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Date:: Mon Feb 7 16:08:20 2022 UTC
Message:: ui_require_input: take a fn pointer instead of the protocol number
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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		 set_scroll_position(struct tab *, size_t, size_t);
54 
55 static void		 restore_curs_x(struct buffer *);
56 
57 static int		 readkey(void);
58 static void		 dispatch_stdio(int, short, void*);
59 static void		 handle_resize(int, short, void*);
60 static void		 handle_resize_nodelay(int, short, void*);
61 static void		 rearrange_windows(void);
62 static void		 line_prefix_and_text(struct vline *, char *, size_t, const char **, const char **);
63 static void		 print_vline(int, int, WINDOW*, struct vline*);
64 static void		 redraw_tabline(void);
65 static void		 redraw_window(WINDOW *, int, int, int, int, struct buffer *);
66 static void		 redraw_download(void);
67 static void		 redraw_help(void);
68 static void		 redraw_body(struct tab*);
69 static void		 redraw_modeline(struct tab*);
70 static void		 redraw_minibuffer(void);
71 static void		 do_redraw_echoarea(void);
72 static void		 do_redraw_minibuffer(void);
73 static void		 do_redraw_minibuffer_compl(void);
74 static void		 place_cursor(int);
75 static void		 redraw_tab(struct tab*);
76 static void		 update_loading_anim(int, short, void*);
77 static void		 stop_loading_anim(struct tab*);
78 
79 static int		 should_rearrange_windows;
80 static int		 show_tab_bar;
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 WINDOW		*download;
100 /* not static so we can see them from download.c */
101 struct buffer		 downloadwin;
102 int			 download_lines;
103 int			 download_cols;
104 
105 static int		 side_window;
106 static int		 in_side_window;
107 
108 static struct timeval	loadingev_timer = { 0, 250000 };
109 
110 static char	keybuf[64];
111 
112 /* XXX: don't forget to init these in main() */
113 struct kmap global_map,
114 	minibuffer_map,
115 	*current_map,
116 	*base_map;
117 
118 static inline void
119 update_x_offset(void)
120 {
121 	if (olivetti_mode && fill_column < body_cols)
122 		x_offset = (body_cols - fill_column)/2;
123 	else
124 		x_offset = 0;
125 }
126 
127 static void
128 set_scroll_position(struct tab *tab, size_t top, size_t cur)
129 {
130 	struct line *last;
131 	struct vline *vl;
132 	size_t i = 0;
133 	int topfound = 0;
134 
135 	last = TAILQ_FIRST(&tab->buffer.page.head);
136 	TAILQ_FOREACH(vl, &tab->buffer.head, vlines) {
137 		if (last != vl->parent) {
138 			last = vl->parent;
139 			i++;
140 		}
141 
142 		if (!topfound && i == top) {
143 			topfound = 1;
144 			tab->buffer.top_line = vl;
145 		}
146 
147 		if (i == cur) {
148 			tab->buffer.current_line = vl;
149 			return;
150 		}
151 	}
152 
153 	if (!topfound)
154 		tab->buffer.top_line = TAILQ_FIRST(&tab->buffer.head);
155 
156 	tab->buffer.current_line = tab->buffer.top_line;
157 }
158 
159 void
160 get_scroll_position(struct tab *tab, size_t *top, size_t *cur)
161 {
162 	struct line *l;
163 	int topfound = 0;
164 
165 	*top = 0;
166 	*cur = 0;
167 
168 	if (tab->buffer.top_line == NULL ||
169 	    tab->buffer.current_line == NULL)
170 		return;
171 
172 	TAILQ_FOREACH(l, &tab->buffer.page.head, lines) {
173 		if (tab->buffer.top_line->parent == l)
174 			topfound = 1;
175 		if (tab->buffer.current_line->parent == l)
176 			return;
177 
178 		if (!topfound)
179 			(*top)++;
180 		(*cur)++;
181 	}
182 }
183 
184 void
185 save_excursion(struct excursion *place, struct buffer *buffer)
186 {
187 	place->curs_x = buffer->curs_x;
188 	place->curs_y = buffer->curs_y;
189 	place->line_off = buffer->line_off;
190 	place->top_line = buffer->top_line;
191 	place->current_line = buffer->current_line;
192 	place->cpoff = buffer->cpoff;
193 }
194 
195 void
196 restore_excursion(struct excursion *place, struct buffer *buffer)
197 {
198 	buffer->curs_x = place->curs_x;
199 	buffer->curs_y = place->curs_y;
200 	buffer->line_off = place->line_off;
201 	buffer->top_line = place->top_line;
202 	buffer->current_line = place->current_line;
203 	buffer->cpoff = place->cpoff;
204 }
205 
206 static void
207 restore_curs_x(struct buffer *buffer)
208 {
209 	struct vline	*vl;
210 	const char	*prfx, *text;
211 
212 	vl = buffer->current_line;
213 	if (vl == NULL || vl->line == NULL)
214 		buffer->curs_x = buffer->cpoff = 0;
215 	else if (vl->parent->data != NULL) {
216 		text = vl->parent->data;
217 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
218 	} else
219 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
220 
221 	/* small hack: don't olivetti-mode the download pane */
222 	if (buffer != &downloadwin)
