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_help(void);
65 static void		 redraw_body(struct tab*);
66 static void		 redraw_modeline(struct tab*);
67 static void		 redraw_minibuffer(void);
68 static void		 do_redraw_echoarea(void);
69 static void		 do_redraw_minibuffer(void);
70 static void		 do_redraw_minibuffer_compl(void);
71 static void		 place_cursor(int);
72 static void		 redraw_tab(struct tab*);
73 static void		 update_loading_anim(int, short, void*);
74 static void		 stop_loading_anim(struct tab*);
75 
76 static int		 should_rearrange_windows;
77 static int		 show_tab_bar;
78 static int		 too_small;
79 static int		 x_offset;
80 
81 struct thiskey	 thiskey;
82 struct tab	*current_tab;
83 
84 static struct event	resizeev;
85 static struct timeval	resize_timer = { 0, 250000 };
86 
87 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
88 
89 int			 body_lines, body_cols;
90 
91 static WINDOW		*help;
92 /* not static so we can see them from help.c */
93 struct buffer		 helpwin;
94 int			 help_lines, help_cols;
95 
96 static int		 side_window;
97 static int		 in_side_window;
98 
99 static struct timeval	loadingev_timer = { 0, 250000 };
100 
101 static char	keybuf[64];
102 
103 /* XXX: don't forget to init these in main() */
104 struct kmap global_map,
105 	minibuffer_map,
106 	*current_map,
107 	*base_map;
108 
109 static inline void
110 update_x_offset(void)
111 {
112 	if (olivetti_mode && fill_column < body_cols)
113 		x_offset = (body_cols - fill_column)/2;
114 	else
115 		x_offset = 0;
116 }
117 
118 void
119 save_excursion(struct excursion *place, struct buffer *buffer)
120 {
121 	place->curs_x = buffer->curs_x;
122 	place->curs_y = buffer->curs_y;
123 	place->line_off = buffer->line_off;
124 	place->top_line = buffer->top_line;
125 	place->current_line = buffer->current_line;
126 	place->cpoff = buffer->cpoff;
127 }
128 
129 void
130 restore_excursion(struct excursion *place, struct buffer *buffer)
131 {
132 	buffer->curs_x = place->curs_x;
133 	buffer->curs_y = place->curs_y;
134 	buffer->line_off = place->line_off;
135 	buffer->top_line = place->top_line;
136 	buffer->current_line = place->current_line;
137 	buffer->cpoff = place->cpoff;
138 }
139 
140 static void
141 restore_curs_x(struct buffer *buffer)
142 {
143 	struct vline	*vl;
144 	const char	*prfx, *text;
145 
146 	vl = buffer->current_line;
147 	if (vl == NULL || vl->line == NULL)
148 		buffer->curs_x = buffer->cpoff = 0;
149 	else if (vl->parent->data != NULL) {
150 		text = vl->parent->data;
151 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
152 	} else
153 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
154 
155 	buffer->curs_x += x_offset;
156 
157 	if (vl == NULL)
158 		return;
159 
160 	if (vl->parent->data != NULL)
161 		buffer->curs_x += utf8_swidth_between(vl->parent->line,
162 		    vl->parent->data);
163 	else {
164 		prfx = line_prefixes[vl->parent->type].prfx1;
165 		buffer->curs_x += utf8_swidth(prfx);
166 	}
167 }
168 
169 void
170 global_key_unbound(void)
171 {
172 	message("%s is undefined", keybuf);
173 }
174 
175 struct buffer *
