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Date:: Sun Jul 18 10:25:43 2021 UTC
Message:: add descr. to completions ; filter by descr. too
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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 <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 int		 readkey(void);
54 static void		 dispatch_stdio(int, short, void*);
55 static void		 handle_clear_echoarea(int, short, void*);
56 static void		 handle_resize(int, short, void*);
57 static void		 handle_resize_nodelay(int, short, void*);
58 static void		 rearrange_windows(void);
59 static int		 wrap_page(struct buffer*, int);
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		 emit_help_item(char*, void*);
74 static void		 rec_compute_help(struct kmap*, char*, size_t);
75 static void		 recompute_help(void);
76 static void		 update_loading_anim(int, short, void*);
77 static void		 stop_loading_anim(struct tab*);
78 
79 /*
80  * Used to know when we're finished loading.
81  */
82 static int		 operating;
83 
84 static int		 should_rearrange_windows;
85 static int		 too_small;
86 static int		 x_offset;
87 
88 struct thiskey	 thiskey;
89 struct tab	*current_tab;
90 
91 static struct event	resizeev;
92 static struct timeval	resize_timer = { 0, 250000 };
93 
94 static WINDOW	*tabline, *body, *modeline, *echoarea, *minibuffer;
95 
96 int			 body_lines, body_cols;
97 
98 static WINDOW		*help;
99 static struct buffer	 helpwin;
100 static int		 help_lines, help_cols;
101 
102 static int		 side_window;
103 
104 static struct event	clechoev;
105 static struct timeval	clechoev_timer = { 5, 0 };
106 static struct timeval	loadingev_timer = { 0, 250000 };
107 
108 static uint32_t		 tab_counter;
109 
110 static char	keybuf[64];
111 
112 struct kmap global_map,
113 	minibuffer_map,
114 	*current_map,
115 	*base_map;
116 
117 int in_minibuffer;
118 
119 static inline void
120 update_x_offset(void)
121 {
122 	if (olivetti_mode && fill_column < body_cols)
123 		x_offset = (body_cols - fill_column)/2;
124 	else
125 		x_offset = 0;
126 }
127 
128 void
129 save_excursion(struct excursion *place, struct buffer *buffer)
130 {
131 	place->curs_x = buffer->curs_x;
132 	place->curs_y = buffer->curs_y;
133 	place->line_off = buffer->line_off;
134 	place->current_line = buffer->current_line;
135 	place->cpoff = buffer->cpoff;
136 }
137 
138 void
139 restore_excursion(struct excursion *place, struct buffer *buffer)
140 {
141 	buffer->curs_x = place->curs_x;
142 	buffer->curs_y = place->curs_y;
143 	buffer->line_off = place->line_off;
144 	buffer->current_line = place->current_line;
145 	buffer->cpoff = place->cpoff;
146 }
147 
148 static void
149 restore_curs_x(struct buffer *buffer)
150 {
151 	struct vline	*vl;
152 	const char	*prfx;
153 
154 	vl = buffer->current_line;
155 	if (vl == NULL || vl->line == NULL)
156 		buffer->curs_x = buffer->cpoff = 0;
157 	else if (vl->parent->data != NULL)
158 		buffer->curs_x = utf8_snwidth(vl->parent->data+1, buffer->cpoff) + 1;
159 	else
160 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
161 
162 	buffer->curs_x += x_offset;
163 
164 	if (vl == NULL)
165 		return;
166 
167 	if (vl->parent->data != NULL)
168 		buffer->curs_x += utf8_swidth_between(vl->parent->line, vl->parent->data);
169 	else {
170 		prfx = line_prefixes[vl->parent->type].prfx1;
171 		buffer->curs_x += utf8_swidth(prfx);
172 	}
173 }
174 
175 void
176 global_key_unbound(void)
177 {
178 	message("%s is undefined", keybuf);
179 }
180 
181 struct buffer *
182 current_buffer(void)
183 {
184 	if (in_minibuffer)
185 		return &ministate.buffer;
186 	return &current_tab->buffer;
187 }
188 
189 static int
190 readkey(void)
191 {
192 	uint32_t state = 0;
193 
194 	if ((thiskey.key = wgetch(body)) == ERR)
