op public repos

Blob

Date:: Fri Jan 21 10:05:48 2022 UTC
Message:: set_scroll_position: always set current_line There's a small chance we may end up finding the topline but not the current line if a page content is abruptedly changed. While here also drop `curfound = 1': it's a dead assignment since it returns in that conditions. Bug found while reading the output of clang' scan-build, but not thanks to clang. scan-build complained about the `curfound' variable, and by re-reading the code I spotted the missing case.
Actions:: History | Blame | Raw File
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, curfound = 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 (!curfound && 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 		tab->buffer.current_line = tab->buffer.top_line;
156 	}
157 
158 	if (!curfound)
159 		tab->buffer.current_line = tab->buffer.top_line;
160 }
161 
162 void
163 get_scroll_position(struct tab *tab, size_t *top, size_t *cur)
164 {
165 	struct line *l;
166 	int topfound = 0;
167 
168 	*top = 0;
169 	*cur = 0;
170 
171 	if (tab->buffer.top_line == NULL ||
172 	    tab->buffer.current_line == NULL)
173 		return;
174 
175 	TAILQ_FOREACH(l, &tab->buffer.page.head, lines) {
176 		if (tab->buffer.top_line->parent == l)
177 			topfound = 1;
178 		if (tab->buffer.current_line->parent == l)
179 			return;
180 
181 		if (!topfound)
182 			(*top)++;
183 		(*cur)++;
184 	}
185 }
186 
187 void
188 save_excursion(struct excursion *place, struct buffer *buffer)
189 {
190 	place->curs_x = buffer->curs_x;
191 	place->curs_y = buffer->curs_y;
192 	place->line_off = buffer->line_off;
193 	place->top_line = buffer->top_line;
194 	place->current_line = buffer->current_line;
195 	place->cpoff = buffer->cpoff;
196 }
197 
198 void
199 restore_excursion(struct excursion *place, struct buffer *buffer)
200 {
201 	buffer->curs_x = place->curs_x;
202 	buffer->curs_y = place->curs_y;
203 	buffer->line_off = place->line_off;
204 	buffer->top_line = place->top_line;
205 	buffer->current_line = place->current_line;
206 	buffer->cpoff = place->cpoff;
207 }
208 
209 static void
210 restore_curs_x(struct buffer *buffer)
211 {
212 	struct vline	*vl;
213 	const char	*prfx, *text;
214 
215 	vl = buffer->current_line;
216 	if (vl == NULL || vl->line == NULL)
217 		buffer->curs_x = buffer->cpoff = 0;
218 	else if (vl->parent->data != NULL) {
219 		text = vl->parent->data;
220 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
221 	} else
222 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
223 
224 	/* small hack: don't olivetti-mode the download pane */
225 	if (buffer != &downloadwin)
226 		buffer->curs_x += x_offset;
227 
228 	if (vl == NULL)
229 		return;
230 
231 	if (vl->parent->data != NULL)
232 		buffer->curs_x += utf8_swidth_between(vl->parent->line,
233 		    vl->parent->data);
234 	else {
235 		prfx = line_prefixes[vl->parent->type].prfx1;
236 		buffer->curs_x += utf8_swidth(prfx);
237 	}
238 }
239 
240 void
241 global_key_unbound(void)
242 {
243 	message("%s is undefined", keybuf);
244 }
245 
246 struct buffer *
247 current_buffer(void)
248 {
249 	if (in_minibuffer)
250 		return &ministate.buffer;
251 	if (in_side_window & SIDE_WINDOW_LEFT)
252 		return &helpwin;
253 	if (in_side_window & SIDE_WINDOW_BOTTOM)
254 		return &downloadwin;
255 	return &current_tab->buffer;
256 }
257 
258 static int
259 readkey(void)
260 {
261 	uint32_t state = 0;
262 
263 	if ((thiskey.key = wgetch(body)) == ERR)
264 		return 0;
265 
266 	thiskey.meta = thiskey.key == '\e';
267 	if (thiskey.meta) {
268 		thiskey.key = wgetch(body);
269 		if (thiskey.key == ERR || thiskey.key == '\e') {
270 			thiskey.meta = 0;
