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Date:: Fri Sep 24 16:36:13 2021 UTC
Message:: refactor print_line_break
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1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 /*
18  * Ncurses UI for telescope.
19  *
20  * Text scrolling
21  * ==============
22  *
23  * ncurses allows you to scroll a window, but when a line goes out of
24  * the visible area it's forgotten.  We keep a list of formatted lines
25  * (``visual lines'') that we know fits in the window, and draw them.
26  *
27  * This means that on every resize we have to clear our list of lines
28  * and re-render everything.  A clever approach would be to do this
29  * ``on-demand'', but it's still missing.
30  *
31  */
32 
33 #include "compat.h"
34 
35 #include <assert.h>
36 #include <curses.h>
37 #include <locale.h>
38 #include <signal.h>
39 #include <stdarg.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "defaults.h"
45 #include "minibuffer.h"
46 #include "session.h"
47 #include "telescope.h"
48 #include "ui.h"
49 #include "utf8.h"
50 
51 static struct event	stdioev, winchev;
52 
53 static void		 restore_curs_x(struct buffer *);
54 
55 static int		 readkey(void);
56 static void		 dispatch_stdio(int, short, void*);
57 static void		 handle_resize(int, short, void*);
58 static void		 handle_resize_nodelay(int, short, void*);
59 static void		 rearrange_windows(void);
60 static void		 line_prefix_and_text(struct vline *, char *, size_t, const char **, const char **);
61 static void		 print_vline(int, int, WINDOW*, struct vline*);
62 static void		 redraw_tabline(void);
63 static void		 redraw_window(WINDOW*, int, int, int, struct buffer*);
64 static void		 redraw_help(void);
65 static void		 redraw_body(struct tab*);
66 static void		 redraw_modeline(struct tab*);
67 static void		 redraw_minibuffer(void);
68 static void		 do_redraw_echoarea(void);
69 static void		 do_redraw_minibuffer(void);
70 static void		 do_redraw_minibuffer_compl(void);
71 static void		 place_cursor(int);
72 static void		 redraw_tab(struct tab*);
73 static void		 update_loading_anim(int, short, void*);
74 static void		 stop_loading_anim(struct tab*);
75 
76 static int		 should_rearrange_windows;
77 static int		 show_tab_bar;
78 static int		 too_small;
79 static int		 x_offset;
80 
81 struct thiskey	 thiskey;
82 struct tab	*current_tab;
83 
84 static struct event	resizeev;
85 static struct timeval	resize_timer = { 0, 250000 };
86 
87 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
88 
89 int			 body_lines, body_cols;
90 
91 static WINDOW		*help;
92 /* not static so we can see them from help.c */
93 struct buffer		 helpwin;
94 int			 help_lines, help_cols;
95 
96 static int		 side_window;
97 static int		 in_side_window;
98 
99 static struct timeval	loadingev_timer = { 0, 250000 };
100 
101 static char	keybuf[64];
102 
103 /* XXX: don't forget to init these in main() */
104 struct kmap global_map,
105 	minibuffer_map,
106 	*current_map,
107 	*base_map;
108 
109 static inline void
110 update_x_offset(void)
111 {
112 	if (olivetti_mode && fill_column < body_cols)
113 		x_offset = (body_cols - fill_column)/2;
114 	else
115 		x_offset = 0;
116 }
117 
118 void
119 save_excursion(struct excursion *place, struct buffer *buffer)
120 {
121 	place->curs_x = buffer->curs_x;
122 	place->curs_y = buffer->curs_y;
123 	place->line_off = buffer->line_off;
124 	place->top_line = buffer->top_line;
125 	place->current_line = buffer->current_line;
126 	place->cpoff = buffer->cpoff;
127 }
128 
129 void
130 restore_excursion(struct excursion *place, struct buffer *buffer)
131 {
132 	buffer->curs_x = place->curs_x;
133 	buffer->curs_y = place->curs_y;
134 	buffer->line_off = place->line_off;
135 	buffer->top_line = place->top_line;
136 	buffer->current_line = place->current_line;
137 	buffer->cpoff = place->cpoff;
138 }
139 
140 static void
141 restore_curs_x(struct buffer *buffer)
142 {
143 	struct vline	*vl;
144 	const char	*prfx, *text;
145 
146 	vl = buffer->current_line;
147 	if (vl == NULL || vl->line == NULL)
148 		buffer->curs_x = buffer->cpoff = 0;
149 	else if (vl->parent->data != NULL) {
150 		text = vl->parent->data;
151 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
152 	} else
153 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
154 
155 	buffer->curs_x += x_offset;
