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Date:: Tue Jul 13 16:40:51 2021 UTC
Message:: simplify conditionals
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 <assert.h>
34 #include <curses.h>
35 #include <event.h>
36 #include <locale.h>
37 #include <signal.h>
38 #include <stdarg.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "defaults.h"
44 #include "minibuffer.h"
45 #include "telescope.h"
46 #include "ui.h"
47 #include "utf8.h"
48 
49 static struct event	stdioev, winchev;
50 
51 static void		 restore_curs_x(struct buffer *);
52 
53 static struct vline	*nth_line(struct buffer*, size_t);
54 static int		 readkey(void);
55 static void		 dispatch_stdio(int, short, void*);
56 static void		 handle_clear_echoarea(int, short, void*);
57 static void		 handle_resize(int, short, void*);
58 static void		 handle_resize_nodelay(int, short, void*);
59 static int		 wrap_page(struct buffer*, int);
60 static void		 print_vline(int, int, WINDOW*, struct vline*);
61 static void		 redraw_tabline(void);
62 static void		 redraw_window(WINDOW*, int, int, struct buffer*);
63 static void		 redraw_help(void);
64 static void		 redraw_body(struct tab*);
65 static void		 redraw_modeline(struct tab*);
66 static void		 redraw_minibuffer(void);
67 static void		 do_redraw_echoarea(void);
68 static void		 do_redraw_minibuffer(void);
69 static void		 place_cursor(int);
70 static void		 redraw_tab(struct tab*);
71 static void		 emit_help_item(char*, void*);
72 static void		 rec_compute_help(struct kmap*, char*, size_t);
73 static void		 recompute_help(void);
74 static void		 update_loading_anim(int, short, void*);
75 static void		 stop_loading_anim(struct tab*);
76 
77 static int		 too_small;
78 static int		 x_offset;
79 
80 struct thiskey thiskey;
81 
82 static struct event	resizeev;
83 static struct timeval	resize_timer = { 0, 250000 };
84 
85 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
86 
87 int			 body_lines, body_cols;
88 
89 static WINDOW		*help;
90 static struct buffer	 helpwin;
91 static int		 help_lines, help_cols;
92 
93 static int		 side_window;
94 
95 static struct event	clechoev;
96 static struct timeval	clechoev_timer = { 5, 0 };
97 static struct timeval	loadingev_timer = { 0, 250000 };
98 
99 static uint32_t		 tab_counter;
100 
101 static char	keybuf[64];
102 
103 struct kmap global_map,
104 	minibuffer_map,
105 	*current_map,
106 	*base_map;
107 
108 int in_minibuffer;
109 
110 static inline void
111 update_x_offset(void)
112 {
113 	if (olivetti_mode && fill_column < body_cols)
114 		x_offset = (body_cols - fill_column)/2;
115 	else
116 		x_offset = 0;
117 }
118 
119 void
120 save_excursion(struct excursion *place, struct buffer *buffer)
121 {
122 	place->curs_x = buffer->curs_x;
123 	place->curs_y = buffer->curs_y;
124 	place->line_off = buffer->line_off;
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->current_line = place->current_line;
136 	buffer->cpoff = place->cpoff;
137 }
138 
139 static void
140 restore_curs_x(struct buffer *buffer)
141 {
142 	struct vline	*vl;
143 	const char	*prfx;
144 
145 	vl = buffer->current_line;
146 	if (vl == NULL || vl->line == NULL)
147 		buffer->curs_x = buffer->cpoff = 0;
148 	else
149 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
150 
151 	buffer->curs_x += x_offset;
152 
153 	if (vl != NULL) {
154 		prfx = line_prefixes[vl->parent->type].prfx1;
155 		buffer->curs_x += utf8_swidth(prfx);
156 	}
157 }
158 
159 void
160 global_key_unbound(void)
161 {
162 	message("%s is undefined", keybuf);
163 }
164 
165 static struct vline *
166 nth_line(struct buffer *buffer, size_t n)
167 {
168 	struct vline	*vl;
169 	size_t		 i;
170 
171 	i = 0;
172 	TAILQ_FOREACH(vl, &buffer->head, vlines) {
