xref: /openbsd-src/usr.bin/tmux/screen.c (revision c90a81c56dcebd6a1b73fe4aff9b03385b8e63b3)
1 /* $OpenBSD: screen.c,v 1.53 2019/01/15 09:56:31 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <vis.h>
25 
26 #include "tmux.h"
27 
28 /* Selected area in screen. */
29 struct screen_sel {
30 	int		 hidden;
31 	int		 rectangle;
32 	int		 modekeys;
33 
34 	u_int		 sx;
35 	u_int		 sy;
36 
37 	u_int		 ex;
38 	u_int		 ey;
39 
40 	struct grid_cell cell;
41 };
42 
43 /* Entry on title stack. */
44 struct screen_title_entry {
45 	char				*text;
46 
47 	TAILQ_ENTRY(screen_title_entry)	 entry;
48 };
49 TAILQ_HEAD(screen_titles, screen_title_entry);
50 
51 static void	screen_resize_x(struct screen *, u_int);
52 static void	screen_resize_y(struct screen *, u_int);
53 
54 static void	screen_reflow(struct screen *, u_int);
55 
56 /* Free titles stack. */
57 static void
58 screen_free_titles(struct screen *s)
59 {
60 	struct screen_title_entry	*title_entry;
61 
62 	if (s->titles == NULL)
63 		return;
64 
65 	while ((title_entry = TAILQ_FIRST(s->titles)) != NULL) {
66 		TAILQ_REMOVE(s->titles, title_entry, entry);
67 		free(title_entry->text);
68 		free(title_entry);
69 	}
70 
71 	free(s->titles);
72 	s->titles = NULL;
73 }
74 
75 /* Create a new screen. */
76 void
77 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
78 {
79 	s->grid = grid_create(sx, sy, hlimit);
80 	s->title = xstrdup("");
81 	s->titles = NULL;
82 
83 	s->cstyle = 0;
84 	s->ccolour = xstrdup("");
85 	s->tabs = NULL;
86 	s->sel = NULL;
87 
88 	screen_reinit(s);
89 }
90 
91 /* Reinitialise screen. */
92 void
93 screen_reinit(struct screen *s)
94 {
95 	s->cx = 0;
96 	s->cy = 0;
97 
98 	s->rupper = 0;
99 	s->rlower = screen_size_y(s) - 1;
100 
101 	s->mode = MODE_CURSOR | MODE_WRAP;
102 
103 	screen_reset_tabs(s);
104 
105 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy, 8);
106 
107 	screen_clear_selection(s);
108 	screen_free_titles(s);
109 }
110 
111 /* Destroy a screen. */
112 void
113 screen_free(struct screen *s)
114 {
115 	free(s->sel);
116 	free(s->tabs);
117 	free(s->title);
118 	free(s->ccolour);
119 
120 	grid_destroy(s->grid);
121 
122 	screen_free_titles(s);
123 }
124 
125 /* Reset tabs to default, eight spaces apart. */
126 void
127 screen_reset_tabs(struct screen *s)
128 {
129 	u_int	i;
130 
131 	free(s->tabs);
132 
133 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
134 		fatal("bit_alloc failed");
135 	for (i = 8; i < screen_size_x(s); i += 8)
136 		bit_set(s->tabs, i);
137 }
138 
139 /* Set screen cursor style. */
140 void
141 screen_set_cursor_style(struct screen *s, u_int style)
142 {
143 	if (style <= 6)
144 		s->cstyle = style;
145 }
146 
147 /* Set screen cursor colour. */
148 void
149 screen_set_cursor_colour(struct screen *s, const char *colour)
150 {
151 	free(s->ccolour);
152 	s->ccolour = xstrdup(colour);
153 }
154 
155 /* Set screen title. */
156 void
157 screen_set_title(struct screen *s, const char *title)
158 {
159 	free(s->title);
160 	utf8_stravis(&s->title, title, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
161 }
162 
163 /* Push the current title onto the stack. */
164 void
165 screen_push_title(struct screen *s)
166 {
167 	struct screen_title_entry *title_entry;
168 
169 	if (s->titles == NULL) {
170 		s->titles = xmalloc(sizeof *s->titles);
171 		TAILQ_INIT(s->titles);
172 	}
173 	title_entry = xmalloc(sizeof *title_entry);
174 	title_entry->text = xstrdup(s->title);
175 	TAILQ_INSERT_HEAD(s->titles, title_entry, entry);
176 }
177 
178 /*
179  * Pop a title from the stack and set it as the screen title. If the stack is
180  * empty, do nothing.