176 current_buffer(void)
177 {
178 	if (in_minibuffer)
179 		return &ministate.buffer;
180 	if (in_side_window)
181 		return &helpwin;
182 	return &current_tab->buffer;
183 }
184 
185 static int
186 readkey(void)
187 {
188 	uint32_t state = 0;
189 
190 	if ((thiskey.key = wgetch(body)) == ERR)
191 		return 0;
192 
193 	thiskey.meta = thiskey.key == 27;
194 	if (thiskey.meta) {
195 		thiskey.key = wgetch(body);
196 		if (thiskey.key == ERR || thiskey.key == 27) {
197 			thiskey.meta = 0;
198 			thiskey.key = 27;
199 		}
200 	}
201 
202 	thiskey.cp = 0;
203 
204 	if ((unsigned int)thiskey.key >= UINT8_MAX)
205 		return 1;
206 
207 	while (1) {
208 		if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
209 			break;
210 		if ((thiskey.key = wgetch(body)) == ERR) {
211 			message("Error decoding user input");
212 			return 0;
213 		}
214 	}
215 
216 	return 1;
217 }
218 
219 static void
220 dispatch_stdio(int fd, short ev, void *d)
221 {
222 	struct keymap	*k;
223 	const char	*keyname;
224 	char		 tmp[5] = {0};
225 
226 	/* TODO: schedule a redraw? */
227 	if (too_small)
228 		return;
229 
230 	if (!readkey())
231 		return;
232 
233 	if (keybuf[0] != '\0')
234 		strlcat(keybuf, " ", sizeof(keybuf));
235 	if (thiskey.meta)
236 		strlcat(keybuf, "M-", sizeof(keybuf));
237 	if (thiskey.cp != 0) {
238 		utf8_encode(thiskey.cp, tmp);
239 		strlcat(keybuf, tmp, sizeof(keybuf));
240 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
241 		strlcat(keybuf, keyname, sizeof(keybuf));
242 	} else {
243 		tmp[0] = thiskey.key;
244 		strlcat(keybuf, tmp, sizeof(keybuf));
245 	}
246 
247 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
248 		if (k->meta == thiskey.meta &&
249 		    k->key == thiskey.key) {
250 			if (k->fn == NULL)
251 				current_map = &k->map;
252 			else {
253 				current_map = base_map;
254 				strlcpy(keybuf, "", sizeof(keybuf));
255 				k->fn(current_buffer());
256 			}
257 			goto done;
258 		}
259 	}
260 
261 	if (current_map->unhandled_input != NULL)
262 		current_map->unhandled_input();
263 	else
264 		global_key_unbound();
265 
266 	strlcpy(keybuf, "", sizeof(keybuf));
267 	current_map = base_map;
268 
269 done:
270 	if (side_window)
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 
314 	should_rearrange_windows = 0;
315 	show_tab_bar = should_show_tab_bar();
316 
317 	lines = LINES;
318 
319 	if ((too_small = lines < 15)) {
320 		erase();
321 		printw("Window too small.");
322 		refresh();
323 		return;
324 	}
325 
326 	/* move and resize the windows, in reverse order! */
327 
328 	if (in_minibuffer == MB_COMPREAD) {
329 		mvwin(minibuffer, lines-10, 0);
330 		wresize(minibuffer, 10, COLS);
331 		lines -= 10;
332 
333 		wrap_page(&ministate.compl.buffer, COLS);
334 	}
335 
336 	mvwin(echoarea, --lines, 0);
337 	wresize(echoarea, 1, COLS);
338 
339 	mvwin(modeline, --lines, 0);
340 	wresize(modeline, 1, COLS);
341 
342 	body_lines = show_tab_bar ? --lines : lines;
343 	body_cols = COLS;
344 
345 	/*
346 	 * Here we make the assumption that show_tab_bar is either 0
347 	 * or 1, and reuse that as argument to mvwin.