271 			thiskey.key = '\e';
272 		}
273 	}
274 
275 	thiskey.cp = 0;
276 
277 	if ((unsigned int)thiskey.key >= UINT8_MAX)
278 		return 1;
279 
280 	while (1) {
281 		if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
282 			break;
283 		if ((thiskey.key = wgetch(body)) == ERR) {
284 			message("Error decoding user input");
285 			return 0;
286 		}
287 	}
288 
289 	return 1;
290 }
291 
292 static void
293 dispatch_stdio(int fd, short ev, void *d)
294 {
295 	int		 lk;
296 	const char	*keyname;
297 	char		 tmp[5] = {0};
298 
299 	/* TODO: schedule a redraw? */
300 	if (too_small)
301 		return;
302 
303 	if (!readkey())
304 		return;
305 
306 	if (keybuf[0] != '\0')
307 		strlcat(keybuf, " ", sizeof(keybuf));
308 	if (thiskey.meta)
309 		strlcat(keybuf, "M-", sizeof(keybuf));
310 	if (thiskey.cp != 0) {
311 		utf8_encode(thiskey.cp, tmp);
312 		strlcat(keybuf, tmp, sizeof(keybuf));
313 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
314 		strlcat(keybuf, keyname, sizeof(keybuf));
315 	} else {
316 		tmp[0] = thiskey.key;
317 		strlcat(keybuf, tmp, sizeof(keybuf));
318 	}
319 
320 	lk = lookup_key(&current_map, &thiskey, current_buffer());
321 	if (lk == LK_UNBOUND) {
322 		if (current_map->unhandled_input != NULL)
323 			current_map->unhandled_input();
324 		else
325 			global_key_unbound();
326 	}
327 	if (lk != LK_ADVANCED_MAP) {
328 		current_map = base_map;
329 		strlcpy(keybuf, "", sizeof(keybuf));
330 	}
331 
332 	if (side_window & SIDE_WINDOW_LEFT)
333 		recompute_help();
334 
335 	if (should_rearrange_windows)
336 		rearrange_windows();
337 	redraw_tab(current_tab);
338 }
339 
340 static void
341 handle_resize(int sig, short ev, void *d)
342 {
343 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
344 		event_del(&resizeev);
345 	}
346 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
347 	evtimer_add(&resizeev, &resize_timer);
348 }
349 
350 static void
351 handle_resize_nodelay(int s, short ev, void *d)
352 {
353 	endwin();
354 	refresh();
355 	clear();
356 
357 	rearrange_windows();
358 }
359 
360 static inline int
361 should_show_tab_bar(void)
362 {
363 	if (tab_bar_show == -1)
364 		return 0;
365 	if (tab_bar_show == 0)
366 		return 1;
367 
368 	return TAILQ_NEXT(TAILQ_FIRST(&tabshead), tabs) != NULL;
369 }
370 
371 static void
372 rearrange_windows(void)
373 {
374 	int		 lines;
375 	int		 minibuffer_lines;
376 
377 	should_rearrange_windows = 0;
378 	show_tab_bar = should_show_tab_bar();
379 
380 	lines = LINES;
381 
382 	/* 3 lines for the ui and 12 for the  */
383 	if ((too_small = lines < 15)) {
384 		erase();
385 		printw("Window too small.");
386 		refresh();
387 		return;
388 	}
389 
390 	/* move and resize the windows, in reverse order! */
391 
392 	if (in_minibuffer == MB_COMPREAD) {
393 		minibuffer_lines = MIN(10, lines/2);
394 		mvwin(minibuffer, lines - minibuffer_lines, 0);
395 		wresize(minibuffer, minibuffer_lines, COLS);
396 		lines -= minibuffer_lines;
397 
398 		wrap_page(&ministate.compl.buffer, COLS);
399 	}
400 
401 	mvwin(echoarea, --lines, 0);
402 	wresize(echoarea, 1, COLS);
403 
404 	mvwin(modeline, --lines, 0);
405 	wresize(modeline, 1, COLS);
406 
407 	if (side_window & SIDE_WINDOW_BOTTOM) {
408 		download_lines = MIN(5, lines/2);
409 		download_cols = COLS;
410 		mvwin(download, lines - download_lines, 0);
411 		wresize(download, download_lines, download_cols);
412 		lines -= download_lines;
413 
414 		wrap_page(&downloadwin, download_cols);
415 	}
416 
417 	body_lines = show_tab_bar ? --lines : lines;
418 	body_cols = COLS;
419 
420 	/*
421 	 * Here we make the assumption that show_tab_bar is either 0
422 	 * or 1, and reuse that as argument to mvwin.