156 
157 	if (vl == NULL)
158 		return;
159 
160 	if (vl->parent->data != NULL)
161 		buffer->curs_x += utf8_swidth_between(vl->parent->line,
162 		    vl->parent->data);
163 	else {
164 		prfx = line_prefixes[vl->parent->type].prfx1;
165 		buffer->curs_x += utf8_swidth(prfx);
166 	}
167 }
168 
169 void
170 global_key_unbound(void)
171 {
172 	message("%s is undefined", keybuf);
173 }
174 
175 struct buffer *
176 current_buffer(void)
177 {
178 	if (in_minibuffer)
179 		return &ministate.buffer;
180 	if (in_side_window)
181 		return &helpwin;
182 	return &current_tab->buffer;
183 }
184 
185 static int
186 readkey(void)
187 {
188 	uint32_t state = 0;
189 
190 	if ((thiskey.key = wgetch(body)) == ERR)
191 		return 0;
192 
193 	thiskey.meta = thiskey.key == 27;
194 	if (thiskey.meta) {
195 		thiskey.key = wgetch(body);
196 		if (thiskey.key == ERR || thiskey.key == 27) {
197 			thiskey.meta = 0;
198 			thiskey.key = 27;
199 		}
200 	}
201 
202 	thiskey.cp = 0;
203 
204 	if ((unsigned int)thiskey.key >= UINT8_MAX)
205 		return 1;
206 
207 	while (1) {
208 		if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
209 			break;
210 		if ((thiskey.key = wgetch(body)) == ERR) {
211 			message("Error decoding user input");
212 			return 0;
213 		}
214 	}
215 
216 	return 1;
217 }
218 
219 static void
220 dispatch_stdio(int fd, short ev, void *d)
221 {
222 	struct keymap	*k;
223 	const char	*keyname;
224 	char		 tmp[5] = {0};
225 
226 	/* TODO: schedule a redraw? */
227 	if (too_small)
228 		return;
229 
230 	if (!readkey())
231 		return;
232 
233 	if (keybuf[0] != '\0')
234 		strlcat(keybuf, " ", sizeof(keybuf));
235 	if (thiskey.meta)
236 		strlcat(keybuf, "M-", sizeof(keybuf));
237 	if (thiskey.cp != 0) {
238 		utf8_encode(thiskey.cp, tmp);
239 		strlcat(keybuf, tmp, sizeof(keybuf));
240 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
241 		strlcat(keybuf, keyname, sizeof(keybuf));
242 	} else {
243 		tmp[0] = thiskey.key;
244 		strlcat(keybuf, tmp, sizeof(keybuf));
245 	}
246 
247 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
248 		if (k->meta == thiskey.meta &&
249 		    k->key == thiskey.key) {
250 			if (k->fn == NULL)
251 				current_map = &k->map;
252 			else {
253 				current_map = base_map;
254 				strlcpy(keybuf, "", sizeof(keybuf));
255 				k->fn(current_buffer());
256 			}
257 			goto done;
258 		}
259 	}
260 
261 	if (current_map->unhandled_input != NULL)
262 		current_map->unhandled_input();
263 	else
264 		global_key_unbound();
265 
266 	strlcpy(keybuf, "", sizeof(keybuf));
267 	current_map = base_map;
268 
269 done:
270 	if (side_window)
271 		recompute_help();
272 
273 	if (should_rearrange_windows)
274 		rearrange_windows();
275 	redraw_tab(current_tab);
276 }
277 
278 static void
279 handle_resize(int sig, short ev, void *d)
280 {
281 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
282 		event_del(&resizeev);
283 	}
284 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
285 	evtimer_add(&resizeev, &resize_timer);
286 }
287 
288 static void
289 handle_resize_nodelay(int s, short ev, void *d)
290 {
291 	endwin();
292 	refresh();
293 	clear();
294 
295 	rearrange_windows();
296 }
297 
298 static inline int
299 should_show_tab_bar(void)
300 {
301 	if (tab_bar_show == -1)
302 		return 0;
303 	if (tab_bar_show == 0)
304 		return 1;
305 
306 	return TAILQ_NEXT(TAILQ_FIRST(&tabshead), tabs) != NULL;
307 }
308 
309 static void
310 rearrange_windows(void)
311 {
312 	int		 lines;
313 
314 	should_rearrange_windows = 0;
315 	show_tab_bar = should_show_tab_bar();
316 
317 	lines = LINES;
318 
319 	if ((too_small = lines < 15)) {
320 		erase();
321 		printw("Window too small.");
322 		refresh();
323 		return;
324 	}
325 
326 	/* move and resize the windows, in reverse order! */
327 
328 	if (in_minibuffer == MB_COMPREAD) {
329 		mvwin(minibuffer, lines-10, 0);
330 		wresize(minibuffer, 10, COLS);
331 		lines -= 10;
332 
333 		wrap_page(&ministate.compl.buffer, COLS);
334 	}
335 
336 	mvwin(echoarea, --lines, 0);
337 	wresize(echoarea, 1, COLS);
338 
339 	mvwin(modeline, --lines, 0);
340 	wresize(modeline, 1, COLS);
341 
342 	body_lines = show_tab_bar ? --lines : lines;
343 	body_cols = COLS;
344 
345 	/*
346 	 * Here we make the assumption that show_tab_bar is either 0
347 	 * or 1, and reuse that as argument to mvwin.
