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Date:: Fri Nov 5 11:04:45 2021 UTC
Message:: annotate why 15 lines
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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 	/* 3 lines for the ui and 12 for the  */
320 	if ((too_small = lines < 15)) {
321 		erase();
322 		printw("Window too small.");
323 		refresh();
324 		return;
325 	}
326 
327 	/* move and resize the windows, in reverse order! */
328 
329 	if (in_minibuffer == MB_COMPREAD) {
330 		mvwin(minibuffer, lines-10, 0);
331 		wresize(minibuffer, 10, COLS);
332 		lines -= 10;
333 
334 		wrap_page(&ministate.compl.buffer, COLS);
335 	}
336 
337 	mvwin(echoarea, --lines, 0);
338 	wresize(echoarea, 1, COLS);
339 
340 	mvwin(modeline, --lines, 0);
341 	wresize(modeline, 1, COLS);
342 
343 	body_lines = show_tab_bar ? --lines : lines;
344 	body_cols = COLS;
345 
346 	/*
347 	 * Here we make the assumption that show_tab_bar is either 0
348 	 * or 1, and reuse that as argument to mvwin.
349 	 */
350 	if (side_window) {
351 		help_cols = 0.3 * COLS;
352 		help_lines = lines;
353 		mvwin(help, show_tab_bar, 0);
354 		wresize(help, help_lines, help_cols);
355 
356 		wrap_page(&helpwin, help_cols);
357 
358 		body_cols = COLS - help_cols - 1;
359 		mvwin(body, show_tab_bar, help_cols);
360 	} else
361 		mvwin(body, show_tab_bar, 0);
362 
363 	update_x_offset();
364 	wresize(body, body_lines, body_cols);
365 
366 	if (show_tab_bar)
367 		wresize(tabline, 1, COLS);
368 
369 	wrap_page(&current_tab->buffer, body_cols);
370 	redraw_tab(current_tab);
371 }
372 
373 static void
374 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
375     const char **prfx_ret, const char **text_ret)
376 {
377 	int type, i, cont, width;
378 	char *space, *t;
379 
380 	if ((*text_ret = vl->line) == NULL)
381 		*text_ret = "";
382 
383 	cont = vl->flags & L_CONTINUATION;
384 	type = vl->parent->type;
385 	if (!cont)
386 		*prfx_ret = line_prefixes[type].prfx1;
387 	else
388 		*prfx_ret = line_prefixes[type].prfx2;
389 
390 	space = vl->parent->data;
391 	if (!emojify_link || type != LINE_LINK || space == NULL)
392 		return;
393 
394 	if (cont) {
395 		memset(buf, 0, len);
396 		width = utf8_swidth_between(vl->parent->line, space);
397 		for (i = 0; i < width + 1; ++i)
398 			strlcat(buf, " ", len);
399 	} else {
400 		strlcpy(buf, *text_ret, len);
401 		if ((t = strchr(buf, ' ')) != NULL)
402 			*t = '\0';
403 		strlcat(buf, " ", len);
404 
405 		/* skip the emoji */
406 		*text_ret += (space - vl->parent->line) + 1;
407 	}
408 
409 	*prfx_ret = buf;
410 }
411 
412 static inline void
413 print_vline_descr(int width, WINDOW *window, struct vline *vl)
414 {
415 	int x, y, goal;
416 
417 	if (vl->parent->type != LINE_COMPL &&
418 	    vl->parent->type != LINE_COMPL_CURRENT &&
419 	    vl->parent->type != LINE_HELP)
420 		return;
421 
422 	if (vl->parent->alt == NULL)
423 		return;
424 
425 	(void)y;
426 	getyx(window, y, x);
427 
428 	if (vl->parent->type == LINE_HELP)
429 		goal = 8;
430 	else
431 		goal = width/2;
432 
433 	if (goal <= x)
434 		wprintw(window, " ");
435 	for (; goal > x; ++x)
436 		wprintw(window, " ");
437 
438 	wprintw(window, "%s", vl->parent->alt);
439 }
440 
441 /*
442  * Core part of the rendering.  It prints a vline starting from the
443  * current cursor position.  Printing a vline consists of skipping
444  * `off' columns (for olivetti-mode), print the correct prefix (which
445  * may be the emoji in case of emojified links-lines), printing the
446  * text itself, filling until width - off and filling off columns
447  * again.
448  */
449 static void
450 print_vline(int off, int width, WINDOW *window, struct vline *vl)
451 {
452 	/*
453 	 * Believe me or not, I've seen emoji ten code points long!
