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Date:: Thu Aug 12 09:09:52 2021 UTC
Message:: replace TAILQ_EMPTY/INSERT_HEAD/TAIL dance with a single TAILQ_INSERT_TAIL Now that all the queues are correctly initialised, there's no need for that dance.
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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 "telescope.h"
47 #include "ui.h"
48 #include "utf8.h"
49 
50 static struct event	stdioev, winchev;
51 
52 static void		 restore_curs_x(struct buffer *);
53 
54 static int		 readkey(void);
55 static void		 dispatch_stdio(int, short, void*);
56 static void		 handle_resize(int, short, void*);
57 static void		 handle_resize_nodelay(int, short, void*);
58 static void		 rearrange_windows(void);
59 static void		 line_prefix_and_text(struct vline *, char *, size_t, const char **, const char **);
60 static void		 print_vline(int, int, WINDOW*, struct vline*);
61 static void		 redraw_tabline(void);
62 static void		 redraw_window(WINDOW*, int, int, int, struct buffer*);
63 static void		 redraw_help(void);
64 static void		 redraw_body(struct tab*);
65 static void		 redraw_modeline(struct tab*);
66 static void		 redraw_minibuffer(void);
67 static void		 do_redraw_echoarea(void);
68 static void		 do_redraw_minibuffer(void);
69 static void		 do_redraw_minibuffer_compl(void);
70 static void		 place_cursor(int);
71 static void		 redraw_tab(struct tab*);
72 static void		 update_loading_anim(int, short, void*);
73 static void		 stop_loading_anim(struct tab*);
74 
75 /*
76  * Used to know when we're finished loading.
77  */
78 static int		 operating;
79 
80 static int		 should_rearrange_windows;
81 static int		 too_small;
82 static int		 x_offset;
83 
84 struct thiskey	 thiskey;
85 struct tab	*current_tab;
86 
87 static struct event	resizeev;
88 static struct timeval	resize_timer = { 0, 250000 };
89 
90 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
91 
92 int			 body_lines, body_cols;
93 
94 static WINDOW		*help;
95 /* not static so we can see them from help.c */
96 struct buffer		 helpwin;
97 int			 help_lines, help_cols;
98 
99 static int		 side_window;
100 static int		 in_side_window;
101 
102 static struct timeval	loadingev_timer = { 0, 250000 };
103 
104 static uint32_t		 tab_counter;
105 
106 static char	keybuf[64];
107 
108 /* XXX: don't forget to init these in main() */
109 struct kmap global_map,
110 	minibuffer_map,
111 	*current_map,
112 	*base_map;
113 
114 static inline void
115 update_x_offset(void)
116 {
117 	if (olivetti_mode && fill_column < body_cols)
118 		x_offset = (body_cols - fill_column)/2;
119 	else
120 		x_offset = 0;
121 }
122 
123 void
124 save_excursion(struct excursion *place, struct buffer *buffer)
125 {
126 	place->curs_x = buffer->curs_x;
127 	place->curs_y = buffer->curs_y;
128 	place->line_off = buffer->line_off;
129 	place->top_line = buffer->top_line;
130 	place->current_line = buffer->current_line;
131 	place->cpoff = buffer->cpoff;
132 }
133 
134 void
135 restore_excursion(struct excursion *place, struct buffer *buffer)
136 {
137 	buffer->curs_x = place->curs_x;
138 	buffer->curs_y = place->curs_y;
139 	buffer->line_off = place->line_off;
140 	buffer->top_line = place->top_line;
141 	buffer->current_line = place->current_line;
142 	buffer->cpoff = place->cpoff;
143 }
144 
145 static void
146 restore_curs_x(struct buffer *buffer)
147 {
148 	struct vline	*vl;
149 	const char	*prfx, *text;
150 
151 	vl = buffer->current_line;