348 	 */
349 	if (side_window) {
350 		help_cols = 0.3 * COLS;
351 		help_lines = lines;
352 		mvwin(help, show_tab_bar, 0);
353 		wresize(help, help_lines, help_cols);
354 
355 		wrap_page(&helpwin, help_cols);
356 
357 		body_cols = COLS - help_cols - 1;
358 		mvwin(body, show_tab_bar, help_cols);
359 	} else
360 		mvwin(body, show_tab_bar, 0);
361 
362 	update_x_offset();
363 	wresize(body, body_lines, body_cols);
364 
365 	if (show_tab_bar)
366 		wresize(tabline, 1, COLS);
367 
368 	wrap_page(&current_tab->buffer, body_cols);
369 	redraw_tab(current_tab);
370 }
371 
372 static void
373 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
374     const char **prfx_ret, const char **text_ret)
375 {
376 	int type, i, cont, width;
377 	char *space, *t;
378 
379 	if ((*text_ret = vl->line) == NULL)
380 		*text_ret = "";
381 
382 	cont = vl->flags & L_CONTINUATION;
383 	type = vl->parent->type;
384 	if (!cont)
385 		*prfx_ret = line_prefixes[type].prfx1;
386 	else
387 		*prfx_ret = line_prefixes[type].prfx2;
388 
389 	space = vl->parent->data;
390 	if (!emojify_link || type != LINE_LINK || space == NULL)
391 		return;
392 
393 	if (cont) {
394 		memset(buf, 0, len);
395 		width = utf8_swidth_between(vl->parent->line, space);
396 		for (i = 0; i < width + 1; ++i)
397 			strlcat(buf, " ", len);
398 	} else {
399 		strlcpy(buf, *text_ret, len);
400 		if ((t = strchr(buf, ' ')) != NULL)
401 			*t = '\0';
402 		strlcat(buf, " ", len);
403 
404 		/* skip the emoji */
405 		*text_ret += (space - vl->parent->line) + 1;
406 	}
407 
408 	*prfx_ret = buf;
409 }
410 
411 static inline void
412 print_vline_descr(int width, WINDOW *window, struct vline *vl)
413 {
414 	int x, y, goal;
415 
416 	if (vl->parent->type != LINE_COMPL &&
417 	    vl->parent->type != LINE_COMPL_CURRENT &&
418 	    vl->parent->type != LINE_HELP)
419 		return;
420 
421 	if (vl->parent->alt == NULL)
422 		return;
423 
424 	(void)y;
425 	getyx(window, y, x);
426 
427 	if (vl->parent->type == LINE_HELP)
428 		goal = 8;
429 	else
430 		goal = width/2;
431 
432 	if (goal <= x)
433 		wprintw(window, " ");
434 	for (; goal > x; ++x)
435 		wprintw(window, " ");
436 
437 	wprintw(window, "%s", vl->parent->alt);
438 }
439 
440 static inline void
441 print_line_break(int width, WINDOW *window)
442 {
443 	int		 x, y, len;
444 	const char	*sep = "-*-*-";
445 
446 	len = utf8_swidth(sep);
447 
448 	getyx(window, y, x);
449 	mvwprintw(window, y, width/2 - len, sep);
450 }
451 
452 /*
453  * Core part of the rendering.  It prints a vline starting from the
454  * current cursor position.  Printing a vline consists of skipping
455  * `off' columns (for olivetti-mode), print the correct prefix (which
456  * may be the emoji in case of emojified links-lines), printing the
457  * text itself, filling until width - off and filling off columns
458  * again.
459  */
460 static void
461 print_vline(int off, int width, WINDOW *window, struct vline *vl)
462 {
463 	/*
464 	 * Believe me or not, I've seen emoji ten code points long!
