xref: /openbsd-src/usr.bin/tmux/screen.c (revision 897fc685943471cf985a0fe38ba076ea6fe74fa5)
1 /* $OpenBSD: screen.c,v 1.50 2017/11/15 19:21:24 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 struct screen_title_entry {
29 	char				*text;
30 
31 	TAILQ_ENTRY(screen_title_entry)	 entry;
32 };
33 TAILQ_HEAD(screen_titles, screen_title_entry);
34 
35 static void	screen_resize_x(struct screen *, u_int);
36 static void	screen_resize_y(struct screen *, u_int);
37 
38 static void	screen_reflow(struct screen *, u_int);
39 
40 /* Free titles stack. */
41 static void
42 screen_free_titles(struct screen *s)
43 {
44 	struct screen_title_entry	*title_entry;
45 
46 	if (s->titles == NULL)
47 		return;
48 
49 	while ((title_entry = TAILQ_FIRST(s->titles)) != NULL) {
50 		TAILQ_REMOVE(s->titles, title_entry, entry);
51 		free(title_entry->text);
52 		free(title_entry);
53 	}
54 
55 	free(s->titles);
56 	s->titles = NULL;
57 }
58 
59 /* Create a new screen. */
60 void
61 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
62 {
63 	s->grid = grid_create(sx, sy, hlimit);
64 	s->title = xstrdup("");
65 	s->titles = NULL;
66 
67 	s->cstyle = 0;
68 	s->ccolour = xstrdup("");
69 	s->tabs = NULL;
70 
71 	screen_reinit(s);
72 }
73 
74 /* Reinitialise screen. */
75 void
76 screen_reinit(struct screen *s)
77 {
78 	s->cx = 0;
79 	s->cy = 0;
80 
81 	s->rupper = 0;
82 	s->rlower = screen_size_y(s) - 1;
83 
84 	s->mode = MODE_CURSOR | MODE_WRAP;
85 
86 	screen_reset_tabs(s);
87 
88 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy, 8);
89 
90 	screen_clear_selection(s);
91 	screen_free_titles(s);
92 }
93 
94 /* Destroy a screen. */
95 void
96 screen_free(struct screen *s)
97 {
98 	free(s->tabs);
99 	free(s->title);
100 	free(s->ccolour);
101 
102 	grid_destroy(s->grid);
103 
104 	screen_free_titles(s);
105 }
106 
107 /* Reset tabs to default, eight spaces apart. */
108 void
109 screen_reset_tabs(struct screen *s)
110 {
111 	u_int	i;
112 
113 	free(s->tabs);
114 
115 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
116 		fatal("bit_alloc failed");
117 	for (i = 8; i < screen_size_x(s); i += 8)
118 		bit_set(s->tabs, i);
119 }
120 
121 /* Set screen cursor style. */
122 void
123 screen_set_cursor_style(struct screen *s, u_int style)
124 {
125 	if (style <= 6)
126 		s->cstyle = style;
127 }
128 
129 /* Set screen cursor colour. */
130 void
131 screen_set_cursor_colour(struct screen *s, const char *colour)
132 {
133 	free(s->ccolour);
134 	s->ccolour = xstrdup(colour);
135 }
136 
137 /* Set screen title. */
138 void
139 screen_set_title(struct screen *s, const char *title)
140 {
141 	free(s->title);
142 	utf8_stravis(&s->title, title, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
143 }
144 
145 /* Push the current title onto the stack. */
146 void
147 screen_push_title(struct screen *s)
148 {
149 	struct screen_title_entry *title_entry;
150 
151 	if (s->titles == NULL) {
152 		s->titles = xmalloc(sizeof *s->titles);
153 		TAILQ_INIT(s->titles);
154 	}
155 	title_entry = xmalloc(sizeof *title_entry);
156 	title_entry->text = xstrdup(s->title);
157 	TAILQ_INSERT_HEAD(s->titles, title_entry, entry);
158 }
159 
160 /*
161  * Pop a title from the stack and set it as the screen title. If the stack is
162  * empty, do nothing.
163  */
164 void
165 screen_pop_title(struct screen *s)
166 {
167 	struct screen_title_entry *title_entry;
168 
169 	if (s->titles == NULL)
170 		return;
171 
172 	title_entry = TAILQ_FIRST(s->titles);
173 	if (title_entry != NULL) {
174 		screen_set_title(s, title_entry->text);
175 
176 		TAILQ_REMOVE(s->titles, title_entry, entry);
177 		free(title_entry->text);
178 		free(title_entry);
179 	}
180 }
181 
182 /* Resize screen. */
183 void
184 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
185 {
186 	if (sx < 1)
187 		sx = 1;
188 	if (sy < 1)
189 		sy = 1;
190 
191 	if (sx != screen_size_x(s)) {
192 		screen_resize_x(s, sx);
193 
194 		/*
195 		 * It is unclear what should happen to tabs on resize. xterm
196 		 * seems to try and maintain them, rxvt resets them. Resetting
197 		 * is simpler and more reliable so let's do that.
