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Date:: Tue Jul 27 07:47:05 2021 UTC
Message:: libevent is already included by telescope.h
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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 struct kmap global_map,
109 	minibuffer_map,
110 	*current_map,
111 	*base_map;
112 
113 static inline void
114 update_x_offset(void)
115 {
116 	if (olivetti_mode && fill_column < body_cols)
117 		x_offset = (body_cols - fill_column)/2;
118 	else
119 		x_offset = 0;
120 }
121 
122 void
123 save_excursion(struct excursion *place, struct buffer *buffer)
124 {
125 	place->curs_x = buffer->curs_x;
126 	place->curs_y = buffer->curs_y;
127 	place->line_off = buffer->line_off;
128 	place->top_line = buffer->top_line;
129 	place->current_line = buffer->current_line;
130 	place->cpoff = buffer->cpoff;
131 }
132 
133 void
134 restore_excursion(struct excursion *place, struct buffer *buffer)
135 {
136 	buffer->curs_x = place->curs_x;
137 	buffer->curs_y = place->curs_y;
138 	buffer->line_off = place->line_off;
139 	buffer->top_line = place->top_line;
140 	buffer->current_line = place->current_line;
141 	buffer->cpoff = place->cpoff;
142 }
143 
144 static void
145 restore_curs_x(struct buffer *buffer)
146 {
147 	struct vline	*vl;
148 	const char	*prfx, *text;
149 
150 	vl = buffer->current_line;
151 	if (vl == NULL || vl->line == NULL)
152 		buffer->curs_x = buffer->cpoff = 0;
153 	else if (vl->parent->data != NULL) {
154 		text = vl->parent->data;
155 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
156 	} else
157 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
158 
159 	buffer->curs_x += x_offset;
160 
161 	if (vl == NULL)
162 		return;
163 
164 	if (vl->parent->data != NULL)
165 		buffer->curs_x += utf8_swidth_between(vl->parent->line, vl->parent->data);
166 	else {
167 		prfx = line_prefixes[vl->parent->type].prfx1;
168 		buffer->curs_x += utf8_swidth(prfx);
169 	}
170 }
171 
172 void
173 global_key_unbound(void)
174 {
175 	message("%s is undefined", keybuf);
176 }
177 
178 struct buffer *
179 current_buffer(void)
180 {
181 	if (in_minibuffer)
182 		return &ministate.buffer;
183 	if (in_side_window)
184 		return &helpwin;
185 	return &current_tab->buffer;
186 }
187 
188 static int
189 readkey(void)
190 {
191 	uint32_t state = 0;
192 
193 	if ((thiskey.key = wgetch(body)) == ERR)
194 		return 0;
195 
196 	thiskey.meta = thiskey.key == 27;
197 	if (thiskey.meta) {
198 		thiskey.key = wgetch(body);
199 		if (thiskey.key == ERR || thiskey.key == 27) {
200 			thiskey.meta = 0;
201 			thiskey.key = 27;
202 		}
203 	}
204 
205 	thiskey.cp = 0;
206 	if ((unsigned int)thiskey.key < UINT8_MAX) {
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 
217 	return 1;
218 }
219 
220 static void
221 dispatch_stdio(int fd, short ev, void *d)
222 {
223 	struct keymap	*k;
224 	const char	*keyname;
225 	char		 tmp[5] = {0};
226 
227 	/* TODO: schedule a redraw? */
228 	if (too_small)
229 		return;
230 
231 	if (!readkey())
232 		return;
233 
234 	if (keybuf[0] != '\0')
235 		strlcat(keybuf, " ", sizeof(keybuf));
236 	if (thiskey.meta)
237 		strlcat(keybuf, "M-", sizeof(keybuf));
238 	if (thiskey.cp != 0) {
