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Date:: Fri Sep 24 15:59:57 2021 UTC
Message:: proposal: use ^L as page separator in text/gemini
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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 "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 static inline void
441 print_line_break(int width, WINDOW *window)
442 {
443 	int x, y;
444 
445 	getyx(window, y, x);
446 	mvwprintw(window, y, width/2 - 4, "-*-*-");
447 }
448 
449 /*
450  * Core part of the rendering.  It prints a vline starting from the
451  * current cursor position.  Printing a vline consists of skipping
452  * `off' columns (for olivetti-mode), print the correct prefix (which
453  * may be the emoji in case of emojified links-lines), printing the
454  * text itself, filling until width - off and filling off columns
455  * again.
456  */
457 static void
458 print_vline(int off, int width, WINDOW *window, struct vline *vl)
459 {
460 	/*
461 	 * Believe me or not, I've seen emoji ten code points long!
462 	 * That means, to stay large, 4*10 bytes + NUL.
463 	 */
464 	char emojibuf[41] = {0};
465 	const char *text, *prfx;
466 	struct line_face *f;
467 	int i, left, x, y;
468 
469 	f = &line_faces[vl->parent->type];
470 
471 	/* unused, set by getyx */
472 	(void)y;
473 
474 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
475 
476 	wattr_on(window, body_face.left, NULL);
477 	for (i = 0; i < off; i++)
478 		waddch(window, ' ');
479 	wattr_off(window, body_face.left, NULL);
480 
481 	if (vl->parent->type == LINE_BREAK) {
482 		print_line_break(width, window);
483 	} else {
484 		wattr_on(window, f->prefix, NULL);
485 		wprintw(window, "%s", prfx);
486 		wattr_off(window, f->prefix, NULL);
487 	}
488 
489 	wattr_on(window, f->text, NULL);
490 	wprintw(window, "%s", text);
491 	print_vline_descr(width, window, vl);
492 	wattr_off(window, f->text, NULL);
493 
494 	getyx(window, y, x);
495 
496 	left = width - x;
497 
498 	wattr_on(window, f->trail, NULL);
499 	for (i = 0; i < left - off; ++i)
500 		waddch(window, ' ');
501 	wattr_off(window, f->trail, NULL);
502 
503 	wattr_on(window, body_face.right, NULL);
504 	for (i = 0; i < off; i++)
505 		waddch(window, ' ');
506 	wattr_off(window, body_face.right, NULL);
507 
508 }
509 
510 static void
511 redraw_tabline(void)
512 {
513 	struct tab	*tab;
514 	size_t		 toskip, ots, tabwidth, space, x;
515 	int		 current, y, truncated, pair;
516 	const char	*title;
517 	char		 buf[25];
518 
519 	x = 0;
520 
521 	/* unused, but setted by a getyx */
522 	(void)y;
523 
524 	tabwidth = sizeof(buf)+1;
525 	space = COLS-2;
526 
527 	toskip = 0;
528 	TAILQ_FOREACH(tab, &tabshead, tabs) {
529 		toskip++;
530 		if (tab == current_tab)
531 			break;
532 	}
533 
534 	if (toskip * tabwidth < space)
535 		toskip = 0;
536 	else {
537 		ots = toskip;
538 		toskip--;
539 		while (toskip != 0 &&
540 		    (ots - toskip+1) * tabwidth < space)