198 		 */
199 		screen_reset_tabs(s);
200 	} else
201 		reflow = 0;
202 
203 	if (sy != screen_size_y(s))
204 		screen_resize_y(s, sy);
205 
206 	if (reflow)
207 		screen_reflow(s, sx);
208 }
209 
210 static void
211 screen_resize_x(struct screen *s, u_int sx)
212 {
213 	struct grid		*gd = s->grid;
214 
215 	if (sx == 0)
216 		fatalx("zero size");
217 
218 	/*
219 	 * Treat resizing horizontally simply: just ensure the cursor is
220 	 * on-screen and change the size. Don't bother to truncate any lines -
221 	 * then the data should be accessible if the size is then increased.
222 	 *
223 	 * The only potential wrinkle is if UTF-8 double-width characters are
224 	 * left in the last column, but UTF-8 terminals should deal with this
225 	 * sanely.
226 	 */
227 	if (s->cx >= sx)
228 		s->cx = sx - 1;
229 	gd->sx = sx;
230 }
231 
232 static void
233 screen_resize_y(struct screen *s, u_int sy)
234 {
235 	struct grid	*gd = s->grid;
236 	u_int		 needed, available, oldy, i;
237 
238 	if (sy == 0)
239 		fatalx("zero size");
240 	oldy = screen_size_y(s);
241 
242 	/*
243 	 * When resizing:
244 	 *
245 	 * If the height is decreasing, delete lines from the bottom until
246 	 * hitting the cursor, then push lines from the top into the history.
247 	 *
248 	 * When increasing, pull as many lines as possible from scrolled
249 	 * history (not explicitly cleared from view) to the top, then fill the
250 	 * remaining with blanks at the bottom.
251 	 */
252 
253 	/* Size decreasing. */
254 	if (sy < oldy) {
255 		needed = oldy - sy;
256 
257 		/* Delete as many lines as possible from the bottom. */
258 		available = oldy - 1 - s->cy;
259 		if (available > 0) {
260 			if (available > needed)
261 				available = needed;
262 			grid_view_delete_lines(gd, oldy - available, available,
263 			    8);
264 		}
265 		needed -= available;
266 
267 		/*
268 		 * Now just increase the history size, if possible, to take
269 		 * over the lines which are left. If history is off, delete
270 		 * lines from the top.
271 		 */
272 		available = s->cy;
273 		if (gd->flags & GRID_HISTORY) {
274 			gd->hscrolled += needed;
275 			gd->hsize += needed;
276 		} else if (needed > 0 && available > 0) {
277 			if (available > needed)
278 				available = needed;
279 			grid_view_delete_lines(gd, 0, available, 8);
280 		}
281 		s->cy -= needed;
282 	}
283 
284 	/* Resize line arrays. */
285 	gd->linedata = xreallocarray(gd->linedata, gd->hsize + sy,
286 	    sizeof *gd->linedata);
287 
288 	/* Size increasing. */
289 	if (sy > oldy) {
290 		needed = sy - oldy;
291 
292 		/*
293 		 * Try to pull as much as possible out of scrolled history, if
294 		 * is is enabled.