348 	 */
349 	if (side_window) {
350 		help_cols = 0.3 * COLS;
351 		help_lines = lines;
352 		mvwin(help, show_tab_bar, 0);
353 		wresize(help, help_lines, help_cols);
354 
355 		wrap_page(&helpwin, help_cols);
356 
357 		body_cols = COLS - help_cols - 1;
358 		mvwin(body, show_tab_bar, help_cols);
359 	} else
360 		mvwin(body, show_tab_bar, 0);
361 
362 	update_x_offset();
363 	wresize(body, body_lines, body_cols);
364 
365 	if (show_tab_bar)
366 		wresize(tabline, 1, COLS);
367 
368 	wrap_page(&current_tab->buffer, body_cols);
369 	redraw_tab(current_tab);
370 }
371 
372 static void
373 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
374     const char **prfx_ret, const char **text_ret)
375 {
376 	int type, i, cont, width;
377 	char *space, *t;
378 
379 	if ((*text_ret = vl->line) == NULL)
380 		*text_ret = "";
381 
382 	cont = vl->flags & L_CONTINUATION;
383 	type = vl->parent->type;
384 	if (!cont)
385 		*prfx_ret = line_prefixes[type].prfx1;
386 	else
387 		*prfx_ret = line_prefixes[type].prfx2;
388 
389 	space = vl->parent->data;
390 	if (!emojify_link || type != LINE_LINK || space == NULL)
391 		return;
392 
393 	if (cont) {
394 		memset(buf, 0, len);
395 		width = utf8_swidth_between(vl->parent->line, space);
396 		for (i = 0; i < width + 1; ++i)
397 			strlcat(buf, " ", len);
398 	} else {
399 		strlcpy(buf, *text_ret, len);
400 		if ((t = strchr(buf, ' ')) != NULL)
401 			*t = '\0';
402 		strlcat(buf, " ", len);
403 
404 		/* skip the emoji */
405                 *text_ret += (space - vl->parent->line) + 1;
406 	}
407 
408 	*prfx_ret = buf;
409 }
410 
411 static inline void
412 print_vline_descr(int width, WINDOW *window, struct vline *vl)
413 {
414 	int x, y, goal;
415 
416 	if (vl->parent->type != LINE_COMPL &&
417 	    vl->parent->type != LINE_COMPL_CURRENT &&
418 	    vl->parent->type != LINE_HELP)
419 		return;
420 
421 	if (vl->parent->alt == NULL)
422 		return;
423 
424 	(void)y;
425 	getyx(window, y, x);
426 
427 	if (vl->parent->type == LINE_HELP)
428 		goal = 8;
429 	else
430 		goal = width/2;
431 
432 	if (goal <= x)
433 		wprintw(window, " ");
434 	for (; goal > x; ++x)
435 		wprintw(window, " ");
436 
437 	wprintw(window, "%s", vl->parent->alt);
438 }
439 
440 /*
441  * Core part of the rendering.  It prints a vline starting from the
442  * current cursor position.  Printing a vline consists of skipping
443  * `off' columns (for olivetti-mode), print the correct prefix (which
444  * may be the emoji in case of emojified links-lines), printing the
445  * text itself, filling until width - off and filling off columns
446  * again.
447  */
448 static void
449 print_vline(int off, int width, WINDOW *window, struct vline *vl)
450 {
451 	/*
452 	 * Believe me or not, I've seen emoji ten code points long!
453 	 * That means, to stay large, 4*10 bytes + NUL.
454 	 */
455 	char emojibuf[41] = {0};
456 	const char *text, *prfx;
457 	struct line_face *f;
458 	int i, left, x, y;
459 
460 	f = &line_faces[vl->parent->type];
461 
462 	/* unused, set by getyx */
463 	(void)y;
464 
465 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
466 
467 	wattr_on(window, body_face.left, NULL);
468 	for (i = 0; i < off; i++)
469 		waddch(window, ' ');
470 	wattr_off(window, body_face.left, NULL);
471 
472 	wattr_on(window, f->prefix, NULL);
473 	wprintw(window, "%s", prfx);
474 	wattr_off(window, f->prefix, NULL);
475 
476 	wattr_on(window, f->text, NULL);
477 	wprintw(window, "%s", text);
478 	print_vline_descr(width, window, vl);
479 	wattr_off(window, f->text, NULL);
480 
481 	getyx(window, y, x);
482 
483 	left = width - x;
484 
485 	wattr_on(window, f->trail, NULL);
486 	for (i = 0; i < left - off; ++i)
487 		waddch(window, ' ');
488 	wattr_off(window, f->trail, NULL);
489 