239 		utf8_encode(thiskey.cp, tmp);
240 		strlcat(keybuf, tmp, sizeof(keybuf));
241 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
242 		strlcat(keybuf, keyname, sizeof(keybuf));
243 	} else {
244 		tmp[0] = thiskey.key;
245 		strlcat(keybuf, tmp, sizeof(keybuf));
246 	}
247 
248 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
249 		if (k->meta == thiskey.meta &&
250 		    k->key == thiskey.key) {
251 			if (k->fn == NULL)
252 				current_map = &k->map;
253 			else {
254 				current_map = base_map;
255 				strlcpy(keybuf, "", sizeof(keybuf));
256 				k->fn(current_buffer());
257 			}
258 			goto done;
259 		}
260 	}
261 
262 	if (current_map->unhandled_input != NULL)
263 		current_map->unhandled_input();
264 	else
265 		global_key_unbound();
266 
267 	strlcpy(keybuf, "", sizeof(keybuf));
268 	current_map = base_map;
269 
270 done:
271 	if (side_window)
272 		recompute_help();
273 
274 	if (should_rearrange_windows)
275 		rearrange_windows();
276 	redraw_tab(current_tab);
277 }
278 
279 static void
280 handle_resize(int sig, short ev, void *d)
281 {
282 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
283 		event_del(&resizeev);
284 	}
285 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
286 	evtimer_add(&resizeev, &resize_timer);
287 }
288 
289 static void
290 handle_resize_nodelay(int s, short ev, void *d)
291 {
292 	endwin();
293 	refresh();
294 	clear();
295 
296 	rearrange_windows();
297 }
298 
299 static void
300 rearrange_windows(void)
301 {
302 	int		 lines;
303 
304 	should_rearrange_windows = 0;
305 
306 	lines = LINES;
307 
308 	if ((too_small = lines < 15)) {
309 		erase();
310 		printw("Window too small.");
311 		refresh();
312 		return;
313 	}
314 
315 	/* move and resize the windows, in reverse order! */
316 
317 	if (in_minibuffer == MB_COMPREAD) {
318 		mvwin(minibuffer, lines-10, 0);
319 		wresize(minibuffer, 10, COLS);
320 		lines -= 10;
321 
322 		wrap_page(&ministate.compl.buffer, COLS);
323 	}
324 
325 	mvwin(echoarea, --lines, 0);
326 	wresize(echoarea, 1, COLS);
327 
328 	mvwin(modeline, --lines, 0);
329 	wresize(modeline, 1, COLS);
330 
331 	body_lines = --lines;
332 	body_cols = COLS;
333 
334 	if (side_window) {
335 		help_cols = 0.3 * COLS;
336 		help_lines = lines;
337 		mvwin(help, 1, 0);
338 		wresize(help, help_lines, help_cols);
339 
340 		wrap_page(&helpwin, help_cols);
341 
342 		body_cols = COLS - help_cols - 1;
343 		mvwin(body, 1, help_cols);
344 	} else
345 		mvwin(body, 1, 0);
346 
347 	update_x_offset();
348 	wresize(body, body_lines, body_cols);
349 
350 	wresize(tabline, 1, COLS);
351 
352 	wrap_page(&current_tab->buffer, body_cols);
353 	redraw_tab(current_tab);
354 }
355 
356 static void
357 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
358     const char **prfx_ret, const char **text_ret)
359 {
360 	int type, i, cont, width;
361 	char *space, *t;
362 
363 	if ((*text_ret = vl->line) == NULL)
364 		*text_ret = "";
365 
366 	cont = vl->flags & L_CONTINUATION;
367 	type = vl->parent->type;
368 	if (!cont)
369 		*prfx_ret = line_prefixes[type].prfx1;
370 	else
371 		*prfx_ret = line_prefixes[type].prfx2;
372 
373 	space = vl->parent->data;
374 	if (!emojify_link || type != LINE_LINK || space == NULL)