223 		buffer->curs_x += x_offset;
224 
225 	if (vl == NULL)
226 		return;
227 
228 	if (vl->parent->data != NULL)
229 		buffer->curs_x += utf8_swidth_between(vl->parent->line,
230 		    vl->parent->data);
231 	else {
232 		prfx = line_prefixes[vl->parent->type].prfx1;
233 		buffer->curs_x += utf8_swidth(prfx);
234 	}
235 }
236 
237 void
238 global_key_unbound(void)
239 {
240 	message("%s is undefined", keybuf);
241 }
242 
243 struct buffer *
244 current_buffer(void)
245 {
246 	if (in_minibuffer)
247 		return &ministate.buffer;
248 	if (in_side_window & SIDE_WINDOW_LEFT)
249 		return &helpwin;
250 	if (in_side_window & SIDE_WINDOW_BOTTOM)
251 		return &downloadwin;
252 	return &current_tab->buffer;
253 }
254 
255 static int
256 readkey(void)
257 {
258 	uint32_t state = 0;
259 
260 	if ((thiskey.key = wgetch(body)) == ERR)
261 		return 0;
262 
263 	thiskey.meta = thiskey.key == '\e';
264 	if (thiskey.meta) {
265 		thiskey.key = wgetch(body);
266 		if (thiskey.key == ERR || thiskey.key == '\e') {
267 			thiskey.meta = 0;
268 			thiskey.key = '\e';
269 		}
270 	}
271 
272 	thiskey.cp = 0;
273 
274 	if ((unsigned int)thiskey.key >= UINT8_MAX)
275 		return 1;
276 
277 	while (1) {
278 		if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
279 			break;
280 		if ((thiskey.key = wgetch(body)) == ERR) {
281 			message("Error decoding user input");
282 			return 0;
283 		}
284 	}
285 
286 	return 1;
287 }
288 
289 static void
290 dispatch_stdio(int fd, short ev, void *d)
291 {
292 	int		 lk;
293 	const char	*keyname;
294 	char		 tmp[5] = {0};
295 
296 	/* TODO: schedule a redraw? */
297 	if (too_small)
298 		return;
299 
300 	if (!readkey())
301 		return;
302 
303 	if (keybuf[0] != '\0')
304 		strlcat(keybuf, " ", sizeof(keybuf));
305 	if (thiskey.meta)
306 		strlcat(keybuf, "M-", sizeof(keybuf));
307 	if (thiskey.cp != 0) {
308 		utf8_encode(thiskey.cp, tmp);
309 		strlcat(keybuf, tmp, sizeof(keybuf));
310 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
311 		strlcat(keybuf, keyname, sizeof(keybuf));
312 	} else {
313 		tmp[0] = thiskey.key;
314 		strlcat(keybuf, tmp, sizeof(keybuf));
315 	}
316 
317 	lk = lookup_key(&current_map, &thiskey, current_buffer());
318 	if (lk == LK_UNBOUND) {
319 		if (current_map->unhandled_input != NULL)
320 			current_map->unhandled_input();
321 		else
322 			global_key_unbound();
323 	}
324 	if (lk != LK_ADVANCED_MAP) {
325 		current_map = base_map;
326 		strlcpy(keybuf, "", sizeof(keybuf));
327 	}
328 
329 	if (side_window & SIDE_WINDOW_LEFT)
330 		recompute_help();
331 
332 	if (should_rearrange_windows)
333 		rearrange_windows();
334 	redraw_tab(current_tab);
335 }
336 
337 static void
338 handle_resize(int sig, short ev, void *d)
339 {
340 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
341 		event_del(&resizeev);
342 	}
343 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
344 	evtimer_add(&resizeev, &resize_timer);
345 }
346 
347 static void
348 handle_resize_nodelay(int s, short ev, void *d)
349 {
350 	endwin();
351 	refresh();
352 	clear();
353 
354 	rearrange_windows();
355 }
356 
357 static inline int
358 should_show_tab_bar(void)
359 {
360 	if (tab_bar_show == -1)
361 		return 0;
362 	if (tab_bar_show == 0)
363 		return 1;
364 
365 	return TAILQ_NEXT(TAILQ_FIRST(&tabshead), tabs) != NULL;
366 }
367 
368 static void
369 rearrange_windows(void)
370 {
371 	int		 lines;
372 	int		 minibuffer_lines;
373 
374 	should_rearrange_windows = 0;
375 	show_tab_bar = should_show_tab_bar();
376 
377 	lines = LINES;
378 
379 	/* 3 lines for the ui and 12 for the  */
380 	if ((too_small = lines < 15)) {
381 		erase();
382 		printw("Window too small.");
383 		refresh();
384 		return;
385 	}
386 
387 	/* move and resize the windows, in reverse order! */
388 
389 	if (in_minibuffer == MB_COMPREAD) {
390 		minibuffer_lines = MIN(10, lines/2);
391 		mvwin(minibuffer, lines - minibuffer_lines, 0);
392 		wresize(minibuffer, minibuffer_lines, COLS);
393 		lines -= minibuffer_lines;
394 
395 		wrap_page(&ministate.compl.buffer, COLS);
396 	}
397 
398 	mvwin(echoarea, --lines, 0);
399 	wresize(echoarea, 1, COLS);
400 
401 	mvwin(modeline, --lines, 0);
402 	wresize(modeline, 1, COLS);
403 
404 	if (side_window & SIDE_WINDOW_BOTTOM) {
405 		download_lines = MIN(5, lines/2);
406 		download_cols = COLS;
407 		mvwin(download, lines - download_lines, 0);
408 		wresize(download, download_lines, download_cols);
409 		lines -= download_lines;
410 
411 		wrap_page(&downloadwin, download_cols);
412 	}
413 
414 	body_lines = show_tab_bar ? --lines : lines;
415 	body_cols = COLS;
416 
417 	/*
418 	 * Here we make the assumption that show_tab_bar is either 0
419 	 * or 1, and reuse that as argument to mvwin.