490 	wattr_on(window, body_face.right, NULL);
491 	for (i = 0; i < off; i++)
492 		waddch(window, ' ');
493 	wattr_off(window, body_face.right, NULL);
494 
495 }
496 
497 static void
498 redraw_tabline(void)
499 {
500 	struct tab	*tab;
501 	size_t		 toskip, ots, tabwidth, space, x;
502 	int		 current, y, truncated, pair;
503 	const char	*title;
504 	char		 buf[25];
505 
506 	x = 0;
507 
508 	/* unused, but setted by a getyx */
509 	(void)y;
510 
511 	tabwidth = sizeof(buf)+1;
512 	space = COLS-2;
513 
514 	toskip = 0;
515 	TAILQ_FOREACH(tab, &tabshead, tabs) {
516 		toskip++;
517 		if (tab == current_tab)
518 			break;
519 	}
520 
521 	if (toskip * tabwidth < space)
522 		toskip = 0;
523 	else {
524 		ots = toskip;
525 		toskip--;
526                 while (toskip != 0 &&
527 		    (ots - toskip+1) * tabwidth < space)
528 			toskip--;
529 	}
530 
531 	werase(tabline);
532 	wattr_on(tabline, tab_face.background, NULL);
533 	wprintw(tabline, toskip == 0 ? " " : "<");
534 	wattr_off(tabline, tab_face.background, NULL);
535 
536 	truncated = 0;
537 	TAILQ_FOREACH(tab, &tabshead, tabs) {
538 		if (truncated)
539 			break;
540 		if (toskip != 0) {
541 			toskip--;
542 			continue;
543 		}
544 
545 		getyx(tabline, y, x);
546 		if (x + sizeof(buf)+2 >= (size_t)COLS)
547 			truncated = 1;
548 
549 		current = tab == current_tab;
550 
551 		if (*(title = tab->buffer.page.title) == '\0')
552 			title = tab->hist_cur->h;
553 
554 		if (tab->flags & TAB_URGENT)
555 			strlcpy(buf, "!", sizeof(buf));
556 		else
557 			strlcpy(buf, " ", sizeof(buf));
558 
559                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
560 			/* truncation happens */
561 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
562 		} else {
563 			/* pad with spaces */
564 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
565 				/* nop */ ;
566 		}
567 
568 		pair = current ? tab_face.current : tab_face.tab;
569 		wattr_on(tabline, pair, NULL);
570 		wprintw(tabline, "%s", buf);
571 		wattr_off(tabline, pair, NULL);
572 
573 		wattr_on(tabline, tab_face.background, NULL);
574 		if (TAILQ_NEXT(tab, tabs) != NULL)
575 			wprintw(tabline, "┃");
576 		wattr_off(tabline, tab_face.background, NULL);
577 	}
578 
579 	wattr_on(tabline, tab_face.background, NULL);
580 	for (; x < (size_t)COLS; ++x)
581 		waddch(tabline, ' ');
582 	if (truncated)
583 		mvwprintw(tabline, 0, COLS-1, ">");
584 	wattr_off(tabline, tab_face.background, NULL);
585 }
586 
587 /*
588  * Compute the first visible line around vl.  Try to search forward
589  * until the end of the buffer; if a visible line is not found, search
590  * backward.  Return NULL if no viable line was found.
591  */
592 struct vline *
593 adjust_line(struct vline *vl, struct buffer *buffer)
594 {
595 	struct vline *t;
596 
597 	if (vl == NULL)
598 		return NULL;
599 
600 	if (!(vl->parent->flags & L_HIDDEN))
601 		return vl;
602 
603 	/* search forward */
604 	for (t = vl;
605 	     t != NULL && t->parent->flags & L_HIDDEN;
606 	     t = TAILQ_NEXT(t, vlines))
607 		;		/* nop */
608 
609 	if (t != NULL)
610 		return t;
611 
612 	/* search backward */
613 	for (t = vl;
614 	     t != NULL && t->parent->flags & L_HIDDEN;
615 	     t = TAILQ_PREV(t, vhead, vlines))
616 		;		/* nop */
617 
618 	return t;
619 }
620 
621 static void
622 redraw_window(WINDOW *win, int off, int height, int width,
623     struct buffer *buffer)
624 {
625 	struct vline	*vl;
626 	int		 l, onscreen;
627 
628 	restore_curs_x(buffer);
629 
630 	/*
631 	 * TODO: ignoring buffer->force_update and always
632 	 * re-rendering.  In theory we can recompute the y position
633 	 * without a re-render, and optimize here.  It's not the only
634 	 * optimisation possible here, wscrl wolud also be an
635 	 * interesting one.