465 	 * That means, to stay large, 4*10 bytes + NUL.
466 	 */
467 	char emojibuf[41] = {0};
468 	const char *text, *prfx;
469 	struct line_face *f;
470 	int i, left, x, y;
471 
472 	f = &line_faces[vl->parent->type];
473 
474 	/* unused, set by getyx */
475 	(void)y;
476 
477 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
478 
479 	wattr_on(window, body_face.left, NULL);
480 	for (i = 0; i < off; i++)
481 		waddch(window, ' ');
482 	wattr_off(window, body_face.left, NULL);
483 
484 	if (vl->parent->type == LINE_BREAK) {
485 		print_line_break(width, window);
486 	} else {
487 		wattr_on(window, f->prefix, NULL);
488 		wprintw(window, "%s", prfx);
489 		wattr_off(window, f->prefix, NULL);
490 	}
491 
492 	wattr_on(window, f->text, NULL);
493 	wprintw(window, "%s", text);
494 	print_vline_descr(width, window, vl);
495 	wattr_off(window, f->text, NULL);
496 
497 	getyx(window, y, x);
498 
499 	left = width - x;
500 
501 	wattr_on(window, f->trail, NULL);
502 	for (i = 0; i < left - off; ++i)
503 		waddch(window, ' ');
504 	wattr_off(window, f->trail, NULL);
505 
506 	wattr_on(window, body_face.right, NULL);
507 	for (i = 0; i < off; i++)
508 		waddch(window, ' ');
509 	wattr_off(window, body_face.right, NULL);
510 
511 }
512 
513 static void
514 redraw_tabline(void)
515 {
516 	struct tab	*tab;
517 	size_t		 toskip, ots, tabwidth, space, x;
518 	int		 current, y, truncated, pair;
519 	const char	*title;
520 	char		 buf[25];
521 
522 	x = 0;
523 
524 	/* unused, but setted by a getyx */
525 	(void)y;
526 
527 	tabwidth = sizeof(buf)+1;
528 	space = COLS-2;
529 
530 	toskip = 0;
531 	TAILQ_FOREACH(tab, &tabshead, tabs) {
532 		toskip++;
533 		if (tab == current_tab)
534 			break;
535 	}
536 
537 	if (toskip * tabwidth < space)
538 		toskip = 0;
539 	else {
540 		ots = toskip;
541 		toskip--;
542 		while (toskip != 0 &&
543 		    (ots - toskip+1) * tabwidth < space)
544 			toskip--;
545 	}
546 
547 	werase(tabline);
548 	wattr_on(tabline, tab_face.background, NULL);
549 	wprintw(tabline, toskip == 0 ? " " : "<");
550 	wattr_off(tabline, tab_face.background, NULL);
551 
552 	truncated = 0;
553 	TAILQ_FOREACH(tab, &tabshead, tabs) {
554 		if (truncated)
555 			break;
556 		if (toskip != 0) {
557 			toskip--;
558 			continue;
559 		}
560 
561 		getyx(tabline, y, x);
562 		if (x + sizeof(buf)+2 >= (size_t)COLS)
563 			truncated = 1;
564 
565 		current = tab == current_tab;
566 
567 		if (*(title = tab->buffer.page.title) == '\0')
568 			title = tab->hist_cur->h;
569 
570 		if (tab->flags & TAB_URGENT)
571 			strlcpy(buf, "!", sizeof(buf));
572 		else
573 			strlcpy(buf, " ", sizeof(buf));
574 
575 		if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
576 			/* truncation happens */
577 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
578 		} else {
579 			/* pad with spaces */
580 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
581 				/* nop */ ;
582 		}
583 
584 		pair = current ? tab_face.current : tab_face.tab;
585 		wattr_on(tabline, pair, NULL);
586 		wprintw(tabline, "%s", buf);
587 		wattr_off(tabline, pair, NULL);
588 
589 		wattr_on(tabline, tab_face.background, NULL);
590 		if (TAILQ_NEXT(tab, tabs) != NULL)
591 			wprintw(tabline, "┃");
592 		wattr_off(tabline, tab_face.background, NULL);
593 	}
594 
595 	wattr_on(tabline, tab_face.background, NULL);
596 	for (; x < (size_t)COLS; ++x)
597 		waddch(tabline, ' ');
598 	if (truncated)
599 		mvwprintw(tabline, 0, COLS-1, ">");
600 	wattr_off(tabline, tab_face.background, NULL);
601 }
602 
603 /*
604  * Compute the first visible line around vl.  Try to search forward
605  * until the end of the buffer; if a visible line is not found, search
606  * backward.  Return NULL if no viable line was found.