152 	if (vl == NULL || vl->line == NULL)
153 		buffer->curs_x = buffer->cpoff = 0;
154 	else if (vl->parent->data != NULL) {
155 		text = vl->parent->data;
156 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
157 	} else
158 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
159 
160 	buffer->curs_x += x_offset;
161 
162 	if (vl == NULL)
163 		return;
164 
165 	if (vl->parent->data != NULL)
166 		buffer->curs_x += utf8_swidth_between(vl->parent->line, vl->parent->data);
167 	else {
168 		prfx = line_prefixes[vl->parent->type].prfx1;
169 		buffer->curs_x += utf8_swidth(prfx);
170 	}
171 }
172 
173 void
174 global_key_unbound(void)
175 {
176 	message("%s is undefined", keybuf);
177 }
178 
179 struct buffer *
180 current_buffer(void)
181 {
182 	if (in_minibuffer)
183 		return &ministate.buffer;
184 	if (in_side_window)
185 		return &helpwin;
186 	return &current_tab->buffer;
187 }
188 
189 static int
190 readkey(void)
191 {
192 	uint32_t state = 0;
193 
194 	if ((thiskey.key = wgetch(body)) == ERR)
195 		return 0;
196 
197 	thiskey.meta = thiskey.key == 27;
198 	if (thiskey.meta) {
199 		thiskey.key = wgetch(body);
200 		if (thiskey.key == ERR || thiskey.key == 27) {
201 			thiskey.meta = 0;
202 			thiskey.key = 27;
203 		}
204 	}
205 
206 	thiskey.cp = 0;
207 	if ((unsigned int)thiskey.key < UINT8_MAX) {
208 		while (1) {
209 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
210 				break;
211 			if ((thiskey.key = wgetch(body)) == ERR) {
212 				message("Error decoding user input");
213 				return 0;
214 			}
215 		}
216 	}
217 
218 	return 1;
219 }
220 
221 static void
222 dispatch_stdio(int fd, short ev, void *d)
223 {
224 	struct keymap	*k;
225 	const char	*keyname;
226 	char		 tmp[5] = {0};
227 
228 	/* TODO: schedule a redraw? */
229 	if (too_small)
230 		return;
231 
232 	if (!readkey())
233 		return;
234 
235 	if (keybuf[0] != '\0')
236 		strlcat(keybuf, " ", sizeof(keybuf));
237 	if (thiskey.meta)
238 		strlcat(keybuf, "M-", sizeof(keybuf));
239 	if (thiskey.cp != 0) {
240 		utf8_encode(thiskey.cp, tmp);
241 		strlcat(keybuf, tmp, sizeof(keybuf));
242 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
243 		strlcat(keybuf, keyname, sizeof(keybuf));
244 	} else {
245 		tmp[0] = thiskey.key;
246 		strlcat(keybuf, tmp, sizeof(keybuf));
247 	}
248 
249 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
250 		if (k->meta == thiskey.meta &&
251 		    k->key == thiskey.key) {
252 			if (k->fn == NULL)
253 				current_map = &k->map;
254 			else {
255 				current_map = base_map;
256 				strlcpy(keybuf, "", sizeof(keybuf));
257 				k->fn(current_buffer());
258 			}
259 			goto done;
260 		}
261 	}
262 
263 	if (current_map->unhandled_input != NULL)
264 		current_map->unhandled_input();
265 	else
266 		global_key_unbound();
267 
268 	strlcpy(keybuf, "", sizeof(keybuf));
269 	current_map = base_map;
270 
271 done:
272 	if (side_window)
273 		recompute_help();
274 
275 	if (should_rearrange_windows)
276 		rearrange_windows();
277 	redraw_tab(current_tab);
278 }
279 
280 static void
281 handle_resize(int sig, short ev, void *d)
282 {
283 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
284 		event_del(&resizeev);
285 	}
286 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
287 	evtimer_add(&resizeev, &resize_timer);
288 }
289 
290 static void
291 handle_resize_nodelay(int s, short ev, void *d)
292 {
293 	endwin();
294 	refresh();
295 	clear();
296 
297 	rearrange_windows();
298 }
299 
300 static void