195 		return 0;
196 
197 	thiskey.meta = thiskey.key == 27;
198 	if (thiskey.meta) {
199 		thiskey.key = wgetch(body);
200 		if (thiskey.key == ERR || thiskey.key == 27) {
201 			thiskey.meta = 0;
202 			thiskey.key = 27;
203 		}
204 	}
205 
206 	thiskey.cp = 0;
207 	if ((unsigned int)thiskey.key < UINT8_MAX) {
208 		while (1) {
209 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
210 				break;
211 			if ((thiskey.key = wgetch(body)) == ERR) {
212 				message("Error decoding user input");
213 				return 0;
214 			}
215 		}
216 	}
217 
218 	return 1;
219 }
220 
221 static void
222 dispatch_stdio(int fd, short ev, void *d)
223 {
224 	struct keymap	*k;
225 	const char	*keyname;
226 	char		 tmp[5] = {0};
227 
228 	/* TODO: schedule a redraw? */
229 	if (too_small)
230 		return;
231 
232 	if (!readkey())
233 		return;
234 
235 	if (keybuf[0] != '\0')
236 		strlcat(keybuf, " ", sizeof(keybuf));
237 	if (thiskey.meta)
238 		strlcat(keybuf, "M-", sizeof(keybuf));
239 	if (thiskey.cp != 0) {
240 		utf8_encode(thiskey.cp, tmp);
241 		strlcat(keybuf, tmp, sizeof(keybuf));
242 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
243 		strlcat(keybuf, keyname, sizeof(keybuf));
244 	} else {
245 		tmp[0] = thiskey.key;
246 		strlcat(keybuf, tmp, sizeof(keybuf));
247 	}
248 
249 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
250 		if (k->meta == thiskey.meta &&
251 		    k->key == thiskey.key) {
252 			if (k->fn == NULL)
253 				current_map = &k->map;
254 			else {
255 				current_map = base_map;
256 				strlcpy(keybuf, "", sizeof(keybuf));
257 				k->fn(current_buffer());
258 			}
259 			goto done;
260 		}
261 	}
262 
263 	if (current_map->unhandled_input != NULL)
264 		current_map->unhandled_input();
265 	else
266 		global_key_unbound();
267 
268 	strlcpy(keybuf, "", sizeof(keybuf));
269 	current_map = base_map;
270 
271 done:
272 	if (side_window)
273 		recompute_help();
274 
275 	if (should_rearrange_windows)
276 		rearrange_windows();
277 	redraw_tab(current_tab);
278 }
279 
280 static void
281 handle_clear_echoarea(int fd, short ev, void *d)
282 {
283 	free(ministate.curmesg);
284 	ministate.curmesg = NULL;
285 
286 	redraw_minibuffer();
287 	place_cursor(0);
288 }
289 
290 static void
291 handle_resize(int sig, short ev, void *d)
292 {
293 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
294 		event_del(&resizeev);
295 	}
296 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
297 	evtimer_add(&resizeev, &resize_timer);
298 }
299 
300 static void
301 handle_resize_nodelay(int s, short ev, void *d)
302 {
303 	endwin();
304 	refresh();
305 	clear();
306 
307 	rearrange_windows();
308 }
309 
310 static void
311 rearrange_windows(void)
312 {
313 	int		 lines;
314 
315 	should_rearrange_windows = 0;
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 = --lines;
343 	body_cols = COLS;
344 
345 	if (side_window) {
346 		help_cols = 0.3 * COLS;
347 		help_lines = lines;
348 		mvwin(help, 1, 0);
349 		wresize(help, help_lines, help_cols);
350 
351 		wrap_page(&helpwin, help_cols);
352 
353 		body_cols = COLS - help_cols - 1;
354 		mvwin(body, 1, help_cols);
355 	} else
356 		mvwin(body, 1, 0);
357 
358 	update_x_offset();
359 	wresize(body, body_lines, body_cols);
360 
361 	wresize(tabline, 1, COLS);
362 
363 	wrap_page(&current_tab->buffer, body_cols);
364 	redraw_tab(current_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 		case LINE_COMPL:
410 		case LINE_COMPL_CURRENT:
411 			wrap_one(buffer, prfx, l, width);
412 			break;
413 		}
414 
415 		if (top_orig == l && buffer->top_line == NULL) {
416 			buffer->line_off = buffer->line_max-1;
417 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
418 
419 			while (1) {
420 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
