 static void
148 restore_curs_x(struct buffer *buffer)
149 {
150 	struct vline	*vl;
151 	const char	*prfx, *text;
152 
153 	vl = buffer->current_line;
154 	if (vl == NULL || vl->line == NULL)
155 		buffer->curs_x = buffer->cpoff = 0;
156 	else if (vl->parent->data != NULL) {
157 		text = vl->parent->data;
158 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
159 	} else
160 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
161 
162 	/* small hack: don't olivetti-mode the download pane */
163 	if (buffer != &downloadwin)
164 		buffer->curs_x += x_offset;
165 
166 	if (vl == NULL)
167 		return;
168 
169 	if (vl->parent->data != NULL)
170 		buffer->curs_x += utf8_swidth_between(vl->parent->line,
171 		    vl->parent->data);
172 	else {
173 		prfx = line_prefixes[vl->parent->type].prfx1;
174 		buffer->curs_x += utf8_swidth(prfx);
175 	}
176 }
177 
178 void
179 global_key_unbound(void)
180 {
181 	message("%s is undefined", keybuf);
182 }
183 
184 struct buffer *
185 current_buffer(void)
186 {
187 	if (in_minibuffer)
188 		return &ministate.buffer;
189 	if (in_side_window & SIDE_WINDOW_LEFT)
190 		return &helpwin;
191 	if (in_side_window & SIDE_WINDOW_BOTTOM)
192 		return &downloadwin;
193 	return &current_tab->buffer;
194 }
195 
196 static int
197 readkey(void)
198 {
199 	uint32_t state = 0;
200 
201 	if ((thiskey.key = wgetch(body)) == ERR)
202 		return 0;
203 
204 	thiskey.meta = thiskey.key == '\e';
205 	if (thiskey.meta) {
206 		thiskey.key = wgetch(body);
207 		if (thiskey.key == ERR || thiskey.key == '\e') {
208 			thiskey.meta = 0;
209 			thiskey.key = '\e';
210 		}
211 	}
212 
213 	thiskey.cp = 0;
214 
215 	if ((unsigned int)thiskey.key >= UINT8_MAX)
216 		return 1;
217 
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 	return 1;
228 }
229 
230 static void
231 dispatch_stdio(int fd, short ev, void *d)
232 {
233 	int		 lk;
234 	const char	*keyname;
235 	char		 tmp[5] = {0};
236 
237 	/* TODO: schedule a redraw? */
238 	if (too_small)
239 		return;
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 if ((keyname = unkbd(thiskey.key)) != NULL) {
252 		strlcat(keybuf, keyname, sizeof(keybuf));
253 	} else {
254 		tmp[0] = thiskey.key;
255 		strlcat(keybuf, tmp, sizeof(keybuf));
256 	}
257 
258 	lk = lookup_key(&current_map, &thiskey, current_buffer());
259 	if (lk == LK_UNBOUND) {
260 		if (current_map->unhandled_input != NULL)
261 			current_map->unhandled_input();
262 		else
263 			global_key_unbound();
264 	}
265 	if (lk != LK_ADVANCED_MAP) {
266 		current_map = base_map;
267 		strlcpy(keybuf, "", sizeof(keybuf));
268 	}
269 
270 	if (side_window & SIDE_WINDOW_LEFT)
271 		recompute_help();
272 
273 	if (should_rearrange_windows)
274 		rearrange_windows();
275 	redraw_tab(current_tab);
276 }
277 
278 static void
279 handle_resize(int sig, short ev, void *d)
280 {
281 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
282 		event_del(&resizeev);
283 	}
284 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
285 	evtimer_add(&resizeev, &resize_timer);
286 }
287 
288 static void
289 handle_resize_nodelay(int s, short ev, void *d)
290 {
291 	endwin();
292 	refresh();
293 	clear();
294 
295 	rearrange_windows();
296 }
297 
298 static inline int
299 should_show_tab_bar(void)
300 {
301 	if (tab_bar_show == -1)