301 rearrange_windows(void)
302 {
303 	int		 lines;
304 
305 	should_rearrange_windows = 0;
306 
307 	lines = LINES;
308 
309 	if ((too_small = lines < 15)) {
310 		erase();
311 		printw("Window too small.");
312 		refresh();
313 		return;
314 	}
315 
316 	/* move and resize the windows, in reverse order! */
317 
318 	if (in_minibuffer == MB_COMPREAD) {
319 		mvwin(minibuffer, lines-10, 0);
320 		wresize(minibuffer, 10, COLS);
321 		lines -= 10;
322 
323 		wrap_page(&ministate.compl.buffer, COLS);
324 	}
325 
326 	mvwin(echoarea, --lines, 0);
327 	wresize(echoarea, 1, COLS);
328 
329 	mvwin(modeline, --lines, 0);
330 	wresize(modeline, 1, COLS);
331 
332 	body_lines = --lines;
333 	body_cols = COLS;
334 
335 	if (side_window) {
336 		help_cols = 0.3 * COLS;
337 		help_lines = lines;
338 		mvwin(help, 1, 0);
339 		wresize(help, help_lines, help_cols);
340 
341 		wrap_page(&helpwin, help_cols);
342 
343 		body_cols = COLS - help_cols - 1;
344 		mvwin(body, 1, help_cols);
345 	} else
346 		mvwin(body, 1, 0);
347 
348 	update_x_offset();
349 	wresize(body, body_lines, body_cols);
350 
351 	wresize(tabline, 1, COLS);
352 
353 	wrap_page(&current_tab->buffer, body_cols);
354 	redraw_tab(current_tab);
355 }
356 
357 static void
358 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
359     const char **prfx_ret, const char **text_ret)
360 {
361 	int type, i, cont, width;
362 	char *space, *t;
363 
364 	if ((*text_ret = vl->line) == NULL)
365 		*text_ret = "";
366 
367 	cont = vl->flags & L_CONTINUATION;
368 	type = vl->parent->type;
369 	if (!cont)
370 		*prfx_ret = line_prefixes[type].prfx1;
371 	else
372 		*prfx_ret = line_prefixes[type].prfx2;
373 
374 	space = vl->parent->data;
375 	if (!emojify_link || type != LINE_LINK || space == NULL)
376 		return;
377 
378 	if (cont) {
379 		memset(buf, 0, len);
380 		width = utf8_swidth_between(vl->parent->line, space);
381 		for (i = 0; i < width + 1; ++i)
382 			strlcat(buf, " ", len);
383 	} else {
384 		strlcpy(buf, *text_ret, len);
385 		if ((t = strchr(buf, ' ')) != NULL)
386 			*t = '\0';
387 		strlcat(buf, " ", len);
388 
389 		/* skip the emoji */
390                 *text_ret += (space - vl->parent->line) + 1;
391 	}
392 
393 	*prfx_ret = buf;
394 }
395 
396 static inline void
397 print_vline_descr(int width, WINDOW *window, struct vline *vl)
398 {
399 	int x, y, goal;
400 
401 	if (vl->parent->type != LINE_COMPL &&
402 	    vl->parent->type != LINE_COMPL_CURRENT &&
403 	    vl->parent->type != LINE_HELP)
404 		return;
405 
406 	if (vl->parent->alt == NULL)
407 		return;
408 
409 	(void)y;
410 	getyx(window, y, x);
411 
412 	if (vl->parent->type == LINE_HELP)
413 		goal = 8;
414 	else
415 		goal = width/2;
416 
417 	if (goal <= x)
418 		wprintw(window, " ");
419 	for (; goal > x; ++x)
420 		wprintw(window, " ");
421 
422 	wprintw(window, "%s", vl->parent->alt);
423 }
424 
425 /*
426  * Core part of the rendering.  It prints a vline starting from the
427  * current cursor position.  Printing a vline consists of skipping
428  * `off' columns (for olivetti-mode), print the correct prefix (which
429  * may be the emoji in case of emojified links-lines), printing the
430  * text itself, filling until width - off and filling off columns
431  * again.
432  */
433 static void
434 print_vline(int off, int width, WINDOW *window, struct vline *vl)
435 {
436 	/*
437 	 * Believe me or not, I've seen emoji ten code points long!
438 	 * That means, to stay large, 4*10 bytes + NUL.