454 	 * That means, to stay large, 4*10 bytes + NUL.
455 	 */
456 	char emojibuf[41] = {0};
457 	const char *text, *prfx;
458 	struct line_face *f;
459 	int i, left, x, y;
460 
461 	f = &line_faces[vl->parent->type];
462 
463 	/* unused, set by getyx */
464 	(void)y;
465 
466 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
467 
468 	wattr_on(window, body_face.left, NULL);
469 	for (i = 0; i < off; i++)
470 		waddch(window, ' ');
471 	wattr_off(window, body_face.left, NULL);
472 
473 	wattr_on(window, f->prefix, NULL);
474 	wprintw(window, "%s", prfx);
475 	wattr_off(window, f->prefix, NULL);
476 
477 	wattr_on(window, f->text, NULL);
478 	wprintw(window, "%s", text);
479 	print_vline_descr(width, window, vl);
480 	wattr_off(window, f->text, NULL);
481 
482 	getyx(window, y, x);
483 
484 	left = width - x;
485 
486 	wattr_on(window, f->trail, NULL);
487 	for (i = 0; i < left - off; ++i)
488 		waddch(window, ' ');
489 	wattr_off(window, f->trail, NULL);
490 
491 	wattr_on(window, body_face.right, NULL);
492 	for (i = 0; i < off; i++)
493 		waddch(window, ' ');
494 	wattr_off(window, body_face.right, NULL);
495 
496 }
497 
498 static void
499 redraw_tabline(void)
500 {
501 	struct tab	*tab;
502 	size_t		 toskip, ots, tabwidth, space, x;
503 	int		 current, y, truncated, pair;
504 	const char	*title;
505 	char		 buf[25];
506 
507 	x = 0;
508 
509 	/* unused, but setted by a getyx */
510 	(void)y;
511 
512 	tabwidth = sizeof(buf)+1;
513 	space = COLS-2;
514 
515 	toskip = 0;
516 	TAILQ_FOREACH(tab, &tabshead, tabs) {
517 		toskip++;
518 		if (tab == current_tab)
519 			break;
520 	}
521 
522 	if (toskip * tabwidth < space)
523 		toskip = 0;
524 	else {
525 		ots = toskip;
526 		toskip--;
527 		while (toskip != 0 &&
528 		    (ots - toskip+1) * tabwidth < space)
529 			toskip--;
530 	}
531 
532 	werase(tabline);
533 	wattr_on(tabline, tab_face.background, NULL);
534 	wprintw(tabline, toskip == 0 ? " " : "<");
535 	wattr_off(tabline, tab_face.background, NULL);
536 
537 	truncated = 0;
538 	TAILQ_FOREACH(tab, &tabshead, tabs) {
539 		if (truncated)
540 			break;
541 		if (toskip != 0) {
542 			toskip--;
543 			continue;
544 		}
545 
546 		getyx(tabline, y, x);
547 		if (x + sizeof(buf)+2 >= (size_t)COLS)
548 			truncated = 1;
549 
550 		current = tab == current_tab;
551 
552 		if (*(title = tab->buffer.page.title) == '\0')
553 			title = tab->hist_cur->h;
554 
555 		if (tab->flags & TAB_URGENT)
556 			strlcpy(buf, "!", sizeof(buf));
557 		else
558 			strlcpy(buf, " ", sizeof(buf));
559 
560 		if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
561 			/* truncation happens */
562 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
563 		} else {
564 			/* pad with spaces */
565 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
566 				/* nop */ ;
567 		}
568 
569 		pair = current ? tab_face.current : tab_face.tab;
570 		wattr_on(tabline, pair, NULL);
571 		wprintw(tabline, "%s", buf);
572 		wattr_off(tabline, pair, NULL);
573 
574 		wattr_on(tabline, tab_face.background, NULL);
575 		if (TAILQ_NEXT(tab, tabs) != NULL)
576 			wprintw(tabline, "┃");
577 		wattr_off(tabline, tab_face.background, NULL);
578 	}
579 
580 	wattr_on(tabline, tab_face.background, NULL);
581 	for (; x < (size_t)COLS; ++x)
582 		waddch(tabline, ' ');
583 	if (truncated)
584 		mvwprintw(tabline, 0, COLS-1, ">");
585 	wattr_off(tabline, tab_face.background, NULL);
586 }
587 
588 /*
589  * Compute the first visible line around vl.  Try to search forward
590  * until the end of the buffer; if a visible line is not found, search
591  * backward.  Return NULL if no viable line was found.
