xref: /netbsd-src/external/bsd/tmux/dist/screen.c (revision f3cfa6f6ce31685c6c4a758bc430e69eb99f50a4)
1 /* $OpenBSD$ */
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 
25 #include "tmux.h"
26 
27 /* Selected area in screen. */
28 struct screen_sel {
29 	int		 hidden;
30 	int		 rectangle;
31 	int		 modekeys;
32 
33 	u_int		 sx;
34 	u_int		 sy;
35 
36 	u_int		 ex;
37 	u_int		 ey;
38 
39 	struct grid_cell cell;
40 };
41 
42 /* Entry on title stack. */
43 struct screen_title_entry {
44 	char				*text;
45 
46 	TAILQ_ENTRY(screen_title_entry)	 entry;
47 };
48 TAILQ_HEAD(screen_titles, screen_title_entry);
49 
50 static void	screen_resize_x(struct screen *, u_int);
51 static void	screen_resize_y(struct screen *, u_int);
52 
53 static void	screen_reflow(struct screen *, u_int);
54 
55 /* Free titles stack. */
56 static void
57 screen_free_titles(struct screen *s)
58 {
59 	struct screen_title_entry	*title_entry;
60 
61 	if (s->titles == NULL)
62 		return;
63 
64 	while ((title_entry = TAILQ_FIRST(s->titles)) != NULL) {
65 		TAILQ_REMOVE(s->titles, title_entry, entry);
66 		free(title_entry->text);
67 		free(title_entry);
68 	}
69 
70 	free(s->titles);
71 	s->titles = NULL;
72 }
73 
74 /* Create a new screen. */
75 void
76 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
77 {
78 	s->grid = grid_create(sx, sy, hlimit);
79 	s->title = xstrdup("");
80 	s->titles = NULL;
81 
82 	s->cstyle = 0;
83 	s->ccolour = xstrdup("");
84 	s->tabs = NULL;
85 	s->sel = NULL;
86 
87 	screen_reinit(s);
88 }
89 
90 /* Reinitialise screen. */
91 void
92 screen_reinit(struct screen *s)
93 {
94 	s->cx = 0;
95 	s->cy = 0;
96 
97 	s->rupper = 0;
98 	s->rlower = screen_size_y(s) - 1;
99 
100 	s->mode = MODE_CURSOR | MODE_WRAP;
101 
102 	screen_reset_tabs(s);
103 
104 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy, 8);
105 
106 	screen_clear_selection(s);
107 	screen_free_titles(s);
108 }
109 
110 /* Destroy a screen. */
111 void
112 screen_free(struct screen *s)
113 {
114 	free(s->sel);
115 	free(s->tabs);
116 	free(s->title);
117 	free(s->ccolour);
118 
119 	grid_destroy(s->grid);
120 
121 	screen_free_titles(s);
122 }
123 
124 /* Reset tabs to default, eight spaces apart. */
125 void
126 screen_reset_tabs(struct screen *s)
127 {
128 	u_int	i;
129 
130 	free(s->tabs);
131 
132 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
133 		fatal("bit_alloc failed");
134 	for (i = 8; i < screen_size_x(s); i += 8)
135 		bit_set(s->tabs, i);
136 }
137 
138 /* Set screen cursor style. */
139 void
140 screen_set_cursor_style(struct screen *s, u_int style)
141 {
142 	if (style <= 6)
143 		s->cstyle = style;
144 }
145 
146 /* Set screen cursor colour. */
147 void
148 screen_set_cursor_colour(struct screen *s, const char *colour)
149 {
150 	free(s->ccolour);
151 	s->ccolour = xstrdup(colour);
152 }
153 
154 /* Set screen title. */
155 void
156 screen_set_title(struct screen *s, const char *title)
157 {
158 	free(s->title);
159 	utf8_stravis(&s->title, title, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
160 }
161 
162 /* Push the current title onto the stack. */
163 void
164 screen_push_title(struct screen *s)
165 {
166 	struct screen_title_entry *title_entry;
167 
168 	if (s->titles == NULL) {
169 		s->titles = xmalloc(sizeof *s->titles);
170 		TAILQ_INIT(s->titles);
171 	}
172 	title_entry = xmalloc(sizeof *title_entry);
173 	title_entry->text = xstrdup(s->title);
174 	TAILQ_INSERT_HEAD(s->titles, title_entry, entry);
175 }
176 
177 /*
178  * Pop a title from the stack and set it as the screen title. If the stack is
179  * empty, do nothing.