439 	 */
440 	char emojibuf[41] = {0};
441 	const char *text, *prfx;
442 	struct line_face *f;
443 	int i, left, x, y;
444 
445 	f = &line_faces[vl->parent->type];
446 
447 	/* unused, set by getyx */
448 	(void)y;
449 
450 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
451 
452 	wattr_on(window, body_face.left, NULL);
453 	for (i = 0; i < off; i++)
454 		waddch(window, ' ');
455 	wattr_off(window, body_face.left, NULL);
456 
457 	wattr_on(window, f->prefix, NULL);
458 	wprintw(window, "%s", prfx);
459 	wattr_off(window, f->prefix, NULL);
460 
461 	wattr_on(window, f->text, NULL);
462 	wprintw(window, "%s", text);
463 	print_vline_descr(width, window, vl);
464 	wattr_off(window, f->text, NULL);
465 
466 	getyx(window, y, x);
467 
468 	left = width - x;
469 
470 	wattr_on(window, f->trail, NULL);
471 	for (i = 0; i < left - off; ++i)
472 		waddch(window, ' ');
473 	wattr_off(window, f->trail, NULL);
474 
475 	wattr_on(window, body_face.right, NULL);
476 	for (i = 0; i < off; i++)
477 		waddch(window, ' ');
478 	wattr_off(window, body_face.right, NULL);
479 
480 }
481 
482 static void
483 redraw_tabline(void)
484 {
485 	struct tab	*tab;
486 	size_t		 toskip, ots, tabwidth, space, x;
487 	int		 current, y, truncated, pair;
488 	const char	*title;
489 	char		 buf[25];
490 
491 	x = 0;
492 
493 	/* unused, but setted by a getyx */
494 	(void)y;
495 
496 	tabwidth = sizeof(buf)+1;
497 	space = COLS-2;
498 
499 	toskip = 0;
500 	TAILQ_FOREACH(tab, &tabshead, tabs) {
501 		toskip++;
502 		if (tab == current_tab)
503 			break;
504 	}
505 
506 	if (toskip * tabwidth < space)
507 		toskip = 0;
508 	else {
509 		ots = toskip;
510 		toskip--;
511                 while (toskip != 0 &&
512 		    (ots - toskip+1) * tabwidth < space)
513 			toskip--;
514 	}
515 
516 	werase(tabline);
517 	wattr_on(tabline, tab_face.background, NULL);
518 	wprintw(tabline, toskip == 0 ? " " : "<");
519 	wattr_off(tabline, tab_face.background, NULL);
520 
521 	truncated = 0;
522 	TAILQ_FOREACH(tab, &tabshead, tabs) {
523 		if (truncated)
524 			break;
525 		if (toskip != 0) {
526 			toskip--;
527 			continue;
528 		}
529 
530 		getyx(tabline, y, x);
531 		if (x + sizeof(buf)+2 >= (size_t)COLS)
532 			truncated = 1;
533 
534 		current = tab == current_tab;
535 
536 		if (*(title = tab->buffer.page.title) == '\0')
537 			title = tab->hist_cur->h;
538 
539 		if (tab->flags & TAB_URGENT)
540 			strlcpy(buf, "!", sizeof(buf));
541 		else
542 			strlcpy(buf, " ", sizeof(buf));
543 
544                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
545 			/* truncation happens */
546 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
547 		} else {
548 			/* pad with spaces */
549 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
550 				/* nop */ ;
551 		}
552 
553 		pair = current ? tab_face.current : tab_face.tab;
554 		wattr_on(tabline, pair, NULL);
555 		wprintw(tabline, "%s", buf);
556 		wattr_off(tabline, pair, NULL);
557 
558 		wattr_on(tabline, tab_face.background, NULL);
559 		if (TAILQ_NEXT(tab, tabs) != NULL)
560 			wprintw(tabline, "┃");
561 		wattr_off(tabline, tab_face.background, NULL);
562 	}
563 
564 	wattr_on(tabline, tab_face.background, NULL);
565 	for (; x < (size_t)COLS; ++x)
566 		waddch(tabline, ' ');
567 	if (truncated)
568 		mvwprintw(tabline, 0, COLS-1, ">");
569 	wattr_off(tabline, tab_face.background, NULL);
570 }
571 
572 /*
573  * Compute the first visible line around vl.  Try to search forward
574  * until the end of the buffer; if a visible line is not found, search
575  * backward.  Return NULL if no viable line was found.
576  */
577 struct vline *
578 adjust_line(struct vline *vl, struct buffer *buffer)
579 {
580 	struct vline *t;
581 
582 	if (vl == NULL)
583 		return NULL;
584 
585 	if (!(vl->parent->flags & L_HIDDEN))
586 		return vl;
587 
588 	/* search forward */
589 	for (t = vl;
590 	     t != NULL && t->parent->flags & L_HIDDEN;
591 	     t = TAILQ_NEXT(t, vlines))
592 		;		/* nop */
593 
594 	if (t != NULL)
595 		return t;
596 
597 	/* search backward */
598 	for (t = vl;
599 	     t != NULL && t->parent->flags & L_HIDDEN;
600 	     t = TAILQ_PREV(t, vhead, vlines))
601 		;		/* nop */
602 
603 	return t;
604 }
605 
606 static void
607 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
608 {
609 	struct vline	*vl;
610 	int		 l, onscreen;
611 
612 	restore_curs_x(buffer);
613 
614 	/*
615 	 * TODO: ignoring buffer->force_update and always
616 	 * re-rendering.  In theory we can recompute the y position
617 	 * without a re-render, and optimize here.  It's not the only
618 	 * optimisation possible here, wscrl wolud also be an
619 	 * interesting one.