420 	 */
421 	if (side_window & SIDE_WINDOW_LEFT) {
422 		help_cols = 0.3 * COLS;
423 		help_lines = lines;
424 		mvwin(help, show_tab_bar, 0);
425 		wresize(help, help_lines, help_cols);
426 
427 		wrap_page(&helpwin, help_cols);
428 
429 		body_cols = COLS - help_cols - 1;
430 		mvwin(body, show_tab_bar, help_cols);
431 	} else
432 		mvwin(body, show_tab_bar, 0);
433 
434 	update_x_offset();
435 	wresize(body, body_lines, body_cols);
436 
437 	if (show_tab_bar)
438 		wresize(tabline, 1, COLS);
439 
440 	wrap_page(&current_tab->buffer, body_cols);
441 	redraw_tab(current_tab);
442 }
443 
444 static void
445 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
446     const char **prfx_ret, const char **text_ret)
447 {
448 	int type, i, cont, width;
449 	char *space, *t;
450 
451 	if ((*text_ret = vl->line) == NULL)
452 		*text_ret = "";
453 
454 	cont = vl->flags & L_CONTINUATION;
455 	type = vl->parent->type;
456 	if (!cont)
457 		*prfx_ret = line_prefixes[type].prfx1;
458 	else
459 		*prfx_ret = line_prefixes[type].prfx2;
460 
461 	space = vl->parent->data;
462 	if (!emojify_link || type != LINE_LINK || space == NULL)
463 		return;
464 
465 	if (cont) {
466 		memset(buf, 0, len);
467 		width = utf8_swidth_between(vl->parent->line, space);
468 		for (i = 0; i < width + 1; ++i)
469 			strlcat(buf, " ", len);
470 	} else {
471 		strlcpy(buf, *text_ret, len);
472 		if ((t = strchr(buf, ' ')) != NULL)
473 			*t = '\0';
474 		strlcat(buf, " ", len);
475 
476 		/* skip the emoji */
477 		*text_ret += (space - vl->parent->line) + 1;
478 	}
479 
480 	*prfx_ret = buf;
481 }
482 
483 static inline void
484 print_vline_descr(int width, WINDOW *window, struct vline *vl)
485 {
486 	int x, y, goal;
487 
488 	switch (vl->parent->type) {
489 	case LINE_COMPL:
490 	case LINE_COMPL_CURRENT:
491 		goal = width/2;
492 		break;
493 	case LINE_DOWNLOAD:
494 	case LINE_DOWNLOAD_DONE:
495 		goal = width/4;
496 		break;
497 	case LINE_HELP:
498 		goal = 8;
499 		break;
500 	default:
501 		return;
502 	}
503 
504 	if (vl->parent->alt == NULL)
505 		return;
506 
507 	(void)y;
508 	getyx(window, y, x);
509 
510 	if (goal <= x)
511 		wprintw(window, " ");
512 	for (; goal > x; ++x)
513 		wprintw(window, " ");
514 
515 	wprintw(window, "%s", vl->parent->alt);
516 }
517 
518 /*
519  * Core part of the rendering.  It prints a vline starting from the
520  * current cursor position.  Printing a vline consists of skipping
521  * `off' columns (for olivetti-mode), print the correct prefix (which
522  * may be the emoji in case of emojified links-lines), printing the
523  * text itself, filling until width - off and filling off columns
524  * again.
525  */
526 static void
527 print_vline(int off, int width, WINDOW *window, struct vline *vl)
528 {
529 	/*
530 	 * Believe me or not, I've seen emoji ten code points long!
531 	 * That means, to stay large, 4*10 bytes + NUL.