173 		if (i == n)
174 			return vl;
175 		i++;
176 	}
177 
178 	/* unreachable */
179 	abort();
180 }
181 
182 struct tab *
183 current_tab(void)
184 {
185 	struct tab *t;
186 
187 	TAILQ_FOREACH(t, &tabshead, tabs) {
188 		if (t->flags & TAB_CURRENT)
189 			return t;
190 	}
191 
192 	/* unreachable */
193 	abort();
194 }
195 
196 struct buffer *
197 current_buffer(void)
198 {
199 	if (in_minibuffer)
200 		return &ministate.buffer;
201 	return &current_tab()->buffer;
202 }
203 
204 static int
205 readkey(void)
206 {
207 	uint32_t state = 0;
208 
209 	if ((thiskey.key = wgetch(body)) == ERR)
210 		return 0;
211 
212 	thiskey.meta = thiskey.key == 27;
213 	if (thiskey.meta) {
214 		thiskey.key = wgetch(body);
215 		if (thiskey.key == ERR || thiskey.key == 27) {
216 			thiskey.meta = 0;
217 			thiskey.key = 27;
218 		}
219 	}
220 
221 	thiskey.cp = 0;
222 	if ((unsigned int)thiskey.key < UINT8_MAX) {
223 		while (1) {
224 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
225 				break;
226 			if ((thiskey.key = wgetch(body)) == ERR) {
227 				message("Error decoding user input");
228 				return 0;
229 			}
230 		}
231 	}
232 
233 	return 1;
234 }
235 
236 static void
237 dispatch_stdio(int fd, short ev, void *d)
238 {
239 	struct keymap	*k;
240 	const char	*keyname;
241 	char		 tmp[5] = {0};
242 
243 	/* TODO: schedule a redraw? */
244 	if (too_small)
245 		return;
246 
247 	if (!readkey())
248 		return;
249 
250 	if (keybuf[0] != '\0')
251 		strlcat(keybuf, " ", sizeof(keybuf));
252 	if (thiskey.meta)
253 		strlcat(keybuf, "M-", sizeof(keybuf));
254 	if (thiskey.cp != 0) {
255 		utf8_encode(thiskey.cp, tmp);
256 		strlcat(keybuf, tmp, sizeof(keybuf));
257 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
258 		strlcat(keybuf, keyname, sizeof(keybuf));
259 	} else {
260 		tmp[0] = thiskey.key;
261 		strlcat(keybuf, tmp, sizeof(keybuf));
262 	}
263 
264 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
265 		if (k->meta == thiskey.meta &&
266 		    k->key == thiskey.key) {
267 			if (k->fn == NULL)
268 				current_map = &k->map;
269 			else {
270 				current_map = base_map;
271 				strlcpy(keybuf, "", sizeof(keybuf));
272 				k->fn(current_buffer());
273 			}
274 			goto done;
275 		}
276 	}
277 
278 	if (current_map->unhandled_input != NULL)
279 		current_map->unhandled_input();
280 	else
281 		global_key_unbound();
282 
283 	strlcpy(keybuf, "", sizeof(keybuf));
284 	current_map = base_map;
285 
286 done:
287 	if (side_window)
288 		recompute_help();
289 
290 	redraw_tab(current_tab());
291 }
292 
293 static void
294 handle_clear_echoarea(int fd, short ev, void *d)
295 {
296 	free(ministate.curmesg);
297 	ministate.curmesg = NULL;
298 
299 	redraw_minibuffer();
300 	place_cursor(0);
301 }
302 
303 static void
304 handle_resize(int sig, short ev, void *d)
305 {
306 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
307 		event_del(&resizeev);
308 	}
309 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
310 	evtimer_add(&resizeev, &resize_timer);
311 }
312 
313 static void
314 handle_resize_nodelay(int s, short ev, void *d)
315 {
316 	struct tab	*tab;
317 	int		 lines;
318 
319 	endwin();
320 	refresh();
321 	clear();
322 
323 	lines = LINES;
324 
325 	if ((too_small = lines < 15)) {
326 		erase();
327 		printw("Window too small.");
328 		refresh();
329 		return;
330 	}
331 
332 	/* move and resize the windows, in reverse order! */
333 
334 	mvwin(echoarea, --lines, 0);
335 	wresize(echoarea, 1, COLS);
336 
337 	mvwin(modeline, --lines, 0);
338 	wresize(modeline, 1, COLS);
339 
340 	body_lines = --lines;
341 	body_cols = COLS;
342 
343 	if (side_window) {
344 		help_cols = 0.3 * COLS;
