op public repos

Blob

Date:: Mon Jul 19 16:24:06 2021 UTC
Message:: evtimer_set is enough don't need to evtimer_add to initialize the event.
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 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->top_line = buffer->top_line;
135 	place->current_line = buffer->current_line;
136 	place->cpoff = buffer->cpoff;
137 }
138 
139 void
140 restore_excursion(struct excursion *place, struct buffer *buffer)
141 {
142 	buffer->curs_x = place->curs_x;
143 	buffer->curs_y = place->curs_y;
144 	buffer->line_off = place->line_off;
145 	buffer->top_line = place->top_line;
146 	buffer->current_line = place->current_line;
147 	buffer->cpoff = place->cpoff;
148 }
149 
150 static void
151 restore_curs_x(struct buffer *buffer)
152 {
153 	struct vline	*vl;
154 	const char	*prfx, *text;
155 
156 	vl = buffer->current_line;
157 	if (vl == NULL || vl->line == NULL)
158 		buffer->curs_x = buffer->cpoff = 0;
159 	else if (vl->parent->data != NULL) {
160 		text = vl->parent->data;
161 		buffer->curs_x = utf8_snwidth(text + 1, buffer->cpoff) + 1;
162 	} else
163 		buffer->curs_x = utf8_snwidth(vl->line, buffer->cpoff);
164 
165 	buffer->curs_x += x_offset;
166 
167 	if (vl == NULL)
168 		return;
169 
170 	if (vl->parent->data != NULL)
171 		buffer->curs_x += utf8_swidth_between(vl->parent->line, vl->parent->data);
172 	else {
173 		prfx = line_prefixes[vl->parent->type].prfx1;
174 		buffer->curs_x += utf8_swidth(prfx);
175 	}
176 }
177 
178 void
179 global_key_unbound(void)
180 {
181 	message("%s is undefined", keybuf);
182 }
183 
184 struct buffer *
185 current_buffer(void)
186 {
187 	if (in_minibuffer)
188 		return &ministate.buffer;
189 	return &current_tab->buffer;
190 }
191 
192 static int
193 readkey(void)
194 {
195 	uint32_t state = 0;
196 
197 	if ((thiskey.key = wgetch(body)) == ERR)
198 		return 0;
199 
200 	thiskey.meta = thiskey.key == 27;
201 	if (thiskey.meta) {
202 		thiskey.key = wgetch(body);
203 		if (thiskey.key == ERR || thiskey.key == 27) {
204 			thiskey.meta = 0;
205 			thiskey.key = 27;
206 		}
207 	}
208 
209 	thiskey.cp = 0;
210 	if ((unsigned int)thiskey.key < UINT8_MAX) {
211 		while (1) {
212 			if (!utf8_decode(&state, &thiskey.cp, (uint8_t)thiskey.key))
213 				break;
214 			if ((thiskey.key = wgetch(body)) == ERR) {
215 				message("Error decoding user input");
216 				return 0;
217 			}
218 		}
219 	}
220 
221 	return 1;
222 }
223 
224 static void
225 dispatch_stdio(int fd, short ev, void *d)
226 {
227 	struct keymap	*k;
228 	const char	*keyname;
229 	char		 tmp[5] = {0};
230 
231 	/* TODO: schedule a redraw? */
232 	if (too_small)
233 		return;
234 
235 	if (!readkey())
236 		return;
237 
238 	if (keybuf[0] != '\0')
239 		strlcat(keybuf, " ", sizeof(keybuf));
240 	if (thiskey.meta)
241 		strlcat(keybuf, "M-", sizeof(keybuf));
242 	if (thiskey.cp != 0) {
243 		utf8_encode(thiskey.cp, tmp);
244 		strlcat(keybuf, tmp, sizeof(keybuf));
245 	} else if ((keyname = unkbd(thiskey.key)) != NULL) {
246 		strlcat(keybuf, keyname, sizeof(keybuf));
247 	} else {
248 		tmp[0] = thiskey.key;
249 		strlcat(keybuf, tmp, sizeof(keybuf));
250 	}
251 
252 	TAILQ_FOREACH(k, &current_map->m, keymaps) {
253 		if (k->meta == thiskey.meta &&
254 		    k->key == thiskey.key) {
255 			if (k->fn == NULL)
256 				current_map = &k->map;
257 			else {
258 				current_map = base_map;
259 				strlcpy(keybuf, "", sizeof(keybuf));
260 				k->fn(current_buffer());
261 			}
262 			goto done;
263 		}
264 	}
265 
266 	if (current_map->unhandled_input != NULL)
267 		current_map->unhandled_input();
268 	else
269 		global_key_unbound();
270 
271 	strlcpy(keybuf, "", sizeof(keybuf));
272 	current_map = base_map;
273 
274 done:
275 	if (side_window)
276 		recompute_help();
277 
278 	if (should_rearrange_windows)
279 		rearrange_windows();
280 	redraw_tab(current_tab);
281 }
282 
283 static void
284 handle_clear_echoarea(int fd, short ev, void *d)
285 {
286 	free(ministate.curmesg);
287 	ministate.curmesg = NULL;
288 
289 	redraw_minibuffer();
290 	place_cursor(0);
291 }
292 
293 static void