302 		return 0;
303 	if (tab_bar_show == 0)
304 		return 1;
305 
306 	return TAILQ_NEXT(TAILQ_FIRST(&tabshead), tabs) != NULL;
307 }
308 
309 static void
310 rearrange_windows(void)
311 {
312 	int		 lines;
313 	int		 minibuffer_lines;
314 
315 	should_rearrange_windows = 0;
316 	show_tab_bar = should_show_tab_bar();
317 
318 	lines = LINES;
319 
320 	/* 3 lines for the ui and 12 for the  */
321 	if ((too_small = lines < 15)) {
322 		erase();
323 		printw("Window too small.");
324 		refresh();
325 		return;
326 	}
327 
328 	/* move and resize the windows, in reverse order! */
329 
330 	if (in_minibuffer == MB_COMPREAD) {
331 		minibuffer_lines = MIN(10, lines/2);
332 		mvwin(minibuffer, lines - minibuffer_lines, 0);
333 		wresize(minibuffer, minibuffer_lines, COLS);
334 		lines -= minibuffer_lines;
335 
336 		wrap_page(&ministate.compl.buffer, COLS);
337 	}
338 
339 	mvwin(echoarea, --lines, 0);
340 	wresize(echoarea, 1, COLS);
341 
342 	mvwin(modeline, --lines, 0);
343 	wresize(modeline, 1, COLS);
344 
345 	if (side_window & SIDE_WINDOW_BOTTOM) {
346 		download_lines = MIN(5, lines/2);
347 		download_cols = COLS;
348 		mvwin(download, lines - download_lines, 0);
349 		wresize(download, download_lines, download_cols);
350 		lines -= download_lines;
351 
352 		wrap_page(&downloadwin, download_cols);
353 	}
354 
355 	body_lines = show_tab_bar ? --lines : lines;
356 	body_cols = COLS;
357 
358 	/*
359 	 * Here we make the assumption that show_tab_bar is either 0
360 	 * or 1, and reuse that as argument to mvwin.
361 	 */
362 	if (side_window & SIDE_WINDOW_LEFT) {
363 		help_cols = 0.3 * COLS;
364 		help_lines = lines;
365 		mvwin(help, show_tab_bar, 0);
366 		wresize(help, help_lines, help_cols);
367 
368 		wrap_page(&helpwin, help_cols);
369 
370 		body_cols = COLS - help_cols - 1;
371 		mvwin(body, show_tab_bar, help_cols);
372 	} else
373 		mvwin(body, show_tab_bar, 0);
374 
375 	update_x_offset();
376 	wresize(body, body_lines, body_cols);
377 
378 	if (show_tab_bar)
379 		wresize(tabline, 1, COLS);
380 
381 	wrap_page(&current_tab->buffer, body_cols);
382 	redraw_tab(current_tab);
383 }
384 
385 static void
386 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
387     const char **prfx_ret, const char **text_ret)
388 {
389 	int type, i, cont, width;
390 	char *space, *t;
391 
392 	if ((*text_ret = vl->line) == NULL)
393 		*text_ret = "";
394 
395 	cont = vl->flags & L_CONTINUATION;
396 	type = vl->parent->type;
397 	if (!cont)
398 		*prfx_ret = line_prefixes[type].prfx1;
399 	else
400 		*prfx_ret = line_prefixes[type].prfx2;
401 
402 	space = vl->parent->data;
403 	if (!emojify_link || type != LINE_LINK || space == NULL)
404 		return;
405 
406 	if (cont) {
407 		memset(buf, 0, len);
408 		width = utf8_swidth_between(vl->parent->line, space);
409 		for (i = 0; i < width + 1; ++i)
410 			strlcat(buf, " ", len);
411 	} else {
412 		strlcpy(buf, *text_ret, len);
413 		if ((t = strchr(buf, ' ')) != NULL)
414 			*t = '\0';
415 		strlcat(buf, " ", len);
416 
417 		/* skip the emoji */
418 		*text_ret += (space - vl->parent->line) + 1;
419 	}
420 
421 	*prfx_ret = buf;
422 }
423 
424 static inline void
425 print_vline_descr(int width, WINDOW *window, struct vline *vl)
426 {
427 	int x, y, goal;
428 
429 	switch (vl->parent->type) {