592  */
593 struct vline *
594 adjust_line(struct vline *vl, struct buffer *buffer)
595 {
596 	struct vline *t;
597 
598 	if (vl == NULL)
599 		return NULL;
600 
601 	if (!(vl->parent->flags & L_HIDDEN))
602 		return vl;
603 
604 	/* search forward */
605 	for (t = vl;
606 	     t != NULL && t->parent->flags & L_HIDDEN;
607 	     t = TAILQ_NEXT(t, vlines))
608 		;		/* nop */
609 
610 	if (t != NULL)
611 		return t;
612 
613 	/* search backward */
614 	for (t = vl;
615 	     t != NULL && t->parent->flags & L_HIDDEN;
616 	     t = TAILQ_PREV(t, vhead, vlines))
617 		;		/* nop */
618 
619 	return t;
620 }
621 
622 static void
623 redraw_window(WINDOW *win, int off, int height, int width,
624     struct buffer *buffer)
625 {
626 	struct vline	*vl;
627 	int		 l, onscreen;
628 
629 	restore_curs_x(buffer);
630 
631 	/*
632 	 * TODO: ignoring buffer->force_update and always
633 	 * re-rendering.  In theory we can recompute the y position
634 	 * without a re-render, and optimize here.  It's not the only
635 	 * optimisation possible here, wscrl wolud also be an
636 	 * interesting one.
637 	 */
638 
639 again:
640 	werase(win);
641 	buffer->curs_y = 0;
642 
643 	if (TAILQ_EMPTY(&buffer->head))
644 		goto end;
645 
646 	if (buffer->top_line == NULL)
647 		buffer->top_line = TAILQ_FIRST(&buffer->head);
648 
649 	buffer->top_line = adjust_line(buffer->top_line, buffer);
650 	if (buffer->top_line == NULL)
651 		goto end;
652 
653 	buffer->current_line = adjust_line(buffer->current_line, buffer);
654 
655 	l = 0;
656 	onscreen = 0;
657 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
658 		if (vl->parent->flags & L_HIDDEN)
659 			continue;
660 
661 		wmove(win, l, 0);
662 		print_vline(off, width, win, vl);
663 
664 		if (vl == buffer->current_line)
665 			onscreen = 1;
666 
667 		if (!onscreen)
668 			buffer->curs_y++;
669 
670 		l++;
671 		if (l == height)
672 			break;
673 	}
674 
675 	if (!onscreen) {
676 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
677 			if (vl == buffer->current_line)
678 				break;
679 			if (vl->parent->flags & L_HIDDEN)
680 				continue;
681 			buffer->line_off++;
682 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
683 		}
684 
685 		if (vl != NULL)
686 			goto again;
687 	}
688 
689 	buffer->last_line_off = buffer->line_off;
690 	buffer->force_redraw = 0;
691 end:
692 	wmove(win, buffer->curs_y, buffer->curs_x);
693 }
694 
695 static void
696 redraw_help(void)
697 {
698 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
699 }
700 
701 static void
702 redraw_body(struct tab *tab)
703 {
704 	static struct tab *last_tab;
705 
706 	if (last_tab != tab)
707 		tab->buffer.force_redraw =1;
708 	last_tab = tab;
709 
710 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
711 }
712 
713 static inline char
714 trust_status_char(enum trust_state ts)
715 {
716 	switch (ts) {
717 	case TS_UNKNOWN:	return '-';
718 	case TS_UNTRUSTED:	return '!';
719 	case TS_TEMP_TRUSTED:	return '!';
720 	case TS_TRUSTED:	return 'v';
721 	case TS_VERIFIED:	return 'V';
722 	default:		return 'X';
723 	}
724 }
725 
726 static void
727 redraw_modeline(struct tab *tab)
728 {
729 	struct buffer	*buffer;
730 	double		 pct;
731 	int		 x, y, max_x, max_y;
732 	const char	*mode;
733 	const char	*spin = "-\\|/";
734 
735 	buffer = current_buffer();
736 	mode = buffer->page.name;