294 handle_resize(int sig, short ev, void *d)
295 {
296 	if (event_pending(&resizeev, EV_TIMEOUT, NULL)) {
297 		event_del(&resizeev);
298 	}
299 	evtimer_set(&resizeev, handle_resize_nodelay, NULL);
300 	evtimer_add(&resizeev, &resize_timer);
301 }
302 
303 static void
304 handle_resize_nodelay(int s, short ev, void *d)
305 {
306 	endwin();
307 	refresh();
308 	clear();
309 
310 	rearrange_windows();
311 }
312 
313 static void
314 rearrange_windows(void)
315 {
316 	int		 lines;
317 
318 	should_rearrange_windows = 0;
319 
320 	lines = LINES;
321 
322 	if ((too_small = lines < 15)) {
323 		erase();
324 		printw("Window too small.");
325 		refresh();
326 		return;
327 	}
328 
329 	/* move and resize the windows, in reverse order! */
330 
331 	if (in_minibuffer == MB_COMPREAD) {
332 		mvwin(minibuffer, lines-10, 0);
333 		wresize(minibuffer, 10, COLS);
334 		lines -= 10;
335 
336 		wrap_page(&ministate.compl.buffer, COLS);
337 	}
338 
339 	mvwin(echoarea, --lines, 0);
340 	wresize(echoarea, 1, COLS);
341 
342 	mvwin(modeline, --lines, 0);
343 	wresize(modeline, 1, COLS);
344 
345 	body_lines = --lines;
346 	body_cols = COLS;
347 
348 	if (side_window) {
349 		help_cols = 0.3 * COLS;
350 		help_lines = lines;
351 		mvwin(help, 1, 0);
352 		wresize(help, help_lines, help_cols);
353 
354 		wrap_page(&helpwin, help_cols);
355 
356 		body_cols = COLS - help_cols - 1;
357 		mvwin(body, 1, help_cols);
358 	} else
359 		mvwin(body, 1, 0);
360 
361 	update_x_offset();
362 	wresize(body, body_lines, body_cols);
363 
364 	wresize(tabline, 1, COLS);
365 
366 	wrap_page(&current_tab->buffer, body_cols);
367 	redraw_tab(current_tab);
368 }
369 
370 static int
371 wrap_page(struct buffer *buffer, int width)
372 {
373 	struct line		*l;
374 	const struct line	*top_orig, *orig;
375 	struct vline		*vl;
376 	int			 pre_width;
377 	const char		*prfx;
378 
379 	top_orig = buffer->top_line == NULL ? NULL : buffer->top_line->parent;
380 	orig = buffer->current_line == NULL ? NULL : buffer->current_line->parent;
381 
382 	buffer->top_line = NULL;
383 	buffer->current_line = NULL;
384 
385 	buffer->force_redraw = 1;
386 	buffer->curs_y = 0;
387 	buffer->line_off = 0;
388 
389 	empty_vlist(buffer);
390 
391 	TAILQ_FOREACH(l, &buffer->page.head, lines) {
392 		prfx = line_prefixes[l->type].prfx1;
393 		switch (l->type) {
394 		case LINE_TEXT:
395 		case LINE_LINK:
396 		case LINE_TITLE_1:
397 		case LINE_TITLE_2:
398 		case LINE_TITLE_3:
399 		case LINE_ITEM:
400 		case LINE_QUOTE:
401 		case LINE_PRE_START:
402 		case LINE_PRE_END:
403 			wrap_text(buffer, prfx, l, MIN(fill_column, width));
404 			break;
405 		case LINE_PRE_CONTENT:
406 			if (olivetti_mode)
407 				pre_width = MIN(fill_column, width);
408 			else
409 				pre_width = width;
410 			hardwrap_text(buffer, l, pre_width);
411 			break;
412 		case LINE_COMPL:
413 		case LINE_COMPL_CURRENT:
414 			wrap_one(buffer, prfx, l, width);
415 			break;
416 		}
417 
418 		if (top_orig == l && buffer->top_line == NULL) {
419 			buffer->line_off = buffer->line_max-1;
420 			buffer->top_line = TAILQ_LAST(&buffer->head, vhead);
421 
422 			while (1) {
423 				vl = TAILQ_PREV(buffer->top_line, vhead, vlines);
424 				if (vl == NULL || vl->parent != orig)
425 					break;
426 				buffer->top_line = vl;
427 				buffer->line_off--;
428 			}
429 		}
430 
431 		if (orig == l && buffer->current_line == NULL) {
432 			buffer->current_line = TAILQ_LAST(&buffer->head, vhead);
433 
434 			while (1) {
435 				vl = TAILQ_PREV(buffer->current_line, vhead, vlines);
436 				if (vl == NULL || vl->parent != orig)
437 					break;
438 				buffer->current_line = vl;
439 			}
440 		}
441 	}
442 
443         if (buffer->current_line == NULL)
444 		buffer->current_line = TAILQ_FIRST(&buffer->head);
445 
446 	if (buffer->top_line == NULL)
447 		buffer->top_line = buffer->current_line;
448 
449 	return 1;
450 }
451 
452 static void
453 line_prefix_and_text(struct vline *vl, char *buf, size_t len,
454     const char **prfx_ret, const char **text_ret)
455 {
456 	int type, i, cont, width;
457 	char *space, *t;