421 				if (vl == NULL || vl->parent != orig)
422 					break;
423 				buffer->top_line = vl;
424 				buffer->line_off--;
425 			}
426 		}
427 
428 		if (orig == l && buffer->current_line == NULL) {
429 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
430 
431 			while (1) {
432 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
433 				if (vl == NULL || vl->parent != orig)
434 					break;
435 				buffer->current_line = vl;
436 			}
437 		}
438 	}
439 
440         if (buffer->current_line == NULL)
441 		buffer->current_line = TAILQ_FIRST(&buffer->head);
442 
443 	if (buffer->top_line == NULL)
444 		buffer->top_line = buffer->current_line;
445 
446 	return 1;
447 }
448 
449 static void
450 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
451     const char **prfx_ret, const char **text_ret)
452 {
453 	int type, i, cont, width;
454 	char *space, *t;
455 
456 	if ((*text_ret = vl->line) == NULL)
457 		*text_ret = "";
458 
459 	cont = vl->flags & L_CONTINUATION;
460 	type = vl->parent->type;
461 	if (!cont)
462 		*prfx_ret = line_prefixes[type].prfx1;
463 	else
464 		*prfx_ret = line_prefixes[type].prfx2;
465 
466 	space = vl->parent->data;
467 	if (!emojify_link || type != LINE_LINK || space == NULL)
468 		return;
469 
470 	if (cont) {
471 		memset(buf, 0, len);
472 		width = utf8_swidth_between(vl->parent->line, space);
473 		for (i = 0; i < width + 1; ++i)
474 			strlcat(buf, " ", len);
475 	} else {
476 		strlcpy(buf, *text_ret, len);
477 		if ((t = strchr(buf, ' ')) != NULL)
478 			*t = '\0';
479 		strlcat(buf, " ", len);
480 
481 		/* skip the emoji */
482                 *text_ret += (space - vl->parent->line) + 1;
483 	}
484 
485 	*prfx_ret = buf;
486 }
487 
488 static inline void
489 print_vline_descr(int width, WINDOW *window, struct vline *vl)
490 {
491 	int x, y, goal;
492 
493 	if (vl->parent->type != LINE_COMPL &&
494 	    vl->parent->type != LINE_COMPL_CURRENT)
495 		return;
496 
497 	if (vl->parent->alt == NULL)
498 		return;
499 
500 	(void)y;
501 	getyx(window, y, x);
502 
503 	goal = width/2;
504 	if (goal <= x)
505 		wprintw(window, " ");
506 	for (; goal > x; ++x)
507 		wprintw(window, " ");
508 
509 	wprintw(window, "%s", vl->parent->alt);
510 }
511 
512 /*
513  * Core part of the rendering.  It prints a vline starting from the
514  * current cursor position.  Printing a vline consists of skipping
515  * `off' columns (for olivetti-mode), print the correct prefix (which
516  * may be the emoji in case of emojified links-lines), printing the
517  * text itself, filling until width - off and filling off columns
518  * again.
519  */
520 static void
521 print_vline(int off, int width, WINDOW *window, struct vline *vl)
522 {
523 	/*
524 	 * Believe me or not, I've seen emoji ten code points long!
525 	 * That means, to stay large, 4*10 bytes + NUL.
526 	 */
527 	char emojibuf[41] = {0};
528 	const char *text, *prfx;
529 	struct line_face *f;
530 	int i, left, x, y;
531 
532 	f = &line_faces[vl->parent->type];
533 
534 	/* unused, set by getyx */
535 	(void)y;
536 
537 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
538 
539 	wattr_on(window, body_face.left, NULL);
540 	for (i = 0; i < off; i++)
541 		waddch(window, ' ');
542 	wattr_off(window, body_face.left, NULL);
543 
544 	wattr_on(window, f->prefix, NULL);
545 	wprintw(window, "%s", prfx);
546 	wattr_off(window, f->prefix, NULL);
547 
548 	wattr_on(window, f->text, NULL);
549 	wprintw(window, "%s", text);
550 	print_vline_descr(width, window, vl);
551 	wattr_off(window, f->text, NULL);
552 
553 	getyx(window, y, x);
554 
555 	left = width - x;
556 
557 	wattr_on(window, f->trail, NULL);
558 	for (i = 0; i < left - off; ++i)
559 		waddch(window, ' ');
560 	wattr_off(window, f->trail, NULL);