423 	 */
424 	if (side_window & SIDE_WINDOW_LEFT) {
425 		help_cols = 0.3 * COLS;
426 		help_lines = lines;
427 		mvwin(help, show_tab_bar, 0);
428 		wresize(help, help_lines, help_cols);
429 
430 		wrap_page(&helpwin, help_cols);
431 
432 		body_cols = COLS - help_cols - 1;
433 		mvwin(body, show_tab_bar, help_cols);
434 	} else
435 		mvwin(body, show_tab_bar, 0);
436 
437 	update_x_offset();
438 	wresize(body, body_lines, body_cols);
439 
440 	if (show_tab_bar)
441 		wresize(tabline, 1, COLS);
442 
443 	wrap_page(&current_tab->buffer, body_cols);
444 	redraw_tab(current_tab);
445 }
446 
447 static void
448 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
449     const char **prfx_ret, const char **text_ret)
450 {
451 	int type, i, cont, width;
452 	char *space, *t;
453 
454 	if ((*text_ret = vl->line) == NULL)
455 		*text_ret = "";
456 
457 	cont = vl->flags & L_CONTINUATION;
458 	type = vl->parent->type;
459 	if (!cont)
460 		*prfx_ret = line_prefixes[type].prfx1;
461 	else
462 		*prfx_ret = line_prefixes[type].prfx2;
463 
464 	space = vl->parent->data;
465 	if (!emojify_link || type != LINE_LINK || space == NULL)
466 		return;
467 
468 	if (cont) {
469 		memset(buf, 0, len);
470 		width = utf8_swidth_between(vl->parent->line, space);
471 		for (i = 0; i < width + 1; ++i)
472 			strlcat(buf, " ", len);
473 	} else {
474 		strlcpy(buf, *text_ret, len);
475 		if ((t = strchr(buf, ' ')) != NULL)
476 			*t = '\0';
477 		strlcat(buf, " ", len);
478 
479 		/* skip the emoji */
480 		*text_ret += (space - vl->parent->line) + 1;
481 	}
482 
483 	*prfx_ret = buf;
484 }
485 
486 static inline void
487 print_vline_descr(int width, WINDOW *window, struct vline *vl)
488 {
489 	int x, y, goal;
490 
491 	switch (vl->parent->type) {
492 	case LINE_COMPL:
493 	case LINE_COMPL_CURRENT:
494 		goal = width/2;
495 		break;
496 	case LINE_DOWNLOAD:
497 	case LINE_DOWNLOAD_DONE:
498 		goal = width/4;
499 		break;
500 	case LINE_HELP:
501 		goal = 8;
502 		break;
503 	default:
504 		return;
505 	}
506 
507 	if (vl->parent->alt == NULL)
508 		return;
509 
510 	(void)y;
511 	getyx(window, y, x);
512 
513 	if (goal <= x)
514 		wprintw(window, " ");
515 	for (; goal > x; ++x)
516 		wprintw(window, " ");
517 
518 	wprintw(window, "%s", vl->parent->alt);
519 }
520 
521 /*
522  * Core part of the rendering.  It prints a vline starting from the
523  * current cursor position.  Printing a vline consists of skipping
524  * `off' columns (for olivetti-mode), print the correct prefix (which
525  * may be the emoji in case of emojified links-lines), printing the
526  * text itself, filling until width - off and filling off columns
527  * again.
528  */
529 static void
530 print_vline(int off, int width, WINDOW *window, struct vline *vl)
531 {
532 	/*
533 	 * Believe me or not, I've seen emoji ten code points long!
534 	 * That means, to stay large, 4*10 bytes + NUL.
535 	 */
536 	char emojibuf[41] = {0};
537 	const char *text, *prfx;
538 	struct line_face *f;
539 	int i, left, x, y;
540 
541 	f = &line_faces[vl->parent->type];
542 
543 	/* unused, set by getyx */
544 	(void)y;
545 
546 	if (vl->parent->type == LINE_FRINGE && fringe_ignore_offset)
547 		off = 0;
548 
549 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
550 
551 	wattr_on(window, body_face.left, NULL);
552 	for (i = 0; i < off; i++)
553 		waddch(window, ' ');
554 	wattr_off(window, body_face.left, NULL);
555 
556 	wattr_on(window, f->prefix, NULL);
557 	wprintw(window, "%s", prfx);
558 	wattr_off(window, f->prefix, NULL);
559 
560 	wattr_on(window, f->text, NULL);
561 	wprintw(window, "%s", text);
562 	print_vline_descr(width, window, vl);
563 	wattr_off(window, f->text, NULL);
564 
565 	getyx(window, y, x);
566 
567 	left = width - x;
568 
569 	wattr_on(window, f->trail, NULL);
570 	for (i = 0; i < left - off; ++i)