620 	 */
621 
622 again:
623 	werase(win);
624 	buffer->curs_y = 0;
625 
626 	if (TAILQ_EMPTY(&buffer->head))
627 		goto end;
628 
629 	if (buffer->top_line == NULL)
630 		buffer->top_line = TAILQ_FIRST(&buffer->head);
631 
632 	buffer->top_line = adjust_line(buffer->top_line, buffer);
633 	if (buffer->top_line == NULL)
634 		goto end;
635 
636 	buffer->current_line = adjust_line(buffer->current_line, buffer);
637 
638 	l = 0;
639 	onscreen = 0;
640 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
641 		if (vl->parent->flags & L_HIDDEN)
642 			continue;
643 
644 		wmove(win, l, 0);
645 		print_vline(off, width, win, vl);
646 
647 		if (vl == buffer->current_line)
648 			onscreen = 1;
649 
650 		if (!onscreen)
651 			buffer->curs_y++;
652 
653 		l++;
654 		if (l == height)
655 			break;
656 	}
657 
658 	if (!onscreen) {
659 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
660 			if (vl == buffer->current_line)
661 				break;
662 			if (vl->parent->flags & L_HIDDEN)
663 				continue;
664 			buffer->line_off++;
665 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
666 		}
667 
668 		if (vl != NULL)
669 			goto again;
670 	}
671 
672 	buffer->last_line_off = buffer->line_off;
673 	buffer->force_redraw = 0;
674 end:
675 	wmove(win, buffer->curs_y, buffer->curs_x);
676 }
677 
678 static void
679 redraw_help(void)
680 {
681 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
682 }
683 
684 static void
685 redraw_body(struct tab *tab)
686 {
687 	static struct tab *last_tab;
688 
689 	if (last_tab != tab)
690 		tab->buffer.force_redraw =1;
691 	last_tab = tab;
692 
693 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
694 }
695 
696 static inline char
697 trust_status_char(enum trust_state ts)
698 {
699 	switch (ts) {
700 	case TS_UNKNOWN:	return '-';
701 	case TS_UNTRUSTED:	return '!';
702 	case TS_TEMP_TRUSTED:	return '!';
703 	case TS_TRUSTED:	return 'v';
704 	case TS_VERIFIED:	return 'V';
705 	default:		return 'X';
706 	}
707 }
708 
709 static void
710 redraw_modeline(struct tab *tab)
711 {
712 	struct buffer	*buffer;
713 	double		 pct;
714 	int		 x, y, max_x, max_y;
715 	const char	*mode;
716 	const char	*spin = "-\\|/";
717 
718 	buffer = current_buffer();
719 	mode = buffer->page.name;
720 
721 	werase(modeline);
722 	wattr_on(modeline, modeline_face.background, NULL);
723 	wmove(modeline, 0, 0);
724 
725 	wprintw(modeline, "-%c%c %s ",
726 	    spin[tab->loading_anim_step],
727 	    trust_status_char(tab->trust),
728 	    mode == NULL ? "(none)" : mode);
729 
730 	pct = (buffer->line_off + buffer->curs_y) * 100.0
731 		/ buffer->line_max;
732 
733 	if (buffer->line_max <= (size_t)body_lines)
734                 wprintw(modeline, "All ");
735 	else if (buffer->line_off == 0)
736                 wprintw(modeline, "Top ");
737 	else if (buffer->line_off + body_lines >= buffer->line_max)
738 		wprintw(modeline, "Bottom ");
739 	else
740 		wprintw(modeline, "%.0f%% ", pct);
741 
742 	wprintw(modeline, "%d/%d %s ",
743 	    buffer->line_off + buffer->curs_y,
744 	    buffer->line_max,
745 	    tab->hist_cur->h);
746 
747 	getyx(modeline, y, x);
748 	getmaxyx(modeline, max_y, max_x);
749 
750 	(void)y;
751 	(void)max_y;
752 
753 	for (; x < max_x; ++x)
754 		waddstr(modeline, "-");
755 
756 	wattr_off(modeline, modeline_face.background, NULL);
757 }
758 
759 static void
760 redraw_minibuffer(void)
761 {
762 	wattr_on(echoarea, minibuffer_face.background, NULL);
763 	werase(echoarea);
764 
765 	if (in_minibuffer)
766 		do_redraw_minibuffer();
767 	else
768 		do_redraw_echoarea();
769 
770 	if (in_minibuffer == MB_COMPREAD)