458 
459 	if ((*text_ret = vl->line) == NULL)
460 		*text_ret = "";
461 
462 	cont = vl->flags & L_CONTINUATION;
463 	type = vl->parent->type;
464 	if (!cont)
465 		*prfx_ret = line_prefixes[type].prfx1;
466 	else
467 		*prfx_ret = line_prefixes[type].prfx2;
468 
469 	space = vl->parent->data;
470 	if (!emojify_link || type != LINE_LINK || space == NULL)
471 		return;
472 
473 	if (cont) {
474 		memset(buf, 0, len);
475 		width = utf8_swidth_between(vl->parent->line, space);
476 		for (i = 0; i < width + 1; ++i)
477 			strlcat(buf, " ", len);
478 	} else {
479 		strlcpy(buf, *text_ret, len);
480 		if ((t = strchr(buf, ' ')) != NULL)
481 			*t = '\0';
482 		strlcat(buf, " ", len);
483 
484 		/* skip the emoji */
485                 *text_ret += (space - vl->parent->line) + 1;
486 	}
487 
488 	*prfx_ret = buf;
489 }
490 
491 static inline void
492 print_vline_descr(int width, WINDOW *window, struct vline *vl)
493 {
494 	int x, y, goal;
495 
496 	if (vl->parent->type != LINE_COMPL &&
497 	    vl->parent->type != LINE_COMPL_CURRENT)
498 		return;
499 
500 	if (vl->parent->alt == NULL)
501 		return;
502 
503 	(void)y;
504 	getyx(window, y, x);
505 
506 	goal = width/2;
507 	if (goal <= x)
508 		wprintw(window, " ");
509 	for (; goal > x; ++x)
510 		wprintw(window, " ");
511 
512 	wprintw(window, "%s", vl->parent->alt);
513 }
514 
515 /*
516  * Core part of the rendering.  It prints a vline starting from the
517  * current cursor position.  Printing a vline consists of skipping
518  * `off' columns (for olivetti-mode), print the correct prefix (which
519  * may be the emoji in case of emojified links-lines), printing the
520  * text itself, filling until width - off and filling off columns
521  * again.
522  */
523 static void
524 print_vline(int off, int width, WINDOW *window, struct vline *vl)
525 {
526 	/*
527 	 * Believe me or not, I've seen emoji ten code points long!
528 	 * That means, to stay large, 4*10 bytes + NUL.
529 	 */
530 	char emojibuf[41] = {0};
531 	const char *text, *prfx;
532 	struct line_face *f;
533 	int i, left, x, y;
534 
535 	f = &line_faces[vl->parent->type];
536 
537 	/* unused, set by getyx */
538 	(void)y;
539 
540 	line_prefix_and_text(vl, emojibuf, sizeof(emojibuf), &prfx, &text);
541 
542 	wattr_on(window, body_face.left, NULL);
543 	for (i = 0; i < off; i++)
544 		waddch(window, ' ');
545 	wattr_off(window, body_face.left, NULL);
546 
547 	wattr_on(window, f->prefix, NULL);
548 	wprintw(window, "%s", prfx);
549 	wattr_off(window, f->prefix, NULL);
550 
551 	wattr_on(window, f->text, NULL);
552 	wprintw(window, "%s", text);
553 	print_vline_descr(width, window, vl);
554 	wattr_off(window, f->text, NULL);
555 
556 	getyx(window, y, x);
557 
558 	left = width - x;
559 
560 	wattr_on(window, f->trail, NULL);
561 	for (i = 0; i < left - off; ++i)
562 		waddch(window, ' ');
563 	wattr_off(window, f->trail, NULL);
564 
565 	wattr_on(window, body_face.right, NULL);
566 	for (i = 0; i < off; i++)
567 		waddch(window, ' ');
568 	wattr_off(window, body_face.right, NULL);
569 
570 }
571 
572 static void
573 redraw_tabline(void)
574 {
575 	struct tab	*tab;
576 	size_t		 toskip, ots, tabwidth, space, x;
577 	int		 current, y, truncated, pair;
578 	const char	*title;
579 	char		 buf[25];
580 
581 	x = 0;
582 
583 	/* unused, but setted by a getyx */
584 	(void)y;
585 
586 	tabwidth = sizeof(buf)+1;
587 	space = COLS-2;
588 
589 	toskip = 0;
590 	TAILQ_FOREACH(tab, &tabshead, tabs) {
591 		toskip++;
592 		if (tab == current_tab)
593 			break;
594 	}
595 
596 	if (toskip * tabwidth < space)
597 		toskip = 0;
598 	else {
599 		ots = toskip;
600 		toskip--;
601                 while (toskip != 0 &&
602 		    (ots - toskip+1) * tabwidth < space)
603 			toskip--;
604 	}
605 
606 	werase(tabline);
607 	wattr_on(tabline, tab_face.background, NULL);
608 	wprintw(tabline, toskip == 0 ? " " : "<");
609 	wattr_off(tabline, tab_face.background, NULL);
610 
611 	truncated = 0;
612 	TAILQ_FOREACH(tab, &tabshead, tabs) {
613 		if (truncated)
614 			break;
615 		if (toskip != 0) {
616 			toskip--;
617 			continue;