571 		waddch(window, ' ');
572 	wattr_off(window, f->trail, NULL);
573 
574 	wattr_on(window, body_face.right, NULL);
575 	for (i = 0; i < off; i++)
576 		waddch(window, ' ');
577 	wattr_off(window, body_face.right, NULL);
578 
579 }
580 
581 static void
582 redraw_tabline(void)
583 {
584 	struct tab	*tab;
585 	size_t		 toskip, ots, tabwidth, space, x;
586 	int		 current, y, truncated, pair;
587 	const char	*title;
588 	char		 buf[25];
589 
590 	x = 0;
591 
592 	/* unused, but setted by a getyx */
593 	(void)y;
594 
595 	tabwidth = sizeof(buf)+1;
596 	space = COLS-2;
597 
598 	toskip = 0;
599 	TAILQ_FOREACH(tab, &tabshead, tabs) {
600 		toskip++;
601 		if (tab == current_tab)
602 			break;
603 	}
604 
605 	if (toskip * tabwidth <= space)
606 		toskip = 0;
607 	else {
608 		ots = toskip;
609 		toskip--;
610 		while (toskip != 0 &&
611 		    (ots - toskip+1) * tabwidth < space)
612 			toskip--;
613 	}
614 
615 	werase(tabline);
616 	wattr_on(tabline, tab_face.background, NULL);
617 	wprintw(tabline, toskip == 0 ? " " : "<");
618 	wattr_off(tabline, tab_face.background, NULL);
619 
620 	truncated = 0;
621 	TAILQ_FOREACH(tab, &tabshead, tabs) {
622 		if (truncated)
623 			break;
624 		if (toskip != 0) {
625 			toskip--;
626 			continue;
627 		}
628 
629 		getyx(tabline, y, x);
630 		if (x + sizeof(buf)+2 >= (size_t)COLS)
631 			truncated = 1;
632 
633 		current = tab == current_tab;
634 
635 		if (*(title = tab->buffer.page.title) == '\0')
636 			title = tab->hist_cur->h;
637 
638 		if (tab->flags & TAB_URGENT)
639 			strlcpy(buf, "!", sizeof(buf));
640 		else
641 			strlcpy(buf, " ", sizeof(buf));
642 
643 		if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
644 			/* truncation happens */
645 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
646 		} else {
647 			/* pad with spaces */
648 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
649 				/* nop */ ;
650 		}
651 
652 		pair = current ? tab_face.current : tab_face.tab;
653 		wattr_on(tabline, pair, NULL);
654 		wprintw(tabline, "%s", buf);
655 		wattr_off(tabline, pair, NULL);
656 
657 		wattr_on(tabline, tab_face.background, NULL);
658 		if (TAILQ_NEXT(tab, tabs) != NULL)
659 			wprintw(tabline, "┃");
660 		wattr_off(tabline, tab_face.background, NULL);
661 	}
662 
663 	wattr_on(tabline, tab_face.background, NULL);
664 	for (; x < (size_t)COLS; ++x)
665 		waddch(tabline, ' ');
666 	if (truncated)
667 		mvwprintw(tabline, 0, COLS-1, ">");
668 	wattr_off(tabline, tab_face.background, NULL);
669 }
670 
671 /*
672  * Compute the first visible line around vl.  Try to search forward
673  * until the end of the buffer; if a visible line is not found, search
674  * backward.  Return NULL if no viable line was found.
675  */
676 struct vline *
677 adjust_line(struct vline *vl, struct buffer *buffer)
678 {
679 	struct vline *t;
680 
681 	if (vl == NULL)
682 		return NULL;
683 
684 	if (!(vl->parent->flags & L_HIDDEN))
685 		return vl;
686 
687 	/* search forward */
688 	for (t = vl;
689 	     t != NULL && t->parent->flags & L_HIDDEN;
690 	     t = TAILQ_NEXT(t, vlines))
691 		;		/* nop */
692 
693 	if (t != NULL)
694 		return t;
695 
696 	/* search backward */
697 	for (t = vl;
698 	     t != NULL && t->parent->flags & L_HIDDEN;
699 	     t = TAILQ_PREV(t, vhead, vlines))
700 		;		/* nop */
701 
702 	return t;
703 }
704 
705 static void
706 redraw_window(WINDOW *win, int off, int height, int width,
707     int show_fringe, struct buffer *buffer)
708 {
709 	struct vline	*vl;
710 	int		 onscreen = 0, l = 0;
711 
712 	restore_curs_x(buffer);
713 
714 	/*
715 	 * TODO: ignoring buffer->force_update and always
716 	 * re-rendering.  In theory we can recompute the y position
717 	 * without a re-render, and optimize here.  It's not the only
718 	 * optimisation possible here, wscrl wolud also be an
719 	 * interesting one.