607  */
608 struct vline *
609 adjust_line(struct vline *vl, struct buffer *buffer)
610 {
611 	struct vline *t;
612 
613 	if (vl == NULL)
614 		return NULL;
615 
616 	if (!(vl->parent->flags & L_HIDDEN))
617 		return vl;
618 
619 	/* search forward */
620 	for (t = vl;
621 	     t != NULL && t->parent->flags & L_HIDDEN;
622 	     t = TAILQ_NEXT(t, vlines))
623 		;		/* nop */
624 
625 	if (t != NULL)
626 		return t;
627 
628 	/* search backward */
629 	for (t = vl;
630 	     t != NULL && t->parent->flags & L_HIDDEN;
631 	     t = TAILQ_PREV(t, vhead, vlines))
632 		;		/* nop */
633 
634 	return t;
635 }
636 
637 static void
638 redraw_window(WINDOW *win, int off, int height, int width,
639     struct buffer *buffer)
640 {
641 	struct vline	*vl;
642 	int		 l, onscreen;
643 
644 	restore_curs_x(buffer);
645 
646 	/*
647 	 * TODO: ignoring buffer->force_update and always
648 	 * re-rendering.  In theory we can recompute the y position
649 	 * without a re-render, and optimize here.  It's not the only
650 	 * optimisation possible here, wscrl wolud also be an
651 	 * interesting one.
652 	 */
653 
654 again:
655 	werase(win);
656 	buffer->curs_y = 0;
657 
658 	if (TAILQ_EMPTY(&buffer->head))
659 		goto end;
660 
661 	if (buffer->top_line == NULL)
662 		buffer->top_line = TAILQ_FIRST(&buffer->head);
663 
664 	buffer->top_line = adjust_line(buffer->top_line, buffer);
665 	if (buffer->top_line == NULL)
666 		goto end;
667 
668 	buffer->current_line = adjust_line(buffer->current_line, buffer);
669 
670 	l = 0;
671 	onscreen = 0;
672 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
673 		if (vl->parent->flags & L_HIDDEN)
674 			continue;
675 
676 		wmove(win, l, 0);
677 		print_vline(off, width, win, vl);
678 
679 		if (vl == buffer->current_line)
680 			onscreen = 1;
681 
682 		if (!onscreen)
683 			buffer->curs_y++;
684 
685 		l++;
686 		if (l == height)
687 			break;
688 	}
689 
690 	if (!onscreen) {
691 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
692 			if (vl == buffer->current_line)
693 				break;
694 			if (vl->parent->flags & L_HIDDEN)
695 				continue;
696 			buffer->line_off++;
697 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
698 		}
699 
700 		if (vl != NULL)
701 			goto again;
702 	}
703 
704 	buffer->last_line_off = buffer->line_off;
705 	buffer->force_redraw = 0;
706 end:
707 	wmove(win, buffer->curs_y, buffer->curs_x);
708 }
709 
710 static void
711 redraw_help(void)
712 {
713 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
714 }
715 
716 static void
717 redraw_body(struct tab *tab)
718 {
719 	static struct tab *last_tab;
720 
721 	if (last_tab != tab)
722 		tab->buffer.force_redraw =1;
723 	last_tab = tab;
724 
725 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
726 }
727 
728 static inline char
729 trust_status_char(enum trust_state ts)
730 {
731 	switch (ts) {
732 	case TS_UNKNOWN:	return '-';
733 	case TS_UNTRUSTED:	return '!';
734 	case TS_TEMP_TRUSTED:	return '!';
735 	case TS_TRUSTED:	return 'v';
736 	case TS_VERIFIED:	return 'V';
737 	default:		return 'X';
738 	}
739 }
740 
741 static void
742 redraw_modeline(struct tab *tab)
743 {
744 	struct buffer	*buffer;
745 	double		 pct;
746 	int		 x, y, max_x, max_y;
747 	const char	*mode;
748 	const char	*spin = "-\\|/";
749 
750 	buffer = current_buffer();
751 	mode = buffer->page.name;