541 			toskip--;
542 	}
543 
544 	werase(tabline);
545 	wattr_on(tabline, tab_face.background, NULL);
546 	wprintw(tabline, toskip == 0 ? " " : "<");
547 	wattr_off(tabline, tab_face.background, NULL);
548 
549 	truncated = 0;
550 	TAILQ_FOREACH(tab, &tabshead, tabs) {
551 		if (truncated)
552 			break;
553 		if (toskip != 0) {
554 			toskip--;
555 			continue;
556 		}
557 
558 		getyx(tabline, y, x);
559 		if (x + sizeof(buf)+2 >= (size_t)COLS)
560 			truncated = 1;
561 
562 		current = tab == current_tab;
563 
564 		if (*(title = tab->buffer.page.title) == '\0')
565 			title = tab->hist_cur->h;
566 
567 		if (tab->flags & TAB_URGENT)
568 			strlcpy(buf, "!", sizeof(buf));
569 		else
570 			strlcpy(buf, " ", sizeof(buf));
571 
572 		if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
573 			/* truncation happens */
574 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
575 		} else {
576 			/* pad with spaces */
577 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
578 				/* nop */ ;
579 		}
580 
581 		pair = current ? tab_face.current : tab_face.tab;
582 		wattr_on(tabline, pair, NULL);
583 		wprintw(tabline, "%s", buf);
584 		wattr_off(tabline, pair, NULL);
585 
586 		wattr_on(tabline, tab_face.background, NULL);
587 		if (TAILQ_NEXT(tab, tabs) != NULL)
588 			wprintw(tabline, "┃");
589 		wattr_off(tabline, tab_face.background, NULL);
590 	}
591 
592 	wattr_on(tabline, tab_face.background, NULL);
593 	for (; x < (size_t)COLS; ++x)
594 		waddch(tabline, ' ');
595 	if (truncated)
596 		mvwprintw(tabline, 0, COLS-1, ">");
597 	wattr_off(tabline, tab_face.background, NULL);
598 }
599 
600 /*
601  * Compute the first visible line around vl.  Try to search forward
602  * until the end of the buffer; if a visible line is not found, search
603  * backward.  Return NULL if no viable line was found.
604  */
605 struct vline *
606 adjust_line(struct vline *vl, struct buffer *buffer)
607 {
608 	struct vline *t;
609 
610 	if (vl == NULL)
611 		return NULL;
612 
613 	if (!(vl->parent->flags & L_HIDDEN))
614 		return vl;
615 
616 	/* search forward */
617 	for (t = vl;
618 	     t != NULL && t->parent->flags & L_HIDDEN;
619 	     t = TAILQ_NEXT(t, vlines))
620 		;		/* nop */
621 
622 	if (t != NULL)
623 		return t;
624 
625 	/* search backward */
626 	for (t = vl;
627 	     t != NULL && t->parent->flags & L_HIDDEN;
628 	     t = TAILQ_PREV(t, vhead, vlines))
629 		;		/* nop */
630 
631 	return t;
632 }
633 
634 static void
635 redraw_window(WINDOW *win, int off, int height, int width,
636     struct buffer *buffer)
637 {
638 	struct vline	*vl;
639 	int		 l, onscreen;
640 
641 	restore_curs_x(buffer);
642 
643 	/*
644 	 * TODO: ignoring buffer->force_update and always
645 	 * re-rendering.  In theory we can recompute the y position
646 	 * without a re-render, and optimize here.  It's not the only
647 	 * optimisation possible here, wscrl wolud also be an
648 	 * interesting one.