295 		 */
296 		available = gd->hscrolled;
297 		if (gd->flags & GRID_HISTORY && available > 0) {
298 			if (available > needed)
299 				available = needed;
300 			gd->hscrolled -= available;
301 			gd->hsize -= available;
302 			s->cy += available;
303 		} else
304 			available = 0;
305 		needed -= available;
306 
307 		/* Then fill the rest in with blanks. */
308 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
309 			memset(&gd->linedata[i], 0, sizeof gd->linedata[i]);
310 	}
311 
312 	/* Set the new size, and reset the scroll region. */
313 	gd->sy = sy;
314 	s->rupper = 0;
315 	s->rlower = screen_size_y(s) - 1;
316 }
317 
318 /* Set selection. */
319 void
320 screen_set_selection(struct screen *s, u_int sx, u_int sy,
321     u_int ex, u_int ey, u_int rectflag, struct grid_cell *gc)
322 {
323 	struct screen_sel	*sel = &s->sel;
324 
325 	memcpy(&sel->cell, gc, sizeof sel->cell);
326 	sel->flag = 1;
327 	sel->hidden = 0;
328 
329 	sel->rectflag = rectflag;
330 
331 	sel->sx = sx; sel->sy = sy;
332 	sel->ex = ex; sel->ey = ey;
333 }
334 
335 /* Clear selection. */
336 void
337 screen_clear_selection(struct screen *s)
338 {
339 	struct screen_sel	*sel = &s->sel;
340 
341 	sel->flag = 0;
342 	sel->hidden = 0;
343 	sel->lineflag = LINE_SEL_NONE;
344 }
345 
346 /* Hide selection. */
347 void
348 screen_hide_selection(struct screen *s)
349 {
350 	struct screen_sel	*sel = &s->sel;
351 
352 	sel->hidden = 1;
353 }
354 
355 /* Check if cell in selection. */
356 int
357 screen_check_selection(struct screen *s, u_int px, u_int py)
358 {
359 	struct screen_sel	*sel = &s->sel;
360 	u_int			 xx;
361 
362 	if (!sel->flag || sel->hidden)
363 		return (0);
364 
365 	if (sel->rectflag) {
366 		if (sel->sy < sel->ey) {
367 			/* start line < end line -- downward selection. */
368 			if (py < sel->sy || py > sel->ey)
369 				return (0);
370 		} else if (sel->sy > sel->ey) {
371 			/* start line > end line -- upward selection. */
372 			if (py > sel->sy || py < sel->ey)
373 				return (0);
374 		} else {
375 			/* starting line == ending line. */
376 			if (py != sel->sy)
377 				return (0);
378 		}
379 
380 		/*
381 		 * Need to include the selection start row, but not the cursor
382 		 * row, which means the selection changes depending on which
383 		 * one is on the left.
384 		 */
385 		if (sel->ex < sel->sx) {
386 			/* Cursor (ex) is on the left. */
387 			if (px < sel->ex)
388 				return (0);
389 
390 			if (px > sel->sx)
391 				return (0);
392 		} else {
393 			/* Selection start (sx) is on the left. */
394 			if (px < sel->sx)
395 				return (0);
396 
397 			if (px > sel->ex)
398 				return (0);
399 		}
400 	} else {
401 		/*
402 		 * Like emacs, keep the top-left-most character, and drop the
403 		 * bottom-right-most, regardless of copy direction.
404 		 */
405 		if (sel->sy < sel->ey) {
406 			/* starting line < ending line -- downward selection. */
407 			if (py < sel->sy || py > sel->ey)
408 				return (0);
409 
410 			if (py == sel->sy && px < sel->sx)
411 				return (0);
412 
413 			if (py == sel->ey && px > sel->ex)
414 				return (0);
415 		} else if (sel->sy > sel->ey) {
416 			/* starting line > ending line -- upward selection. */
417 			if (py > sel->sy || py < sel->ey)
418 				return (0);
419 
420 			if (py == sel->ey && px < sel->ex)
421 				return (0);
422 
423 			if (sel->modekeys == MODEKEY_EMACS)
424 				xx = sel->sx - 1;
425 			else
426 				xx = sel->sx;
427 			if (py == sel->sy && (sel->sx == 0 || px > xx))
428 				return (0);
429 		} else {
430 			/* starting line == ending line. */
431 			if (py != sel->sy)
432 				return (0);
433 
434 			if (sel->ex < sel->sx) {
435 				/* cursor (ex) is on the left */
436 				if (sel->modekeys == MODEKEY_EMACS)
437 					xx = sel->sx - 1;
438 				else
439 					xx = sel->sx;
440 				if (px > xx || px < sel->ex)
441 					return (0);
442 			} else {
443 				/* selection start (sx) is on the left */
444 				if (px < sel->sx || px > sel->ex)
445 					return (0);
446 			}
447 		}
448 	}
449 
450 	return (1);
451 }
452 
453 /* Get selected grid cell. */
454 void
455 screen_select_cell(struct screen *s, struct grid_cell *dst,
456     const struct grid_cell *src)
457 {
458 	if (!s->sel.flag || s->sel.hidden)
459 		return;
460 
461 	memcpy(dst, &s->sel.cell, sizeof *dst);
462 
463 	utf8_copy(&dst->data, &src->data);
464 	dst->attr = dst->attr & ~GRID_ATTR_CHARSET;
465 	dst->attr |= src->attr & GRID_ATTR_CHARSET;
466 	dst->flags = src->flags;
467 }
468 
469 /* Reflow wrapped lines. */
470 static void
471 screen_reflow(struct screen *s, u_int new_x)
472 {
473 	grid_reflow(s->grid, new_x, &s->cy);
474 }
475