752 
753 	werase(modeline);
754 	wattr_on(modeline, modeline_face.background, NULL);
755 	wmove(modeline, 0, 0);
756 
757 	wprintw(modeline, "-%c%c %s ",
758 	    spin[tab->loading_anim_step],
759 	    trust_status_char(tab->trust),
760 	    mode == NULL ? "(none)" : mode);
761 
762 	pct = (buffer->line_off + buffer->curs_y) * 100.0
763 		/ buffer->line_max;
764 
765 	if (buffer->line_max <= (size_t)body_lines)
766 		wprintw(modeline, "All ");
767 	else if (buffer->line_off == 0)
768 		wprintw(modeline, "Top ");
769 	else if (buffer->line_off + body_lines >= buffer->line_max)
770 		wprintw(modeline, "Bottom ");
771 	else
772 		wprintw(modeline, "%.0f%% ", pct);
773 
774 	wprintw(modeline, "%d/%d %s ",
775 	    buffer->line_off + buffer->curs_y,
776 	    buffer->line_max,
777 	    tab->hist_cur->h);
778 
779 	getyx(modeline, y, x);
780 	getmaxyx(modeline, max_y, max_x);
781 
782 	(void)y;
783 	(void)max_y;
784 
785 	for (; x < max_x; ++x)
786 		waddstr(modeline, "-");
787 
788 	wattr_off(modeline, modeline_face.background, NULL);
789 }
790 
791 static void
792 redraw_minibuffer(void)
793 {
794 	wattr_on(echoarea, minibuffer_face.background, NULL);
795 	werase(echoarea);
796 
797 	if (in_minibuffer)
798 		do_redraw_minibuffer();
799 	else
800 		do_redraw_echoarea();
801 
802 	if (in_minibuffer == MB_COMPREAD)
803 		do_redraw_minibuffer_compl();
804 
805 	wattr_off(echoarea, minibuffer_face.background, NULL);
806 }
807 
808 static void
809 do_redraw_echoarea(void)
810 {
811 	struct vline *vl;
812 
813 	if (ministate.curmesg != NULL)
814 		wprintw(echoarea, "%s", ministate.curmesg);
815 	else if (*keybuf != '\0')
816 		waddstr(echoarea, keybuf);
817 	else {
818 		/* If nothing else, show the URL at point */
819 		vl = current_tab->buffer.current_line;
820 		if (vl != NULL && vl->parent->type == LINE_LINK)
821 			waddstr(echoarea, vl->parent->alt);
822 	}
823 }
824 
825 static void
826 do_redraw_minibuffer(void)
827 {
828 	struct buffer	*cmplbuf, *buffer;
829 	size_t		 off_y, off_x = 0;
830 	const char	*start, *c;
831 
832 	cmplbuf = &ministate.compl.buffer;
833 	buffer = &ministate.buffer;
834 	(void)off_y;		/* unused, set by getyx */
835 
836 	wmove(echoarea, 0, 0);
837 
838 	if (in_minibuffer == MB_COMPREAD)
839 		wprintw(echoarea, "(%2d) ",
840 		    cmplbuf->line_max);
841 
842 	wprintw(echoarea, "%s", ministate.prompt);
843 	if (ministate.hist_cur != NULL)
844 		wprintw(echoarea, "(%zu/%zu) ",
845 		    ministate.hist_off + 1,
846 		    ministate.history->len);
847 
848 	getyx(echoarea, off_y, off_x);
849 
850 	start = ministate.hist_cur != NULL
851 		? ministate.hist_cur->h
852 		: ministate.buf;
853 	c = utf8_nth(buffer->current_line->line, buffer->cpoff);
854 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
855 		start = utf8_next_cp(start);
856 	}
857 
858 	waddstr(echoarea, start);
859 
860 	if (ministate.curmesg != NULL)
861 		wprintw(echoarea, " [%s]", ministate.curmesg);
862 
863 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
864 }
865 
866 static void
867 do_redraw_minibuffer_compl(void)
868 {
869 	redraw_window(minibuffer, 0, 10, COLS,
870 	    &ministate.compl.buffer);
871 }
872 
873 /*
874  * Place the cursor in the right ncurses window.  If soft is 1, use
875  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
876  * wrefresh.