636 	 */
637 
638 again:
639 	werase(win);
640 	buffer->curs_y = 0;
641 
642 	if (TAILQ_EMPTY(&buffer->head))
643 		goto end;
644 
645 	if (buffer->top_line == NULL)
646 		buffer->top_line = TAILQ_FIRST(&buffer->head);
647 
648 	buffer->top_line = adjust_line(buffer->top_line, buffer);
649 	if (buffer->top_line == NULL)
650 		goto end;
651 
652 	buffer->current_line = adjust_line(buffer->current_line, buffer);
653 
654 	l = 0;
655 	onscreen = 0;
656 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
657 		if (vl->parent->flags & L_HIDDEN)
658 			continue;
659 
660 		wmove(win, l, 0);
661 		print_vline(off, width, win, vl);
662 
663 		if (vl == buffer->current_line)
664 			onscreen = 1;
665 
666 		if (!onscreen)
667 			buffer->curs_y++;
668 
669 		l++;
670 		if (l == height)
671 			break;
672 	}
673 
674 	if (!onscreen) {
675 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
676 			if (vl == buffer->current_line)
677 				break;
678 			if (vl->parent->flags & L_HIDDEN)
679 				continue;
680 			buffer->line_off++;
681 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
682 		}
683 
684 		if (vl != NULL)
685 			goto again;
686 	}
687 
688 	buffer->last_line_off = buffer->line_off;
689 	buffer->force_redraw = 0;
690 end:
691 	wmove(win, buffer->curs_y, buffer->curs_x);
692 }
693 
694 static void
695 redraw_help(void)
696 {
697 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
698 }
699 
700 static void
701 redraw_body(struct tab *tab)
702 {
703 	static struct tab *last_tab;
704 
705 	if (last_tab != tab)
706 		tab->buffer.force_redraw =1;
707 	last_tab = tab;
708 
709 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
710 }
711 
712 static inline char
713 trust_status_char(enum trust_state ts)
714 {
715 	switch (ts) {
716 	case TS_UNKNOWN:	return '-';
717 	case TS_UNTRUSTED:	return '!';
718 	case TS_TEMP_TRUSTED:	return '!';
719 	case TS_TRUSTED:	return 'v';
720 	case TS_VERIFIED:	return 'V';
721 	default:		return 'X';
722 	}
723 }
724 
725 static void
726 redraw_modeline(struct tab *tab)
727 {
728 	struct buffer	*buffer;
729 	double		 pct;
730 	int		 x, y, max_x, max_y;
731 	const char	*mode;
732 	const char	*spin = "-\\|/";
733 
734 	buffer = current_buffer();
735 	mode = buffer->page.name;
736 
737 	werase(modeline);
738 	wattr_on(modeline, modeline_face.background, NULL);
739 	wmove(modeline, 0, 0);
740 
741 	wprintw(modeline, "-%c%c %s ",
742 	    spin[tab->loading_anim_step],
743 	    trust_status_char(tab->trust),
744 	    mode == NULL ? "(none)" : mode);
745 
746 	pct = (buffer->line_off + buffer->curs_y) * 100.0
747 		/ buffer->line_max;
748 
749 	if (buffer->line_max <= (size_t)body_lines)
750                 wprintw(modeline, "All ");
751 	else if (buffer->line_off == 0)
752                 wprintw(modeline, "Top ");