430 	case LINE_COMPL:
431 	case LINE_COMPL_CURRENT:
432 		goal = width/2;
433 		break;
434 	case LINE_DOWNLOAD:
435 	case LINE_DOWNLOAD_DONE:
436 		goal = width/4;
437 		break;
438 	case LINE_HELP:
439 		goal = 8;
440 		break;
441 	default:
442 		return;
443 	}
444 
445 	if (vl->parent->alt == NULL)
446 		return;
447 
448 	(void)y;
449 	getyx(window, y, x);
450 
451 	if (goal <= x)
452 		wprintw(window, " ");
453 	for (; goal > x; ++x)
454 		wprintw(window, " ");
455 
456 	wprintw(window, "%s", vl->parent->alt);
457 }
458 
459 /*
460  * Core part of the rendering.  It prints a vline starting from the
461  * current cursor position.  Printing a vline consists of skipping
462  * `off' columns (for olivetti-mode), print the correct prefix (which
463  * may be the emoji in case of emojified links-lines), printing the
464  * text itself, filling until width - off and filling off columns
465  * again.
466  */
467 static void
468 print_vline(int off, int width, WINDOW *window, struct vline *vl)
469 {
470 	/*
471 	 * Believe me or not, I've seen emoji ten code points long!
472 	 * That means, to stay large, 4*10 bytes + NUL.
473 	 */
474 	char emojibuf[41] = {0};
475 	const char *text, *prfx;
476 	struct line_face *f;
477 	int i, left, x, y;
478 
479 	f = &line_faces[vl->parent->type];
480 
481 	/* unused, set by getyx */
482 	(void)y;
483 
484 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
485 
486 	wattr_on(window, body_face.left, NULL);
487 	for (i = 0; i < off; i++)
488 		waddch(window, ' ');
489 	wattr_off(window, body_face.left, NULL);
490 
491 	wattr_on(window, f->prefix, NULL);
492 	wprintw(window, "%s", prfx);
493 	wattr_off(window, f->prefix, NULL);
494 
495 	wattr_on(window, f->text, NULL);
496 	wprintw(window, "%s", text);
497 	print_vline_descr(width, window, vl);
498 	wattr_off(window, f->text, NULL);
499 
500 	getyx(window, y, x);
501 
502 	left = width - x;
503 
504 	wattr_on(window, f->trail, NULL);
505 	for (i = 0; i < left - off; ++i)
506 		waddch(window, ' ');
507 	wattr_off(window, f->trail, NULL);
508 
509 	wattr_on(window, body_face.right, NULL);
510 	for (i = 0; i < off; i++)
511 		waddch(window, ' ');
512 	wattr_off(window, body_face.right, NULL);
513 
514 }
515 
516 static void
517 redraw_tabline(void)
518 {
519 	struct tab	*tab;
520 	size_t		 toskip, ots, tabwidth, space, x;
521 	int		 current, y, truncated, pair;
522 	const char	*title;
523 	char		 buf[25];
524 
525 	x = 0;
526 
527 	/* unused, but setted by a getyx */
528 	(void)y;
529 
530 	tabwidth = sizeof(buf)+1;
531 	space = COLS-2;
532 
533 	toskip = 0;
534 	TAILQ_FOREACH(tab, &tabshead, tabs) {
535 		toskip++;
536 		if (tab == current_tab)
537 			break;
538 	}
539 
540 	if (toskip * tabwidth < space)
541 		toskip = 0;
542 	else {
543 		ots = toskip;
544 		toskip--;
545 		while (toskip != 0 &&
546 		    (ots - toskip+1) * tabwidth < space)
547 			toskip--;
548 	}
549 
550 	werase(tabline);
551 	wattr_on(tabline, tab_face.background, NULL);
552 	wprintw(tabline, toskip == 0 ? " " : "<");
553 	wattr_off(tabline, tab_face.background, NULL);
554 
555 	truncated = 0;
556 	TAILQ_FOREACH(tab, &tabshead, tabs) {
557 		if (truncated)
558 			break;
559 		if (toskip != 0) {
560 			toskip--;
561 			continue;
562 		}
563 
564 		getyx(tabline, y, x);