345 		help_lines = lines;
346 		mvwin(help, 1, 0);
347 		wresize(help, help_lines, help_cols);
348 
349 		wrap_page(&helpwin, help_cols);
350 
351 		body_cols = COLS - help_cols - 1;
352 		mvwin(body, 1, help_cols);
353 	} else
354 		mvwin(body, 1, 0);
355 
356 	update_x_offset();
357 	wresize(body, body_lines, body_cols);
358 
359 	wresize(tabline, 1, COLS);
360 
361 	tab = current_tab();
362 
363 	wrap_page(&tab->buffer, body_cols);
364 	redraw_tab(tab);
365 }
366 
367 static int
368 wrap_page(struct buffer *buffer, int width)
369 {
370 	struct line		*l;
371 	const struct line	*top_orig, *orig;
372 	struct vline		*vl;
373 	int			 pre_width;
374 	const char		*prfx;
375 
376 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
377 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
378 
379 	buffer->top_line = NULL;
380 	buffer->current_line = NULL;
381 
382 	buffer->force_redraw = 1;
383 	buffer->curs_y = 0;
384 	buffer->line_off = 0;
385 
386 	empty_vlist(buffer);
387 
388 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
389 		prfx = line_prefixes[l->type].prfx1;
390 		switch (l->type) {
391 		case LINE_TEXT:
392 		case LINE_LINK:
393 		case LINE_TITLE_1:
394 		case LINE_TITLE_2:
395 		case LINE_TITLE_3:
396 		case LINE_ITEM:
397 		case LINE_QUOTE:
398 		case LINE_PRE_START:
399 		case LINE_PRE_END:
400 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
401 			break;
402 		case LINE_PRE_CONTENT:
403 			if (olivetti_mode)
404 				pre_width = MIN(fill_column, width);
405 			else
406 				pre_width = width;
407 			hardwrap_text(buffer, l, pre_width);
408 			break;
409 		}
410 
411 		if (top_orig == l && buffer->top_line == NULL) {
412 			buffer->line_off = buffer->line_max-1;
413 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
414 
415 			while (1) {
416 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
417 				if (vl == NULL || vl->parent != orig)
418 					break;
419 				buffer->top_line = vl;
420 				buffer->line_off--;
421 			}
422 		}
423 
424 		if (orig == l && buffer->current_line == NULL) {
425 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
426 
427 			while (1) {
428 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
429 				if (vl == NULL || vl->parent != orig)
430 					break;
431 				buffer->current_line = vl;
432 			}
433 		}
434 	}
435 
436         if (buffer->current_line == NULL)
437 		buffer->current_line = TAILQ_FIRST(&buffer->head);
438 
439 	if (buffer->top_line == NULL)
440 		buffer->top_line = buffer->current_line;
441 
442 	return 1;
443 }
444 
445 static void
446 print_vline(int off, int width, WINDOW *window, struct vline *vl)
447 {
448 	const char *text;
449 	const char *prfx;
450 	struct line_face *f;
451 	int i, left, x, y;
452 
453 	f = &line_faces[vl->parent->type];
454 
455 	/* unused, set by getyx */
456 	(void)y;
457 
458 	if (!vl->flags)
459 		prfx = line_prefixes[vl->parent->type].prfx1;
460 	else
461 		prfx = line_prefixes[vl->parent->type].prfx2;
462 
463 	text = vl->line;
464 	if (text == NULL)
465 		text = "";
466 
467 	wattr_on(window, body_face.left, NULL);
468 	for (i = 0; i < off; i++)
469 		waddch(window, ' ');
470 	wattr_off(window, body_face.left, NULL);
471 
472 	wattr_on(window, f->prefix, NULL);
473 	wprintw(window, "%s", prfx);
474 	wattr_off(window, f->prefix, NULL);
475 
476 	wattr_on(window, f->text, NULL);
477 	wprintw(window, "%s", text);
478 	wattr_off(window, f->text, NULL);
479 
480 	getyx(window, y, x);
481 
482 	left = width - x;
483 
484 	wattr_on(window, f->trail, NULL);
485 	for (i = 0; i < left - off; ++i)
486 		waddch(window, ' ');
487 	wattr_off(window, f->trail, NULL);
488 
489 	wattr_on(window, body_face.right, NULL);
490 	for (i = 0; i < off; i++)