375 		return;
376 
377 	if (cont) {
378 		memset(buf, 0, len);
379 		width = utf8_swidth_between(vl->parent->line, space);
380 		for (i = 0; i < width + 1; ++i)
381 			strlcat(buf, " ", len);
382 	} else {
383 		strlcpy(buf, *text_ret, len);
384 		if ((t = strchr(buf, ' ')) != NULL)
385 			*t = '\0';
386 		strlcat(buf, " ", len);
387 
388 		/* skip the emoji */
389                 *text_ret += (space - vl->parent->line) + 1;
390 	}
391 
392 	*prfx_ret = buf;
393 }
394 
395 static inline void
396 print_vline_descr(int width, WINDOW *window, struct vline *vl)
397 {
398 	int x, y, goal;
399 
400 	if (vl->parent->type != LINE_COMPL &&
401 	    vl->parent->type != LINE_COMPL_CURRENT &&
402 	    vl->parent->type != LINE_HELP)
403 		return;
404 
405 	if (vl->parent->alt == NULL)
406 		return;
407 
408 	(void)y;
409 	getyx(window, y, x);
410 
411 	if (vl->parent->type == LINE_HELP)
412 		goal = 8;
413 	else
414 		goal = width/2;
415 
416 	if (goal <= x)
417 		wprintw(window, " ");
418 	for (; goal > x; ++x)
419 		wprintw(window, " ");
420 
421 	wprintw(window, "%s", vl->parent->alt);
422 }
423 
424 /*
425  * Core part of the rendering.  It prints a vline starting from the
426  * current cursor position.  Printing a vline consists of skipping
427  * `off' columns (for olivetti-mode), print the correct prefix (which
428  * may be the emoji in case of emojified links-lines), printing the
429  * text itself, filling until width - off and filling off columns
430  * again.
431  */
432 static void
433 print_vline(int off, int width, WINDOW *window, struct vline *vl)
434 {
435 	/*
436 	 * Believe me or not, I've seen emoji ten code points long!
437 	 * That means, to stay large, 4*10 bytes + NUL.
438 	 */
439 	char emojibuf[41] = {0};
440 	const char *text, *prfx;
441 	struct line_face *f;
442 	int i, left, x, y;
443 
444 	f = &line_faces[vl->parent->type];
445 
446 	/* unused, set by getyx */
447 	(void)y;
448 
449 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
450 
451 	wattr_on(window, body_face.left, NULL);
452 	for (i = 0; i < off; i++)
453 		waddch(window, ' ');
454 	wattr_off(window, body_face.left, NULL);
455 
456 	wattr_on(window, f->prefix, NULL);
457 	wprintw(window, "%s", prfx);
458 	wattr_off(window, f->prefix, NULL);
459 
460 	wattr_on(window, f->text, NULL);
461 	wprintw(window, "%s", text);
462 	print_vline_descr(width, window, vl);
463 	wattr_off(window, f->text, NULL);
464 
465 	getyx(window, y, x);
466 
467 	left = width - x;
468 
469 	wattr_on(window, f->trail, NULL);
470 	for (i = 0; i < left - off; ++i)
471 		waddch(window, ' ');
472 	wattr_off(window, f->trail, NULL);
473 
474 	wattr_on(window, body_face.right, NULL);
475 	for (i = 0; i < off; i++)
476 		waddch(window, ' ');
477 	wattr_off(window, body_face.right, NULL);
478 
479 }
480 
481 static void
482 redraw_tabline(void)
483 {
484 	struct tab	*tab;
485 	size_t		 toskip, ots, tabwidth, space, x;
486 	int		 current, y, truncated, pair;
487 	const char	*title;
488 	char		 buf[25];
489 
490 	x = 0;
491 
492 	/* unused, but setted by a getyx */
493 	(void)y;
494 
495 	tabwidth = sizeof(buf)+1;
496 	space = COLS-2;
497 
498 	toskip = 0;