532 	 */
533 	char emojibuf[41] = {0};
534 	const char *text, *prfx;
535 	struct line_face *f;
536 	int i, left, x, y;
537 
538 	f = &line_faces[vl->parent->type];
539 
540 	/* unused, set by getyx */
541 	(void)y;
542 
543 	if (vl->parent->type == LINE_FRINGE && fringe_ignore_offset)
544 		off = 0;
545 
546 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
547 
548 	wattr_on(window, body_face.left, NULL);
549 	for (i = 0; i < off; i++)
550 		waddch(window, ' ');
551 	wattr_off(window, body_face.left, NULL);
552 
553 	wattr_on(window, f->prefix, NULL);
554 	wprintw(window, "%s", prfx);
555 	wattr_off(window, f->prefix, NULL);
556 
557 	wattr_on(window, f->text, NULL);
558 	wprintw(window, "%s", text);
559 	print_vline_descr(width, window, vl);
560 	wattr_off(window, f->text, NULL);
561 
562 	getyx(window, y, x);
563 
564 	left = width - x;
565 
566 	wattr_on(window, f->trail, NULL);
567 	for (i = 0; i < left - off; ++i)
568 		waddch(window, ' ');
569 	wattr_off(window, f->trail, NULL);
570 
571 	wattr_on(window, body_face.right, NULL);
572 	for (i = 0; i < off; i++)
573 		waddch(window, ' ');
574 	wattr_off(window, body_face.right, NULL);
575 
576 }
577 
578 static void
579 redraw_tabline(void)
580 {
581 	struct tab	*tab;
582 	size_t		 toskip, ots, tabwidth, space, x;
583 	int		 current, y, truncated, pair;
584 	const char	*title;
585 	char		 buf[25];
586 
587 	x = 0;
588 
589 	/* unused, but setted by a getyx */
590 	(void)y;
591 
592 	tabwidth = sizeof(buf)+1;
593 	space = COLS-2;
594 
595 	toskip = 0;
596 	TAILQ_FOREACH(tab, &tabshead, tabs) {
597 		toskip++;
598 		if (tab == current_tab)
599 			break;
600 	}
601 
602 	if (toskip * tabwidth <= space)
603 		toskip = 0;
604 	else {
605 		ots = toskip;
606 		toskip--;
607 		while (toskip != 0 &&
608 		    (ots - toskip+1) * tabwidth < space)
609 			toskip--;
610 	}
611 
612 	werase(tabline);
613 	wattr_on(tabline, tab_face.background, NULL);
614 	wprintw(tabline, toskip == 0 ? " " : "<");
615 	wattr_off(tabline, tab_face.background, NULL);
616 
617 	truncated = 0;
618 	TAILQ_FOREACH(tab, &tabshead, tabs) {
619 		if (truncated)
620 			break;
621 		if (toskip != 0) {
622 			toskip--;
623 			continue;
624 		}
625 
626 		getyx(tabline, y, x);
627 		if (x + sizeof(buf)+2 >= (size_t)COLS)
628 			truncated = 1;
629 
630 		current = tab == current_tab;
631 
632 		if (*(title = tab->buffer.page.title) == '\0')
633 			title = tab->hist_cur->h;
634 
635 		if (tab->flags & TAB_URGENT)
636 			strlcpy(buf, "!", sizeof(buf));
637 		else
638 			strlcpy(buf, " ", sizeof(buf));
639 
640 		if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
641 			/* truncation happens */
642 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
643 		} else {
644 			/* pad with spaces */
645 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
646 				/* nop */ ;
647 		}
648 
649 		pair = current ? tab_face.current : tab_face.tab;
650 		wattr_on(tabline, pair, NULL);
651 		wprintw(tabline, "%s", buf);
652 		wattr_off(tabline, pair, NULL);
653 
654 		wattr_on(tabline, tab_face.background, NULL);
655 		if (TAILQ_NEXT(tab, tabs) != NULL)
656 			wprintw(tabline, "┃");
657 		wattr_off(tabline, tab_face.background, NULL);
658 	}
659 
660 	wattr_on(tabline, tab_face.background, NULL);
661 	for (; x < (size_t)COLS; ++x)
662 		waddch(tabline, ' ');
663 	if (truncated)
664 		mvwprintw(tabline, 0, COLS-1, ">");
665 	wattr_off(tabline, tab_face.background, NULL);
666 }
667 
668 /*
669  * Compute the first visible line around vl.  Try to search forward
670  * until the end of the buffer; if a visible line is not found, search
671  * backward.  Return NULL if no viable line was found.