618 		}
619 
620 		getyx(tabline, y, x);
621 		if (x + sizeof(buf)+2 >= (size_t)COLS)
622 			truncated = 1;
623 
624 		current = tab == current_tab;
625 
626 		if (*(title = tab->buffer.page.title) == '\0')
627 			title = tab->hist_cur->h;
628 
629 		if (tab->flags & TAB_URGENT)
630 			strlcpy(buf, "!", sizeof(buf));
631 		else
632 			strlcpy(buf, " ", sizeof(buf));
633 
634                 if (strlcat(buf, title, sizeof(buf)) >= sizeof(buf)) {
635 			/* truncation happens */
636 			strlcpy(&buf[sizeof(buf)-4], "...", 4);
637 		} else {
638 			/* pad with spaces */
639 			while (strlcat(buf, "    ", sizeof(buf)) < sizeof(buf))
640 				/* nop */ ;
641 		}
642 
643 		pair = current ? tab_face.current : tab_face.tab;
644 		wattr_on(tabline, pair, NULL);
645 		wprintw(tabline, "%s", buf);
646 		wattr_off(tabline, pair, NULL);
647 
648 		wattr_on(tabline, tab_face.background, NULL);
649 		if (TAILQ_NEXT(tab, tabs) != NULL)
650 			wprintw(tabline, "│");
651 		wattr_off(tabline, tab_face.background, NULL);
652 	}
653 
654 	wattr_on(tabline, tab_face.background, NULL);
655 	for (; x < (size_t)COLS; ++x)
656 		waddch(tabline, ' ');
657 	if (truncated)
658 		mvwprintw(tabline, 0, COLS-1, ">");
659 	wattr_off(tabline, tab_face.background, NULL);
660 }
661 
662 /*
663  * Compute the first visible line around vl.  Try to search forward
664  * until the end of the buffer; if a visible line is not found, search
665  * backward.  Return NULL if no viable line was found.
666  */
667 struct vline *
668 adjust_line(struct vline *vl, struct buffer *buffer)
669 {
670 	struct vline *t;
671 
672 	if (vl == NULL)
673 		return NULL;
674 
675 	if (!(vl->parent->flags & L_HIDDEN))
676 		return vl;
677 
678 	/* search forward */
679 	for (t = vl;
680 	     t != NULL && t->parent->flags & L_HIDDEN;
681 	     t = TAILQ_NEXT(t, vlines))
682 		;		/* nop */
683 
684 	if (t != NULL)
685 		return t;
686 
687 	/* search backward */
688 	for (t = vl;
689 	     t != NULL && t->parent->flags & L_HIDDEN;
690 	     t = TAILQ_PREV(t, vhead, vlines))
691 		;		/* nop */
692 
693 	return t;
694 }
695 
696 static void
697 redraw_window(WINDOW *win, int off, int height, int width, struct buffer *buffer)
698 {
699         struct vline	*vl;
700 	int		 l, onscreen;
701 
702 	restore_curs_x(buffer);
703 
704 	/*
705 	 * TODO: ignoring buffer->force_update and always
706 	 * re-rendering.  In theory we can recompute the y position
707 	 * without a re-render, and optimize here.  It's not the only
708 	 * optimisation possible here, wscrl wolud also be an
709 	 * interesting one.
710 	 */
711 
712 again:
713 	werase(win);
714 	buffer->curs_y = 0;
715 
716 	if (TAILQ_EMPTY(&buffer->head))
717 		goto end;
718 
719 	if (buffer->top_line == NULL)
720 		buffer->top_line = TAILQ_FIRST(&buffer->head);
721 
722 	buffer->top_line = adjust_line(buffer->top_line, buffer);
723 	if (buffer->top_line == NULL)
724 		goto end;
725 
726 	buffer->current_line = adjust_line(buffer->current_line, buffer);
727 
728 	l = 0;
729 	onscreen = 0;
730 	for (vl = buffer->top_line; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
731 		if (vl->parent->flags & L_HIDDEN)
732 			continue;
733 
734 		wmove(win, l, 0);
735 		print_vline(off, width, win, vl);
736 
737 		if (vl == buffer->current_line)
738 			onscreen = 1;
739 
740 		if (!onscreen)
741 			buffer->curs_y++;
742 
743 		l++;
744 		if (l == height)
745 			break;
746 	}
747 
748 	if (!onscreen) {
749 		for (; vl != NULL; vl = TAILQ_NEXT(vl, vlines)) {
750 			if (vl == buffer->current_line)
751 				break;
752 			if (vl->parent->flags & L_HIDDEN)
753 				continue;
754 			buffer->line_off++;
755 			buffer->top_line = TAILQ_NEXT(buffer->top_line, vlines);
756 		}
757 
758 		if (vl != NULL)
759 			goto again;
760 	}
761 
762 	buffer->last_line_off = buffer->line_off;
763 	buffer->force_redraw = 0;
764 end:
765 	wmove(win, buffer->curs_y, buffer->curs_x);
766 }
767 
768 static void
769 redraw_help(void)
770 {
771 	redraw_window(help, 0, help_lines, help_cols, &helpwin);
772 }
773 
774 static void
775 redraw_body(struct tab *tab)