499 	TAILQ_FOREACH(tab, &tabshead, tabs) {
500 		toskip++;
501 		if (tab == current_tab)
502 			break;
503 	}
504 
505 	if (toskip * tabwidth < space)
506 		toskip = 0;
507 	else {
508 		ots = toskip;
509 		toskip--;
510                 while (toskip != 0 &&
511 		    (ots - toskip+1) * tabwidth < space)
512 			toskip--;
513 	}
514 
515 	werase(tabline);
516 	wattr_on(tabline, tab_face.background, NULL);
517 	wprintw(tabline, toskip == 0 ? " " : "<");
518 	wattr_off(tabline, tab_face.background, NULL);
519 
520 	truncated = 0;
521 	TAILQ_FOREACH(tab, &tabshead, tabs) {
522 		if (truncated)
523 			break;
524 		if (toskip != 0) {
525 			toskip--;
526 			continue;
527 		}
528 
529 		getyx(tabline, y, x);
530 		if (x + sizeof(buf)+2 >= (size_t)COLS)
531 			truncated = 1;
532 
533 		current = tab == current_tab;
534 
535 		if (*(title = tab->buffer.page.title) == '\0')
536 			title = tab->hist_cur->h;
537 
538 		if (tab->flags & TAB_URGENT)
539 			strlcpy(buf, "!", sizeof(buf));
540 		else
541 			strlcpy(buf, " ", sizeof(buf));
542 
543                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
544 			/* truncation happens */
545 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
546 		} else {
547 			/* pad with spaces */
548 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
549 				/* nop */ ;
550 		}
551 
552 		pair = current ? tab_face.current : tab_face.tab;
553 		wattr_on(tabline, pair, NULL);
554 		wprintw(tabline, "%s", buf);
555 		wattr_off(tabline, pair, NULL);
556 
557 		wattr_on(tabline, tab_face.background, NULL);
558 		if (TAILQ_NEXT(tab, tabs) != NULL)
559 			wprintw(tabline, "┃");
560 		wattr_off(tabline, tab_face.background, NULL);
561 	}
562 
563 	wattr_on(tabline, tab_face.background, NULL);
564 	for (; x < (size_t)COLS; ++x)
565 		waddch(tabline, ' ');
566 	if (truncated)
567 		mvwprintw(tabline, 0, COLS-1, ">");
568 	wattr_off(tabline, tab_face.background, NULL);
569 }
570 
571 /*
572  * Compute the first visible line around vl.  Try to search forward
573  * until the end of the buffer; if a visible line is not found, search
574  * backward.  Return NULL if no viable line was found.
575  */
576 struct vline *
577 adjust_line(struct vline *vl, struct buffer *buffer)
578 {
579 	struct vline *t;
580 
581 	if (vl == NULL)
582 		return NULL;
583 
584 	if (!(vl->parent->flags & L_HIDDEN))
585 		return vl;
586 
587 	/* search forward */
588 	for (t = vl;
589 	     t != NULL && t->parent->flags & L_HIDDEN;
590 	     t = TAILQ_NEXT(t, vlines))
591 		;		/* nop */
592 
593 	if (t != NULL)
594 		return t;
595 
596 	/* search backward */
597 	for (t = vl;
598 	     t != NULL && t->parent->flags & L_HIDDEN;
599 	     t = TAILQ_PREV(t, vhead, vlines))
600 		;		/* nop */
601 
602 	return t;
603 }
604 
605 static void
606 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
607 {
608 	struct vline	*vl;
609 	int		 l, onscreen;
610 
611 	restore_curs_x(buffer);
612 
613 	/*
614 	 * TODO: ignoring buffer->force_update and always
615 	 * re-rendering.  In theory we can recompute the y position
616 	 * without a re-render, and optimize here.  It's not the only
617 	 * optimisation possible here, wscrl wolud also be an
618 	 * interesting one.