877  */
878 static void
879 place_cursor(int soft)
880 {
881 	int (*touch)(WINDOW *);
882 
883 	if (soft)
884 		touch = wnoutrefresh;
885 	else
886 		touch = wrefresh;
887 
888 	if (in_minibuffer) {
889 		if (side_window)
890 			touch(help);
891 		touch(body);
892 		touch(echoarea);
893 	} else if (in_side_window) {
894 		touch(body);
895 		touch(echoarea);
896 		touch(help);
897 	} else {
898 		if (side_window)
899 			touch(help);
900 		touch(echoarea);
901 		touch(body);
902 	}
903 }
904 
905 static void
906 redraw_tab(struct tab *tab)
907 {
908 	if (too_small)
909 		return;
910 
911 	if (side_window) {
912 		redraw_help();
913 		wnoutrefresh(help);
914 	}
915 
916 	if (show_tab_bar)
917 		redraw_tabline();
918 
919 	redraw_body(tab);
920 	redraw_modeline(tab);
921 	redraw_minibuffer();
922 
923 	wnoutrefresh(tabline);
924 	wnoutrefresh(modeline);
925 
926 	if (in_minibuffer == MB_COMPREAD)
927 		wnoutrefresh(minibuffer);
928 
929 	place_cursor(1);
930 
931 	doupdate();
932 
933 	if (set_title)
934 		dprintf(1, "\033]2;%s - Telescope\a",
935 		    current_tab->buffer.page.title);
936 }
937 
938 void
939 start_loading_anim(struct tab *tab)
940 {
941 	if (tab->loading_anim)
942 		return;
943 	tab->loading_anim = 1;
944 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
945 	evtimer_add(&tab->loadingev, &loadingev_timer);
946 }
947 
948 static void
949 update_loading_anim(int fd, short ev, void *d)
950 {
951 	struct tab	*tab = d;
952 
953 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
954 
955 	if (tab == current_tab) {
956 		redraw_modeline(tab);
957 		wrefresh(modeline);
958 		wrefresh(body);
959 		if (in_minibuffer)
960 			wrefresh(echoarea);
961 	}
962 
963 	evtimer_add(&tab->loadingev, &loadingev_timer);
964 }
965 
966 static void
967 stop_loading_anim(struct tab *tab)
968 {
969 	if (!tab->loading_anim)
970 		return;
971 	evtimer_del(&tab->loadingev);
972 	tab->loading_anim = 0;
973 	tab->loading_anim_step = 0;
974 
975 	if (tab != current_tab)
976 		return;
977 
978 	redraw_modeline(tab);
979 
980 	wrefresh(modeline);
981 	wrefresh(body);
982 	if (in_minibuffer)
983 		wrefresh(echoarea);
984 }
985 
986 int
987 ui_print_colors(void)
988 {
989 	int colors = 0, pairs = 0, can_change = 0;
990 	int columns = 16, lines, color, i, j;
991 
992 	initscr();
993 	if (has_colors()) {
994 		start_color();
995 		use_default_colors();
996 
997 		colors = COLORS;
998 		pairs = COLOR_PAIRS;
999 		can_change = can_change_color();
1000 	}
1001 	endwin();
1002 
1003 	printf("Term info:\n");
1004 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1005 	    getenv("TERM"), colors, pairs, can_change);
1006 	printf("\n");
1007 
1008 	if (colors == 0) {
1009 		printf("No color support\n");
1010 		return 0;
1011 	}
1012 
1013 	printf("Available colors:\n\n");
1014 	lines = (colors - 1) / columns + 1;
1015 	color = 0;
1016 	for (i = 0; i < lines; ++i) {
1017 		for (j = 0; j < columns; ++j, ++color) {
1018 			printf("\033[0;38;5;%dm %03d", color, color);
1019 		}
1020 		printf("\n");
1021 	}
1022 
1023 	printf("\033[0m");
1024 	fflush(stdout);
1025 	return 0;
1026 }
1027 
1028 int
1029 ui_init()
1030 {
1031 	setlocale(LC_ALL, "");
1032 
1033 	if (TAILQ_EMPTY(&global_map.m)) {
1034 		fprintf(stderr, "no keys defined!\n");
1035 		return 0;
1036 	}
1037 
1038 	minibuffer_init();
1039 
1040 	/* initialize help window */
1041 	TAILQ_INIT(&helpwin.head);
1042 	TAILQ_INIT(&helpwin.page.head);
1043 
1044 	base_map = &global_map;
1045 	current_map = &global_map;
1046 
1047 	initscr();
1048 
1049 	if (enable_colors) {
1050 		if (has_colors()) {
1051 			start_color();
1052 			use_default_colors();
1053 		} else
1054 			enable_colors = 0;
1055 	}
1056 
1057 	config_apply_style();
1058 
1059 	raw();
1060 	noecho();
1061 	nonl();
1062 	intrflush(stdscr, FALSE);
1063 
1064 	if ((tabline = newwin(1, 1, 0, 0)) == NULL)