776 {
777 	static struct tab *last_tab;
778 
779 	if (last_tab != tab)
780 		tab->buffer.force_redraw =1;
781 	last_tab = tab;
782 
783 	redraw_window(body, x_offset, body_lines, body_cols, &tab->buffer);
784 }
785 
786 static inline char
787 trust_status_char(enum trust_state ts)
788 {
789 	switch (ts) {
790 	case TS_UNKNOWN:	return 'u';
791 	case TS_UNTRUSTED:	return '!';
792 	case TS_TEMP_TRUSTED:	return '!';
793 	case TS_TRUSTED:	return 'v';
794 	case TS_VERIFIED:	return 'V';
795 	default:		return 'X';
796 	}
797 }
798 
799 static void
800 redraw_modeline(struct tab *tab)
801 {
802 	double		 pct;
803 	int		 x, y, max_x, max_y;
804 	const char	*mode = tab->buffer.page.name;
805 	const char	*spin = "-\\|/";
806 
807 	werase(modeline);
808 	wattr_on(modeline, modeline_face.background, NULL);
809 	wmove(modeline, 0, 0);
810 
811 	wprintw(modeline, "-%c%c %s ",
812 	    spin[tab->loading_anim_step],
813 	    trust_status_char(tab->trust),
814 	    mode == NULL ? "(none)" : mode);
815 
816 	pct = (tab->buffer.line_off + tab->buffer.curs_y) * 100.0
817 		/ tab->buffer.line_max;
818 
819 	if (tab->buffer.line_max <= (size_t)body_lines)
820                 wprintw(modeline, "All ");
821 	else if (tab->buffer.line_off == 0)
822                 wprintw(modeline, "Top ");
823 	else if (tab->buffer.line_off + body_lines >= tab->buffer.line_max)
824 		wprintw(modeline, "Bottom ");
825 	else
826 		wprintw(modeline, "%.0f%% ", pct);
827 
828 	wprintw(modeline, "%d/%d %s ",
829 	    tab->buffer.line_off + tab->buffer.curs_y,
830 	    tab->buffer.line_max,
831 	    tab->hist_cur->h);
832 
833 	getyx(modeline, y, x);
834 	getmaxyx(modeline, max_y, max_x);
835 
836 	(void)y;
837 	(void)max_y;
838 
839 	for (; x < max_x; ++x)
840 		waddstr(modeline, "-");
841 
842 	wattr_off(modeline, modeline_face.background, NULL);
843 }
844 
845 static void
846 redraw_minibuffer(void)
847 {
848 	wattr_on(echoarea, minibuffer_face.background, NULL);
849 	werase(echoarea);
850 
851 	if (in_minibuffer)
852 		do_redraw_minibuffer();
853 	else
854 		do_redraw_echoarea();
855 
856 	if (in_minibuffer == MB_COMPREAD)
857 		do_redraw_minibuffer_compl();
858 
859 	wattr_off(echoarea, minibuffer_face.background, NULL);
860 }
861 
862 static void
863 do_redraw_echoarea(void)
864 {
865 	struct vline *vl;
866 
867 	if (ministate.curmesg != NULL)
868                 wprintw(echoarea, "%s", ministate.curmesg);
869 	else if (*keybuf != '\0')
870 		waddstr(echoarea, keybuf);
871 	else {
872 		/* If nothing else, show the URL at point */
873 		vl = current_tab->buffer.current_line;
874 		if (vl != NULL && vl->parent->type == LINE_LINK)
875 			waddstr(echoarea, vl->parent->alt);
876 	}
877 }
878 
879 static void
880 do_redraw_minibuffer(void)
881 {
882 	size_t		 off_y, off_x = 0;
883 	const char	*start, *c;
884 
885 	/* unused, set by getyx */
886 	(void)off_y;
887 
888 	wmove(echoarea, 0, 0);
889 
890 	if (in_minibuffer == MB_COMPREAD)
891 		wprintw(echoarea, "(%2d) ",
892 		    ministate.compl.buffer.line_max);
893 
894 	wprintw(echoarea, "%s", ministate.prompt);
895 	if (ministate.hist_cur != NULL)
896 		wprintw(echoarea, "(%zu/%zu) ",
897 		    ministate.hist_off + 1,
898 		    ministate.history->len);
899 
900 	getyx(echoarea, off_y, off_x);
901 
902 	start = ministate.hist_cur != NULL
903 		? ministate.hist_cur->h
904 		: ministate.buf;
905 	c = utf8_nth(ministate.buffer.current_line->line,
906 	    ministate.buffer.cpoff);
907 	while (utf8_swidth_between(start, c) > (size_t)COLS/2) {
908 		start = utf8_next_cp(start);
909 	}
910 
911 	waddstr(echoarea, start);
912 
913 	if (ministate.curmesg != NULL)
914 		wprintw(echoarea, " [%s]", ministate.curmesg);
915 
916 	wmove(echoarea, 0, off_x + utf8_swidth_between(start, c));
917 }
918 
919 static void
920 do_redraw_minibuffer_compl(void)
921 {
922 	redraw_window(minibuffer, 0, 10, body_cols,
923 	    &ministate.compl.buffer);
924 }
925 
926 /*
927  * Place the cursor in the right ncurses window.  If soft is 1, use
928  * wnoutrefresh (which shouldn't cause any I/O); otherwise use
929  * wrefresh.