619 	 */
620 
621 again:
622 	werase(win);
623 	buffer->curs_y = 0;
624 
625 	if (TAILQ_EMPTY(&buffer->head))
626 		goto end;
627 
628 	if (buffer->top_line == NULL)
629 		buffer->top_line = TAILQ_FIRST(&buffer->head);
630 
631 	buffer->top_line = adjust_line(buffer->top_line, buffer);
632 	if (buffer->top_line == NULL)
633 		goto end;
634 
635 	buffer->current_line = adjust_line(buffer->current_line, buffer);
636 
637 	l = 0;
638 	onscreen = 0;
639 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
640 		if (vl->parent->flags & L_HIDDEN)
641 			continue;
642 
643 		wmove(win, l, 0);
644 		print_vline(off, width, win, vl);
645 
646 		if (vl == buffer->current_line)
647 			onscreen = 1;
648 
649 		if (!onscreen)
650 			buffer->curs_y++;
651 
652 		l++;
653 		if (l == height)
654 			break;
655 	}
656 
657 	if (!onscreen) {
658 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
659 			if (vl == buffer->current_line)
660 				break;
661 			if (vl->parent->flags & L_HIDDEN)
662 				continue;
663 			buffer->line_off++;
664 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
665 		}
666 
667 		if (vl != NULL)
668 			goto again;
669 	}
670 
671 	buffer->last_line_off = buffer->line_off;
672 	buffer->force_redraw = 0;
673 end:
674 	wmove(win, buffer->curs_y, buffer->curs_x);
675 }
676 
677 static void
678 redraw_help(void)
679 {
680 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
681 }
682 
683 static void
684 redraw_body(struct tab *tab)
685 {
686 	static struct tab *last_tab;
687 
688 	if (last_tab != tab)
689 		tab->buffer.force_redraw =1;
690 	last_tab = tab;
691 
692 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
693 }
694 
695 static inline char
696 trust_status_char(enum trust_state ts)
697 {
698 	switch (ts) {
699 	case TS_UNKNOWN:	return '-';
700 	case TS_UNTRUSTED:	return '!';
701 	case TS_TEMP_TRUSTED:	return '!';
702 	case TS_TRUSTED:	return 'v';
703 	case TS_VERIFIED:	return 'V';
704 	default:		return 'X';
705 	}
706 }
707 
708 static void
709 redraw_modeline(struct tab *tab)
710 {
711 	struct buffer	*buffer;
712 	double		 pct;
713 	int		 x, y, max_x, max_y;
714 	const char	*mode;
715 	const char	*spin = "-\\|/";
716 
717 	buffer = current_buffer();
718 	mode = buffer->page.name;
719 
720 	werase(modeline);
721 	wattr_on(modeline, modeline_face.background, NULL);
722 	wmove(modeline, 0, 0);
723 
724 	wprintw(modeline, "-%c%c %s ",
725 	    spin[tab->loading_anim_step],
726 	    trust_status_char(tab->trust),
727 	    mode == NULL ? "(none)" : mode);
728 
729 	pct = (buffer->line_off + buffer->curs_y) * 100.0
730 		/ buffer->line_max;
731 
732 	if (buffer->line_max <= (size_t)body_lines)
733                 wprintw(modeline, "All ");
734 	else if (buffer->line_off == 0)
735                 wprintw(modeline, "Top ");
736 	else if (buffer->line_off + body_lines >= buffer->line_max)
737 		wprintw(modeline, "Bottom ");
738 	else
739 		wprintw(modeline, "%.0f%% ", pct);
740 
741 	wprintw(modeline, "%d/%d %s ",
742 	    buffer->line_off + buffer->curs_y,
743 	    buffer->line_max,
744 	    tab->hist_cur->h);
745 
746 	getyx(modeline, y, x);
747 	getmaxyx(modeline, max_y, max_x);
748 
749 	(void)y;
750 	(void)max_y;
751 
752 	for (; x < max_x; ++x)
753 		waddstr(modeline, "-");
754 
755 	wattr_off(modeline, modeline_face.background, NULL);
756 }
757 
758 static void
759 redraw_minibuffer(void)
760 {
761 	wattr_on(echoarea, minibuffer_face.background, NULL);
762 	werase(echoarea);
763 
764 	if (in_minibuffer)
765 		do_redraw_minibuffer();
766 	else