491 		waddch(window, ' ');
492 	wattr_off(window, body_face.right, NULL);
493 
494 }
495 
496 static void
497 redraw_tabline(void)
498 {
499 	struct tab	*tab;
500 	size_t		 toskip, ots, tabwidth, space, x;
501 	int		 current, y, truncated;
502 	const char	*title;
503 	char		 buf[25];
504 
505 	x = 0;
506 
507 	/* unused, but setted by a getyx */
508 	(void)y;
509 
510 	tabwidth = sizeof(buf)+1;
511 	space = COLS-2;
512 
513 	toskip = 0;
514 	TAILQ_FOREACH(tab, &tabshead, tabs) {
515 		toskip++;
516 		if (tab->flags & TAB_CURRENT)
517 			break;
518 	}
519 
520 	if (toskip * tabwidth < space)
521 		toskip = 0;
522 	else {
523 		ots = toskip;
524 		toskip--;
525                 while (toskip != 0 &&
526 		    (ots - toskip+1) * tabwidth < space)
527 			toskip--;
528 	}
529 
530 	werase(tabline);
531 	wattr_on(tabline, tab_face.background, NULL);
532 	wprintw(tabline, toskip == 0 ? " " : "<");
533 	wattr_off(tabline, tab_face.background, NULL);
534 
535 	truncated = 0;
536 	TAILQ_FOREACH(tab, &tabshead, tabs) {
537 		if (truncated)
538 			break;
539 		if (toskip != 0) {
540 			toskip--;
541 			continue;
542 		}
543 
544 		getyx(tabline, y, x);
545 		if (x + sizeof(buf)+2 >= (size_t)COLS)
546 			truncated = 1;
547 
548 		current = tab->flags & TAB_CURRENT;
549 
550 		if (*(title = tab->buffer.page.title) == '\0')
551 			title = tab->hist_cur->h;
552 
553 		if (tab->flags & TAB_URGENT)
554 			strlcpy(buf, "!", sizeof(buf));
555 		else
556 			strlcpy(buf, " ", sizeof(buf));
557 
558                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
559 			/* truncation happens */
560 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
561 		} else {
562 			/* pad with spaces */
563 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
564 				/* nop */ ;
565 		}
566 
567 		if (current)
568 			wattr_on(tabline, tab_face.current, NULL);
569 		else
570 			wattr_on(tabline, tab_face.tab, NULL);
571 
572 		wprintw(tabline, "%s", buf);
573 		if (TAILQ_NEXT(tab, tabs) != NULL)
574 			wprintw(tabline, " ");
575 
576 		if (current)
577 			wattr_off(tabline, tab_face.current, NULL);
578 		else
579 			wattr_off(tabline, tab_face.tab, NULL);
580 	}
581 
582 	wattr_on(tabline, tab_face.background, NULL);
583 	for (; x < (size_t)COLS; ++x)
584 		waddch(tabline, ' ');
585 	if (truncated)
586 		mvwprintw(tabline, 0, COLS-1, ">");
587 	wattr_off(tabline, tab_face.background, NULL);
588 }
589 
590 /*
591  * Compute the first visible line around vl.  Try to search forward
592  * until the end of the buffer; if a visible line is not found, search
593  * backward.  Return NULL if no viable line was found.
594  */
595 static inline struct vline *
596 adjust_line(struct vline *vl, struct buffer *buffer)
597 {
598 	struct vline *t;
599 
600 	if (!(vl->parent->flags & L_HIDDEN))
601 		return vl;
602 
603 	/* search forward */
604 	for (t = vl;
605 	     t != NULL && t->parent->flags & L_HIDDEN;
606 	     t = TAILQ_NEXT(t, vlines))
607 		;		/* nop */
608 
609 	if (t != NULL)
610 		return t;
611 
612 	/* search backward */
613 	for (t = vl;
614 	     t != NULL && t->parent->flags & L_HIDDEN;
615 	     t = TAILQ_PREV(t, vhead, vlines))
616 		;		/* nop */
617 
618 	return t;
619 }
620 
621 static void
622 redraw_window(WINDOW *win, int height, int width, struct buffer *buffer)
623 {
624         struct vline	*vl;
625 	int		 l, onscreen;
626 
627 	restore_curs_x(buffer);
628 
629 	/*
630 	 * TODO: ignoring buffer->force_update and always
631 	 * re-rendering.  In theory we can recompute the y position
632 	 * without a re-render, and optimize here.  It's not the only
633 	 * optimisation possible here, wscrl wolud also be an
634 	 * interesting one.