649 	 */
650 
651 again:
652 	werase(win);
653 	buffer->curs_y = 0;
654 
655 	if (TAILQ_EMPTY(&buffer->head))
656 		goto end;
657 
658 	if (buffer->top_line == NULL)
659 		buffer->top_line = TAILQ_FIRST(&buffer->head);
660 
661 	buffer->top_line = adjust_line(buffer->top_line, buffer);
662 	if (buffer->top_line == NULL)
663 		goto end;
664 
665 	buffer->current_line = adjust_line(buffer->current_line, buffer);
666 
667 	l = 0;
668 	onscreen = 0;
669 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
670 		if (vl->parent->flags & L_HIDDEN)
671 			continue;
672 
673 		wmove(win, l, 0);
674 		print_vline(off, width, win, vl);
675 
676 		if (vl == buffer->current_line)
677 			onscreen = 1;
678 
679 		if (!onscreen)
680 			buffer->curs_y++;
681 
682 		l++;
683 		if (l == height)
684 			break;
685 	}
686 
687 	if (!onscreen) {
688 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
689 			if (vl == buffer->current_line)
690 				break;
691 			if (vl->parent->flags & L_HIDDEN)
692 				continue;
693 			buffer->line_off++;
694 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
695 		}
696 
697 		if (vl != NULL)
698 			goto again;
699 	}
700 
701 	buffer->last_line_off = buffer->line_off;
702 	buffer->force_redraw = 0;
703 end:
704 	wmove(win, buffer->curs_y, buffer->curs_x);
705 }
706 
707 static void
708 redraw_help(void)
709 {
710 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
711 }
712 
713 static void
714 redraw_body(struct tab *tab)
715 {
716 	static struct tab *last_tab;
717 
718 	if (last_tab != tab)
719 		tab->buffer.force_redraw =1;
720 	last_tab = tab;
721 
722 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
723 }
724 
725 static inline char
726 trust_status_char(enum trust_state ts)
727 {
728 	switch (ts) {
729 	case TS_UNKNOWN:	return '-';
730 	case TS_UNTRUSTED:	return '!';
731 	case TS_TEMP_TRUSTED:	return '!';
732 	case TS_TRUSTED:	return 'v';
733 	case TS_VERIFIED:	return 'V';
734 	default:		return 'X';
735 	}
736 }
737 
738 static void
739 redraw_modeline(struct tab *tab)
740 {
741 	struct buffer	*buffer;
742 	double		 pct;
743 	int		 x, y, max_x, max_y;
744 	const char	*mode;
745 	const char	*spin = "-\\|/";
746 
747 	buffer = current_buffer();
748 	mode = buffer->page.name;
749 
750 	werase(modeline);
751 	wattr_on(modeline, modeline_face.background, NULL);
752 	wmove(modeline, 0, 0);
753 
754 	wprintw(modeline, "-%c%c %s ",
755 	    spin[tab->loading_anim_step],
756 	    trust_status_char(tab->trust),
757 	    mode == NULL ? "(none)" : mode);
758 
759 	pct = (buffer->line_off + buffer->curs_y) * 100.0
760 		/ buffer->line_max;
761 
762 	if (buffer->line_max <= (size_t)body_lines)
763 		wprintw(modeline, "All ");
764 	else if (buffer->line_off == 0)
765 		wprintw(modeline, "Top ");
766 	else if (buffer->line_off + body_lines >= buffer->line_max)
767 		wprintw(modeline, "Bottom ");
768 	else
769 		wprintw(modeline, "%.0f%% ", pct);
770 
771 	wprintw(modeline, "%d/%d %s ",
772 	    buffer->line_off + buffer->curs_y,
773 	    buffer->line_max,
774 	    tab->hist_cur->h);
775 
776 	getyx(modeline, y, x);
777 	getmaxyx(modeline, max_y, max_x);
778 
779 	(void)y;
780 	(void)max_y;
781 
782 	for (; x < max_x; ++x)
783 		waddstr(modeline, "-");
784 
785 	wattr_off(modeline, modeline_face.background, NULL);
786 }
787 
788 static void