767 		do_redraw_echoarea();
768 
769 	if (in_minibuffer == MB_COMPREAD)
770 		do_redraw_minibuffer_compl();
771 
772 	wattr_off(echoarea, minibuffer_face.background, NULL);
773 }
774 
775 static void
776 do_redraw_echoarea(void)
777 {
778 	struct vline *vl;
779 
780 	if (ministate.curmesg != NULL)
781                 wprintw(echoarea, "%s", ministate.curmesg);
782 	else if (*keybuf != '\0')
783 		waddstr(echoarea, keybuf);
784 	else {
785 		/* If nothing else, show the URL at point */
786 		vl = current_tab->buffer.current_line;
787 		if (vl != NULL && vl->parent->type == LINE_LINK)
788 			waddstr(echoarea, vl->parent->alt);
789 	}
790 }
791 
792 static void
793 do_redraw_minibuffer(void)
794 {
795 	struct buffer	*cmplbuf, *buffer;
796 	size_t		 off_y, off_x = 0;
797 	const char	*start, *c;
798 
799 	cmplbuf = &ministate.compl.buffer;
800 	buffer = &ministate.buffer;
801 	(void)off_y;		/* unused, set by getyx */
802 
803 	wmove(echoarea, 0, 0);
804 
805 	if (in_minibuffer == MB_COMPREAD)
806 		wprintw(echoarea, "(%2d) ",
807 		    cmplbuf->line_max);
808 
809 	wprintw(echoarea, "%s", ministate.prompt);
810 	if (ministate.hist_cur != NULL)
811 		wprintw(echoarea, "(%zu/%zu) ",
812 		    ministate.hist_off + 1,
813 		    ministate.history->len);
814 
815 	getyx(echoarea, off_y, off_x);
816 
817 	start = ministate.hist_cur != NULL
818 		? ministate.hist_cur->h
819 		: ministate.buf;
820 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
821 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
822 		start = utf8_next_cp(start);
823 	}
824 
825 	waddstr(echoarea, start);
826 
827 	if (ministate.curmesg != NULL)
828 		wprintw(echoarea, " [%s]", ministate.curmesg);
829 
830 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
831 }
832 
833 static void
834 do_redraw_minibuffer_compl(void)
835 {
836 	redraw_window(minibuffer, 0, 10, COLS,
837 	    &ministate.compl.buffer);
838 }
839 
840 /*
841  * Place the cursor in the right ncurses window.  If soft is 1, use
842  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
843  * wrefresh.
844  */
845 static void
846 place_cursor(int soft)
847 {
848 	int (*touch)(WINDOW *);
849 
850 	if (soft)
851 		touch = wnoutrefresh;
852 	else
853 		touch = wrefresh;
854 
855 	if (in_minibuffer) {
856 		if (side_window)
857 			touch(help);
858 		touch(body);
859 		touch(echoarea);
860 	} else if (in_side_window) {
861 		touch(body);
862 		touch(echoarea);
863 		touch(help);
864 	} else {
865 		if (side_window)
866 			touch(help);
867 		touch(echoarea);
868 		touch(body);
869 	}
870 }
871 
872 static void
873 redraw_tab(struct tab *tab)
874 {
875 	if (too_small)
876 		return;
877 
878 	if (side_window) {
879 		redraw_help();
880 		wnoutrefresh(help);
881 	}
882 
883 	redraw_tabline();
884 	redraw_body(tab);
885 	redraw_modeline(tab);
886 	redraw_minibuffer();
887 
888 	wnoutrefresh(tabline);
889 	wnoutrefresh(modeline);
890 
891 	if (in_minibuffer == MB_COMPREAD)
892 		wnoutrefresh(minibuffer);
893 
894 	place_cursor(1);
895 
896 	doupdate();
897 
898 	if (set_title)
899 		dprintf(1, "\033]0;%s - Telescope\a",
900 		    current_tab->buffer.page.title);
901 }
902 
903 void
904 start_loading_anim(struct tab *tab)
905 {
906 	if (tab->loading_anim)
907 		return;
908 	tab->loading_anim = 1;
909 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
910 	evtimer_add(&tab->loadingev, &loadingev_timer);
911 }
912 
913 static void
914 update_loading_anim(int fd, short ev, void *d)
915 {
916 	struct tab	*tab = d;
917 
918 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