720 	 */
721 
722 again:
723 	werase(win);
724 	buffer->curs_y = 0;
725 
726 	if (TAILQ_EMPTY(&buffer->head))
727 		goto end;
728 
729 	if (buffer->top_line == NULL)
730 		buffer->top_line = TAILQ_FIRST(&buffer->head);
731 
732 	buffer->top_line = adjust_line(buffer->top_line, buffer);
733 	if (buffer->top_line == NULL)
734 		goto end;
735 
736 	buffer->current_line = adjust_line(buffer->current_line, buffer);
737 
738 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
739 		if (vl->parent->flags & L_HIDDEN)
740 			continue;
741 
742 		wmove(win, l, 0);
743 		print_vline(off, width, win, vl);
744 
745 		if (vl == buffer->current_line)
746 			onscreen = 1;
747 
748 		if (!onscreen)
749 			buffer->curs_y++;
750 
751 		l++;
752 		if (l == height)
753 			break;
754 	}
755 
756 	if (!onscreen) {
757 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
758 			if (vl == buffer->current_line)
759 				break;
760 			if (vl->parent->flags & L_HIDDEN)
761 				continue;
762 			buffer->line_off++;
763 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
764 		}
765 
766 		if (vl != NULL)
767 			goto again;
768 	}
769 
770 	buffer->last_line_off = buffer->line_off;
771 	buffer->force_redraw = 0;
772 end:
773 	for (; show_fringe && l < height; l++)
774 		print_vline(off, width, win, &fringe);
775 
776 	wmove(win, buffer->curs_y, buffer->curs_x);
777 }
778 
779 static void
780 redraw_download(void)
781 {
782 	redraw_window(download, 0, download_lines, COLS, 0, &downloadwin);
783 }
784 
785 static void
786 redraw_help(void)
787 {
788 	redraw_window(help, 0, help_lines, help_cols, 1, &helpwin);
789 }
790 
791 static void
792 redraw_body(struct tab *tab)
793 {
794 	static struct tab *last_tab;
795 
796 	if (last_tab != tab)
797 		tab->buffer.force_redraw =1;
798 	last_tab = tab;
799 
800 	redraw_window(body, x_offset, body_lines, body_cols, 1, &tab->buffer);
801 }
802 
803 static inline char
804 trust_status_char(enum trust_state ts)
805 {
806 	switch (ts) {
807 	case TS_UNKNOWN:	return '-';
808 	case TS_UNTRUSTED:	return '!';
809 	case TS_TEMP_TRUSTED:	return '!';
810 	case TS_TRUSTED:	return 'v';
811 	case TS_VERIFIED:	return 'V';
812 	default:		return 'X';
813 	}
814 }
815 
816 static void
817 redraw_modeline(struct tab *tab)
818 {
819 	struct buffer	*buffer;
820 	double		 pct;
821 	int		 x, y, max_x, max_y;
822 	const char	*mode;
823 	const char	*spin = "-\\|/";
824 
825 	buffer = current_buffer();
826 	mode = buffer->page.name;
827 
828 	werase(modeline);
829 	wattr_on(modeline, modeline_face.background, NULL);
830 	wmove(modeline, 0, 0);
831 
832 	wprintw(modeline, "-%c%c- %s ",
833 	    spin[tab->loading_anim_step],
834 	    trust_status_char(tab->trust),
835 	    mode == NULL ? "(none)" : mode);
836 
837 	pct = (buffer->line_off + buffer->curs_y) * 100.0
838 		/ buffer->line_max;
839 
840 	if (buffer->line_max <= (size_t)body_lines)
841 		wprintw(modeline, "All ");
842 	else if (buffer->line_off == 0)
843 		wprintw(modeline, "Top ");
844 	else if (buffer->line_off + body_lines >= buffer->line_max)
845 		wprintw(modeline, "Bottom ");
846 	else
847 		wprintw(modeline, "%.0f%% ", pct);
848 
849 	wprintw(modeline, "%zu/%zu %s ",
850 	    buffer->line_off + buffer->curs_y,
851 	    buffer->line_max,
852 	    tab->hist_cur->h);
853 
854 	getyx(modeline, y, x);
855 	getmaxyx(modeline, max_y, max_x);
856 
857 	(void)y;
858 	(void)max_y;
859 
860 	for (; x < max_x; ++x)
861 		waddstr(modeline, "-");
862 
863 	wattr_off(modeline, modeline_face.background, NULL);
864 }
865 
866 static void
867 redraw_minibuffer(void)
868 {
869 	wattr_on(echoarea, minibuffer_face.background, NULL);
870 	werase(echoarea);
871 
872 	if (in_minibuffer)
873 		do_redraw_minibuffer();
874 	else
875 		do_redraw_echoarea();
876 
877 	if (in_minibuffer == MB_COMPREAD)
878 		do_redraw_minibuffer_compl();
879 
880 	wattr_off(echoarea, minibuffer_face.background, NULL);