181  */
182 void
183 screen_pop_title(struct screen *s)
184 {
185 	struct screen_title_entry *title_entry;
186 
187 	if (s->titles == NULL)
188 		return;
189 
190 	title_entry = TAILQ_FIRST(s->titles);
191 	if (title_entry != NULL) {
192 		screen_set_title(s, title_entry->text);
193 
194 		TAILQ_REMOVE(s->titles, title_entry, entry);
195 		free(title_entry->text);
196 		free(title_entry);
197 	}
198 }
199 
200 /* Resize screen. */
201 void
202 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
203 {
204 	if (sx < 1)
205 		sx = 1;
206 	if (sy < 1)
207 		sy = 1;
208 
209 	if (sx != screen_size_x(s)) {
210 		screen_resize_x(s, sx);
211 
212 		/*
213 		 * It is unclear what should happen to tabs on resize. xterm
214 		 * seems to try and maintain them, rxvt resets them. Resetting
215 		 * is simpler and more reliable so let's do that.
216 		 */
217 		screen_reset_tabs(s);
218 	} else
219 		reflow = 0;
220 
221 	if (sy != screen_size_y(s))
222 		screen_resize_y(s, sy);
223 
224 	if (reflow)
225 		screen_reflow(s, sx);
226 }
227 
228 static void
229 screen_resize_x(struct screen *s, u_int sx)
230 {
231 	struct grid		*gd = s->grid;
232 
233 	if (sx == 0)
234 		fatalx("zero size");
235 
236 	/*
237 	 * Treat resizing horizontally simply: just ensure the cursor is
238 	 * on-screen and change the size. Don't bother to truncate any lines -
239 	 * then the data should be accessible if the size is then increased.
240 	 *
241 	 * The only potential wrinkle is if UTF-8 double-width characters are
242 	 * left in the last column, but UTF-8 terminals should deal with this
243 	 * sanely.
244 	 */
245 	if (s->cx >= sx)
246 		s->cx = sx - 1;
247 	gd->sx = sx;
248 }
249 
250 static void
251 screen_resize_y(struct screen *s, u_int sy)
252 {
253 	struct grid	*gd = s->grid;
254 	u_int		 needed, available, oldy, i;
255 
256 	if (sy == 0)
257 		fatalx("zero size");
258 	oldy = screen_size_y(s);
259 
260 	/*
261 	 * When resizing:
262 	 *
263 	 * If the height is decreasing, delete lines from the bottom until
264 	 * hitting the cursor, then push lines from the top into the history.
265 	 *
266 	 * When increasing, pull as many lines as possible from scrolled
267 	 * history (not explicitly cleared from view) to the top, then fill the
268 	 * remaining with blanks at the bottom.
269 	 */
270 
271 	/* Size decreasing. */
272 	if (sy < oldy) {
273 		needed = oldy - sy;
274 
275 		/* Delete as many lines as possible from the bottom. */
276 		available = oldy - 1 - s->cy;
277 		if (available > 0) {
278 			if (available > needed)
279 				available = needed;
280 			grid_view_delete_lines(gd, oldy - available, available,
281 			    8);
282 		}
283 		needed -= available;
284 
285 		/*
286 		 * Now just increase the history size, if possible, to take
287 		 * over the lines which are left. If history is off, delete
288 		 * lines from the top.
289 		 */
290 		available = s->cy;
291 		if (gd->flags & GRID_HISTORY) {
292 			gd->hscrolled += needed;
293 			gd->hsize += needed;
294 		} else if (needed > 0 && available > 0) {
295 			if (available > needed)
296 				available = needed;
297 			grid_view_delete_lines(gd, 0, available, 8);
298 		}
299 		s->cy -= needed;
300 	}
301 
302 	/* Resize line array. */
303 	grid_adjust_lines(gd, gd->hsize + sy);
304 
305 	/* Size increasing. */
306 	if (sy > oldy) {
307 		needed = sy - oldy;
308 
309 		/*
310 		 * Try to pull as much as possible out of scrolled history, if
311 		 * is is enabled.