919 
920 	if (tab == current_tab) {
921 		redraw_modeline(tab);
922 		wrefresh(modeline);
923 		wrefresh(body);
924 		if (in_minibuffer)
925 			wrefresh(echoarea);
926 	}
927 
928 	evtimer_add(&tab->loadingev, &loadingev_timer);
929 }
930 
931 static void
932 stop_loading_anim(struct tab *tab)
933 {
934 	if (!tab->loading_anim)
935 		return;
936 	evtimer_del(&tab->loadingev);
937 	tab->loading_anim = 0;
938 	tab->loading_anim_step = 0;
939 
940 	if (tab != current_tab)
941 		return;
942 
943 	redraw_modeline(tab);
944 
945 	wrefresh(modeline);
946 	wrefresh(body);
947 	if (in_minibuffer)
948 		wrefresh(echoarea);
949 }
950 
951 void
952 load_url_in_tab(struct tab *tab, const char *url, const char *base)
953 {
954 	if (!operating) {
955 		load_url(tab, url, base);
956 		return;
957 	}
958 
959 	message("Loading %s...", url);
960 	start_loading_anim(tab);
961 	load_url(tab, url, base);
962 
963 	redraw_tab(tab);
964 }
965 
966 void
967 switch_to_tab(struct tab *tab)
968 {
969 	current_tab = tab;
970 	tab->flags &= ~TAB_URGENT;
971 
972 	if (operating && tab->flags & TAB_LAZY)
973 		load_url_in_tab(tab, tab->hist_cur->h, NULL);
974 }
975 
976 unsigned int
977 tab_new_id(void)
978 {
979 	return tab_counter++;
980 }
981 
982 struct tab *
983 new_tab(const char *url, const char *base)
984 {
985 	struct tab	*tab;
986 
987 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
988 		event_loopbreak();
989 		return NULL;
990 	}
991 	tab->fd = -1;
992 
993 	TAILQ_INIT(&tab->hist.head);
994 
995 	TAILQ_INIT(&tab->buffer.head);
996 
997 	tab->id = tab_new_id();
998 	if (!operating)
999 		tab->flags |= TAB_LAZY;
1000 	switch_to_tab(tab);
1001 
1002 	if (TAILQ_EMPTY(&tabshead))
1003 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1004 	else
1005 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1006 
1007 	load_url_in_tab(tab, url, base);
1008 	return tab;
1009 }
1010 
1011 int
1012 ui_print_colors(void)
1013 {
1014 	int colors = 0, pairs = 0, can_change = 0;
1015 	int columns = 16, lines, color, i, j;
1016 
1017 	initscr();
1018 	if (has_colors()) {
1019 		start_color();
1020 		use_default_colors();
1021 
1022 		colors = COLORS;
1023 		pairs = COLOR_PAIRS;
1024 		can_change = can_change_color();
1025 	}
1026 	endwin();
1027 
1028 	printf("Term info:\n");
1029 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1030 	    getenv("TERM"), colors, pairs, can_change);
1031 	printf("\n");
1032 
1033 	if (colors == 0) {
1034 		printf("No color support\n");
1035 		return 0;
1036 	}
1037 
1038 	printf("Available colors:\n\n");
1039 	lines = (colors - 1) / columns + 1;
1040 	color = 0;
1041 	for (i = 0; i < lines; ++i) {
1042 		for (j = 0; j < columns; ++j, ++color) {
1043 			printf("\033[0;38;5;%dm %03d", color, color);
1044 		}
1045 		printf("\n");
1046 	}
1047 
1048 	printf("\033[0m");
1049 	fflush(stdout);
1050 	return 0;
1051 }
1052 
1053 int
1054 ui_init()
1055 {
1056 	setlocale(LC_ALL, "");
1057 
1058 	minibuffer_init();
1059 
1060 	/* initialize help window */
1061 	TAILQ_INIT(&helpwin.head);
1062 
1063 	base_map = &global_map;
1064 	current_map = &global_map;
1065 
1066 	initscr();
1067 
1068 	if (enable_colors) {
1069 		if (has_colors()) {
1070 			start_color();
1071 			use_default_colors();
1072 		} else
1073 			enable_colors = 0;
1074 	}
1075 
1076 	config_apply_style();
1077 
1078 	raw();
1079 	noecho();
1080 	nonl();
1081 	intrflush(stdscr, FALSE);
1082 
1083 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1084 		return 0;