635 	 */
636 
637 again:
638 	werase(win);
639 	buffer->curs_y = 0;
640 
641 	if (TAILQ_EMPTY(&buffer->head))
642 		goto end;
643 
644 	buffer->top_line = adjust_line(buffer->top_line, buffer);
645 	if (buffer->top_line == NULL)
646 		goto end;
647 
648 	buffer->current_line = adjust_line(buffer->current_line, buffer);
649 
650 	l = 0;
651 	onscreen = 0;
652 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
653 		if (vl->parent->flags & L_HIDDEN)
654 			continue;
655 
656 		wmove(win, l, 0);
657 		print_vline(x_offset, width, win, vl);
658 
659 		if (vl == buffer->current_line)
660 			onscreen = 1;
661 
662 		if (!onscreen)
663 			buffer->curs_y++;
664 
665 		l++;
666 		if (l == height)
667 			break;
668 	}
669 
670 	if (!onscreen) {
671 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
672 			if (vl == buffer->current_line)
673 				break;
674 			if (vl->parent->flags & L_HIDDEN)
675 				continue;
676 			buffer->line_off++;
677 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
678 		}
679 
680 		goto again;
681 	}
682 
683 	buffer->last_line_off = buffer->line_off;
684 	buffer->force_redraw = 0;
685 end:
686 	wmove(win, buffer->curs_y, buffer->curs_x);
687 }
688 
689 static void
690 redraw_help(void)
691 {
692 	redraw_window(help, help_lines, help_cols, &helpwin);
693 }
694 
695 static void
696 redraw_body(struct tab *tab)
697 {
698 	static struct tab *last_tab;
699 
700 	if (last_tab != tab)
701 		tab->buffer.force_redraw =1;
702 	last_tab = tab;
703 
704 	redraw_window(body, body_lines, body_cols, &tab->buffer);
705 }
706 
707 static inline char
708 trust_status_char(enum trust_state ts)
709 {
710 	switch (ts) {
711 	case TS_UNKNOWN:	return 'u';
712 	case TS_UNTRUSTED:	return '!';
713 	case TS_TEMP_TRUSTED:	return '!';
714 	case TS_TRUSTED:	return 'v';
715 	case TS_VERIFIED:	return 'V';
716 	default:		return 'X';
717 	}
718 }
719 
720 static void
721 redraw_modeline(struct tab *tab)
722 {
723 	double		 pct;
724 	int		 x, y, max_x, max_y;
725 	const char	*mode = tab->buffer.page.name;
726 	const char	*spin = "-\\|/";
727 
728 	werase(modeline);
729 	wattr_on(modeline, modeline_face.background, NULL);
730 	wmove(modeline, 0, 0);
731 
732 	wprintw(modeline, "-%c%c %s ",
733 	    spin[tab->loading_anim_step],
734 	    trust_status_char(tab->trust),
735 	    mode == NULL ? "(none)" : mode);
736 
737 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0 / tab->buffer.line_max;
738 
739 	if (tab->buffer.line_max <= (size_t)body_lines)
740                 wprintw(modeline, "All ");
741 	else if (tab->buffer.line_off == 0)
742                 wprintw(modeline, "Top ");
743 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
744 		wprintw(modeline, "Bottom ");
745 	else
746 		wprintw(modeline, "%.0f%% ", pct);
747 
748 	wprintw(modeline, "%d/%d %s ",
749 	    tab->buffer.line_off + tab->buffer.curs_y,
750 	    tab->buffer.line_max,
751 	    tab->hist_cur->h);
752 
753 	getyx(modeline, y, x);
754 	getmaxyx(modeline, max_y, max_x);
755 
756 	(void)y;
757 	(void)max_y;
758 
759 	for (; x < max_x; ++x)
760 		waddstr(modeline, "-");
761 
762 	wattr_off(modeline, modeline_face.background, NULL);
763 }
764 
765 static void
766 redraw_minibuffer(void)
767 {
768 	wattr_on(echoarea, minibuffer_face.background, NULL);
769 	werase(echoarea);
770 
771 	if (in_minibuffer)
772 		do_redraw_minibuffer();
773 	else
774 		do_redraw_echoarea();
775 
776 	wattr_off(echoarea, minibuffer_face.background, NULL);
777 }
778 
779 static void
780 do_redraw_echoarea(void)
781 {
782 	struct tab *tab;
783 
784 	if (ministate.curmesg != NULL)
785                 wprintw(echoarea, "%s", ministate.curmesg);
786 	else if (*keybuf != '\0')
787 		waddstr(echoarea, keybuf);
788 	else {
789 		/* If nothing else, show the URL at point */
790 		tab = current_tab();
791 		if (tab->buffer.current_line != NULL &&
792 		    tab->buffer.current_line->parent->type == LINE_LINK)