672  */
673 struct vline *
674 adjust_line(struct vline *vl, struct buffer *buffer)
675 {
676 	struct vline *t;
677 
678 	if (vl == NULL)
679 		return NULL;
680 
681 	if (!(vl->parent->flags & L_HIDDEN))
682 		return vl;
683 
684 	/* search forward */
685 	for (t = vl;
686 	     t != NULL && t->parent->flags & L_HIDDEN;
687 	     t = TAILQ_NEXT(t, vlines))
688 		;		/* nop */
689 
690 	if (t != NULL)
691 		return t;
692 
693 	/* search backward */
694 	for (t = vl;
695 	     t != NULL && t->parent->flags & L_HIDDEN;
696 	     t = TAILQ_PREV(t, vhead, vlines))
697 		;		/* nop */
698 
699 	return t;
700 }
701 
702 static void
703 redraw_window(WINDOW *win, int off, int height, int width,
704     int show_fringe, struct buffer *buffer)
705 {
706 	struct vline	*vl;
707 	int		 onscreen = 0, l = 0;
708 
709 	restore_curs_x(buffer);
710 
711 	/*
712 	 * TODO: ignoring buffer->force_update and always
713 	 * re-rendering.  In theory we can recompute the y position
714 	 * without a re-render, and optimize here.  It's not the only
715 	 * optimisation possible here, wscrl wolud also be an
716 	 * interesting one.
717 	 */
718 
719 again:
720 	werase(win);
721 	buffer->curs_y = 0;
722 
723 	if (TAILQ_EMPTY(&buffer->head))
724 		goto end;
725 
726 	if (buffer->top_line == NULL)
727 		buffer->top_line = TAILQ_FIRST(&buffer->head);
728 
729 	buffer->top_line = adjust_line(buffer->top_line, buffer);
730 	if (buffer->top_line == NULL)
731 		goto end;
732 
733 	buffer->current_line = adjust_line(buffer->current_line, buffer);
734 
735 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
736 		if (vl->parent->flags & L_HIDDEN)
737 			continue;
738 
739 		wmove(win, l, 0);
740 		print_vline(off, width, win, vl);
741 
742 		if (vl == buffer->current_line)
743 			onscreen = 1;
744 
745 		if (!onscreen)
746 			buffer->curs_y++;
747 
748 		l++;
749 		if (l == height)
750 			break;
751 	}
752 
753 	if (!onscreen) {
754 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
755 			if (vl == buffer->current_line)
756 				break;
757 			if (vl->parent->flags & L_HIDDEN)
758 				continue;
759 			buffer->line_off++;
760 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
761 		}
762 
763 		if (vl != NULL)
764 			goto again;
765 	}
766 
767 	buffer->last_line_off = buffer->line_off;
768 	buffer->force_redraw = 0;
769 end:
770 	for (; show_fringe && l < height; l++)
771 		print_vline(off, width, win, &fringe);
772 
773 	wmove(win, buffer->curs_y, buffer->curs_x);
774 }
775 
776 static void
777 redraw_download(void)
778 {
779 	redraw_window(download, 0, download_lines, COLS, 0, &downloadwin);
780 }
781 
782 static void
783 redraw_help(void)
784 {
785 	redraw_window(help, 0, help_lines, help_cols, 1, &helpwin);
786 }
787 
788 static void
789 redraw_body(struct tab *tab)
790 {
791 	static struct tab *last_tab;
792 
793 	if (last_tab != tab)
794 		tab->buffer.force_redraw =1;
795 	last_tab = tab;
796 
797 	redraw_window(body, x_offset, body_lines, body_cols, 1, &tab->buffer);
798 }
799 
800 static inline char
801 trust_status_char(enum trust_state ts)
802 {
803 	switch (ts) {
804 	case TS_UNKNOWN:	return '-';
805 	case TS_UNTRUSTED:	return '!';
806 	case TS_TEMP_TRUSTED:	return '!';
807 	case TS_TRUSTED:	return 'v';
808 	case TS_VERIFIED:	return 'V';
809 	default:		return 'X';
810 	}
811 }
812 
813 static void
814 redraw_modeline(struct tab *tab)
815 {
816 	struct buffer	*buffer;
817 	double		 pct;
818 	int		 x, y, max_x, max_y;
819 	const char	*mode;
820 	const char	*spin = "-\\|/";
821 
822 	buffer = current_buffer();
823 	mode = buffer->page.name;
824 
825 	werase(modeline);
826 	wattr_on(modeline, modeline_face.background, NULL);
827 	wmove(modeline, 0, 0);
828 
829 	wprintw(modeline, "-%c%c- %s ",
830 	    spin[tab->loading_anim_step],
831 	    trust_status_char(tab->trust),
832 	    mode == NULL ? "(none)" : mode);
833 
834 	pct = (buffer->line_off + buffer->curs_y) * 100.0
835 		/ buffer->line_max;
836 
837 	if (buffer->line_max <= (size_t)body_lines)
838 		wprintw(modeline, "All ");
839 	else if (buffer->line_off == 0)
840 		wprintw(modeline, "Top ");