565 		if (x + sizeof(buf)+2 >= (size_t)COLS)
566 			truncated = 1;
567 
568 		current = tab == current_tab;
569 
570 		if (*(title = tab->buffer.page.title) == '\0')
571 			title = tab->hist_cur->h;
572 
573 		if (tab->flags & TAB_URGENT)
574 			strlcpy(buf, "!", sizeof(buf));
575 		else
576 			strlcpy(buf, " ", sizeof(buf));
577 
578 		if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
579 			/* truncation happens */
580 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
581 		} else {
582 			/* pad with spaces */
583 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
584 				/* nop */ ;
585 		}
586 
587 		pair = current ? tab_face.current : tab_face.tab;
588 		wattr_on(tabline, pair, NULL);
589 		wprintw(tabline, "%s", buf);
590 		wattr_off(tabline, pair, NULL);
591 
592 		wattr_on(tabline, tab_face.background, NULL);
593 		if (TAILQ_NEXT(tab, tabs) != NULL)
594 			wprintw(tabline, "┃");
595 		wattr_off(tabline, tab_face.background, NULL);
596 	}
597 
598 	wattr_on(tabline, tab_face.background, NULL);
599 	for (; x < (size_t)COLS; ++x)
600 		waddch(tabline, ' ');
601 	if (truncated)
602 		mvwprintw(tabline, 0, COLS-1, ">");
603 	wattr_off(tabline, tab_face.background, NULL);
604 }
605 
606 /*
607  * Compute the first visible line around vl.  Try to search forward
608  * until the end of the buffer; if a visible line is not found, search
609  * backward.  Return NULL if no viable line was found.
610  */
611 struct vline *
612 adjust_line(struct vline *vl, struct buffer *buffer)
613 {
614 	struct vline *t;
615 
616 	if (vl == NULL)
617 		return NULL;
618 
619 	if (!(vl->parent->flags & L_HIDDEN))
620 		return vl;
621 
622 	/* search forward */
623 	for (t = vl;
624 	     t != NULL && t->parent->flags & L_HIDDEN;
625 	     t = TAILQ_NEXT(t, vlines))
626 		;		/* nop */
627 
628 	if (t != NULL)
629 		return t;
630 
631 	/* search backward */
632 	for (t = vl;
633 	     t != NULL && t->parent->flags & L_HIDDEN;
634 	     t = TAILQ_PREV(t, vhead, vlines))
635 		;		/* nop */
636 
637 	return t;
638 }
639 
640 static void
641 redraw_window(WINDOW *win, int off, int height, int width,
642     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(off, 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_download(void)
715 {
716 	redraw_window(download, 0, download_lines, COLS, &downloadwin);
717 }
718 
719 static void
720 redraw_help(void)
721 {
722 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
723 }
724 
725 static void
726 redraw_body(struct tab *tab)
727 {
728 	static struct tab *last_tab;
729 
730 	if (last_tab != tab)
731 		tab->buffer.force_redraw =1;
732 	last_tab = tab;
733 
734 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
735 }
736 
737 static inline char
738 trust_status_char(enum trust_state ts)
739 {
740 	switch (ts) {
741 	case TS_UNKNOWN:	return '-';
742 	case TS_UNTRUSTED:	return '!';
743 	case TS_TEMP_TRUSTED:	return '!';
744 	case TS_TRUSTED:	return 'v';
745 	case TS_VERIFIED:	return 'V';
746 	default:		return 'X';
747 	}
748 }
749 
750 static void
751 redraw_modeline(struct tab *tab)
752 {
753 	struct buffer	*buffer;
754 	double		 pct;
755 	int		 x, y, max_x, max_y;
756 	const char	*mode;
757 	const char	*spin = "-\\|/";
758 
759 	buffer = current_buffer();
760 	mode = buffer->page.name;
761 
762 	werase(modeline);