753 	else if (buffer->line_off + body_lines >= buffer->line_max)
754 		wprintw(modeline, "Bottom ");
755 	else
756 		wprintw(modeline, "%.0f%% ", pct);
757 
758 	wprintw(modeline, "%d/%d %s ",
759 	    buffer->line_off + buffer->curs_y,
760 	    buffer->line_max,
761 	    tab->hist_cur->h);
762 
763 	getyx(modeline, y, x);
764 	getmaxyx(modeline, max_y, max_x);
765 
766 	(void)y;
767 	(void)max_y;
768 
769 	for (; x < max_x; ++x)
770 		waddstr(modeline, "-");
771 
772 	wattr_off(modeline, modeline_face.background, NULL);
773 }
774 
775 static void
776 redraw_minibuffer(void)
777 {
778 	wattr_on(echoarea, minibuffer_face.background, NULL);
779 	werase(echoarea);
780 
781 	if (in_minibuffer)
782 		do_redraw_minibuffer();
783 	else
784 		do_redraw_echoarea();
785 
786 	if (in_minibuffer == MB_COMPREAD)
787 		do_redraw_minibuffer_compl();
788 
789 	wattr_off(echoarea, minibuffer_face.background, NULL);
790 }
791 
792 static void
793 do_redraw_echoarea(void)
794 {
795 	struct vline *vl;
796 
797 	if (ministate.curmesg != NULL)
798                 wprintw(echoarea, "%s", ministate.curmesg);
799 	else if (*keybuf != '\0')
800 		waddstr(echoarea, keybuf);
801 	else {
802 		/* If nothing else, show the URL at point */
803 		vl = current_tab->buffer.current_line;
804 		if (vl != NULL && vl->parent->type == LINE_LINK)
805 			waddstr(echoarea, vl->parent->alt);
806 	}
807 }
808 
809 static void
810 do_redraw_minibuffer(void)
811 {
812 	struct buffer	*cmplbuf, *buffer;
813 	size_t		 off_y, off_x = 0;
814 	const char	*start, *c;
815 
816 	cmplbuf = &ministate.compl.buffer;
817 	buffer = &ministate.buffer;
818 	(void)off_y;		/* unused, set by getyx */
819 
820 	wmove(echoarea, 0, 0);
821 
822 	if (in_minibuffer == MB_COMPREAD)
823 		wprintw(echoarea, "(%2d) ",
824 		    cmplbuf->line_max);
825 
826 	wprintw(echoarea, "%s", ministate.prompt);
827 	if (ministate.hist_cur != NULL)
828 		wprintw(echoarea, "(%zu/%zu) ",
829 		    ministate.hist_off + 1,
830 		    ministate.history->len);
831 
832 	getyx(echoarea, off_y, off_x);
833 
834 	start = ministate.hist_cur != NULL
835 		? ministate.hist_cur->h
836 		: ministate.buf;
837 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
838 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
839 		start = utf8_next_cp(start);
840 	}
841 
842 	waddstr(echoarea, start);
843 
844 	if (ministate.curmesg != NULL)
845 		wprintw(echoarea, " [%s]", ministate.curmesg);
846 
847 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
848 }
849 
850 static void
851 do_redraw_minibuffer_compl(void)
852 {
853 	redraw_window(minibuffer, 0, 10, COLS,
854 	    &ministate.compl.buffer);
855 }
856 
857 /*
858  * Place the cursor in the right ncurses window.  If soft is 1, use
859  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
860  * wrefresh.