737 
738 	werase(modeline);
739 	wattr_on(modeline, modeline_face.background, NULL);
740 	wmove(modeline, 0, 0);
741 
742 	wprintw(modeline, "-%c%c %s ",
743 	    spin[tab->loading_anim_step],
744 	    trust_status_char(tab->trust),
745 	    mode == NULL ? "(none)" : mode);
746 
747 	pct = (buffer->line_off + buffer->curs_y) * 100.0
748 		/ buffer->line_max;
749 
750 	if (buffer->line_max <= (size_t)body_lines)
751 		wprintw(modeline, "All ");
752 	else if (buffer->line_off == 0)
753 		wprintw(modeline, "Top ");
754 	else if (buffer->line_off + body_lines >= buffer->line_max)
755 		wprintw(modeline, "Bottom ");
756 	else
757 		wprintw(modeline, "%.0f%% ", pct);
758 
759 	wprintw(modeline, "%d/%d %s ",
760 	    buffer->line_off + buffer->curs_y,
761 	    buffer->line_max,
762 	    tab->hist_cur->h);
763 
764 	getyx(modeline, y, x);
765 	getmaxyx(modeline, max_y, max_x);
766 
767 	(void)y;
768 	(void)max_y;
769 
770 	for (; x < max_x; ++x)
771 		waddstr(modeline, "-");
772 
773 	wattr_off(modeline, modeline_face.background, NULL);
774 }
775 
776 static void
777 redraw_minibuffer(void)
778 {
779 	wattr_on(echoarea, minibuffer_face.background, NULL);
780 	werase(echoarea);
781 
782 	if (in_minibuffer)
783 		do_redraw_minibuffer();
784 	else
785 		do_redraw_echoarea();
786 
787 	if (in_minibuffer == MB_COMPREAD)
788 		do_redraw_minibuffer_compl();
789 
790 	wattr_off(echoarea, minibuffer_face.background, NULL);
791 }
792 
793 static void
794 do_redraw_echoarea(void)
795 {
796 	struct vline *vl;
797 
798 	if (ministate.curmesg != NULL)
799 		wprintw(echoarea, "%s", ministate.curmesg);
800 	else if (*keybuf != '\0')
801 		waddstr(echoarea, keybuf);
802 	else {
803 		/* If nothing else, show the URL at point */
804 		vl = current_tab->buffer.current_line;
805 		if (vl != NULL && vl->parent->type == LINE_LINK)
806 			waddstr(echoarea, vl->parent->alt);
807 	}
808 }
809 
810 static void
811 do_redraw_minibuffer(void)
812 {
813 	struct buffer	*cmplbuf, *buffer;
814 	size_t		 off_y, off_x = 0;
815 	const char	*start, *c;
816 
817 	cmplbuf = &ministate.compl.buffer;
818 	buffer = &ministate.buffer;
819 	(void)off_y;		/* unused, set by getyx */
820 
821 	wmove(echoarea, 0, 0);
822 
823 	if (in_minibuffer == MB_COMPREAD)
824 		wprintw(echoarea, "(%2d) ",
825 		    cmplbuf->line_max);
826 
827 	wprintw(echoarea, "%s", ministate.prompt);
828 	if (ministate.hist_cur != NULL)
829 		wprintw(echoarea, "(%zu/%zu) ",
830 		    ministate.hist_off + 1,
831 		    ministate.history->len);
832 
833 	getyx(echoarea, off_y, off_x);
834 
835 	start = ministate.hist_cur != NULL
836 		? ministate.hist_cur->h
837 		: ministate.buf;
838 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
839 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
840 		start = utf8_next_cp(start);
841 	}
842 
843 	waddstr(echoarea, start);
844 
845 	if (ministate.curmesg != NULL)
846 		wprintw(echoarea, " [%s]", ministate.curmesg);
847 
848 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
849 }
850 
851 static void
852 do_redraw_minibuffer_compl(void)
853 {
854 	redraw_window(minibuffer, 0, 10, COLS,
855 	    &ministate.compl.buffer);
856 }
857 
858 /*
859  * Place the cursor in the right ncurses window.  If soft is 1, use
860  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
861  * wrefresh.