763 	wattr_on(modeline, modeline_face.background, NULL);
764 	wmove(modeline, 0, 0);
765 
766 	wprintw(modeline, "-%c%c %s ",
767 	    spin[tab->loading_anim_step],
768 	    trust_status_char(tab->trust),
769 	    mode == NULL ? "(none)" : mode);
770 
771 	pct = (buffer->line_off + buffer->curs_y) * 100.0
772 		/ buffer->line_max;
773 
774 	if (buffer->line_max <= (size_t)body_lines)
775 		wprintw(modeline, "All ");
776 	else if (buffer->line_off == 0)
777 		wprintw(modeline, "Top ");
778 	else if (buffer->line_off + body_lines >= buffer->line_max)
779 		wprintw(modeline, "Bottom ");
780 	else
781 		wprintw(modeline, "%.0f%% ", pct);
782 
783 	wprintw(modeline, "%d/%d %s ",
784 	    buffer->line_off + buffer->curs_y,
785 	    buffer->line_max,
786 	    tab->hist_cur->h);
787 
788 	getyx(modeline, y, x);
789 	getmaxyx(modeline, max_y, max_x);
790 
791 	(void)y;
792 	(void)max_y;
793 
794 	for (; x < max_x; ++x)
795 		waddstr(modeline, "-");
796 
797 	wattr_off(modeline, modeline_face.background, NULL);
798 }
799 
800 static void
801 redraw_minibuffer(void)
802 {
803 	wattr_on(echoarea, minibuffer_face.background, NULL);
804 	werase(echoarea);
805 
806 	if (in_minibuffer)
807 		do_redraw_minibuffer();
808 	else
809 		do_redraw_echoarea();
810 
811 	if (in_minibuffer == MB_COMPREAD)
812 		do_redraw_minibuffer_compl();
813 
814 	wattr_off(echoarea, minibuffer_face.background, NULL);
815 }
816 
817 static void
818 do_redraw_echoarea(void)
819 {
820 	struct vline *vl;
821 
822 	if (ministate.curmesg != NULL)
823 		wprintw(echoarea, "%s", ministate.curmesg);
824 	else if (*keybuf != '\0')
825 		waddstr(echoarea, keybuf);
826 	else {
827 		/* If nothing else, show the URL at point */
828 		vl = current_tab->buffer.current_line;
829 		if (vl != NULL && vl->parent->type == LINE_LINK)
830 			waddstr(echoarea, vl->parent->alt);
831 	}
832 }
833 
834 static void
835 do_redraw_minibuffer(void)
836 {
837 	struct buffer	*cmplbuf, *buffer;
838 	size_t		 off_y, off_x = 0;
839 	const char	*start, *c;
840 
841 	cmplbuf = &ministate.compl.buffer;
842 	buffer = &ministate.buffer;
843 	(void)off_y;		/* unused, set by getyx */
844 
845 	wmove(echoarea, 0, 0);
846 
847 	if (in_minibuffer == MB_COMPREAD)
848 		wprintw(echoarea, "(%2d) ",
849 		    cmplbuf->line_max);
850 
851 	wprintw(echoarea, "%s", ministate.prompt);
852 	if (ministate.hist_cur != NULL)
853 		wprintw(echoarea, "(%zu/%zu) ",
854 		    ministate.hist_off + 1,
855 		    ministate.history->len);
856 
857 	getyx(echoarea, off_y, off_x);
858 
859 	start = ministate.hist_cur != NULL
860 		? ministate.hist_cur->h
861 		: ministate.buf;
862 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
863 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
864 		start = utf8_next_cp(start);
865 	}
866 
867 	waddstr(echoarea, start);
868 
869 	if (ministate.curmesg != NULL)
870 		wprintw(echoarea, " [%s]", ministate.curmesg);
871 
872 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
873 }
874 
875 static void
876 do_redraw_minibuffer_compl(void)
877 {
878 	redraw_window(minibuffer, 0, 10, COLS,
879 	    &ministate.compl.buffer);
880 }
881 
882 /*
883  * Place the cursor in the right ncurses window.  If soft is 1, use
884  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
885  * wrefresh.