561 
562 	wattr_on(window, body_face.right, NULL);
563 	for (i = 0; i < off; i++)
564 		waddch(window, ' ');
565 	wattr_off(window, body_face.right, NULL);
566 
567 }
568 
569 static void
570 redraw_tabline(void)
571 {
572 	struct tab	*tab;
573 	size_t		 toskip, ots, tabwidth, space, x;
574 	int		 current, y, truncated, pair;
575 	const char	*title;
576 	char		 buf[25];
577 
578 	x = 0;
579 
580 	/* unused, but setted by a getyx */
581 	(void)y;
582 
583 	tabwidth = sizeof(buf)+1;
584 	space = COLS-2;
585 
586 	toskip = 0;
587 	TAILQ_FOREACH(tab, &tabshead, tabs) {
588 		toskip++;
589 		if (tab == current_tab)
590 			break;
591 	}
592 
593 	if (toskip * tabwidth < space)
594 		toskip = 0;
595 	else {
596 		ots = toskip;
597 		toskip--;
598                 while (toskip != 0 &&
599 		    (ots - toskip+1) * tabwidth < space)
600 			toskip--;
601 	}
602 
603 	werase(tabline);
604 	wattr_on(tabline, tab_face.background, NULL);
605 	wprintw(tabline, toskip == 0 ? " " : "<");
606 	wattr_off(tabline, tab_face.background, NULL);
607 
608 	truncated = 0;
609 	TAILQ_FOREACH(tab, &tabshead, tabs) {
610 		if (truncated)
611 			break;
612 		if (toskip != 0) {
613 			toskip--;
614 			continue;
615 		}
616 
617 		getyx(tabline, y, x);
618 		if (x + sizeof(buf)+2 >= (size_t)COLS)
619 			truncated = 1;
620 
621 		current = tab == current_tab;
622 
623 		if (*(title = tab->buffer.page.title) == '\0')
624 			title = tab->hist_cur->h;
625 
626 		if (tab->flags & TAB_URGENT)
627 			strlcpy(buf, "!", sizeof(buf));
628 		else
629 			strlcpy(buf, " ", sizeof(buf));
630 
631                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
632 			/* truncation happens */
633 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
634 		} else {
635 			/* pad with spaces */
636 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
637 				/* nop */ ;
638 		}
639 
640 		pair = current ? tab_face.current : tab_face.tab;
641 		wattr_on(tabline, pair, NULL);
642 		wprintw(tabline, "%s", buf);
643 		wattr_off(tabline, pair, NULL);
644 
645 		wattr_on(tabline, tab_face.background, NULL);
646 		if (TAILQ_NEXT(tab, tabs) != NULL)
647 			wprintw(tabline, "│");
648 		wattr_off(tabline, tab_face.background, NULL);
649 	}
650 
651 	wattr_on(tabline, tab_face.background, NULL);
652 	for (; x < (size_t)COLS; ++x)
653 		waddch(tabline, ' ');
654 	if (truncated)
655 		mvwprintw(tabline, 0, COLS-1, ">");
656 	wattr_off(tabline, tab_face.background, NULL);
657 }
658 
659 /*
660  * Compute the first visible line around vl.  Try to search forward
661  * until the end of the buffer; if a visible line is not found, search
662  * backward.  Return NULL if no viable line was found.
663  */
664 struct vline *
665 adjust_line(struct vline *vl, struct buffer *buffer)
666 {
667 	struct vline *t;
668 
669 	if (vl == NULL)
670 		return NULL;
671 
672 	if (!(vl->parent->flags & L_HIDDEN))
673 		return vl;
674 
675 	/* search forward */
676 	for (t = vl;
677 	     t != NULL && t->parent->flags & L_HIDDEN;
678 	     t = TAILQ_NEXT(t, vlines))
679 		;		/* nop */
680 
681 	if (t != NULL)
682 		return t;
683 
684 	/* search backward */
685 	for (t = vl;
686 	     t != NULL && t->parent->flags & L_HIDDEN;
687 	     t = TAILQ_PREV(t, vhead, vlines))
688 		;		/* nop */
689 
690 	return t;
691 }
692 
693 static void
694 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
695 {
696         struct vline	*vl;
697 	int		 l, onscreen;
698 
699 	restore_curs_x(buffer);
700 
701 	/*
702 	 * TODO: ignoring buffer->force_update and always
703 	 * re-rendering.  In theory we can recompute the y position
704 	 * without a re-render, and optimize here.  It's not the only
705 	 * optimisation possible here, wscrl wolud also be an
706 	 * interesting one.