793 			waddstr(echoarea, tab->buffer.current_line->parent->alt);
794 	}
795 }
796 
797 static void
798 do_redraw_minibuffer(void)
799 {
800 	size_t		 off_y, off_x = 0;
801 	const char	*start, *c;
802 
803 	/* unused, set by getyx */
804 	(void)off_y;
805 
806 	mvwprintw(echoarea, 0, 0, "%s", ministate.prompt);
807 	if (ministate.hist_cur != NULL)
808 		wprintw(echoarea, "(%zu/%zu) ",
809 		    ministate.hist_off + 1,
810 		    ministate.history->len);
811 
812 	getyx(echoarea, off_y, off_x);
813 
814 	start = ministate.hist_cur != NULL
815 		? ministate.hist_cur->h
816 		: ministate.buf;
817 	c = utf8_nth(ministate.buffer.current_line->line,
818 	    ministate.buffer.cpoff);
819 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
820 		start = utf8_next_cp(start);
821 	}
822 
823 	waddstr(echoarea, start);
824 
825 	if (ministate.curmesg != NULL)
826 		wprintw(echoarea, " [%s]", ministate.curmesg);
827 
828 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
829 }
830 
831 /*
832  * Place the cursor in the right ncurses window.  If soft is 1, use
833  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
834  * wrefresh.
835  */
836 static void
837 place_cursor(int soft)
838 {
839 	int (*touch)(WINDOW *);
840 
841 	if (soft)
842 		touch = wnoutrefresh;
843 	else
844 		touch = wrefresh;
845 
846 	if (in_minibuffer) {
847 		touch(body);
848 		touch(echoarea);
849 	} else {
850 		touch(echoarea);
851 		touch(body);
852 	}
853 }
854 
855 static void
856 redraw_tab(struct tab *tab)
857 {
858 	if (too_small)
859 		return;
860 
861 	if (side_window) {
862 		redraw_help();
863 		wnoutrefresh(help);
864 	}
865 
866 	redraw_tabline();
867 	redraw_body(tab);
868 	redraw_modeline(tab);
869 	redraw_minibuffer();
870 
871 	wnoutrefresh(tabline);
872 	wnoutrefresh(modeline);
873 
874 	place_cursor(1);
875 
876 	doupdate();
877 }
878 
879 static void
880 emit_help_item(char *prfx, void *fn)
881 {
882 	struct line	*l;
883 	struct cmd	*cmd;
884 
885 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
886 		if (fn == cmd->fn)
887 			break;
888 	}
889 	assert(cmd != NULL);
890 
891 	if ((l = calloc(1, sizeof(*l))) == NULL)
892 		abort();
893 
894 	l->type = LINE_TEXT;
895 	l->alt = NULL;
896 
897 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
898 
899 	if (TAILQ_EMPTY(&helpwin.page.head))
900 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
901 	else
902 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
903 }
904 
905 static void
906 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
907 {
908 	struct keymap	*k;
909 	char		 p[32];
910 	const char	*kn;
911 
912 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
913 		strlcpy(p, prfx, sizeof(p));
914 		if (*p != '\0')
915 			strlcat(p, " ", sizeof(p));
916 		if (k->meta)
917 			strlcat(p, "M-", sizeof(p));
918 		if ((kn = unkbd(k->key)) != NULL)
919 			strlcat(p, kn, sizeof(p));
920 		else
921 			strlcat(p, keyname(k->key), sizeof(p));
922 
923 		if (k->fn == NULL)
924 			rec_compute_help(&k->map, p, sizeof(p));
925 		else
926 			emit_help_item(p, k->fn);
927 	}
928 }
929 
930 static void
931 recompute_help(void)
932 {
933 	char	p[32] = { 0 };
934 
935 	empty_vlist(&helpwin);
936 	empty_linelist(&helpwin);
937 	rec_compute_help(current_map, p, sizeof(p));
938 	wrap_page(&helpwin, help_cols);
939 }
940 
941 void
942 vmessage(const char *fmt, va_list ap)
943 {
944 	if (evtimer_pending(&clechoev, NULL))
945 		evtimer_del(&clechoev);
946 
947 	free(ministate.curmesg);
948 	ministate.curmesg = NULL;
949 
950 	if (fmt != NULL) {
951 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
952 		evtimer_add(&clechoev, &clechoev_timer);
953 
954 		/* TODO: what to do if the allocation fails here? */
955 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
956 			ministate.curmesg = NULL;
957 	}
958 
959 	redraw_minibuffer();
960         place_cursor(0);
961 }
962 
963 void
964 message(const char *fmt, ...)