886  */
887 static void
888 place_cursor(int soft)
889 {
890 	int (*touch)(WINDOW *);
891 
892 	if (soft)
893 		touch = wnoutrefresh;
894 	else
895 		touch = wrefresh;
896 
897 	if (in_minibuffer) {
898 		if (side_window & SIDE_WINDOW_LEFT)
899 			touch(help);
900 		if (side_window & SIDE_WINDOW_BOTTOM)
901 			touch(download);
902 		touch(body);
903 		touch(echoarea);
904 	} else if (in_side_window & SIDE_WINDOW_LEFT) {
905 		touch(body);
906 		touch(echoarea);
907                 if (in_side_window & SIDE_WINDOW_BOTTOM)
908 			touch(download);
909 		touch(help);
910 	} else if (in_side_window & SIDE_WINDOW_BOTTOM) {
911 		touch(body);
912 		touch(echoarea);
913 		if (in_side_window & SIDE_WINDOW_LEFT)
914 			touch(help);
915 		touch(download);
916 	} else {
917 		if (side_window & SIDE_WINDOW_LEFT)
918 			touch(help);
919 		if (side_window & SIDE_WINDOW_BOTTOM)
920 			touch(download);
921 		touch(echoarea);
922 		touch(body);
923 	}
924 }
925 
926 static void
927 redraw_tab(struct tab *tab)
928 {
929 	if (too_small)
930 		return;
931 
932 	if (side_window & SIDE_WINDOW_LEFT) {
933 		redraw_help();
934 		wnoutrefresh(help);
935 	}
936 
937 	if (side_window & SIDE_WINDOW_BOTTOM) {
938 		redraw_download();
939 		wnoutrefresh(download);
940 	}
941 
942 	if (show_tab_bar)
943 		redraw_tabline();
944 
945 	redraw_body(tab);
946 	redraw_modeline(tab);
947 	redraw_minibuffer();
948 
949 	wnoutrefresh(tabline);
950 	wnoutrefresh(modeline);
951 
952 	if (in_minibuffer == MB_COMPREAD)
953 		wnoutrefresh(minibuffer);
954 
955 	place_cursor(1);
956 
957 	doupdate();
958 
959 	if (set_title)
960 		dprintf(1, "\033]2;%s - Telescope\a",
961 		    current_tab->buffer.page.title);
962 }
963 
964 void
965 start_loading_anim(struct tab *tab)
966 {
967 	if (tab->loading_anim)
968 		return;
969 	tab->loading_anim = 1;
970 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
971 	evtimer_add(&tab->loadingev, &loadingev_timer);
972 }
973 
974 static void
975 update_loading_anim(int fd, short ev, void *d)
976 {
977 	struct tab	*tab = d;
978 
979 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
980 
981 	if (tab == current_tab) {
982 		redraw_modeline(tab);
983 		wrefresh(modeline);
984 		wrefresh(body);
985 		if (in_minibuffer)
986 			wrefresh(echoarea);
987 	}
988 
989 	evtimer_add(&tab->loadingev, &loadingev_timer);
990 }
991 
992 static void
993 stop_loading_anim(struct tab *tab)
994 {
995 	if (!tab->loading_anim)
996 		return;
997 	evtimer_del(&tab->loadingev);
998 	tab->loading_anim = 0;
999 	tab->loading_anim_step = 0;
1000 
1001 	if (tab != current_tab)
1002 		return;
1003 
1004 	redraw_modeline(tab);
1005 
1006 	wrefresh(modeline);
1007 	wrefresh(body);
1008 	if (in_minibuffer)
1009 		wrefresh(echoarea);
1010 }
1011 
1012 int
1013 ui_print_colors(void)
1014 {
1015 	int colors = 0, pairs = 0, can_change = 0;
1016 	int columns = 16, lines, color, i, j;
1017 
1018 	initscr();
1019 	if (has_colors()) {
1020 		start_color();
1021 		use_default_colors();
1022 
1023 		colors = COLORS;
1024 		pairs = COLOR_PAIRS;
1025 		can_change = can_change_color();
1026 	}
1027 	endwin();
1028 
1029 	printf("Term info:\n");
1030 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1031 	    getenv("TERM"), colors, pairs, can_change);
1032 	printf("\n");
1033 
1034 	if (colors == 0) {
1035 		printf("No color support\n");
1036 		return 0;
1037 	}
1038 
1039 	printf("Available colors:\n\n");
1040 	lines = (colors - 1) / columns + 1;
1041 	color = 0;
1042 	for (i = 0; i < lines; ++i) {
1043 		for (j = 0; j < columns; ++j, ++color) {