771 		do_redraw_minibuffer_compl();
772 
773 	wattr_off(echoarea, minibuffer_face.background, NULL);
774 }
775 
776 static void
777 do_redraw_echoarea(void)
778 {
779 	struct vline *vl;
780 
781 	if (ministate.curmesg != NULL)
782                 wprintw(echoarea, "%s", ministate.curmesg);
783 	else if (*keybuf != '\0')
784 		waddstr(echoarea, keybuf);
785 	else {
786 		/* If nothing else, show the URL at point */
787 		vl = current_tab->buffer.current_line;
788 		if (vl != NULL && vl->parent->type == LINE_LINK)
789 			waddstr(echoarea, vl->parent->alt);
790 	}
791 }
792 
793 static void
794 do_redraw_minibuffer(void)
795 {
796 	struct buffer	*cmplbuf, *buffer;
797 	size_t		 off_y, off_x = 0;
798 	const char	*start, *c;
799 
800 	cmplbuf = &ministate.compl.buffer;
801 	buffer = &ministate.buffer;
802 	(void)off_y;		/* unused, set by getyx */
803 
804 	wmove(echoarea, 0, 0);
805 
806 	if (in_minibuffer == MB_COMPREAD)
807 		wprintw(echoarea, "(%2d) ",
808 		    cmplbuf->line_max);
809 
810 	wprintw(echoarea, "%s", ministate.prompt);
811 	if (ministate.hist_cur != NULL)
812 		wprintw(echoarea, "(%zu/%zu) ",
813 		    ministate.hist_off + 1,
814 		    ministate.history->len);
815 
816 	getyx(echoarea, off_y, off_x);
817 
818 	start = ministate.hist_cur != NULL
819 		? ministate.hist_cur->h
820 		: ministate.buf;
821 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
822 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
823 		start = utf8_next_cp(start);
824 	}
825 
826 	waddstr(echoarea, start);
827 
828 	if (ministate.curmesg != NULL)
829 		wprintw(echoarea, " [%s]", ministate.curmesg);
830 
831 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
832 }
833 
834 static void
835 do_redraw_minibuffer_compl(void)
836 {
837 	redraw_window(minibuffer, 0, 10, COLS,
838 	    &ministate.compl.buffer);
839 }
840 
841 /*
842  * Place the cursor in the right ncurses window.  If soft is 1, use
843  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
844  * wrefresh.
845  */
846 static void
847 place_cursor(int soft)
848 {
849 	int (*touch)(WINDOW *);
850 
851 	if (soft)
852 		touch = wnoutrefresh;
853 	else
854 		touch = wrefresh;
855 
856 	if (in_minibuffer) {
857 		if (side_window)
858 			touch(help);
859 		touch(body);
860 		touch(echoarea);
861 	} else if (in_side_window) {
862 		touch(body);
863 		touch(echoarea);
864 		touch(help);
865 	} else {
866 		if (side_window)
867 			touch(help);
868 		touch(echoarea);
869 		touch(body);
870 	}
871 }
872 
873 static void
874 redraw_tab(struct tab *tab)
875 {
876 	if (too_small)
877 		return;
878 
879 	if (side_window) {
880 		redraw_help();
881 		wnoutrefresh(help);
882 	}
883 
884 	redraw_tabline();
885 	redraw_body(tab);
886 	redraw_modeline(tab);
887 	redraw_minibuffer();
888 
889 	wnoutrefresh(tabline);
890 	wnoutrefresh(modeline);
891 
892 	if (in_minibuffer == MB_COMPREAD)
893 		wnoutrefresh(minibuffer);
894 
895 	place_cursor(1);
896 
897 	doupdate();
898 
899 	if (set_title)
900 		dprintf(1, "\033]0;%s - Telescope\a",
901 		    current_tab->buffer.page.title);
902 }
903 
904 void
905 start_loading_anim(struct tab *tab)
906 {
907 	if (tab->loading_anim)
908 		return;
909 	tab->loading_anim = 1;
910 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
911 	evtimer_add(&tab->loadingev, &loadingev_timer);
912 }
913 
914 static void
915 update_loading_anim(int fd, short ev, void *d)
916 {
917 	struct tab	*tab = d;
918 
919 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
920 
921 	if (tab == current_tab) {
922 		redraw_modeline(tab);
923 		wrefresh(modeline);
924 		wrefresh(body);
925 		if (in_minibuffer)