930  */
931 static void
932 place_cursor(int soft)
933 {
934 	int (*touch)(WINDOW *);
935 
936 	if (soft)
937 		touch = wnoutrefresh;
938 	else
939 		touch = wrefresh;
940 
941 	if (in_minibuffer) {
942 		touch(body);
943 		touch(echoarea);
944 	} else {
945 		touch(echoarea);
946 		touch(body);
947 	}
948 }
949 
950 static void
951 redraw_tab(struct tab *tab)
952 {
953 	if (too_small)
954 		return;
955 
956 	if (side_window) {
957 		redraw_help();
958 		wnoutrefresh(help);
959 	}
960 
961 	redraw_tabline();
962 	redraw_body(tab);
963 	redraw_modeline(tab);
964 	redraw_minibuffer();
965 
966 	wnoutrefresh(tabline);
967 	wnoutrefresh(modeline);
968 
969 	if (in_minibuffer == MB_COMPREAD)
970 		wnoutrefresh(minibuffer);
971 
972 	place_cursor(1);
973 
974 	doupdate();
975 
976 	if (set_title)
977 		dprintf(1, "\033]0;%s - Telescope\a",
978 		    current_tab->buffer.page.title);
979 }
980 
981 static void
982 emit_help_item(char *prfx, void *fn)
983 {
984 	struct line	*l;
985 	struct cmd	*cmd;
986 
987 	for (cmd = cmds; cmd->cmd != NULL; ++cmd) {
988 		if (fn == cmd->fn)
989 			break;
990 	}
991 	assert(cmd != NULL);
992 
993 	if ((l = calloc(1, sizeof(*l))) == NULL)
994 		abort();
995 
996 	l->type = LINE_TEXT;
997 	l->alt = NULL;
998 
999 	asprintf(&l->line, "%s %s", prfx, cmd->cmd);
1000 
1001 	if (TAILQ_EMPTY(&helpwin.page.head))
1002 		TAILQ_INSERT_HEAD(&helpwin.page.head, l, lines);
1003 	else
1004 		TAILQ_INSERT_TAIL(&helpwin.page.head, l, lines);
1005 }
1006 
1007 static void
1008 rec_compute_help(struct kmap *keymap, char *prfx, size_t len)
1009 {
1010 	struct keymap	*k;
1011 	char		 p[32];
1012 	const char	*kn;
1013 
1014 	TAILQ_FOREACH(k, &keymap->m, keymaps) {
1015 		strlcpy(p, prfx, sizeof(p));
1016 		if (*p != '\0')
1017 			strlcat(p, " ", sizeof(p));
1018 		if (k->meta)
1019 			strlcat(p, "M-", sizeof(p));
1020 		if ((kn = unkbd(k->key)) != NULL)
1021 			strlcat(p, kn, sizeof(p));
1022 		else
1023 			strlcat(p, keyname(k->key), sizeof(p));
1024 
1025 		if (k->fn == NULL)
1026 			rec_compute_help(&k->map, p, sizeof(p));
1027 		else
1028 			emit_help_item(p, k->fn);
1029 	}
1030 }
1031 
1032 static void
1033 recompute_help(void)
1034 {
1035 	char	p[32] = { 0 };
1036 
1037 	empty_vlist(&helpwin);
1038 	empty_linelist(&helpwin);
1039 	rec_compute_help(current_map, p, sizeof(p));
1040 	wrap_page(&helpwin, help_cols);
1041 }
1042 
1043 void
1044 vmessage(const char *fmt, va_list ap)
1045 {
1046 	if (evtimer_pending(&clechoev, NULL))
1047 		evtimer_del(&clechoev);
1048 
1049 	free(ministate.curmesg);
1050 	ministate.curmesg = NULL;
1051 
1052 	if (fmt != NULL) {
1053 		evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1054 		evtimer_add(&clechoev, &clechoev_timer);
1055 
1056 		/* TODO: what to do if the allocation fails here? */
1057 		if (vasprintf(&ministate.curmesg, fmt, ap) == -1)
1058 			ministate.curmesg = NULL;
1059 	}
1060 
1061 	redraw_minibuffer();
1062         place_cursor(0);
1063 }
1064 
1065 void
1066 message(const char *fmt, ...)