1044 			printf("\033[0;38;5;%dm %03d", color, color);
1045 		}
1046 		printf("\n");
1047 	}
1048 
1049 	printf("\033[0m");
1050 	fflush(stdout);
1051 	return 0;
1052 }
1053 
1054 int
1055 ui_init()
1056 {
1057 	setlocale(LC_ALL, "");
1058 
1059 	if (TAILQ_EMPTY(&global_map.m)) {
1060 		fprintf(stderr, "no keys defined!\n");
1061 		return 0;
1062 	}
1063 
1064 	minibuffer_init();
1065 
1066 	/* initialize download window */
1067 	TAILQ_INIT(&downloadwin.head);
1068 	TAILQ_INIT(&downloadwin.page.head);
1069 
1070 	/* initialize help window */
1071 	TAILQ_INIT(&helpwin.head);
1072 	TAILQ_INIT(&helpwin.page.head);
1073 
1074 	base_map = &global_map;
1075 	current_map = &global_map;
1076 
1077 	initscr();
1078 
1079 	if (enable_colors) {
1080 		if (has_colors()) {
1081 			start_color();
1082 			use_default_colors();
1083 		} else
1084 			enable_colors = 0;
1085 	}
1086 
1087 	config_apply_style();
1088 
1089 	raw();
1090 	noecho();
1091 	nonl();
1092 	intrflush(stdscr, FALSE);
1093 
1094 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1095 		return 0;
1096 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1097 		return 0;
1098 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1099 		return 0;
1100 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1101 		return 0;
1102 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1103 		return 0;
1104 	if ((download = newwin(1, 1, 0, 0)) == NULL)
1105 		return 0;
1106 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1107 		return 0;
1108 
1109 	wbkgd(body, body_face.body);
1110 	wbkgd(download, download_face.background);
1111 	wbkgd(echoarea, minibuffer_face.background);
1112 
1113 	update_x_offset();
1114 
1115 	keypad(body, TRUE);
1116 	scrollok(body, FALSE);
1117 
1118 	/* non-blocking input */
1119 	wtimeout(body, 0);
1120 	wtimeout(help, 0);
1121 
1122 	mvwprintw(body, 0, 0, "");
1123 
1124 	return 1;
1125 }
1126 
1127 void
1128 ui_main_loop(void)
1129 {
1130 	evtimer_set(&resizeev, handle_resize, NULL);
1131 
1132 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1133 	event_add(&stdioev, NULL);
1134 
1135 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1136 	signal_add(&winchev, NULL);
1137 
1138 	switch_to_tab(current_tab);
1139 	rearrange_windows();
1140 }
1141 
1142 void
1143 ui_on_tab_loaded(struct tab *tab)
1144 {
1145 	stop_loading_anim(tab);
1146 	message("Loaded %s", tab->hist_cur->h);
1147 
1148 	if (show_tab_bar)
1149 		redraw_tabline();
1150 
1151 	wrefresh(tabline);
1152 	place_cursor(0);
1153 }
1154 
1155 void
1156 ui_on_tab_refresh(struct tab *tab)
1157 {
1158 	wrap_page(&tab->buffer, body_cols);
1159 	if (tab == current_tab)
1160 		redraw_tab(tab);
1161 	else
1162 		tab->flags |= TAB_URGENT;
1163 }
1164 
1165 void
1166 ui_on_download_refresh(void)
1167 {
1168 	if (side_window & SIDE_WINDOW_BOTTOM) {
1169 		recompute_downloads();
1170 		redraw_tab(current_tab);
1171 	}
1172 }
1173 
1174 const char *
1175 ui_keyname(int k)
1176 {
1177 	return keyname(k);
1178 }
1179 
1180 void
1181 ui_toggle_side_window(int kind)
1182 {
1183 	if (in_side_window & kind)
1184 		ui_other_window();
1185 
1186 	side_window ^= kind;
1187 	if (side_window & SIDE_WINDOW_LEFT)
1188 		recompute_help();
1189 	if (side_window & SIDE_WINDOW_BOTTOM)
1190 		recompute_downloads();
1191 
1192 	/*
1193 	 * ugly hack, but otherwise the window doesn't get updated
1194 	 * until I call rearrange_windows a second time (e.g. via
1195 	 * C-l).  I will be happy to know why something like this is
1196 	 * needed.