926 			wrefresh(echoarea);
927 	}
928 
929 	evtimer_add(&tab->loadingev, &loadingev_timer);
930 }
931 
932 static void
933 stop_loading_anim(struct tab *tab)
934 {
935 	if (!tab->loading_anim)
936 		return;
937 	evtimer_del(&tab->loadingev);
938 	tab->loading_anim = 0;
939 	tab->loading_anim_step = 0;
940 
941 	if (tab != current_tab)
942 		return;
943 
944 	redraw_modeline(tab);
945 
946 	wrefresh(modeline);
947 	wrefresh(body);
948 	if (in_minibuffer)
949 		wrefresh(echoarea);
950 }
951 
952 void
953 load_url_in_tab(struct tab *tab, const char *url, const char *base, int nohist)
954 {
955 	if (!operating) {
956 		load_url(tab, url, base, nohist);
957 		return;
958 	}
959 
960 	message("Loading %s...", url);
961 	start_loading_anim(tab);
962 	load_url(tab, url, base, nohist);
963 
964 	redraw_tab(tab);
965 }
966 
967 void
968 switch_to_tab(struct tab *tab)
969 {
970 	current_tab = tab;
971 	tab->flags &= ~TAB_URGENT;
972 
973 	if (operating && tab->flags & TAB_LAZY)
974 		load_url_in_tab(tab, tab->hist_cur->h, NULL, 0);
975 }
976 
977 unsigned int
978 tab_new_id(void)
979 {
980 	return tab_counter++;
981 }
982 
983 struct tab *
984 new_tab(const char *url, const char *base, struct tab *after)
985 {
986 	struct tab	*tab;
987 
988 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
989 		event_loopbreak();
990 		return NULL;
991 	}
992 	tab->fd = -1;
993 
994 	TAILQ_INIT(&tab->hist.head);
995 
996 	TAILQ_INIT(&tab->buffer.head);
997 	TAILQ_INIT(&tab->buffer.page.head);
998 
999 	tab->id = tab_new_id();
1000 	if (!operating)
1001 		tab->flags |= TAB_LAZY;
1002 	switch_to_tab(tab);
1003 
1004 	if (after != NULL)
1005 		TAILQ_INSERT_AFTER(&tabshead, after, tab, tabs);
1006 	else
1007 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1008 
1009 	load_url_in_tab(tab, url, base, 0);
1010 	return tab;
1011 }
1012 
1013 int
1014 ui_print_colors(void)
1015 {
1016 	int colors = 0, pairs = 0, can_change = 0;
1017 	int columns = 16, lines, color, i, j;
1018 
1019 	initscr();
1020 	if (has_colors()) {
1021 		start_color();
1022 		use_default_colors();
1023 
1024 		colors = COLORS;
1025 		pairs = COLOR_PAIRS;
1026 		can_change = can_change_color();
1027 	}
1028 	endwin();
1029 
1030 	printf("Term info:\n");
1031 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1032 	    getenv("TERM"), colors, pairs, can_change);
1033 	printf("\n");
1034 
1035 	if (colors == 0) {
1036 		printf("No color support\n");
1037 		return 0;
1038 	}
1039 
1040 	printf("Available colors:\n\n");
1041 	lines = (colors - 1) / columns + 1;
1042 	color = 0;
1043 	for (i = 0; i < lines; ++i) {
1044 		for (j = 0; j < columns; ++j, ++color) {
1045 			printf("\033[0;38;5;%dm %03d", color, color);
1046 		}
1047 		printf("\n");
1048 	}
1049 
1050 	printf("\033[0m");
1051 	fflush(stdout);
1052 	return 0;
1053 }
1054 
1055 int
1056 ui_init()
1057 {
1058 	setlocale(LC_ALL, "");
1059 
1060 	minibuffer_init();
1061 
1062 	/* initialize help window */
1063 	TAILQ_INIT(&helpwin.head);
1064 	TAILQ_INIT(&helpwin.page.head);
1065 
1066 	base_map = &global_map;
1067 	current_map = &global_map;
1068 
1069 	initscr();
1070 
1071 	if (enable_colors) {
1072 		if (has_colors()) {
1073 			start_color();
1074 			use_default_colors();
1075 		} else
1076 			enable_colors = 0;
1077 	}
1078 
1079 	config_apply_style();
1080 
1081 	raw();
1082 	noecho();
1083 	nonl();
1084 	intrflush(stdscr, FALSE);
1085 
1086 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1087 		return 0;
1088 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1089 		return 0;
1090 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1091 		return 0;