180  */
181 void
182 screen_pop_title(struct screen *s)
183 {
184 	struct screen_title_entry *title_entry;
185 
186 	if (s->titles == NULL)
187 		return;
188 
189 	title_entry = TAILQ_FIRST(s->titles);
190 	if (title_entry != NULL) {
191 		screen_set_title(s, title_entry->text);
192 
193 		TAILQ_REMOVE(s->titles, title_entry, entry);
194 		free(title_entry->text);
195 		free(title_entry);
196 	}
197 }
198 
199 /* Resize screen. */
200 void
201 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
202 {
203 	if (sx < 1)
204 		sx = 1;
205 	if (sy < 1)
206 		sy = 1;
207 
208 	if (sx != screen_size_x(s)) {
209 		screen_resize_x(s, sx);
210 
211 		/*
212 		 * It is unclear what should happen to tabs on resize. xterm
213 		 * seems to try and maintain them, rxvt resets them. Resetting
214 		 * is simpler and more reliable so let's do that.
215 		 */
216 		screen_reset_tabs(s);
217 	} else
218 		reflow = 0;
219 
220 	if (sy != screen_size_y(s))
221 		screen_resize_y(s, sy);
222 
223 	if (reflow)
224 		screen_reflow(s, sx);
225 }
226 
227 static void
228 screen_resize_x(struct screen *s, u_int sx)
229 {
230 	struct grid		*gd = s->grid;
231 
232 	if (sx == 0)
233 		fatalx("zero size");
234 
235 	/*
236 	 * Treat resizing horizontally simply: just ensure the cursor is
237 	 * on-screen and change the size. Don't bother to truncate any lines -
238 	 * then the data should be accessible if the size is then increased.
239 	 *
240 	 * The only potential wrinkle is if UTF-8 double-width characters are
241 	 * left in the last column, but UTF-8 terminals should deal with this
242 	 * sanely.
243 	 */
244 	if (s->cx >= sx)
245 		s->cx = sx - 1;
246 	gd->sx = sx;
247 }
248 
249 static void
250 screen_resize_y(struct screen *s, u_int sy)
251 {
252 	struct grid	*gd = s->grid;
253 	u_int		 needed, available, oldy, i;
254 
255 	if (sy == 0)
256 		fatalx("zero size");
257 	oldy = screen_size_y(s);
258 
259 	/*
260 	 * When resizing:
261 	 *
262 	 * If the height is decreasing, delete lines from the bottom until
263 	 * hitting the cursor, then push lines from the top into the history.
264 	 *
265 	 * When increasing, pull as many lines as possible from scrolled
266 	 * history (not explicitly cleared from view) to the top, then fill the
267 	 * remaining with blanks at the bottom.
268 	 */
269 
270 	/* Size decreasing. */
271 	if (sy < oldy) {
272 		needed = oldy - sy;
273 
274 		/* Delete as many lines as possible from the bottom. */
275 		available = oldy - 1 - s->cy;
276 		if (available > 0) {
277 			if (available > needed)
278 				available = needed;
279 			grid_view_delete_lines(gd, oldy - available, available,
280 			    8);
281 		}
282 		needed -= available;
283 
284 		/*
285 		 * Now just increase the history size, if possible, to take
286 		 * over the lines which are left. If history is off, delete
287 		 * lines from the top.
288 		 */
289 		available = s->cy;
290 		if (gd->flags & GRID_HISTORY) {
291 			gd->hscrolled += needed;
292 			gd->hsize += needed;
293 		} else if (needed > 0 && available > 0) {
294 			if (available > needed)
295 				available = needed;
296 			grid_view_delete_lines(gd, 0, available, 8);
297 		}
298 		s->cy -= needed;
299 	}
300 
301 	/* Resize line array. */
302 	grid_adjust_lines(gd, gd->hsize + sy);
303 
304 	/* Size increasing. */
305 	if (sy > oldy) {
306 		needed = sy - oldy;
307 
308 		/*
309 		 * Try to pull as much as possible out of scrolled history, if
310 		 * is is enabled.