862  */
863 static void
864 place_cursor(int soft)
865 {
866 	int (*touch)(WINDOW *);
867 
868 	if (soft)
869 		touch = wnoutrefresh;
870 	else
871 		touch = wrefresh;
872 
873 	if (in_minibuffer) {
874 		if (side_window)
875 			touch(help);
876 		touch(body);
877 		touch(echoarea);
878 	} else if (in_side_window) {
879 		touch(body);
880 		touch(echoarea);
881 		touch(help);
882 	} else {
883 		if (side_window)
884 			touch(help);
885 		touch(echoarea);
886 		touch(body);
887 	}
888 }
889 
890 static void
891 redraw_tab(struct tab *tab)
892 {
893 	if (too_small)
894 		return;
895 
896 	if (side_window) {
897 		redraw_help();
898 		wnoutrefresh(help);
899 	}
900 
901 	if (show_tab_bar)
902 		redraw_tabline();
903 
904 	redraw_body(tab);
905 	redraw_modeline(tab);
906 	redraw_minibuffer();
907 
908 	wnoutrefresh(tabline);
909 	wnoutrefresh(modeline);
910 
911 	if (in_minibuffer == MB_COMPREAD)
912 		wnoutrefresh(minibuffer);
913 
914 	place_cursor(1);
915 
916 	doupdate();
917 
918 	if (set_title)
919 		dprintf(1, "\033]2;%s - Telescope\a",
920 		    current_tab->buffer.page.title);
921 }
922 
923 void
924 start_loading_anim(struct tab *tab)
925 {
926 	if (tab->loading_anim)
927 		return;
928 	tab->loading_anim = 1;
929 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
930 	evtimer_add(&tab->loadingev, &loadingev_timer);
931 }
932 
933 static void
934 update_loading_anim(int fd, short ev, void *d)
935 {
936 	struct tab	*tab = d;
937 
938 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
939 
940 	if (tab == current_tab) {
941 		redraw_modeline(tab);
942 		wrefresh(modeline);
943 		wrefresh(body);
944 		if (in_minibuffer)
945 			wrefresh(echoarea);
946 	}
947 
948 	evtimer_add(&tab->loadingev, &loadingev_timer);
949 }
950 
951 static void
952 stop_loading_anim(struct tab *tab)
953 {
954 	if (!tab->loading_anim)
955 		return;
956 	evtimer_del(&tab->loadingev);
957 	tab->loading_anim = 0;
958 	tab->loading_anim_step = 0;
959 
960 	if (tab != current_tab)
961 		return;
962 
963 	redraw_modeline(tab);
964 
965 	wrefresh(modeline);
966 	wrefresh(body);
967 	if (in_minibuffer)
968 		wrefresh(echoarea);
969 }
970 
971 int
972 ui_print_colors(void)
973 {
974 	int colors = 0, pairs = 0, can_change = 0;
975 	int columns = 16, lines, color, i, j;
976 
977 	initscr();
978 	if (has_colors()) {
979 		start_color();
980 		use_default_colors();
981 
982 		colors = COLORS;
983 		pairs = COLOR_PAIRS;
984 		can_change = can_change_color();
985 	}
986 	endwin();
987 
988 	printf("Term info:\n");
989 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
990 	    getenv("TERM"), colors, pairs, can_change);
991 	printf("\n");
992 
993 	if (colors == 0) {
994 		printf("No color support\n");
995 		return 0;
996 	}
997 
998 	printf("Available colors:\n\n");
999 	lines = (colors - 1) / columns + 1;
1000 	color = 0;
1001 	for (i = 0; i < lines; ++i) {
1002 		for (j = 0; j < columns; ++j, ++color) {
1003 			printf("\033[0;38;5;%dm %03d", color, color);
1004 		}
1005 		printf("\n");
1006 	}
1007 
1008 	printf("\033[0m");
1009 	fflush(stdout);
1010 	return 0;
1011 }
1012 
1013 int
1014 ui_init()
1015 {
1016 	setlocale(LC_ALL, "");
1017 
1018 	if (TAILQ_EMPTY(&global_map.m)) {
1019 		fprintf(stderr, "no keys defined!\n");
1020 		return 0;
1021 	}
1022 
1023 	minibuffer_init();
1024 
1025 	/* initialize help window */
1026 	TAILQ_INIT(&helpwin.head);
1027 	TAILQ_INIT(&helpwin.page.head);
1028 
1029 	base_map = &global_map;
1030 	current_map = &global_map;
1031 
1032 	initscr();
1033 
1034 	if (enable_colors) {
1035 		if (has_colors()) {
1036 			start_color();
1037 			use_default_colors();
1038 		} else
1039 			enable_colors = 0;
1040 	}
1041 
1042 	config_apply_style();
1043 
1044 	raw();
1045 	noecho();
1046 	nonl();
1047 	intrflush(stdscr, FALSE);
1048 
1049 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1050 		return 0;