312 		 */
313 		available = gd->hscrolled;
314 		if (gd->flags & GRID_HISTORY && available > 0) {
315 			if (available > needed)
316 				available = needed;
317 			gd->hscrolled -= available;
318 			gd->hsize -= available;
319 			s->cy += available;
320 		} else
321 			available = 0;
322 		needed -= available;
323 
324 		/* Then fill the rest in with blanks. */
325 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
326 			memset(grid_get_line(gd, i), 0, sizeof(struct grid_line));
327 	}
328 
329 	/* Set the new size, and reset the scroll region. */
330 	gd->sy = sy;
331 	s->rupper = 0;
332 	s->rlower = screen_size_y(s) - 1;
333 }
334 
335 /* Set selection. */
336 void
337 screen_set_selection(struct screen *s, u_int sx, u_int sy,
338     u_int ex, u_int ey, u_int rectangle, int modekeys, struct grid_cell *gc)
339 {
340 	if (s->sel == NULL)
341 		s->sel = xcalloc(1, sizeof *s->sel);
342 
343 	memcpy(&s->sel->cell, gc, sizeof s->sel->cell);
344 	s->sel->hidden = 0;
345 	s->sel->rectangle = rectangle;
346 	s->sel->modekeys = modekeys;
347 
348 	s->sel->sx = sx;
349 	s->sel->sy = sy;
350 	s->sel->ex = ex;
351 	s->sel->ey = ey;
352 }
353 
354 /* Clear selection. */
355 void
356 screen_clear_selection(struct screen *s)
357 {
358 	free(s->sel);
359 	s->sel = NULL;
360 }
361 
362 /* Hide selection. */
363 void
364 screen_hide_selection(struct screen *s)
365 {
366 	if (s->sel != NULL)
367 		s->sel->hidden = 1;
368 }
369 
370 /* Check if cell in selection. */
371 int
372 screen_check_selection(struct screen *s, u_int px, u_int py)
373 {
374 	struct screen_sel	*sel = s->sel;
375 	u_int			 xx;
376 
377 	if (sel == NULL || sel->hidden)
378 		return (0);
379 
380 	if (sel->rectangle) {
381 		if (sel->sy < sel->ey) {
382 			/* start line < end line -- downward selection. */
383 			if (py < sel->sy || py > sel->ey)
384 				return (0);
385 		} else if (sel->sy > sel->ey) {
386 			/* start line > end line -- upward selection. */
387 			if (py > sel->sy || py < sel->ey)
388 				return (0);
389 		} else {
390 			/* starting line == ending line. */
391 			if (py != sel->sy)
392 				return (0);
393 		}
394 
395 		/*
396 		 * Need to include the selection start row, but not the cursor
397 		 * row, which means the selection changes depending on which
398 		 * one is on the left.
399 		 */
400 		if (sel->ex < sel->sx) {
401 			/* Cursor (ex) is on the left. */
402 			if (px < sel->ex)
403 				return (0);
404 
405 			if (px > sel->sx)
406 				return (0);
407 		} else {
408 			/* Selection start (sx) is on the left. */
409 			if (px < sel->sx)
410 				return (0);
411 
412 			if (px > sel->ex)
413 				return (0);
414 		}
415 	} else {
416 		/*
417 		 * Like emacs, keep the top-left-most character, and drop the
418 		 * bottom-right-most, regardless of copy direction.
419 		 */
420 		if (sel->sy < sel->ey) {
421 			/* starting line < ending line -- downward selection. */
422 			if (py < sel->sy || py > sel->ey)
423 				return (0);
424 
425 			if (py == sel->sy && px < sel->sx)
426 				return (0);
427 
428 			if (sel->modekeys == MODEKEY_EMACS)
429 				xx = (sel->ex == 0 ? 0 : sel->ex - 1);
430 			else
431 				xx = sel->ex;
432 			if (py == sel->ey && px > xx)
433 				return (0);
434 		} else if (sel->sy > sel->ey) {
435 			/* starting line > ending line -- upward selection. */
436 			if (py > sel->sy || py < sel->ey)
437 				return (0);
438 
439 			if (py == sel->ey && px < sel->ex)
440 				return (0);
441 
442 			if (sel->modekeys == MODEKEY_EMACS)
443 				xx = sel->sx - 1;
444 			else
445 				xx = sel->sx;
446 			if (py == sel->sy && (sel->sx == 0 || px > xx))
447 				return (0);
448 		} else {
449 			/* starting line == ending line. */
450 			if (py != sel->sy)
451 				return (0);
452 
453 			if (sel->ex < sel->sx) {
454 				/* cursor (ex) is on the left */
455 				if (sel->modekeys == MODEKEY_EMACS)
456 					xx = sel->sx - 1;
457 				else
458 					xx = sel->sx;
459 				if (px > xx || px < sel->ex)
460 					return (0);
461 			} else {
462 				/* selection start (sx) is on the left */
463 				if (sel->modekeys == MODEKEY_EMACS)
464 					xx = (sel->ex == 0 ? 0 : sel->ex - 1);
465 				else
466 					xx = sel->ex;
467 				if (px < sel->sx || px > xx)
468 					return (0);
469 			}
470 		}
471 	}
472 
473 	return (1);
474 }
475 
476 /* Get selected grid cell. */
477 void
478 screen_select_cell(struct screen *s, struct grid_cell *dst,
479     const struct grid_cell *src)
480 {
481 	if (s->sel == NULL || s->sel->hidden)
482 		return;
483 
484 	memcpy(dst, &s->sel->cell, sizeof *dst);
485 
486 	utf8_copy(&dst->data, &src->data);
487 	dst->attr = dst->attr & ~GRID_ATTR_CHARSET;
488 	dst->attr |= src->attr & GRID_ATTR_CHARSET;
489 	dst->flags = src->flags;
490 }
491 
492 /* Reflow wrapped lines. */
493 static void
494 screen_reflow(struct screen *s, u_int new_x)
495 {
496 	grid_reflow(s->grid, new_x, &s->cy);
497 }
498