841 	else if (buffer->line_off + body_lines >= buffer->line_max)
842 		wprintw(modeline, "Bottom ");
843 	else
844 		wprintw(modeline, "%.0f%% ", pct);
845 
846 	wprintw(modeline, "%zu/%zu %s ",
847 	    buffer->line_off + buffer->curs_y,
848 	    buffer->line_max,
849 	    tab->hist_cur->h);
850 
851 	getyx(modeline, y, x);
852 	getmaxyx(modeline, max_y, max_x);
853 
854 	(void)y;
855 	(void)max_y;
856 
857 	for (; x < max_x; ++x)
858 		waddstr(modeline, "-");
859 
860 	wattr_off(modeline, modeline_face.background, NULL);
861 }
862 
863 static void
864 redraw_minibuffer(void)
865 {
866 	wattr_on(echoarea, minibuffer_face.background, NULL);
867 	werase(echoarea);
868 
869 	if (in_minibuffer)
870 		do_redraw_minibuffer();
871 	else
872 		do_redraw_echoarea();
873 
874 	if (in_minibuffer == MB_COMPREAD)
875 		do_redraw_minibuffer_compl();
876 
877 	wattr_off(echoarea, minibuffer_face.background, NULL);
878 }
879 
880 static void
881 do_redraw_echoarea(void)
882 {
883 	struct vline *vl;
884 
885 	if (ministate.curmesg != NULL)
886 		wprintw(echoarea, "%s", ministate.curmesg);
887 	else if (*keybuf != '\0')
888 		waddstr(echoarea, keybuf);
889 	else {
890 		/* If nothing else, show the URL at point */
891 		vl = current_tab->buffer.current_line;
892 		if (vl != NULL && vl->parent->type == LINE_LINK)
893 			waddstr(echoarea, vl->parent->alt);
894 	}
895 }
896 
897 static void
898 do_redraw_minibuffer(void)
899 {
900 	struct buffer	*cmplbuf, *buffer;
901 	size_t		 off_y, off_x = 0;
902 	const char	*start, *c;
903 
904 	cmplbuf = &ministate.compl.buffer;
905 	buffer = &ministate.buffer;
906 	(void)off_y;		/* unused, set by getyx */
907 
908 	wmove(echoarea, 0, 0);
909 
910 	if (in_minibuffer == MB_COMPREAD)
911 		wprintw(echoarea, "(%2zu) ",
912 		    cmplbuf->line_max);
913 
914 	wprintw(echoarea, "%s", ministate.prompt);
915 	if (ministate.hist_cur != NULL)
916 		wprintw(echoarea, "(%zu/%zu) ",
917 		    ministate.hist_off + 1,
918 		    ministate.history->len);
919 
920 	getyx(echoarea, off_y, off_x);
921 
922 	start = ministate.hist_cur != NULL
923 		? ministate.hist_cur->h
924 		: ministate.buf;
925 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
926 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
927 		start = utf8_next_cp(start);
928 	}
929 
930 	waddstr(echoarea, start);
931 
932 	if (ministate.curmesg != NULL)
933 		wprintw(echoarea, " [%s]", ministate.curmesg);
934 
935 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
936 }
937 
938 static void
939 do_redraw_minibuffer_compl(void)
940 {
941 	redraw_window(minibuffer, 0, 10, COLS, 1,
942 	    &ministate.compl.buffer);
943 }
944 
945 /*
946  * Place the cursor in the right ncurses window.  If soft is 1, use
947  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
948  * wrefresh.
949  */
950 static void
951 place_cursor(int soft)
952 {
953 	int (*touch)(WINDOW *);
954 
955 	if (soft)
956 		touch = wnoutrefresh;
957 	else
958 		touch = wrefresh;
959 
960 	if (in_minibuffer) {
961 		if (side_window & SIDE_WINDOW_LEFT)
962 			touch(help);
963 		if (side_window & SIDE_WINDOW_BOTTOM)
964 			touch(download);
965 		touch(body);
966 		touch(echoarea);
967 	} else if (in_side_window & SIDE_WINDOW_LEFT) {
968 		touch(body);
969 		touch(echoarea);
970                 if (in_side_window & SIDE_WINDOW_BOTTOM)
971 			touch(download);
972 		touch(help);
973 	} else if (in_side_window & SIDE_WINDOW_BOTTOM) {
974 		touch(body);
975 		touch(echoarea);
976 		if (in_side_window & SIDE_WINDOW_LEFT)
977 			touch(help);
978 		touch(download);
979 	} else {
980 		if (side_window & SIDE_WINDOW_LEFT)
981 			touch(help);
982 		if (side_window & SIDE_WINDOW_BOTTOM)
983 			touch(download);
984 		touch(echoarea);
985 		touch(body);
986 	}
987 }
988 
989 static void
990 redraw_tab(struct tab *tab)
991 {
992 	if (too_small)
993 		return;
994 
995 	if (side_window & SIDE_WINDOW_LEFT) {
996 		redraw_help();
997 		wnoutrefresh(help);
998 	}
999 
1000 	if (side_window & SIDE_WINDOW_BOTTOM) {
1001 		redraw_download();
1002 		wnoutrefresh(download);
1003 	}
1004 
1005 	if (show_tab_bar)
1006 		redraw_tabline();