789 redraw_minibuffer(void)
790 {
791 	wattr_on(echoarea, minibuffer_face.background, NULL);
792 	werase(echoarea);
793 
794 	if (in_minibuffer)
795 		do_redraw_minibuffer();
796 	else
797 		do_redraw_echoarea();
798 
799 	if (in_minibuffer == MB_COMPREAD)
800 		do_redraw_minibuffer_compl();
801 
802 	wattr_off(echoarea, minibuffer_face.background, NULL);
803 }
804 
805 static void
806 do_redraw_echoarea(void)
807 {
808 	struct vline *vl;
809 
810 	if (ministate.curmesg != NULL)
811 		wprintw(echoarea, "%s", ministate.curmesg);
812 	else if (*keybuf != '\0')
813 		waddstr(echoarea, keybuf);
814 	else {
815 		/* If nothing else, show the URL at point */
816 		vl = current_tab->buffer.current_line;
817 		if (vl != NULL && vl->parent->type == LINE_LINK)
818 			waddstr(echoarea, vl->parent->alt);
819 	}
820 }
821 
822 static void
823 do_redraw_minibuffer(void)
824 {
825 	struct buffer	*cmplbuf, *buffer;
826 	size_t		 off_y, off_x = 0;
827 	const char	*start, *c;
828 
829 	cmplbuf = &ministate.compl.buffer;
830 	buffer = &ministate.buffer;
831 	(void)off_y;		/* unused, set by getyx */
832 
833 	wmove(echoarea, 0, 0);
834 
835 	if (in_minibuffer == MB_COMPREAD)
836 		wprintw(echoarea, "(%2d) ",
837 		    cmplbuf->line_max);
838 
839 	wprintw(echoarea, "%s", ministate.prompt);
840 	if (ministate.hist_cur != NULL)
841 		wprintw(echoarea, "(%zu/%zu) ",
842 		    ministate.hist_off + 1,
843 		    ministate.history->len);
844 
845 	getyx(echoarea, off_y, off_x);
846 
847 	start = ministate.hist_cur != NULL
848 		? ministate.hist_cur->h
849 		: ministate.buf;
850 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
851 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
852 		start = utf8_next_cp(start);
853 	}
854 
855 	waddstr(echoarea, start);
856 
857 	if (ministate.curmesg != NULL)
858 		wprintw(echoarea, " [%s]", ministate.curmesg);
859 
860 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
861 }
862 
863 static void
864 do_redraw_minibuffer_compl(void)
865 {
866 	redraw_window(minibuffer, 0, 10, COLS,
867 	    &ministate.compl.buffer);
868 }
869 
870 /*
871  * Place the cursor in the right ncurses window.  If soft is 1, use
872  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
873  * wrefresh.
874  */
875 static void
876 place_cursor(int soft)
877 {
878 	int (*touch)(WINDOW *);
879 
880 	if (soft)
881 		touch = wnoutrefresh;
882 	else
883 		touch = wrefresh;
884 
885 	if (in_minibuffer) {
886 		if (side_window)
887 			touch(help);
888 		touch(body);
889 		touch(echoarea);
890 	} else if (in_side_window) {
891 		touch(body);
892 		touch(echoarea);
893 		touch(help);
894 	} else {
895 		if (side_window)
896 			touch(help);
897 		touch(echoarea);
898 		touch(body);
899 	}
900 }
901 
902 static void
903 redraw_tab(struct tab *tab)
904 {
905 	if (too_small)
906 		return;
907 
908 	if (side_window) {
909 		redraw_help();
910 		wnoutrefresh(help);
911 	}
912 
913 	if (show_tab_bar)
914 		redraw_tabline();
915 
916 	redraw_body(tab);
917 	redraw_modeline(tab);
918 	redraw_minibuffer();
919 
920 	wnoutrefresh(tabline);
921 	wnoutrefresh(modeline);
922 
923 	if (in_minibuffer == MB_COMPREAD)
924 		wnoutrefresh(minibuffer);
925 
926 	place_cursor(1);
927 
928 	doupdate();
929 
930 	if (set_title)
931 		dprintf(1, "\033]2;%s - Telescope\a",
932 		    current_tab->buffer.page.title);