707 	 */
708 
709 again:
710 	werase(win);
711 	buffer->curs_y = 0;
712 
713 	if (TAILQ_EMPTY(&buffer->head))
714 		goto end;
715 
716 	if (buffer->top_line == NULL)
717 		buffer->top_line = TAILQ_FIRST(&buffer->head);
718 
719 	buffer->top_line = adjust_line(buffer->top_line, buffer);
720 	if (buffer->top_line == NULL)
721 		goto end;
722 
723 	buffer->current_line = adjust_line(buffer->current_line, buffer);
724 
725 	l = 0;
726 	onscreen = 0;
727 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
728 		if (vl->parent->flags & L_HIDDEN)
729 			continue;
730 
731 		wmove(win, l, 0);
732 		print_vline(off, width, win, vl);
733 
734 		if (vl == buffer->current_line)
735 			onscreen = 1;
736 
737 		if (!onscreen)
738 			buffer->curs_y++;
739 
740 		l++;
741 		if (l == height)
742 			break;
743 	}
744 
745 	if (!onscreen) {
746 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
747 			if (vl == buffer->current_line)
748 				break;
749 			if (vl->parent->flags & L_HIDDEN)
750 				continue;
751 			buffer->line_off++;
752 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
753 		}
754 
755 		if (vl != NULL)
756 			goto again;
757 	}
758 
759 	buffer->last_line_off = buffer->line_off;
760 	buffer->force_redraw = 0;
761 end:
762 	wmove(win, buffer->curs_y, buffer->curs_x);
763 }
764 
765 static void
766 redraw_help(void)
767 {
768 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
769 }
770 
771 static void
772 redraw_body(struct tab *tab)
773 {
774 	static struct tab *last_tab;
775 
776 	if (last_tab != tab)
777 		tab->buffer.force_redraw =1;
778 	last_tab = tab;
779 
780 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
781 }
782 
783 static inline char
784 trust_status_char(enum trust_state ts)
785 {
786 	switch (ts) {
787 	case TS_UNKNOWN:	return 'u';
788 	case TS_UNTRUSTED:	return '!';
789 	case TS_TEMP_TRUSTED:	return '!';
790 	case TS_TRUSTED:	return 'v';
791 	case TS_VERIFIED:	return 'V';
792 	default:		return 'X';
793 	}
794 }
795 
796 static void
797 redraw_modeline(struct tab *tab)
798 {
799 	double		 pct;
800 	int		 x, y, max_x, max_y;
801 	const char	*mode = tab->buffer.page.name;
802 	const char	*spin = "-\\|/";
803 
804 	werase(modeline);
805 	wattr_on(modeline, modeline_face.background, NULL);
806 	wmove(modeline, 0, 0);
807 
808 	wprintw(modeline, "-%c%c %s ",
809 	    spin[tab->loading_anim_step],
810 	    trust_status_char(tab->trust),
811 	    mode == NULL ? "(none)" : mode);
812 
813 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0
814 		/ tab->buffer.line_max;
815 
816 	if (tab->buffer.line_max <= (size_t)body_lines)
817                 wprintw(modeline, "All ");
818 	else if (tab->buffer.line_off == 0)
819                 wprintw(modeline, "Top ");
820 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
821 		wprintw(modeline, "Bottom ");
822 	else
823 		wprintw(modeline, "%.0f%% ", pct);
824 
825 	wprintw(modeline, "%d/%d %s ",
826 	    tab->buffer.line_off + tab->buffer.curs_y,
827 	    tab->buffer.line_max,
828 	    tab->hist_cur->h);
829 
830 	getyx(modeline, y, x);
831 	getmaxyx(modeline, max_y, max_x);
832 
833 	(void)y;
834 	(void)max_y;
835 
836 	for (; x < max_x; ++x)
837 		waddstr(modeline, "-");
838 
839 	wattr_off(modeline, modeline_face.background, NULL);
840 }
841 
842 static void
843 redraw_minibuffer(void)
844 {
845 	wattr_on(echoarea, minibuffer_face.background, NULL);
846 	werase(echoarea);
847 
848 	if (in_minibuffer)
849 		do_redraw_minibuffer();
850 	else
851 		do_redraw_echoarea();
852 
853 	if (in_minibuffer == MB_COMPREAD)
854 		do_redraw_minibuffer_compl();
855 
856 	wattr_off(echoarea, minibuffer_face.background, NULL);
857 }
858 
859 static void
860 do_redraw_echoarea(void)
861 {
862 	struct vline *vl;
863 
864 	if (ministate.curmesg != NULL)
865                 wprintw(echoarea, "%s", ministate.curmesg);
866 	else if (*keybuf != '\0')
867 		waddstr(echoarea, keybuf);
868 	else {
869 		/* If nothing else, show the URL at point */
870 		vl = current_tab->buffer.current_line;
871 		if (vl != NULL && vl->parent->type == LINE_LINK)
872 			waddstr(echoarea, vl->parent->alt);
873 	}
874 }
875 
876 static void
877 do_redraw_minibuffer(void)
878 {
879 	size_t		 off_y, off_x = 0;
880 	const char	*start, *c;
881 
882 	/* unused, set by getyx */
883 	(void)off_y;
884 
885 	wmove(echoarea, 0, 0);
886 
887 	if (in_minibuffer == MB_COMPREAD)
888 		wprintw(echoarea, "(%2d) ",
889 		    ministate.compl.buffer.line_max);
890 
891 	wprintw(echoarea, "%s", ministate.prompt);
892 	if (ministate.hist_cur != NULL)
893 		wprintw(echoarea, "(%zu/%zu) ",
894 		    ministate.hist_off + 1,
895 		    ministate.history->len);
896 
897 	getyx(echoarea, off_y, off_x);
898 
899 	start = ministate.hist_cur != NULL
900 		? ministate.hist_cur->h
901 		: ministate.buf;
902 	c = utf8_nth(ministate.buffer.current_line->line,
903 	    ministate.buffer.cpoff);
904 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
905 		start = utf8_next_cp(start);
906 	}
907 
908 	waddstr(echoarea, start);
909 
910 	if (ministate.curmesg != NULL)
911 		wprintw(echoarea, " [%s]", ministate.curmesg);
912 
913 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
914 }
915 
916 static void
917 do_redraw_minibuffer_compl(void)
918 {
919 	redraw_window(minibuffer, 0, 10, body_cols,
920 	    &ministate.compl.buffer);
921 }
922 
923 /*
924  * Place the cursor in the right ncurses window.  If soft is 1, use
925  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
926  * wrefresh.