1051 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1052 		return 0;
1053 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1054 		return 0;
1055 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1056 		return 0;
1057 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1058 		return 0;
1059 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1060 		return 0;
1061 
1062 	wbkgd(body, body_face.body);
1063 	wbkgd(echoarea, minibuffer_face.background);
1064 
1065 	update_x_offset();
1066 
1067 	keypad(body, TRUE);
1068 	scrollok(body, FALSE);
1069 
1070 	/* non-blocking input */
1071 	wtimeout(body, 0);
1072 	wtimeout(help, 0);
1073 
1074 	mvwprintw(body, 0, 0, "");
1075 
1076 	evtimer_set(&resizeev, handle_resize, NULL);
1077 
1078 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1079 	event_add(&stdioev, NULL);
1080 
1081 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1082 	signal_add(&winchev, NULL);
1083 
1084 	return 1;
1085 }
1086 
1087 void
1088 ui_main_loop(void)
1089 {
1090 	switch_to_tab(current_tab);
1091 	rearrange_windows();
1092 
1093 	event_dispatch();
1094 }
1095 
1096 void
1097 ui_on_tab_loaded(struct tab *tab)
1098 {
1099 	stop_loading_anim(tab);
1100 	message("Loaded %s", tab->hist_cur->h);
1101 
1102 	if (show_tab_bar)
1103 		redraw_tabline();
1104 
1105 	wrefresh(tabline);
1106 	place_cursor(0);
1107 }
1108 
1109 void
1110 ui_on_tab_refresh(struct tab *tab)
1111 {
1112 	wrap_page(&tab->buffer, body_cols);
1113 	if (tab == current_tab)
1114 		redraw_tab(tab);
1115 	else
1116 		tab->flags |= TAB_URGENT;
1117 }
1118 
1119 const char *
1120 ui_keyname(int k)
1121 {
1122 	return keyname(k);
1123 }
1124 
1125 void
1126 ui_toggle_side_window(void)
1127 {
1128 	side_window = !side_window;
1129 	if (side_window)
1130 		recompute_help();
1131 	else
1132 		in_side_window = 0;
1133 
1134 	/*
1135 	 * ugly hack, but otherwise the window doesn't get updated
1136 	 * until I call rearrange_windows a second time (e.g. via
1137 	 * C-l).  I will be happy to know why something like this is
1138 	 * needed.
1139 	 */
1140 	rearrange_windows();
1141 	rearrange_windows();
1142 }
1143 
1144 void
1145 ui_schedule_redraw(void)
1146 {
1147 	should_rearrange_windows = 1;
1148 }
1149 
1150 void
1151 ui_require_input(struct tab *tab, int hide, int proto)
1152 {
1153 	void (*fn)(void);
1154 
1155 	if (proto == PROTO_GEMINI)
1156 		fn = ir_select_gemini;
1157 	else if (proto == PROTO_GOPHER)
1158 		fn = ir_select_gopher;
1159 	else
1160 		abort();
1161 
1162 	/* TODO: hard-switching to another tab is ugly */
1163 	switch_to_tab(tab);
1164 
1165 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1166 	    &ir_history, NULL, NULL);
1167 	strlcpy(ministate.prompt, "Input required: ",
1168 	    sizeof(ministate.prompt));
1169 	redraw_tab(tab);
1170 }
1171 
1172 void
1173 ui_after_message_hook(void)
1174 {
1175 	redraw_minibuffer();
1176 	place_cursor(0);
1177 }
1178 
1179 void
1180 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1181     struct tab *data)
1182 {
1183 	yornp(prompt, fn, data);
1184 	redraw_tab(current_tab);
1185 }
1186 
1187 void
1188 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1189     struct tab *data, const char *input)
1190 {
1191 	minibuffer_read(prompt, fn, data);
1192 
1193 	if (input != NULL) {
1194 		strlcpy(ministate.buf, input, sizeof(ministate.buf));
1195 		cmd_move_end_of_line(&ministate.buffer);
1196 	}
1197 
1198 	redraw_tab(current_tab);
1199 }
1200 
1201 void
1202 ui_other_window(void)
1203 {
1204 	if (side_window)
1205 		in_side_window = !in_side_window;
1206 	else
1207 		message("No other window to select");
1208 }
1209 
1210 void
1211 ui_suspend(void)
1212 {
1213 	endwin();
1214 
1215 	kill(getpid(), SIGSTOP);
1216 
1217 	refresh();
1218 	clear();
1219 	rearrange_windows();
1220 }
1221 
1222 void
1223 ui_end(void)
1224 {
1225 	endwin();
1226 }