1092 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1093 		return 0;
1094 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1095 		return 0;
1096 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1097 		return 0;
1098 
1099 	body_lines = LINES-3;
1100 	body_cols = COLS;
1101 
1102 	wbkgd(body, body_face.body);
1103 	wbkgd(echoarea, minibuffer_face.background);
1104 
1105 	update_x_offset();
1106 
1107 	keypad(body, TRUE);
1108 	scrollok(body, FALSE);
1109 
1110 	/* non-blocking input */
1111 	wtimeout(body, 0);
1112 	wtimeout(help, 0);
1113 
1114 	mvwprintw(body, 0, 0, "");
1115 
1116 	evtimer_set(&resizeev, handle_resize, NULL);
1117 
1118 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1119 	event_add(&stdioev, NULL);
1120 
1121 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1122 	signal_add(&winchev, NULL);
1123 
1124 	return 1;
1125 }
1126 
1127 void
1128 ui_main_loop(void)
1129 {
1130 	operating = 1;
1131 	switch_to_tab(current_tab);
1132 	redraw_tab(current_tab);
1133 
1134 	event_dispatch();
1135 }
1136 
1137 void
1138 ui_on_tab_loaded(struct tab *tab)
1139 {
1140 	stop_loading_anim(tab);
1141 	message("Loaded %s", tab->hist_cur->h);
1142 
1143 	redraw_tabline();
1144 	wrefresh(tabline);
1145 	place_cursor(0);
1146 }
1147 
1148 void
1149 ui_on_tab_refresh(struct tab *tab)
1150 {
1151 	wrap_page(&tab->buffer, body_cols);
1152 	if (tab == current_tab)
1153 		redraw_tab(tab);
1154 	else
1155 		tab->flags |= TAB_URGENT;
1156 }
1157 
1158 const char *
1159 ui_keyname(int k)
1160 {
1161 	return keyname(k);
1162 }
1163 
1164 void
1165 ui_toggle_side_window(void)
1166 {
1167 	side_window = !side_window;
1168 	if (side_window)
1169 		recompute_help();
1170 	else
1171 		in_side_window = 0;
1172 
1173 	/*
1174 	 * ugly hack, but otherwise the window doesn't get updated
1175 	 * until I call rearrange_windows a second time (e.g. via
1176 	 * C-l).  I will be happy to know why something like this is
1177 	 * needed.
1178 	 */
1179 	rearrange_windows();
1180 	rearrange_windows();
1181 }
1182 
1183 void
1184 ui_schedule_redraw(void)
1185 {
1186 	should_rearrange_windows = 1;
1187 }
1188 
1189 void
1190 ui_require_input(struct tab *tab, int hide, int proto)
1191 {
1192 	void (*fn)(void);
1193 
1194 	if (proto == PROTO_GEMINI)
1195 		fn = ir_select_gemini;
1196 	else if (proto == PROTO_GOPHER)
1197 		fn = ir_select_gopher;
1198 	else
1199 		abort();
1200 
1201 	/* TODO: hard-switching to another tab is ugly */
1202 	switch_to_tab(tab);
1203 
1204 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1205 	    &ir_history, NULL, NULL);
1206 	strlcpy(ministate.prompt, "Input required: ",
1207 	    sizeof(ministate.prompt));
1208 	redraw_tab(tab);
1209 }
1210 
1211 void
1212 ui_after_message_hook(void)
1213 {
1214 	redraw_minibuffer();
1215 	place_cursor(0);
1216 }
1217 
1218 void
1219 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1220     struct tab *data)
1221 {
1222 	yornp(prompt, fn, data);
1223 	redraw_tab(current_tab);
1224 }
1225 
1226 void
1227 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1228     struct tab *data)
1229 {
1230 	minibuffer_read(prompt, fn, data);
1231 	redraw_tab(current_tab);
1232 }
1233 
1234 void
1235 ui_other_window(void)
1236 {
1237 	if (side_window)
1238 		in_side_window = !in_side_window;
1239 	else
1240 		message("No other window to select");
1241 }
1242 
1243 void
1244 ui_suspend(void)
1245 {
1246 	endwin();
1247 
1248 	kill(getpid(), SIGSTOP);
1249 
1250 	refresh();
1251 	clear();
1252 	rearrange_windows();
1253 }
1254 
1255 void
1256 ui_end(void)
1257 {
1258 	endwin();
1259 }