927  */
928 static void
929 place_cursor(int soft)
930 {
931 	int (*touch)(WINDOW *);
932 
933 	if (soft)
934 		touch = wnoutrefresh;
935 	else
936 		touch = wrefresh;
937 
938 	if (in_minibuffer) {
939 		touch(body);
940 		touch(echoarea);
941 	} else {
942 		touch(echoarea);
943 		touch(body);
944 	}
945 }
946 
947 static void
948 redraw_tab(struct tab *tab)
949 {
950 	if (too_small)
951 		return;
952 
953 	if (side_window) {
954 		redraw_help();
955 		wnoutrefresh(help);
956 	}
957 
958 	redraw_tabline();
959 	redraw_body(tab);
960 	redraw_modeline(tab);
961 	redraw_minibuffer();
962 
963 	wnoutrefresh(tabline);
964 	wnoutrefresh(modeline);
965 
966 	if (in_minibuffer == MB_COMPREAD)
967 		wnoutrefresh(minibuffer);
968 
969 	place_cursor(1);
970 
971 	doupdate();
972 
973 	if (set_title)
974 		dprintf(1, "\033]0;%s - Telescope\a",
975 		    current_tab->buffer.page.title);
976 }
977 
978 static void
979 emit_help_item(char *prfx, void *fn)
980 {
981 	struct line	*l;
982 	struct cmd	*cmd;
983 
984 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
985 		if (fn == cmd->fn)
986 			break;
987 	}
988 	assert(cmd != NULL);
989 
990 	if ((l = calloc(1, sizeof(*l))) == NULL)
991 		abort();
992 
993 	l->type = LINE_TEXT;
994 	l->alt = NULL;
995 
996 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
997 
998 	if (TAILQ_EMPTY(&helpwin.page.head))
999 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
1000 	else
1001 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
1002 }
1003 
1004 static void
1005 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
1006 {
1007 	struct keymap	*k;
1008 	char		 p[32];
1009 	const char	*kn;
1010 
1011 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
1012 		strlcpy(p, prfx, sizeof(p));
1013 		if (*p != '\0')
1014 			strlcat(p, " ", sizeof(p));
1015 		if (k->meta)
1016 			strlcat(p, "M-", sizeof(p));
1017 		if ((kn = unkbd(k->key)) != NULL)
1018 			strlcat(p, kn, sizeof(p));
1019 		else
1020 			strlcat(p, keyname(k->key), sizeof(p));
1021 
1022 		if (k->fn == NULL)
1023 			rec_compute_help(&k->map, p, sizeof(p));
1024 		else
1025 			emit_help_item(p, k->fn);
1026 	}
1027 }
1028 
1029 static void
1030 recompute_help(void)
1031 {
1032 	char	p[32] = { 0 };
1033 
1034 	empty_vlist(&helpwin);
1035 	empty_linelist(&helpwin);
1036 	rec_compute_help(current_map, p, sizeof(p));
1037 	wrap_page(&helpwin, help_cols);
1038 }
1039 
1040 void
1041 vmessage(const char *fmt, va_list ap)
1042 {
1043 	if (evtimer_pending(&clechoev, NULL))
1044 		evtimer_del(&clechoev);
1045 
1046 	free(ministate.curmesg);
1047 	ministate.curmesg = NULL;
1048 
1049 	if (fmt != NULL) {
1050 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1051 		evtimer_add(&clechoev, &clechoev_timer);
1052 
1053 		/* TODO: what to do if the allocation fails here? */
1054 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
1055 			ministate.curmesg = NULL;
1056 	}
1057 
1058 	redraw_minibuffer();
1059         place_cursor(0);
1060 }
1061 
1062 void
1063 message(const char *fmt, ...)