881 }
882 
883 static void
884 do_redraw_echoarea(void)
885 {
886 	struct vline *vl;
887 
888 	if (ministate.curmesg != NULL)
889 		wprintw(echoarea, "%s", ministate.curmesg);
890 	else if (*keybuf != '\0')
891 		waddstr(echoarea, keybuf);
892 	else {
893 		/* If nothing else, show the URL at point */
894 		vl = current_tab->buffer.current_line;
895 		if (vl != NULL && vl->parent->type == LINE_LINK)
896 			waddstr(echoarea, vl->parent->alt);
897 	}
898 }
899 
900 static void
901 do_redraw_minibuffer(void)
902 {
903 	struct buffer	*cmplbuf, *buffer;
904 	size_t		 off_y, off_x = 0;
905 	const char	*start, *c;
906 
907 	cmplbuf = &ministate.compl.buffer;
908 	buffer = &ministate.buffer;
909 	(void)off_y;		/* unused, set by getyx */
910 
911 	wmove(echoarea, 0, 0);
912 
913 	if (in_minibuffer == MB_COMPREAD)
914 		wprintw(echoarea, "(%2zu) ",
915 		    cmplbuf->line_max);
916 
917 	wprintw(echoarea, "%s", ministate.prompt);
918 	if (ministate.hist_cur != NULL)
919 		wprintw(echoarea, "(%zu/%zu) ",
920 		    ministate.hist_off + 1,
921 		    ministate.history->len);
922 
923 	getyx(echoarea, off_y, off_x);
924 
925 	start = ministate.hist_cur != NULL
926 		? ministate.hist_cur->h
927 		: ministate.buf;
928 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
929 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
930 		start = utf8_next_cp(start);
931 	}
932 
933 	waddstr(echoarea, start);
934 
935 	if (ministate.curmesg != NULL)
936 		wprintw(echoarea, " [%s]", ministate.curmesg);
937 
938 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
939 }
940 
941 static void
942 do_redraw_minibuffer_compl(void)
943 {
944 	redraw_window(minibuffer, 0, 10, COLS, 1,
945 	    &ministate.compl.buffer);
946 }
947 
948 /*
949  * Place the cursor in the right ncurses window.  If soft is 1, use
950  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
951  * wrefresh.
952  */
953 static void
954 place_cursor(int soft)
955 {
956 	int (*touch)(WINDOW *);
957 
958 	if (soft)
959 		touch = wnoutrefresh;
960 	else
961 		touch = wrefresh;
962 
963 	if (in_minibuffer) {
964 		if (side_window & SIDE_WINDOW_LEFT)
965 			touch(help);
966 		if (side_window & SIDE_WINDOW_BOTTOM)
967 			touch(download);
968 		touch(body);
969 		touch(echoarea);
970 	} else if (in_side_window & SIDE_WINDOW_LEFT) {
971 		touch(body);
972 		touch(echoarea);
973                 if (in_side_window & SIDE_WINDOW_BOTTOM)
974 			touch(download);
975 		touch(help);
976 	} else if (in_side_window & SIDE_WINDOW_BOTTOM) {
977 		touch(body);
978 		touch(echoarea);
979 		if (in_side_window & SIDE_WINDOW_LEFT)
980 			touch(help);
981 		touch(download);
982 	} else {
983 		if (side_window & SIDE_WINDOW_LEFT)
984 			touch(help);
985 		if (side_window & SIDE_WINDOW_BOTTOM)
986 			touch(download);
987 		touch(echoarea);
988 		touch(body);
989 	}
990 }
991 
992 static void
993 redraw_tab(struct tab *tab)
994 {
995 	if (too_small)
996 		return;
997 
998 	if (side_window & SIDE_WINDOW_LEFT) {
999 		redraw_help();
1000 		wnoutrefresh(help);
1001 	}
1002 
1003 	if (side_window & SIDE_WINDOW_BOTTOM) {
1004 		redraw_download();
1005 		wnoutrefresh(download);
1006 	}
1007 
1008 	if (show_tab_bar)
1009 		redraw_tabline();
1010 
1011 	redraw_body(tab);
1012 	redraw_modeline(tab);
1013 	redraw_minibuffer();
1014 
1015 	wnoutrefresh(tabline);
1016 	wnoutrefresh(modeline);
1017 
1018 	if (in_minibuffer == MB_COMPREAD)
1019 		wnoutrefresh(minibuffer);
1020 
1021 	place_cursor(1);
1022 
1023 	doupdate();
1024 
1025 	if (set_title)
1026 		dprintf(1, "\033]2;%s - Telescope\a",
1027 		    current_tab->buffer.page.title);
1028 }
1029 
1030 void
1031 start_loading_anim(struct tab *tab)
1032 {
1033 	if (tab->loading_anim)
1034 		return;
1035 	tab->loading_anim = 1;
1036 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1037 	evtimer_add(&tab->loadingev, &loadingev_timer);