933 }
934 
935 void
936 start_loading_anim(struct tab *tab)
937 {
938 	if (tab->loading_anim)
939 		return;
940 	tab->loading_anim = 1;
941 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
942 	evtimer_add(&tab->loadingev, &loadingev_timer);
943 }
944 
945 static void
946 update_loading_anim(int fd, short ev, void *d)
947 {
948 	struct tab	*tab = d;
949 
950 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
951 
952 	if (tab == current_tab) {
953 		redraw_modeline(tab);
954 		wrefresh(modeline);
955 		wrefresh(body);
956 		if (in_minibuffer)
957 			wrefresh(echoarea);
958 	}
959 
960 	evtimer_add(&tab->loadingev, &loadingev_timer);
961 }
962 
963 static void
964 stop_loading_anim(struct tab *tab)
965 {
966 	if (!tab->loading_anim)
967 		return;
968 	evtimer_del(&tab->loadingev);
969 	tab->loading_anim = 0;
970 	tab->loading_anim_step = 0;
971 
972 	if (tab != current_tab)
973 		return;
974 
975 	redraw_modeline(tab);
976 
977 	wrefresh(modeline);
978 	wrefresh(body);
979 	if (in_minibuffer)
980 		wrefresh(echoarea);
981 }
982 
983 int
984 ui_print_colors(void)
985 {
986 	int colors = 0, pairs = 0, can_change = 0;
987 	int columns = 16, lines, color, i, j;
988 
989 	initscr();
990 	if (has_colors()) {
991 		start_color();
992 		use_default_colors();
993 
994 		colors = COLORS;
995 		pairs = COLOR_PAIRS;
996 		can_change = can_change_color();
997 	}
998 	endwin();
999 
1000 	printf("Term info:\n");
1001 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1002 	    getenv("TERM"), colors, pairs, can_change);
1003 	printf("\n");
1004 
1005 	if (colors == 0) {
1006 		printf("No color support\n");
1007 		return 0;
1008 	}
1009 
1010 	printf("Available colors:\n\n");
1011 	lines = (colors - 1) / columns + 1;
1012 	color = 0;
1013 	for (i = 0; i < lines; ++i) {
1014 		for (j = 0; j < columns; ++j, ++color) {
1015 			printf("\033[0;38;5;%dm %03d", color, color);
1016 		}
1017 		printf("\n");
1018 	}
1019 
1020 	printf("\033[0m");
1021 	fflush(stdout);
1022 	return 0;
1023 }
1024 
1025 int
1026 ui_init()
1027 {
1028 	setlocale(LC_ALL, "");
1029 
1030 	if (TAILQ_EMPTY(&global_map.m)) {
1031 		fprintf(stderr, "no keys defined!\n");
1032 		return 0;
1033 	}
1034 
1035 	minibuffer_init();
1036 
1037 	/* initialize help window */
1038 	TAILQ_INIT(&helpwin.head);
1039 	TAILQ_INIT(&helpwin.page.head);
1040 
1041 	base_map = &global_map;
1042 	current_map = &global_map;
1043 
1044 	initscr();
1045 
1046 	if (enable_colors) {
1047 		if (has_colors()) {
1048 			start_color();
1049 			use_default_colors();
1050 		} else
1051 			enable_colors = 0;
1052 	}
1053 
1054 	config_apply_style();
1055 
1056 	raw();
1057 	noecho();
1058 	nonl();
1059 	intrflush(stdscr, FALSE);
1060 
1061 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1062 		return 0;
1063 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1064 		return 0;
1065 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1066 		return 0;
1067 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1068 		return 0;
1069 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1070 		return 0;
1071 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1072 		return 0;
1073 
1074 	wbkgd(body, body_face.body);
1075 	wbkgd(echoarea, minibuffer_face.background);
1076 
1077 	update_x_offset();
1078 
1079 	keypad(body, TRUE);