1064 {
1065 	va_list ap;
1066 
1067 	va_start(ap, fmt);
1068 	vmessage(fmt, ap);
1069 	va_end(ap);
1070 }
1071 
1072 void
1073 start_loading_anim(struct tab *tab)
1074 {
1075 	if (tab->loading_anim)
1076 		return;
1077 	tab->loading_anim = 1;
1078 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1079 	evtimer_add(&tab->loadingev, &loadingev_timer);
1080 }
1081 
1082 static void
1083 update_loading_anim(int fd, short ev, void *d)
1084 {
1085 	struct tab	*tab = d;
1086 
1087 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1088 
1089 	if (tab == current_tab) {
1090 		redraw_modeline(tab);
1091 		wrefresh(modeline);
1092 		wrefresh(body);
1093 		if (in_minibuffer)
1094 			wrefresh(echoarea);
1095 	}
1096 
1097 	evtimer_add(&tab->loadingev, &loadingev_timer);
1098 }
1099 
1100 static void
1101 stop_loading_anim(struct tab *tab)
1102 {
1103 	if (!tab->loading_anim)
1104 		return;
1105 	evtimer_del(&tab->loadingev);
1106 	tab->loading_anim = 0;
1107 	tab->loading_anim_step = 0;
1108 
1109 	if (tab != current_tab)
1110 		return;
1111 
1112 	redraw_modeline(tab);
1113 
1114 	wrefresh(modeline);
1115 	wrefresh(body);
1116 	if (in_minibuffer)
1117 		wrefresh(echoarea);
1118 }
1119 
1120 void
1121 load_url_in_tab(struct tab *tab, const char *url)
1122 {
1123 	if (!operating) {
1124 		load_url(tab, url);
1125 		return;
1126 	}
1127 
1128 	message("Loading %s...", url);
1129 	start_loading_anim(tab);
1130 	load_url(tab, url);
1131 
1132 	redraw_tab(tab);
1133 }
1134 
1135 void
1136 switch_to_tab(struct tab *tab)
1137 {
1138 	current_tab = tab;
1139 	tab->flags &= ~TAB_URGENT;
1140 
1141 	if (operating && tab->flags & TAB_LAZY)
1142 		load_url_in_tab(tab, tab->hist_cur->h);
1143 }
1144 
1145 unsigned int
1146 tab_new_id(void)
1147 {
1148 	return tab_counter++;
1149 }
1150 
1151 struct tab *
1152 new_tab(const char *url)
1153 {
1154 	struct tab	*tab;
1155 
1156 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1157 		event_loopbreak();
1158 		return NULL;
1159 	}
1160 	tab->fd = -1;
1161 
1162 	TAILQ_INIT(&tab->hist.head);
1163 
1164 	TAILQ_INIT(&tab->buffer.head);
1165 
1166 	tab->id = tab_new_id();
1167 	if (!operating)
1168 		tab->flags |= TAB_LAZY;
1169 	switch_to_tab(tab);
1170 
1171 	if (TAILQ_EMPTY(&tabshead))
1172 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1173 	else
1174 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1175 
1176 	load_url_in_tab(tab, url);
1177 	return tab;
1178 }
1179 
1180 int
1181 ui_print_colors(void)
1182 {
1183 	int colors = 0, pairs = 0, can_change = 0;
1184 	int columns = 16, lines, color, i, j;
1185 
1186 	initscr();
1187 	if (has_colors()) {
1188 		start_color();
1189 		use_default_colors();
1190 
1191 		colors = COLORS;
1192 		pairs = COLOR_PAIRS;
1193 		can_change = can_change_color();
1194 	}
1195 	endwin();
1196 
1197 	printf("Term info:\n");
1198 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1199 	    getenv("TERM"), colors, pairs, can_change);
1200 	printf("\n");
1201 
1202 	if (colors == 0) {
1203 		printf("No color support\n");
1204 		return 0;
1205 	}
1206 
1207 	printf("Available colors:\n\n");
1208 	lines = (colors - 1) / columns + 1;
1209 	color = 0;
1210 	for (i = 0; i < lines; ++i) {
1211 		for (j = 0; j < columns; ++j, ++color) {
1212 			printf("\033[0;38;5;%dm %03d", color, color);
1213 		}
1214 		printf("\n");
1215 	}
1216 
1217 	printf("\033[0m");
1218 	fflush(stdout);
1219 	return 0;
1220 }
1221 
1222 int
1223 ui_init()
1224 {
1225 	setlocale(LC_ALL, "");
1226 
1227 	TAILQ_INIT(&eecmd_history.head);
1228 	TAILQ_INIT(&ir_history.head);
1229 	TAILQ_INIT(&lu_history.head);
1230 
1231 	ministate.line.type = LINE_TEXT;
1232 	ministate.vline.parent = &ministate.line;
1233 	ministate.buffer.current_line = &ministate.vline;
1234 
1235 	/* initialize help window */
1236 	TAILQ_INIT(&helpwin.head);
1237 
1238 	base_map = &global_map;
1239 	current_map = &global_map;