1038 }
1039 
1040 static void
1041 update_loading_anim(int fd, short ev, void *d)
1042 {
1043 	struct tab	*tab = d;
1044 
1045 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1046 
1047 	if (tab == current_tab) {
1048 		redraw_modeline(tab);
1049 		wrefresh(modeline);
1050 		wrefresh(body);
1051 		if (in_minibuffer)
1052 			wrefresh(echoarea);
1053 	}
1054 
1055 	evtimer_add(&tab->loadingev, &loadingev_timer);
1056 }
1057 
1058 static void
1059 stop_loading_anim(struct tab *tab)
1060 {
1061 	if (!tab->loading_anim)
1062 		return;
1063 	evtimer_del(&tab->loadingev);
1064 	tab->loading_anim = 0;
1065 	tab->loading_anim_step = 0;
1066 
1067 	if (tab != current_tab)
1068 		return;
1069 
1070 	redraw_modeline(tab);
1071 
1072 	wrefresh(modeline);
1073 	wrefresh(body);
1074 	if (in_minibuffer)
1075 		wrefresh(echoarea);
1076 }
1077 
1078 int
1079 ui_print_colors(void)
1080 {
1081 	int colors = 0, pairs = 0, can_change = 0;
1082 	int columns = 16, lines, color, i, j;
1083 
1084 	initscr();
1085 	if (has_colors()) {
1086 		start_color();
1087 		use_default_colors();
1088 
1089 		colors = COLORS;
1090 		pairs = COLOR_PAIRS;
1091 		can_change = can_change_color();
1092 	}
1093 	endwin();
1094 
1095 	printf("Term info:\n");
1096 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1097 	    getenv("TERM"), colors, pairs, can_change);
1098 	printf("\n");
1099 
1100 	if (colors == 0) {
1101 		printf("No color support\n");
1102 		return 0;
1103 	}
1104 
1105 	printf("Available colors:\n\n");
1106 	lines = (colors - 1) / columns + 1;
1107 	color = 0;
1108 	for (i = 0; i < lines; ++i) {
1109 		for (j = 0; j < columns; ++j, ++color) {
1110 			printf("\033[0;38;5;%dm %03d", color, color);
1111 		}
1112 		printf("\n");
1113 	}
1114 
1115 	printf("\033[0m");
1116 	fflush(stdout);
1117 	return 0;
1118 }
1119 
1120 int
1121 ui_init()
1122 {
1123 	setlocale(LC_ALL, "");
1124 
1125 	if (TAILQ_EMPTY(&global_map.m)) {
1126 		fprintf(stderr, "no keys defined!\n");
1127 		return 0;
1128 	}
1129 
1130 	minibuffer_init();
1131 
1132 	/* initialize download window */
1133 	TAILQ_INIT(&downloadwin.head);
1134 	TAILQ_INIT(&downloadwin.page.head);
1135 
1136 	/* initialize help window */
1137 	TAILQ_INIT(&helpwin.head);
1138 	TAILQ_INIT(&helpwin.page.head);
1139 
1140 	base_map = &global_map;
1141 	current_map = &global_map;
1142 
1143 	initscr();
1144 
1145 	if (enable_colors) {
1146 		if (has_colors()) {
1147 			start_color();
1148 			use_default_colors();
1149 		} else
1150 			enable_colors = 0;
1151 	}
1152 
1153 	config_apply_style();
1154 
1155 	raw();
1156 	noecho();
1157 	nonl();
1158 	intrflush(stdscr, FALSE);
1159 
1160 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1161 		return 0;
1162 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1163 		return 0;
1164 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1165 		return 0;
1166 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1167 		return 0;
1168 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1169 		return 0;
1170 	if ((download = newwin(1, 1, 0, 0)) == NULL)
1171 		return 0;
1172 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1173 		return 0;
1174 
1175 	wbkgd(body, body_face.body);
1176 	wbkgd(download, download_face.background);
1177 	wbkgd(echoarea, minibuffer_face.background);
1178 
1179 	update_x_offset();
1180 
1181 	keypad(body, TRUE);
1182 	scrollok(body, FALSE);
1183 
1184 	/* non-blocking input */
1185 	wtimeout(body, 0);
1186 	wtimeout(help, 0);
1187 
1188 	mvwprintw(body, 0, 0, "");
1189 
1190 	return 1;
1191 }
1192 
1193 void
1194 ui_main_loop(void)
1195 {
1196 	evtimer_set(&resizeev, handle_resize, NULL);
1197 
1198 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1199 	event_add(&stdioev, NULL);
1200 
1201 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1202 	signal_add(&winchev, NULL);
1203 