1065 		return 0;
1066 	if ((body = newwin(1, 1, 0, 0)) == NULL)
1067 		return 0;
1068 	if ((modeline = newwin(1, 1, 0, 0)) == NULL)
1069 		return 0;
1070 	if ((echoarea = newwin(1, 1, 0, 0)) == NULL)
1071 		return 0;
1072 	if ((minibuffer = newwin(1, 1, 0, 0)) == NULL)
1073 		return 0;
1074 	if ((help = newwin(1, 1, 0, 0)) == NULL)
1075 		return 0;
1076 
1077 	wbkgd(body, body_face.body);
1078 	wbkgd(echoarea, minibuffer_face.background);
1079 
1080 	update_x_offset();
1081 
1082 	keypad(body, TRUE);
1083 	scrollok(body, FALSE);
1084 
1085 	/* non-blocking input */
1086 	wtimeout(body, 0);
1087 	wtimeout(help, 0);
1088 
1089 	mvwprintw(body, 0, 0, "");
1090 
1091 	evtimer_set(&resizeev, handle_resize, NULL);
1092 
1093 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1094 	event_add(&stdioev, NULL);
1095 
1096 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1097 	signal_add(&winchev, NULL);
1098 
1099 	return 1;
1100 }
1101 
1102 void
1103 ui_main_loop(void)
1104 {
1105 	switch_to_tab(current_tab);
1106 	rearrange_windows();
1107 
1108 	event_dispatch();
1109 }
1110 
1111 void
1112 ui_on_tab_loaded(struct tab *tab)
1113 {
1114 	stop_loading_anim(tab);
1115 	message("Loaded %s", tab->hist_cur->h);
1116 
1117 	if (show_tab_bar)
1118 		redraw_tabline();
1119 
1120 	wrefresh(tabline);
1121 	place_cursor(0);
1122 }
1123 
1124 void
1125 ui_on_tab_refresh(struct tab *tab)
1126 {
1127 	wrap_page(&tab->buffer, body_cols);
1128 	if (tab == current_tab)
1129 		redraw_tab(tab);
1130 	else
1131 		tab->flags |= TAB_URGENT;
1132 }
1133 
1134 const char *
1135 ui_keyname(int k)
1136 {
1137 	return keyname(k);
1138 }
1139 
1140 void
1141 ui_toggle_side_window(void)
1142 {
1143 	side_window = !side_window;
1144 	if (side_window)
1145 		recompute_help();
1146 	else
1147 		in_side_window = 0;
1148 
1149 	/*
1150 	 * ugly hack, but otherwise the window doesn't get updated
1151 	 * until I call rearrange_windows a second time (e.g. via
1152 	 * C-l).  I will be happy to know why something like this is
1153 	 * needed.
1154 	 */
1155 	rearrange_windows();
1156 	rearrange_windows();
1157 }
1158 
1159 void
1160 ui_schedule_redraw(void)
1161 {
1162 	should_rearrange_windows = 1;
1163 }
1164 
1165 void
1166 ui_require_input(struct tab *tab, int hide, int proto)
1167 {
1168 	void (*fn)(void);
1169 
1170 	if (proto == PROTO_GEMINI)
1171 		fn = ir_select_gemini;
1172 	else if (proto == PROTO_GOPHER)
1173 		fn = ir_select_gopher;
1174 	else
1175 		abort();
1176 
1177 	/* TODO: hard-switching to another tab is ugly */
1178 	switch_to_tab(tab);
1179 
1180 	enter_minibuffer(sensible_self_insert, fn, exit_minibuffer,
1181 	    &ir_history, NULL, NULL);
1182 	strlcpy(ministate.prompt, "Input required: ",
1183 	    sizeof(ministate.prompt));
1184 	redraw_tab(tab);
1185 }
1186 
1187 void
1188 ui_after_message_hook(void)
1189 {
1190 	redraw_minibuffer();
1191 	place_cursor(0);
1192 }
1193 
1194 void
1195 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1196     struct tab *data)
1197 {
1198 	yornp(prompt, fn, data);
1199 	redraw_tab(current_tab);
1200 }
1201 
1202 void
1203 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1204     struct tab *data, const char *input)
1205 {
1206 	minibuffer_read(prompt, fn, data);
1207 
1208 	if (input != NULL) {
1209 		strlcpy(ministate.buf, input, sizeof(ministate.buf));
1210 		cmd_move_end_of_line(&ministate.buffer);
1211 	}
1212 
1213 	redraw_tab(current_tab);
1214 }
1215 
1216 void
1217 ui_other_window(void)
1218 {
1219 	if (side_window)
1220 		in_side_window = !in_side_window;
1221 	else
1222 		message("No other window to select");
1223 }
1224 
1225 void
1226 ui_suspend(void)
1227 {
1228 	endwin();
1229 
1230 	kill(getpid(), SIGSTOP);
1231 
1232 	refresh();
1233 	clear();
1234 	rearrange_windows();
1235 }
1236 
1237 void
1238 ui_end(void)
1239 {
1240 	endwin();
1241 }