1240 
1241 	initscr();
1242 
1243 	if (enable_colors) {
1244 		if (has_colors()) {
1245 			start_color();
1246 			use_default_colors();
1247 		} else
1248 			enable_colors = 0;
1249 	}
1250 
1251 	config_apply_style();
1252 
1253 	raw();
1254 	noecho();
1255 	nonl();
1256 	intrflush(stdscr, FALSE);
1257 
1258 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1259 		return 0;
1260 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1261 		return 0;
1262 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1263 		return 0;
1264 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1265 		return 0;
1266 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1267 		return 0;
1268 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1269 		return 0;
1270 
1271 	body_lines = LINES-3;
1272 	body_cols = COLS;
1273 
1274 	wbkgd(body, body_face.body);
1275 	wbkgd(echoarea, minibuffer_face.background);
1276 
1277 	update_x_offset();
1278 
1279 	keypad(body, TRUE);
1280 	scrollok(body, FALSE);
1281 
1282 	/* non-blocking input */
1283 	wtimeout(body, 0);
1284 
1285 	mvwprintw(body, 0, 0, "");
1286 
1287 	/*
1288 	 * Dummy so libevent2 won't complain that no event_base is set
1289 	 * when checking event_pending for the first time
1290 	 */
1291 	evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1292 	evtimer_add(&clechoev, &clechoev_timer);
1293 	evtimer_set(&resizeev, handle_resize, NULL);
1294 	evtimer_add(&resizeev, &resize_timer);
1295 
1296 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1297 	event_add(&stdioev, NULL);
1298 
1299 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1300 	signal_add(&winchev, NULL);
1301 
1302 	return 1;
1303 }
1304 
1305 void
1306 ui_main_loop(void)
1307 {
1308 	operating = 1;
1309 	switch_to_tab(current_tab);
1310 	redraw_tab(current_tab);
1311 
1312 	event_dispatch();
1313 }
1314 
1315 void
1316 ui_on_tab_loaded(struct tab *tab)
1317 {
1318 	stop_loading_anim(tab);
1319 	message("Loaded %s", tab->hist_cur->h);
1320 
1321 	redraw_tabline();
1322 	wrefresh(tabline);
1323 	place_cursor(0);
1324 }
1325 
1326 void
1327 ui_on_tab_refresh(struct tab *tab)
1328 {
1329 	wrap_page(&tab->buffer, body_cols);
1330 	if (tab == current_tab)
1331 		redraw_tab(tab);
1332 	else
1333 		tab->flags |= TAB_URGENT;
1334 }
1335 
1336 const char *
1337 ui_keyname(int k)
1338 {
1339 	return keyname(k);
1340 }
1341 
1342 void
1343 ui_toggle_side_window(void)
1344 {
1345 	side_window = !side_window;
1346 	if (side_window)
1347 		recompute_help();
1348 
1349 	/*
1350 	 * ugly hack, but otherwise the window doesn't get updated
1351 	 * until I call rearrange_windows a second time (e.g. via
1352 	 * C-l).  I will be happy to know why something like this is
1353 	 * needed.
1354 	 */
1355 	rearrange_windows();
1356 	rearrange_windows();
1357 }
1358 
1359 void
1360 ui_schedule_redraw(void)
1361 {
1362 	should_rearrange_windows = 1;
1363 }
1364 
1365 void
1366 ui_require_input(struct tab *tab, int hide)
1367 {
1368 	/* TODO: hard-switching to another tab is ugly */
1369 	switch_to_tab(tab);
1370 
1371 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1372 	    &ir_history, NULL, NULL);
1373 	strlcpy(ministate.prompt, "Input required: ",
1374 	    sizeof(ministate.prompt));
1375 	redraw_tab(tab);
1376 }
1377 
1378 void
1379 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1380     struct tab *data)
1381 {
1382 	yornp(prompt, fn, data);
1383 	redraw_tab(current_tab);
1384 }
1385 
1386 void
1387 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1388     struct tab *data)
1389 {
1390 	completing_read(prompt, fn, data);
1391 	redraw_tab(current_tab);
1392 }
1393 
1394 void
1395 ui_suspend(void)
1396 {
1397 	endwin();
1398 
1399 	kill(getpid(), SIGSTOP);
1400 
1401 	refresh();
1402 	clear();
1403 	rearrange_windows();
1404 }
1405 
1406 void
1407 ui_end(void)
1408 {
1409 	endwin();
1410 }