311 		 */
312 		available = gd->hscrolled;
313 		if (gd->flags & GRID_HISTORY && available > 0) {
314 			if (available > needed)
315 				available = needed;
316 			gd->hscrolled -= available;
317 			gd->hsize -= available;
318 			s->cy += available;
319 		} else
320 			available = 0;
321 		needed -= available;
322 
323 		/* Then fill the rest in with blanks. */
324 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
325 			memset(grid_get_line(gd, i), 0, sizeof(struct grid_line));
326 	}
327 
328 	/* Set the new size, and reset the scroll region. */
329 	gd->sy = sy;
330 	s->rupper = 0;
331 	s->rlower = screen_size_y(s) - 1;
332 }
333 
334 /* Set selection. */
335 void
336 screen_set_selection(struct screen *s, u_int sx, u_int sy,
337     u_int ex, u_int ey, u_int rectangle, int modekeys, struct grid_cell *gc)
338 {
339 	if (s->sel == NULL)
340 		s->sel = xcalloc(1, sizeof *s->sel);
341 
342 	memcpy(&s->sel->cell, gc, sizeof s->sel->cell);
343 	s->sel->hidden = 0;
344 	s->sel->rectangle = rectangle;
345 	s->sel->modekeys = modekeys;
346 
347 	s->sel->sx = sx;
348 	s->sel->sy = sy;
349 	s->sel->ex = ex;
350 	s->sel->ey = ey;
351 }
352 
353 /* Clear selection. */
354 void
355 screen_clear_selection(struct screen *s)
356 {
357 	free(s->sel);
358 	s->sel = NULL;
359 }
360 
361 /* Hide selection. */
362 void
363 screen_hide_selection(struct screen *s)
364 {
365 	if (s->sel != NULL)
366 		s->sel->hidden = 1;
367 }
368 
369 /* Check if cell in selection. */
370 int
371 screen_check_selection(struct screen *s, u_int px, u_int py)
372 {
373 	struct screen_sel	*sel = s->sel;
374 	u_int			 xx;
375 
376 	if (sel == NULL || sel->hidden)
377 		return (0);
378 
379 	if (sel->rectangle) {
380 		if (sel->sy < sel->ey) {
381 			/* start line < end line -- downward selection. */
382 			if (py < sel->sy || py > sel->ey)
383 				return (0);
384 		} else if (sel->sy > sel->ey) {
385 			/* start line > end line -- upward selection. */
386 			if (py > sel->sy || py < sel->ey)
387 				return (0);
388 		} else {
389 			/* starting line == ending line. */
390 			if (py != sel->sy)
391 				return (0);
392 		}
393 
394 		/*
395 		 * Need to include the selection start row, but not the cursor
396 		 * row, which means the selection changes depending on which
397 		 * one is on the left.
398 		 */
399 		if (sel->ex < sel->sx) {
400 			/* Cursor (ex) is on the left. */
401 			if (px < sel->ex)
402 				return (0);
403 
404 			if (px > sel->sx)
405 				return (0);
406 		} else {
407 			/* Selection start (sx) is on the left. */
408 			if (px < sel->sx)
409 				return (0);
410 
411 			if (px > sel->ex)
412 				return (0);
413 		}
414 	} else {
415 		/*
416 		 * Like emacs, keep the top-left-most character, and drop the
417 		 * bottom-right-most, regardless of copy direction.
418 		 */
419 		if (sel->sy < sel->ey) {
420 			/* starting line < ending line -- downward selection. */
421 			if (py < sel->sy || py > sel->ey)
422 				return (0);
423 
424 			if (py == sel->sy && px < sel->sx)
425 				return (0);
426 
427 			if (py == sel->ey && px > sel->ex)
428 				return (0);
429 		} else if (sel->sy > sel->ey) {
430 			/* starting line > ending line -- upward selection. */
431 			if (py > sel->sy || py < sel->ey)
432 				return (0);
433 
434 			if (py == sel->ey && px < sel->ex)
435 				return (0);
436 
437 			if (sel->modekeys == MODEKEY_EMACS)
438 				xx = sel->sx - 1;
439 			else
440 				xx = sel->sx;
441 			if (py == sel->sy && (sel->sx == 0 || px > xx))
442 				return (0);
443 		} else {
444 			/* starting line == ending line. */
445 			if (py != sel->sy)
446 				return (0);
447 
448 			if (sel->ex < sel->sx) {
449 				/* cursor (ex) is on the left */
450 				if (sel->modekeys == MODEKEY_EMACS)
451 					xx = sel->sx - 1;
452 				else
453 					xx = sel->sx;
454 				if (px > xx || px < sel->ex)
455 					return (0);
456 			} else {
457 				/* selection start (sx) is on the left */
458 				if (px < sel->sx || px > sel->ex)
459 					return (0);
460 			}
461 		}
462 	}
463 
464 	return (1);
465 }
466 
467 /* Get selected grid cell. */
468 void
469 screen_select_cell(struct screen *s, struct grid_cell *dst,
470     const struct grid_cell *src)
471 {
472 	if (s->sel == NULL || s->sel->hidden)
473 		return;
474 
475 	memcpy(dst, &s->sel->cell, sizeof *dst);
476 
477 	utf8_copy(&dst->data, &src->data);
478 	dst->attr = dst->attr & ~GRID_ATTR_CHARSET;
479 	dst->attr |= src->attr & GRID_ATTR_CHARSET;
480 	dst->flags = src->flags;
481 }
482 
483 /* Reflow wrapped lines. */
484 static void
485 screen_reflow(struct screen *s, u_int new_x)
486 {
487 	grid_reflow(s->grid, new_x, &s->cy);
488 }
489