1080 	scrollok(body, FALSE);
1081 
1082 	/* non-blocking input */
1083 	wtimeout(body, 0);
1084 	wtimeout(help, 0);
1085 
1086 	mvwprintw(body, 0, 0, "");
1087 
1088 	evtimer_set(&resizeev, handle_resize, NULL);
1089 
1090 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1091 	event_add(&stdioev, NULL);
1092 
1093 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1094 	signal_add(&winchev, NULL);
1095 
1096 	return 1;
1097 }
1098 
1099 void
1100 ui_main_loop(void)
1101 {
1102 	switch_to_tab(current_tab);
1103 	rearrange_windows();
1104 
1105 	event_dispatch();
1106 }
1107 
1108 void
1109 ui_on_tab_loaded(struct tab *tab)
1110 {
1111 	stop_loading_anim(tab);
1112 	message("Loaded %s", tab->hist_cur->h);
1113 
1114 	if (show_tab_bar)
1115 		redraw_tabline();
1116 
1117 	wrefresh(tabline);
1118 	place_cursor(0);
1119 }
1120 
1121 void
1122 ui_on_tab_refresh(struct tab *tab)
1123 {
1124 	wrap_page(&tab->buffer, body_cols);
1125 	if (tab == current_tab)
1126 		redraw_tab(tab);
1127 	else
1128 		tab->flags |= TAB_URGENT;
1129 }
1130 
1131 const char *
1132 ui_keyname(int k)
1133 {
1134 	return keyname(k);
1135 }
1136 
1137 void
1138 ui_toggle_side_window(void)
1139 {
1140 	side_window = !side_window;
1141 	if (side_window)
1142 		recompute_help();
1143 	else
1144 		in_side_window = 0;
1145 
1146 	/*
1147 	 * ugly hack, but otherwise the window doesn't get updated
1148 	 * until I call rearrange_windows a second time (e.g. via
1149 	 * C-l).  I will be happy to know why something like this is
1150 	 * needed.
1151 	 */
1152 	rearrange_windows();
1153 	rearrange_windows();
1154 }
1155 
1156 void
1157 ui_schedule_redraw(void)
1158 {
1159 	should_rearrange_windows = 1;
1160 }
1161 
1162 void
1163 ui_require_input(struct tab *tab, int hide, int proto)
1164 {
1165 	void (*fn)(void);
1166 
1167 	if (proto == PROTO_GEMINI)
1168 		fn = ir_select_gemini;
1169 	else if (proto == PROTO_GOPHER)
1170 		fn = ir_select_gopher;
1171 	else
1172 		abort();
1173 
1174 	/* TODO: hard-switching to another tab is ugly */
1175 	switch_to_tab(tab);
1176 
1177 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1178 	    &ir_history, NULL, NULL);
1179 	strlcpy(ministate.prompt, "Input required: ",
1180 	    sizeof(ministate.prompt));
1181 	redraw_tab(tab);
1182 }
1183 
1184 void
1185 ui_after_message_hook(void)
1186 {
1187 	redraw_minibuffer();
1188 	place_cursor(0);
1189 }
1190 
1191 void
1192 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1193     struct tab *data)
1194 {
1195 	yornp(prompt, fn, data);
1196 	redraw_tab(current_tab);
1197 }
1198 
1199 void
1200 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1201     struct tab *data, const char *input)
1202 {
1203 	minibuffer_read(prompt, fn, data);
1204 
1205 	if (input != NULL) {
1206 		strlcpy(ministate.buf, input, sizeof(ministate.buf));
1207 		cmd_move_end_of_line(&ministate.buffer);
1208 	}
1209 
1210 	redraw_tab(current_tab);
1211 }
1212 
1213 void
1214 ui_other_window(void)
1215 {
1216 	if (side_window)
1217 		in_side_window = !in_side_window;
1218 	else
1219 		message("No other window to select");
1220 }
1221 
1222 void
1223 ui_suspend(void)
1224 {
1225 	endwin();
1226 
1227 	kill(getpid(), SIGSTOP);
1228 
1229 	refresh();
1230 	clear();
1231 	rearrange_windows();
1232 }
1233 
1234 void
1235 ui_end(void)
1236 {
1237 	endwin();
1238 }