1085 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1086 		return 0;
1087 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1088 		return 0;
1089 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1090 		return 0;
1091 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1092 		return 0;
1093 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1094 		return 0;
1095 
1096 	body_lines = LINES-3;
1097 	body_cols = COLS;
1098 
1099 	wbkgd(body, body_face.body);
1100 	wbkgd(echoarea, minibuffer_face.background);
1101 
1102 	update_x_offset();
1103 
1104 	keypad(body, TRUE);
1105 	scrollok(body, FALSE);
1106 
1107 	/* non-blocking input */
1108 	wtimeout(body, 0);
1109 	wtimeout(help, 0);
1110 
1111 	mvwprintw(body, 0, 0, "");
1112 
1113 	evtimer_set(&resizeev, handle_resize, NULL);
1114 
1115 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1116 	event_add(&stdioev, NULL);
1117 
1118 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1119 	signal_add(&winchev, NULL);
1120 
1121 	return 1;
1122 }
1123 
1124 void
1125 ui_main_loop(void)
1126 {
1127 	operating = 1;
1128 	switch_to_tab(current_tab);
1129 	redraw_tab(current_tab);
1130 
1131 	event_dispatch();
1132 }
1133 
1134 void
1135 ui_on_tab_loaded(struct tab *tab)
1136 {
1137 	stop_loading_anim(tab);
1138 	message("Loaded %s", tab->hist_cur->h);
1139 
1140 	redraw_tabline();
1141 	wrefresh(tabline);
1142 	place_cursor(0);
1143 }
1144 
1145 void
1146 ui_on_tab_refresh(struct tab *tab)
1147 {
1148 	wrap_page(&tab->buffer, body_cols);
1149 	if (tab == current_tab)
1150 		redraw_tab(tab);
1151 	else
1152 		tab->flags |= TAB_URGENT;
1153 }
1154 
1155 const char *
1156 ui_keyname(int k)
1157 {
1158 	return keyname(k);
1159 }
1160 
1161 void
1162 ui_toggle_side_window(void)
1163 {
1164 	side_window = !side_window;
1165 	if (side_window)
1166 		recompute_help();
1167 	else
1168 		in_side_window = 0;
1169 
1170 	/*
1171 	 * ugly hack, but otherwise the window doesn't get updated
1172 	 * until I call rearrange_windows a second time (e.g. via
1173 	 * C-l).  I will be happy to know why something like this is
1174 	 * needed.
1175 	 */
1176 	rearrange_windows();
1177 	rearrange_windows();
1178 }
1179 
1180 void
1181 ui_schedule_redraw(void)
1182 {
1183 	should_rearrange_windows = 1;
1184 }
1185 
1186 void
1187 ui_require_input(struct tab *tab, int hide)
1188 {
1189 	/* TODO: hard-switching to another tab is ugly */
1190 	switch_to_tab(tab);
1191 
1192 	enter_minibuffer(sensible_self_insert, ir_select, exit_minibuffer,
1193 	    &ir_history, NULL, NULL);
1194 	strlcpy(ministate.prompt, "Input required: ",
1195 	    sizeof(ministate.prompt));
1196 	redraw_tab(tab);
1197 }
1198 
1199 void
1200 ui_after_message_hook(void)
1201 {
1202 	redraw_minibuffer();
1203 	place_cursor(0);
1204 }
1205 
1206 void
1207 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1208     struct tab *data)
1209 {
1210 	yornp(prompt, fn, data);
1211 	redraw_tab(current_tab);
1212 }
1213 
1214 void
1215 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1216     struct tab *data)
1217 {
1218 	minibuffer_read(prompt, fn, data);
1219 	redraw_tab(current_tab);
1220 }
1221 
1222 void
1223 ui_other_window(void)
1224 {
1225 	if (side_window)
1226 		in_side_window = !in_side_window;
1227 	else
1228 		message("No other window to select");
1229 }
1230 
1231 void
1232 ui_suspend(void)
1233 {
1234 	endwin();
1235 
1236 	kill(getpid(), SIGSTOP);
1237 
1238 	refresh();
1239 	clear();
1240 	rearrange_windows();
1241 }
1242 
1243 void
1244 ui_end(void)
1245 {
1246 	endwin();
1247 }