1007 
1008 	redraw_body(tab);
1009 	redraw_modeline(tab);
1010 	redraw_minibuffer();
1011 
1012 	wnoutrefresh(tabline);
1013 	wnoutrefresh(modeline);
1014 
1015 	if (in_minibuffer == MB_COMPREAD)
1016 		wnoutrefresh(minibuffer);
1017 
1018 	place_cursor(1);
1019 
1020 	doupdate();
1021 
1022 	if (set_title)
1023 		dprintf(1, "\033]2;%s - Telescope\a",
1024 		    current_tab->buffer.page.title);
1025 }
1026 
1027 void
1028 start_loading_anim(struct tab *tab)
1029 {
1030 	if (tab->loading_anim)
1031 		return;
1032 	tab->loading_anim = 1;
1033 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1034 	evtimer_add(&tab->loadingev, &loadingev_timer);
1035 }
1036 
1037 static void
1038 update_loading_anim(int fd, short ev, void *d)
1039 {
1040 	struct tab	*tab = d;
1041 
1042 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1043 
1044 	if (tab == current_tab) {
1045 		redraw_modeline(tab);
1046 		wrefresh(modeline);
1047 		wrefresh(body);
1048 		if (in_minibuffer)
1049 			wrefresh(echoarea);
1050 	}
1051 
1052 	evtimer_add(&tab->loadingev, &loadingev_timer);
1053 }
1054 
1055 static void
1056 stop_loading_anim(struct tab *tab)
1057 {
1058 	if (!tab->loading_anim)
1059 		return;
1060 	evtimer_del(&tab->loadingev);
1061 	tab->loading_anim = 0;
1062 	tab->loading_anim_step = 0;
1063 
1064 	if (tab != current_tab)
1065 		return;
1066 
1067 	redraw_modeline(tab);
1068 
1069 	wrefresh(modeline);
1070 	wrefresh(body);
1071 	if (in_minibuffer)
1072 		wrefresh(echoarea);
1073 }
1074 
1075 int
1076 ui_print_colors(void)
1077 {
1078 	int colors = 0, pairs = 0, can_change = 0;
1079 	int columns = 16, lines, color, i, j;
1080 
1081 	initscr();
1082 	if (has_colors()) {
1083 		start_color();
1084 		use_default_colors();
1085 
1086 		colors = COLORS;
1087 		pairs = COLOR_PAIRS;
1088 		can_change = can_change_color();
1089 	}
1090 	endwin();
1091 
1092 	printf("Term info:\n");
1093 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1094 	    getenv("TERM"), colors, pairs, can_change);
1095 	printf("\n");
1096 
1097 	if (colors == 0) {
1098 		printf("No color support\n");
1099 		return 0;
1100 	}
1101 
1102 	printf("Available colors:\n\n");
1103 	lines = (colors - 1) / columns + 1;
1104 	color = 0;
1105 	for (i = 0; i < lines; ++i) {
1106 		for (j = 0; j < columns; ++j, ++color) {
1107 			printf("\033[0;38;5;%dm %03d", color, color);
1108 		}
1109 		printf("\n");
1110 	}
1111 
1112 	printf("\033[0m");
1113 	fflush(stdout);
1114 	return 0;
1115 }
1116 
1117 int
1118 ui_init()
1119 {
1120 	setlocale(LC_ALL, "");
1121 
1122 	if (TAILQ_EMPTY(&global_map.m)) {
1123 		fprintf(stderr, "no keys defined!\n");
1124 		return 0;
1125 	}
1126 
1127 	minibuffer_init();
1128 
1129 	/* initialize download window */
1130 	TAILQ_INIT(&downloadwin.head);
1131 	TAILQ_INIT(&downloadwin.page.head);
1132 
1133 	/* initialize help window */
1134 	TAILQ_INIT(&helpwin.head);
1135 	TAILQ_INIT(&helpwin.page.head);
1136 
1137 	base_map = &global_map;
1138 	current_map = &global_map;
1139 
1140 	initscr();
1141 
1142 	if (enable_colors) {
1143 		if (has_colors()) {
1144 			start_color();
1145 			use_default_colors();
1146 		} else
1147 			enable_colors = 0;
1148 	}
1149 
1150 	config_apply_style();
1151 
1152 	raw();
1153 	noecho();
1154 	nonl();
1155 	intrflush(stdscr, FALSE);
1156 
1157 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1158 		return 0;
1159 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1160 		return 0;
1161 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1162 		return 0;
1163 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1164 		return 0;
1165 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1166 		return 0;
1167 	if ((download = newwin(1, 1, 0, 0)) == NULL)
1168 		return 0;
1169 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1170 		return 0;
1171 
1172 	wbkgd(body, body_face.body);
1173 	wbkgd(download, download_face.background);
1174 	wbkgd(echoarea, minibuffer_face.background);
1175 
1176 	update_x_offset();
1177 
1178 	keypad(body, TRUE);
1179 	scrollok(body, FALSE);
1180 
1181 	/* non-blocking input */