861  */
862 static void
863 place_cursor(int soft)
864 {
865 	int (*touch)(WINDOW *);
866 
867 	if (soft)
868 		touch = wnoutrefresh;
869 	else
870 		touch = wrefresh;
871 
872 	if (in_minibuffer) {
873 		if (side_window)
874 			touch(help);
875 		touch(body);
876 		touch(echoarea);
877 	} else if (in_side_window) {
878 		touch(body);
879 		touch(echoarea);
880 		touch(help);
881 	} else {
882 		if (side_window)
883 			touch(help);
884 		touch(echoarea);
885 		touch(body);
886 	}
887 }
888 
889 static void
890 redraw_tab(struct tab *tab)
891 {
892 	if (too_small)
893 		return;
894 
895 	if (side_window) {
896 		redraw_help();
897 		wnoutrefresh(help);
898 	}
899 
900 	if (show_tab_bar)
901 		redraw_tabline();
902 
903 	redraw_body(tab);
904 	redraw_modeline(tab);
905 	redraw_minibuffer();
906 
907 	wnoutrefresh(tabline);
908 	wnoutrefresh(modeline);
909 
910 	if (in_minibuffer == MB_COMPREAD)
911 		wnoutrefresh(minibuffer);
912 
913 	place_cursor(1);
914 
915 	doupdate();
916 
917 	if (set_title)
918 		dprintf(1, "\033]2;%s - Telescope\a",
919 		    current_tab->buffer.page.title);
920 }
921 
922 void
923 start_loading_anim(struct tab *tab)
924 {
925 	if (tab->loading_anim)
926 		return;
927 	tab->loading_anim = 1;
928 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
929 	evtimer_add(&tab->loadingev, &loadingev_timer);
930 }
931 
932 static void
933 update_loading_anim(int fd, short ev, void *d)
934 {
935 	struct tab	*tab = d;
936 
937 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
938 
939 	if (tab == current_tab) {
940 		redraw_modeline(tab);
941 		wrefresh(modeline);
942 		wrefresh(body);
943 		if (in_minibuffer)
944 			wrefresh(echoarea);
945 	}
946 
947 	evtimer_add(&tab->loadingev, &loadingev_timer);
948 }
949 
950 static void
951 stop_loading_anim(struct tab *tab)
952 {
953 	if (!tab->loading_anim)
954 		return;
955 	evtimer_del(&tab->loadingev);
956 	tab->loading_anim = 0;
957 	tab->loading_anim_step = 0;
958 
959 	if (tab != current_tab)
960 		return;
961 
962 	redraw_modeline(tab);
963 
964 	wrefresh(modeline);
965 	wrefresh(body);
966 	if (in_minibuffer)
967 		wrefresh(echoarea);
968 }
969 
970 int
971 ui_print_colors(void)
972 {
973 	int colors = 0, pairs = 0, can_change = 0;
974 	int columns = 16, lines, color, i, j;
975 
976 	initscr();
977 	if (has_colors()) {
978 		start_color();
979 		use_default_colors();
980 
981 		colors = COLORS;
982 		pairs = COLOR_PAIRS;
983 		can_change = can_change_color();
984 	}
985 	endwin();
986 
987 	printf("Term info:\n");
988 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
989 	    getenv("TERM"), colors, pairs, can_change);
990 	printf("\n");
991 
992 	if (colors == 0) {
993 		printf("No color support\n");
994 		return 0;
995 	}
996 
997 	printf("Available colors:\n\n");
998 	lines = (colors - 1) / columns + 1;
999 	color = 0;
1000 	for (i = 0; i < lines; ++i) {
1001 		for (j = 0; j < columns; ++j, ++color) {
1002 			printf("\033[0;38;5;%dm %03d", color, color);
1003 		}
1004 		printf("\n");
1005 	}
1006 
1007 	printf("\033[0m");
1008 	fflush(stdout);
1009 	return 0;
1010 }
1011 
1012 int
1013 ui_init()
1014 {
1015 	setlocale(LC_ALL, "");
1016 
1017 	if (TAILQ_EMPTY(&global_map.m)) {
1018 		fprintf(stderr, "no keys defined!\n");
1019 		return 0;
1020 	}
1021 
1022 	minibuffer_init();
1023 
1024 	/* initialize help window */
1025 	TAILQ_INIT(&helpwin.head);
1026 	TAILQ_INIT(&helpwin.page.head);
1027 
1028 	base_map = &global_map;
1029 	current_map = &global_map;
1030 
1031 	initscr();
1032 
1033 	if (enable_colors) {
1034 		if (has_colors()) {
1035 			start_color();
1036 			use_default_colors();
1037 		} else
1038 			enable_colors = 0;
1039 	}
1040 
1041 	config_apply_style();
1042 
1043 	raw();
1044 	noecho();
1045 	nonl();
1046 	intrflush(stdscr, FALSE);