1204 	switch_to_tab(current_tab);
1205 	rearrange_windows();
1206 }
1207 
1208 void
1209 ui_on_tab_loaded(struct tab *tab)
1210 {
1211 	stop_loading_anim(tab);
1212 	message("Loaded %s", tab->hist_cur->h);
1213 
1214 	if (tab->hist_cur->current_off != 0 &&
1215 	    tab->buffer.current_line == TAILQ_FIRST(&tab->buffer.head)) {
1216 		set_scroll_position(tab, tab->hist_cur->line_off,
1217 		    tab->hist_cur->current_off);
1218 		redraw_tab(tab);
1219 		return;
1220 	}
1221 
1222 	if (show_tab_bar)
1223 		redraw_tabline();
1224 
1225 	wrefresh(tabline);
1226 	place_cursor(0);
1227 }
1228 
1229 void
1230 ui_on_tab_refresh(struct tab *tab)
1231 {
1232 	wrap_page(&tab->buffer, body_cols);
1233 	if (tab == current_tab)
1234 		redraw_tab(tab);
1235 	else
1236 		tab->flags |= TAB_URGENT;
1237 }
1238 
1239 void
1240 ui_on_download_refresh(void)
1241 {
1242 	if (side_window & SIDE_WINDOW_BOTTOM) {
1243 		recompute_downloads();
1244 		redraw_tab(current_tab);
1245 	}
1246 }
1247 
1248 const char *
1249 ui_keyname(int k)
1250 {
1251 	return keyname(k);
1252 }
1253 
1254 void
1255 ui_toggle_side_window(int kind)
1256 {
1257 	if (in_side_window & kind)
1258 		ui_other_window();
1259 
1260 	side_window ^= kind;
1261 	if (side_window & SIDE_WINDOW_LEFT)
1262 		recompute_help();
1263 	if (side_window & SIDE_WINDOW_BOTTOM)
1264 		recompute_downloads();
1265 
1266 	/*
1267 	 * ugly hack, but otherwise the window doesn't get updated
1268 	 * until I call rearrange_windows a second time (e.g. via
1269 	 * C-l).  I will be happy to know why something like this is
1270 	 * needed.
1271 	 */
1272 	rearrange_windows();
1273 	rearrange_windows();
1274 }
1275 
1276 void
1277 ui_show_downloads_pane(void)
1278 {
1279 	if (!(side_window & SIDE_WINDOW_BOTTOM))
1280 		ui_toggle_side_window(SIDE_WINDOW_BOTTOM);
1281 }
1282 
1283 void
1284 ui_schedule_redraw(void)
1285 {
1286 	should_rearrange_windows = 1;
1287 }
1288 
1289 void
1290 ui_require_input(struct tab *tab, int hide, int proto)
1291 {
1292 	void (*fn)(void);
1293 
1294 	if (proto == PROTO_GEMINI)
1295 		fn = ir_select_gemini;
1296 	else if (proto == PROTO_GOPHER)
1297 		fn = ir_select_gopher;
1298 	else
1299 		abort();
1300 
1301 	/* TODO: hard-switching to another tab is ugly */
1302 	switch_to_tab(tab);
1303 
1304 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1305 	    &ir_history, NULL, NULL);
1306 	strlcpy(ministate.prompt, "Input required: ",
1307 	    sizeof(ministate.prompt));
1308 	redraw_tab(tab);
1309 }
1310 
1311 void
1312 ui_after_message_hook(void)
1313 {
1314 	redraw_minibuffer();
1315 	place_cursor(0);
1316 }
1317 
1318 void
1319 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1320     struct tab *data)
1321 {
1322 	yornp(prompt, fn, data);
1323 	redraw_tab(current_tab);
1324 }
1325 
1326 void
1327 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1328     struct tab *data, const char *input)
1329 {
1330 	minibuffer_read(prompt, fn, data);
1331 
1332 	if (input != NULL) {
1333 		strlcpy(ministate.buf, input, sizeof(ministate.buf));
1334 		cmd_move_end_of_line(&ministate.buffer);
1335 	}
1336 
1337 	redraw_tab(current_tab);
1338 }
1339 
1340 void
1341 ui_other_window(void)
1342 {
1343 	if (in_side_window & SIDE_WINDOW_LEFT &&
1344 	    side_window & SIDE_WINDOW_BOTTOM)
1345 		in_side_window = SIDE_WINDOW_BOTTOM;
1346 	else if (in_side_window)
1347 		in_side_window = 0;
1348 	else if (!in_side_window && side_window & SIDE_WINDOW_LEFT)
1349 		in_side_window = SIDE_WINDOW_LEFT;
1350 	else if (!in_side_window && side_window)
1351 		in_side_window = SIDE_WINDOW_BOTTOM;
1352 	else
1353 		message("No other window to select");
1354 }
1355 
1356 void
1357 ui_suspend(void)
1358 {
1359 	endwin();
1360 
1361 	kill(getpid(), SIGSTOP);
1362 
1363 	refresh();
1364 	clear();
1365 	rearrange_windows();
1366 }
1367 
1368 void
1369 ui_end(void)
1370 {
1371 	endwin();
1372 }