1182 	wtimeout(body, 0);
1183 	wtimeout(help, 0);
1184 
1185 	mvwprintw(body, 0, 0, "");
1186 
1187 	return 1;
1188 }
1189 
1190 void
1191 ui_main_loop(void)
1192 {
1193 	evtimer_set(&resizeev, handle_resize, NULL);
1194 
1195 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1196 	event_add(&stdioev, NULL);
1197 
1198 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1199 	signal_add(&winchev, NULL);
1200 
1201 	switch_to_tab(current_tab);
1202 	rearrange_windows();
1203 }
1204 
1205 void
1206 ui_on_tab_loaded(struct tab *tab)
1207 {
1208 	stop_loading_anim(tab);
1209 	message("Loaded %s", tab->hist_cur->h);
1210 
1211 	if (tab->hist_cur->current_off != 0 &&
1212 	    tab->buffer.current_line == TAILQ_FIRST(&tab->buffer.head)) {
1213 		set_scroll_position(tab, tab->hist_cur->line_off,
1214 		    tab->hist_cur->current_off);
1215 		redraw_tab(tab);
1216 		return;
1217 	}
1218 
1219 	if (show_tab_bar)
1220 		redraw_tabline();
1221 
1222 	wrefresh(tabline);
1223 	place_cursor(0);
1224 }
1225 
1226 void
1227 ui_on_tab_refresh(struct tab *tab)
1228 {
1229 	wrap_page(&tab->buffer, body_cols);
1230 	if (tab == current_tab)
1231 		redraw_tab(tab);
1232 	else
1233 		tab->flags |= TAB_URGENT;
1234 }
1235 
1236 void
1237 ui_on_download_refresh(void)
1238 {
1239 	if (side_window & SIDE_WINDOW_BOTTOM) {
1240 		recompute_downloads();
1241 		redraw_tab(current_tab);
1242 	}
1243 }
1244 
1245 const char *
1246 ui_keyname(int k)
1247 {
1248 	return keyname(k);
1249 }
1250 
1251 void
1252 ui_toggle_side_window(int kind)
1253 {
1254 	if (in_side_window & kind)
1255 		ui_other_window();
1256 
1257 	side_window ^= kind;
1258 	if (side_window & SIDE_WINDOW_LEFT)
1259 		recompute_help();
1260 	if (side_window & SIDE_WINDOW_BOTTOM)
1261 		recompute_downloads();
1262 
1263 	/*
1264 	 * ugly hack, but otherwise the window doesn't get updated
1265 	 * until I call rearrange_windows a second time (e.g. via
1266 	 * C-l).  I will be happy to know why something like this is
1267 	 * needed.
1268 	 */
1269 	rearrange_windows();
1270 	rearrange_windows();
1271 }
1272 
1273 void
1274 ui_show_downloads_pane(void)
1275 {
1276 	if (!(side_window & SIDE_WINDOW_BOTTOM))
1277 		ui_toggle_side_window(SIDE_WINDOW_BOTTOM);
1278 }
1279 
1280 void
1281 ui_schedule_redraw(void)
1282 {
1283 	should_rearrange_windows = 1;
1284 }
1285 
1286 void
1287 ui_require_input(struct tab *tab, int hide, void (*fn)(void))
1288 {
1289 	/* TODO: hard-switching to another tab is ugly */
1290 	switch_to_tab(tab);
1291 
1292 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1293 	    &ir_history, NULL, NULL);
1294 	strlcpy(ministate.prompt, "Input required: ",
1295 	    sizeof(ministate.prompt));
1296 	redraw_tab(tab);
1297 }
1298 
1299 void
1300 ui_after_message_hook(void)
1301 {
1302 	redraw_minibuffer();
1303 	place_cursor(0);
1304 }
1305 
1306 void
1307 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1308     struct tab *data)
1309 {
1310 	yornp(prompt, fn, data);
1311 	redraw_tab(current_tab);
1312 }
1313 
1314 void
1315 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1316     struct tab *data, const char *input)
1317 {
1318 	minibuffer_read(prompt, fn, data);
1319 
1320 	if (input != NULL) {
1321 		strlcpy(ministate.buf, input, sizeof(ministate.buf));
1322 		cmd_move_end_of_line(&ministate.buffer);
1323 	}
1324 
1325 	redraw_tab(current_tab);
1326 }
1327 
1328 void
1329 ui_other_window(void)
1330 {
1331 	if (in_side_window & SIDE_WINDOW_LEFT &&
1332 	    side_window & SIDE_WINDOW_BOTTOM)
1333 		in_side_window = SIDE_WINDOW_BOTTOM;
1334 	else if (in_side_window)
1335 		in_side_window = 0;
1336 	else if (!in_side_window && side_window & SIDE_WINDOW_LEFT)
1337 		in_side_window = SIDE_WINDOW_LEFT;
1338 	else if (!in_side_window && side_window)
1339 		in_side_window = SIDE_WINDOW_BOTTOM;
1340 	else
1341 		message("No other window to select");
1342 }
1343 
1344 void
1345 ui_suspend(void)
1346 {
1347 	endwin();
1348 
1349 	kill(getpid(), SIGSTOP);
1350 
1351 	refresh();
1352 	clear();
1353 	rearrange_windows();
1354 }
1355 
1356 void
1357 ui_end(void)
1358 {
1359 	endwin();
1360 }