1067 {
1068 	va_list ap;
1069 
1070 	va_start(ap, fmt);
1071 	vmessage(fmt, ap);
1072 	va_end(ap);
1073 }
1074 
1075 void
1076 start_loading_anim(struct tab *tab)
1077 {
1078 	if (tab->loading_anim)
1079 		return;
1080 	tab->loading_anim = 1;
1081 	evtimer_set(&tab->loadingev, update_loading_anim, tab);
1082 	evtimer_add(&tab->loadingev, &loadingev_timer);
1083 }
1084 
1085 static void
1086 update_loading_anim(int fd, short ev, void *d)
1087 {
1088 	struct tab	*tab = d;
1089 
1090 	tab->loading_anim_step = (tab->loading_anim_step+1)%4;
1091 
1092 	if (tab == current_tab) {
1093 		redraw_modeline(tab);
1094 		wrefresh(modeline);
1095 		wrefresh(body);
1096 		if (in_minibuffer)
1097 			wrefresh(echoarea);
1098 	}
1099 
1100 	evtimer_add(&tab->loadingev, &loadingev_timer);
1101 }
1102 
1103 static void
1104 stop_loading_anim(struct tab *tab)
1105 {
1106 	if (!tab->loading_anim)
1107 		return;
1108 	evtimer_del(&tab->loadingev);
1109 	tab->loading_anim = 0;
1110 	tab->loading_anim_step = 0;
1111 
1112 	if (tab != current_tab)
1113 		return;
1114 
1115 	redraw_modeline(tab);
1116 
1117 	wrefresh(modeline);
1118 	wrefresh(body);
1119 	if (in_minibuffer)
1120 		wrefresh(echoarea);
1121 }
1122 
1123 void
1124 load_url_in_tab(struct tab *tab, const char *url)
1125 {
1126 	if (!operating) {
1127 		load_url(tab, url);
1128 		return;
1129 	}
1130 
1131 	message("Loading %s...", url);
1132 	start_loading_anim(tab);
1133 	load_url(tab, url);
1134 
1135 	redraw_tab(tab);
1136 }
1137 
1138 void
1139 switch_to_tab(struct tab *tab)
1140 {
1141 	current_tab = tab;
1142 	tab->flags &= ~TAB_URGENT;
1143 
1144 	if (operating && tab->flags & TAB_LAZY)
1145 		load_url_in_tab(tab, tab->hist_cur->h);
1146 }
1147 
1148 unsigned int
1149 tab_new_id(void)
1150 {
1151 	return tab_counter++;
1152 }
1153 
1154 struct tab *
1155 new_tab(const char *url)
1156 {
1157 	struct tab	*tab;
1158 
1159 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
1160 		event_loopbreak();
1161 		return NULL;
1162 	}
1163 	tab->fd = -1;
1164 
1165 	TAILQ_INIT(&tab->hist.head);
1166 
1167 	TAILQ_INIT(&tab->buffer.head);
1168 
1169 	tab->id = tab_new_id();
1170 	if (!operating)
1171 		tab->flags |= TAB_LAZY;
1172 	switch_to_tab(tab);
1173 
1174 	if (TAILQ_EMPTY(&tabshead))
1175 		TAILQ_INSERT_HEAD(&tabshead, tab, tabs);
1176 	else
1177 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
1178 
1179 	load_url_in_tab(tab, url);
1180 	return tab;
1181 }
1182 
1183 int
1184 ui_print_colors(void)
1185 {
1186 	int colors = 0, pairs = 0, can_change = 0;
1187 	int columns = 16, lines, color, i, j;
1188 
1189 	initscr();
1190 	if (has_colors()) {
1191 		start_color();
1192 		use_default_colors();
1193 
1194 		colors = COLORS;
1195 		pairs = COLOR_PAIRS;
1196 		can_change = can_change_color();
1197 	}
1198 	endwin();
1199 
1200 	printf("Term info:\n");
1201 	printf("TERM=%s COLORS=%d COLOR_PAIRS=%d can_change_colors=%d\n",
1202 	    getenv("TERM"), colors, pairs, can_change);
1203 	printf("\n");
1204 
1205 	if (colors == 0) {
1206 		printf("No color support\n");
1207 		return 0;
1208 	}
1209 
1210 	printf("Available colors:\n\n");
1211 	lines = (colors - 1) / columns + 1;
1212 	color = 0;
1213 	for (i = 0; i < lines; ++i) {
1214 		for (j = 0; j < columns; ++j, ++color) {
1215 			printf("\033[0;38;5;%dm %03d", color, color);
1216 		}
1217 		printf("\n");
1218 	}
1219 
1220 	printf("\033[0m");
1221 	fflush(stdout);
1222 	return 0;
1223 }
1224 
1225 int
1226 ui_init()
1227 {
1228 	setlocale(LC_ALL, "");
1229 
1230 	TAILQ_INIT(&eecmd_history.head);
1231 	TAILQ_INIT(&ir_history.head);
1232 	TAILQ_INIT(&lu_history.head);
1233 
1234 	ministate.line.type = LINE_TEXT;
1235 	ministate.vline.parent = &ministate.line;
1236 	ministate.buffer.current_line = &ministate.vline;
1237 
1238 	/* initialize help window */
1239 	TAILQ_INIT(&helpwin.head);
1240 