965 {
966 	va_list ap;
967 
968 	va_start(ap, fmt);
969 	vmessage(fmt, ap);
970 	va_end(ap);
971 }
972 
973 void
974 start_loading_anim(struct tab *tab)
975 {
976 	if (tab->loading_anim)
977 		return;
978 	tab->loading_anim = 1;
979 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
980 	evtimer_add(&tab->loadingev, &loadingev_timer);
981 }
982 
983 static void
984 update_loading_anim(int fd, short ev, void *d)
985 {
986 	struct tab	*tab = d;
987 
988 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
989 
990 	if (tab->flags & TAB_CURRENT) {
991 		redraw_modeline(tab);
992 		wrefresh(modeline);
993 		wrefresh(body);
994 		if (in_minibuffer)
995 			wrefresh(echoarea);
996 	}
997 
998 	evtimer_add(&tab->loadingev, &loadingev_timer);
999 }
1000 
1001 static void
1002 stop_loading_anim(struct tab *tab)
1003 {
1004 	if (!tab->loading_anim)
1005 		return;
1006 	evtimer_del(&tab->loadingev);
1007 	tab->loading_anim = 0;
1008 	tab->loading_anim_step = 0;
1009 
1010 	if (!(tab->flags & TAB_CURRENT))
1011 		return;
1012 
1013 	redraw_modeline(tab);
1014 
1015 	wrefresh(modeline);
1016 	wrefresh(body);
1017 	if (in_minibuffer)
1018 		wrefresh(echoarea);
1019 }
1020 
1021 void
1022 load_url_in_tab(struct tab *tab, const char *url)
1023 {
1024 	message("Loading %s...", url);
1025 	start_loading_anim(tab);
1026 	load_url(tab, url);
1027 
1028 	tab->buffer.curs_x = 0;
1029 	tab->buffer.curs_y = 0;
1030 	redraw_tab(tab);
1031 }
1032 
1033 void
1034 switch_to_tab(struct tab *tab)
1035 {
1036 	struct tab	*t;
1037 
1038 	TAILQ_FOREACH(t, &tabshead, tabs) {
1039 		t->flags &= ~TAB_CURRENT;
1040 	}
1041 
1042 	tab->flags |= TAB_CURRENT;
1043 	tab->flags &= ~TAB_URGENT;
1044 }
1045 
1046 unsigned int
1047 tab_new_id(void)
1048 {
1049 	return tab_counter++;
1050 }
1051 
1052 struct tab *
1053 new_tab(const char *url)
1054 {
1055 	struct tab	*tab;
1056 
1057 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1058 		event_loopbreak();
1059 		return NULL;
1060 	}
1061 	tab->fd = -1;
1062 
1063 	TAILQ_INIT(&tab->hist.head);
1064 
1065 	TAILQ_INIT(&tab->buffer.head);
1066 
1067 	tab->id = tab_new_id();
1068 	switch_to_tab(tab);
1069 
1070 	if (TAILQ_EMPTY(&tabshead))
1071 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1072 	else
1073 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1074 
1075 	load_url_in_tab(tab, url);
1076 	return tab;
1077 }
1078 
1079 int
1080 ui_init()
1081 {
1082 	setlocale(LC_ALL, "");
1083 
1084 	TAILQ_INIT(&eecmd_history.head);
1085 	TAILQ_INIT(&ir_history.head);
1086 	TAILQ_INIT(&lu_history.head);
1087 
1088 	ministate.line.type = LINE_TEXT;
1089 	ministate.vline.parent = &ministate.line;
1090 	ministate.buffer.current_line = &ministate.vline;
1091 
1092 	/* initialize help window */
1093 	TAILQ_INIT(&helpwin.head);
1094 
1095 	base_map = &global_map;
1096 	current_map = &global_map;
1097 
1098 	initscr();
1099 
1100 	if (enable_colors) {
1101 		if (has_colors()) {
1102 			start_color();
1103 			use_default_colors();
1104 		} else
1105 			enable_colors = 0;