1047 
1048 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1049 		return 0;
1050 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1051 		return 0;
1052 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1053 		return 0;
1054 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1055 		return 0;
1056 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1057 		return 0;
1058 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1059 		return 0;
1060 
1061 	wbkgd(body, body_face.body);
1062 	wbkgd(echoarea, minibuffer_face.background);
1063 
1064 	update_x_offset();
1065 
1066 	keypad(body, TRUE);
1067 	scrollok(body, FALSE);
1068 
1069 	/* non-blocking input */
1070 	wtimeout(body, 0);
1071 	wtimeout(help, 0);
1072 
1073 	mvwprintw(body, 0, 0, "");
1074 
1075 	evtimer_set(&resizeev, handle_resize, NULL);
1076 
1077 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1078 	event_add(&stdioev, NULL);
1079 
1080 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1081 	signal_add(&winchev, NULL);
1082 
1083 	return 1;
1084 }
1085 
1086 void
1087 ui_main_loop(void)
1088 {
1089 	switch_to_tab(current_tab);
1090 	rearrange_windows();
1091 
1092 	event_dispatch();
1093 }
1094 
1095 void
1096 ui_on_tab_loaded(struct tab *tab)
1097 {
1098 	stop_loading_anim(tab);
1099 	message("Loaded %s", tab->hist_cur->h);
1100 
1101 	if (show_tab_bar)
1102 		redraw_tabline();
1103 
1104 	wrefresh(tabline);
1105 	place_cursor(0);
1106 }
1107 
1108 void
1109 ui_on_tab_refresh(struct tab *tab)
1110 {
1111 	wrap_page(&tab->buffer, body_cols);
1112 	if (tab == current_tab)
1113 		redraw_tab(tab);
1114 	else
1115 		tab->flags |= TAB_URGENT;
1116 }
1117 
1118 const char *
1119 ui_keyname(int k)
1120 {
1121 	return keyname(k);
1122 }
1123 
1124 void
1125 ui_toggle_side_window(void)
1126 {
1127 	side_window = !side_window;
1128 	if (side_window)
1129 		recompute_help();
1130 	else
1131 		in_side_window = 0;
1132 
1133 	/*
1134 	 * ugly hack, but otherwise the window doesn't get updated
1135 	 * until I call rearrange_windows a second time (e.g. via
1136 	 * C-l).  I will be happy to know why something like this is
1137 	 * needed.
1138 	 */
1139 	rearrange_windows();
1140 	rearrange_windows();
1141 }
1142 
1143 void
1144 ui_schedule_redraw(void)
1145 {
1146 	should_rearrange_windows = 1;
1147 }
1148 
1149 void
1150 ui_require_input(struct tab *tab, int hide, int proto)
1151 {
1152 	void (*fn)(void);
1153 
1154 	if (proto == PROTO_GEMINI)
1155 		fn = ir_select_gemini;
1156 	else if (proto == PROTO_GOPHER)
1157 		fn = ir_select_gopher;
1158 	else
1159 		abort();
1160 
1161 	/* TODO: hard-switching to another tab is ugly */
1162 	switch_to_tab(tab);
1163 
1164 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1165 	    &ir_history, NULL, NULL);
1166 	strlcpy(ministate.prompt, "Input required: ",
1167 	    sizeof(ministate.prompt));
1168 	redraw_tab(tab);
1169 }
1170 
1171 void
1172 ui_after_message_hook(void)
1173 {
1174 	redraw_minibuffer();
1175 	place_cursor(0);
1176 }
1177 
1178 void
1179 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1180     struct tab *data)
1181 {
1182 	yornp(prompt, fn, data);
1183 	redraw_tab(current_tab);
1184 }
1185 
1186 void
1187 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1188     struct tab *data)
1189 {
1190 	minibuffer_read(prompt, fn, data);
1191 	redraw_tab(current_tab);
1192 }
1193 
1194 void
1195 ui_other_window(void)
1196 {
1197 	if (side_window)
1198 		in_side_window = !in_side_window;
1199 	else
1200 		message("No other window to select");
1201 }
1202 
1203 void
1204 ui_suspend(void)
1205 {
1206 	endwin();
1207 
1208 	kill(getpid(), SIGSTOP);
1209 
1210 	refresh();
1211 	clear();
1212 	rearrange_windows();
1213 }
1214 
1215 void
1216 ui_end(void)
1217 {
1218 	endwin();
1219 }