1241 	base_map = &global_map;
1242 	current_map = &global_map;
1243 
1244 	initscr();
1245 
1246 	if (enable_colors) {
1247 		if (has_colors()) {
1248 			start_color();
1249 			use_default_colors();
1250 		} else
1251 			enable_colors = 0;
1252 	}
1253 
1254 	config_apply_style();
1255 
1256 	raw();
1257 	noecho();
1258 	nonl();
1259 	intrflush(stdscr, FALSE);
1260 
1261 	if ((tabline = newwin(1, COLS, 0, 0)) == NULL)
1262 		return 0;
1263 	if ((body = newwin(LINES - 3, COLS, 1, 0)) == NULL)
1264 		return 0;
1265 	if ((modeline = newwin(1, COLS, LINES-2, 0)) == NULL)
1266 		return 0;
1267 	if ((echoarea = newwin(1, COLS, LINES-1, 0)) == NULL)
1268 		return 0;
1269 	if ((minibuffer = newwin(1, COLS, LINES-1, 0)) == NULL)
1270 		return 0;
1271 	if ((help = newwin(1, 1, 1, 0)) == NULL)
1272 		return 0;
1273 
1274 	body_lines = LINES-3;
1275 	body_cols = COLS;
1276 
1277 	wbkgd(body, body_face.body);
1278 	wbkgd(echoarea, minibuffer_face.background);
1279 
1280 	update_x_offset();
1281 
1282 	keypad(body, TRUE);
1283 	scrollok(body, FALSE);
1284 
1285 	/* non-blocking input */
1286 	wtimeout(body, 0);
1287 
1288 	mvwprintw(body, 0, 0, "");
1289 
1290 	/*
1291 	 * Dummy so libevent2 won't complain that no event_base is set
1292 	 * when checking event_pending for the first time
1293 	 */
1294 	evtimer_set(&clechoev, handle_clear_echoarea, NULL);
1295 	evtimer_set(&resizeev, handle_resize, NULL);
1296 
1297 	event_set(&stdioev, 0, EV_READ | EV_PERSIST, dispatch_stdio, NULL);
1298 	event_add(&stdioev, NULL);
1299 
1300 	signal_set(&winchev, SIGWINCH, handle_resize, NULL);
1301 	signal_add(&winchev, NULL);
1302 
1303 	return 1;
1304 }
1305 
1306 void
1307 ui_main_loop(void)
1308 {
1309 	operating = 1;
1310 	switch_to_tab(current_tab);
1311 	redraw_tab(current_tab);
1312 
1313 	event_dispatch();
1314 }
1315 
1316 void
1317 ui_on_tab_loaded(struct tab *tab)
1318 {
1319 	stop_loading_anim(tab);
1320 	message("Loaded %s", tab->hist_cur->h);
1321 
1322 	redraw_tabline();
1323 	wrefresh(tabline);
1324 	place_cursor(0);
1325 }
1326 
1327 void
1328 ui_on_tab_refresh(struct tab *tab)
1329 {
1330 	wrap_page(&tab->buffer, body_cols);
1331 	if (tab == current_tab)
1332 		redraw_tab(tab);
1333 	else
1334 		tab->flags |= TAB_URGENT;
1335 }
1336 
1337 const char *
1338 ui_keyname(int k)
1339 {
1340 	return keyname(k);
1341 }
1342 
1343 void
1344 ui_toggle_side_window(void)
1345 {
1346 	side_window = !side_window;
1347 	if (side_window)
1348 		recompute_help();
1349 
1350 	/*
1351 	 * ugly hack, but otherwise the window doesn't get updated
1352 	 * until I call rearrange_windows a second time (e.g. via
1353 	 * C-l).  I will be happy to know why something like this is
1354 	 * needed.
1355 	 */
1356 	rearrange_windows();
1357 	rearrange_windows();
1358 }
1359 
1360 void
1361 ui_schedule_redraw(void)
1362 {
1363 	should_rearrange_windows = 1;
1364 }
1365 
1366 void
1367 ui_require_input(struct tab *tab, int hide)
1368 {
1369 	/* TODO: hard-switching to another tab is ugly */
1370 	switch_to_tab(tab);
1371 
1372 	enter_minibuffer(ir_self_insert, ir_select, exit_minibuffer,
1373 	    &ir_history, NULL, NULL);
1374 	strlcpy(ministate.prompt, "Input required: ",
1375 	    sizeof(ministate.prompt));
1376 	redraw_tab(tab);
1377 }
1378 
1379 void
1380 ui_yornp(const char *prompt, void (*fn)(int, struct tab *),
1381     struct tab *data)
1382 {
1383 	yornp(prompt, fn, data);
1384 	redraw_tab(current_tab);
1385 }
1386 
1387 void
1388 ui_read(const char *prompt, void (*fn)(const char*, struct tab *),
1389     struct tab *data)
1390 {
1391 	completing_read(prompt, fn, data);
1392 	redraw_tab(current_tab);
1393 }
1394 
1395 void
1396 ui_suspend(void)
1397 {
1398 	endwin();
1399 
1400 	kill(getpid(), SIGSTOP);
1401 
1402 	refresh();
1403 	clear();
1404 	rearrange_windows();
1405 }
1406 
1407 void
1408 ui_end(void)
1409 {
1410 	endwin();
1411 }