1197 	 */
1198 	rearrange_windows();
1199 	rearrange_windows();
1200 }
1201 
1202 void
1203 ui_show_downloads_pane(void)
1204 {
1205 	if (!(side_window & SIDE_WINDOW_BOTTOM))
1206 		ui_toggle_side_window(SIDE_WINDOW_BOTTOM);
1207 }
1208 
1209 void
1210 ui_schedule_redraw(void)
1211 {
1212 	should_rearrange_windows = 1;
1213 }
1214 
1215 void
1216 ui_require_input(struct tab *tab, int hide, int proto)
1217 {
1218 	void (*fn)(void);
1219 
1220 	if (proto == PROTO_GEMINI)
1221 		fn = ir_select_gemini;
1222 	else if (proto == PROTO_GOPHER)
1223 		fn = ir_select_gopher;
1224 	else
1225 		abort();
1226 
1227 	/* TODO: hard-switching to another tab is ugly */
1228 	switch_to_tab(tab);
1229 
1230 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1231 	    &ir_history, NULL, NULL);
1232 	strlcpy(ministate.prompt, "Input required: ",
1233 	    sizeof(ministate.prompt));
1234 	redraw_tab(tab);
1235 }
1236 
1237 void
1238 ui_after_message_hook(void)
1239 {
1240 	redraw_minibuffer();
1241 	place_cursor(0);
1242 }
1243 
1244 void
1245 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1246     struct tab *data)
1247 {
1248 	yornp(prompt, fn, data);
1249 	redraw_tab(current_tab);
1250 }
1251 
1252 void
1253 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1254     struct tab *data, const char *input)
1255 {
1256 	minibuffer_read(prompt, fn, data);
1257 
1258 	if (input != NULL) {
1259 		strlcpy(ministate.buf, input, sizeof(ministate.buf));
1260 		cmd_move_end_of_line(&ministate.buffer);
1261 	}
1262 
1263 	redraw_tab(current_tab);
1264 }
1265 
1266 void
1267 ui_other_window(void)
1268 {
1269 	if (in_side_window & SIDE_WINDOW_LEFT &&
1270 	    side_window & SIDE_WINDOW_BOTTOM)
1271 		in_side_window = SIDE_WINDOW_BOTTOM;
1272 	else if (in_side_window)
1273 		in_side_window = 0;
1274 	else if (!in_side_window && side_window & SIDE_WINDOW_LEFT)
1275 		in_side_window = SIDE_WINDOW_LEFT;
1276 	else if (!in_side_window && side_window)
1277 		in_side_window = SIDE_WINDOW_BOTTOM;
1278 	else
1279 		message("No other window to select");
1280 }
1281 
1282 void
1283 ui_suspend(void)
1284 {
1285 	endwin();
1286 
1287 	kill(getpid(), SIGSTOP);
1288 
1289 	refresh();
1290 	clear();
1291 	rearrange_windows();
1292 }
1293 
1294 void
1295 ui_end(void)
1296 {
1297 	endwin();
1298 }