1106 	}
1107 
1108 	config_apply_style();
1109 
1110 	raw();
1111 	noecho();
1112 	nonl();
1113 	intrflush(stdscr, FALSE);
1114 
1115 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1116 		return 0;
1117 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1118 		return 0;
1119 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1120 		return 0;
1121 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1122 		return 0;
1123 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1124 		return 0;
1125 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1126 		return 0;
1127 
1128 	body_lines = LINES-3;
1129 	body_cols = COLS;
1130 
1131 	wbkgd(body, body_face.body);
1132 	wbkgd(echoarea, minibuffer_face.background);
1133 
1134 	update_x_offset();
1135 
1136 	keypad(body, TRUE);
1137 	scrollok(body, FALSE);
1138 
1139 	/* non-blocking input */
1140 	wtimeout(body, 0);
1141 
1142 	mvwprintw(body, 0, 0, "");
1143 
1144 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1145 	event_add(&stdioev, NULL);
1146 
1147 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1148 	signal_add(&winchev, NULL);
1149 
1150 	return 1;
1151 }
1152 
1153 void
1154 ui_on_tab_loaded(struct tab *tab)
1155 {
1156 	stop_loading_anim(tab);
1157 	message("Loaded %s", tab->hist_cur->h);
1158 
1159 	redraw_tabline();
1160 	wrefresh(tabline);
1161 	place_cursor(0);
1162 }
1163 
1164 void
1165 ui_on_tab_refresh(struct tab *tab)
1166 {
1167 	wrap_page(&tab->buffer, body_cols);
1168 	if (tab->flags & TAB_CURRENT)
1169 		redraw_tab(tab);
1170 	else
1171 		tab->flags |= TAB_URGENT;
1172 }
1173 
1174 const char *
1175 ui_keyname(int k)
1176 {
1177 	return keyname(k);
1178 }
1179 
1180 void
1181 ui_toggle_side_window(void)
1182 {
1183 	side_window = !side_window;
1184 	if (side_window)
1185 		recompute_help();
1186 
1187 	/*
1188 	 * ugly hack, but otherwise the window doesn't get updated
1189 	 * until I call handle_resize a second time (i.e. C-l).  I
1190 	 * will be happy to know why something like this is needed.
1191 	 */
1192 	handle_resize_nodelay(0, 0, NULL);
1193 	handle_resize_nodelay(0, 0, NULL);
1194 }
1195 
1196 void
1197 ui_schedule_redraw(void)
1198 {
1199 	handle_resize_nodelay(0, 0, NULL);
1200 }
1201 
1202 void
1203 ui_require_input(struct tab *tab, int hide)
1204 {
1205 	/* TODO: hard-switching to another tab is ugly */
1206 	switch_to_tab(tab);
1207 
1208 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1209 	    &ir_history, NULL, NULL);
1210 	strlcpy(ministate.prompt, "Input required: ",
1211 	    sizeof(ministate.prompt));
1212 	redraw_tab(tab);
1213 }
1214 
1215 void
1216 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1217     struct tab *data)
1218 {
1219 	yornp(prompt, fn, data);
1220 	redraw_tab(current_tab());
1221 }
1222 
1223 void
1224 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1225     struct tab *data)
1226 {
1227 	completing_read(prompt, fn, data, NULL, NULL);
1228 	redraw_tab(current_tab());
1229 }
1230 
1231 void
1232 ui_end(void)
1233 {
1234 	endwin();
1235 }