xref: /openbsd/usr.bin/tmux/layout-custom.c (revision 3bef86f7)
1 /* $OpenBSD: layout-custom.c,v 1.22 2023/02/02 09:24:59 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2010 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 <ctype.h>
22 #include <string.h>
23 
24 #include "tmux.h"
25 
26 static struct layout_cell	*layout_find_bottomright(struct layout_cell *);
27 static u_short			 layout_checksum(const char *);
28 static int			 layout_append(struct layout_cell *, char *,
29 				     size_t);
30 static struct layout_cell	*layout_construct(struct layout_cell *,
31 				     const char **);
32 static void			 layout_assign(struct window_pane **,
33 				     struct layout_cell *);
34 
35 /* Find the bottom-right cell. */
36 static struct layout_cell *
37 layout_find_bottomright(struct layout_cell *lc)
38 {
39 	if (lc->type == LAYOUT_WINDOWPANE)
40 		return (lc);
41 	lc = TAILQ_LAST(&lc->cells, layout_cells);
42 	return (layout_find_bottomright(lc));
43 }
44 
45 /* Calculate layout checksum. */
46 static u_short
47 layout_checksum(const char *layout)
48 {
49 	u_short	csum;
50 
51 	csum = 0;
52 	for (; *layout != '\0'; layout++) {
53 		csum = (csum >> 1) + ((csum & 1) << 15);
54 		csum += *layout;
55 	}
56 	return (csum);
57 }
58 
59 /* Dump layout as a string. */
60 char *
61 layout_dump(struct layout_cell *root)
62 {
63 	char	layout[8192], *out;
64 
65 	*layout = '\0';
66 	if (layout_append(root, layout, sizeof layout) != 0)
67 		return (NULL);
68 
69 	xasprintf(&out, "%04hx,%s", layout_checksum(layout), layout);
70 	return (out);
71 }
72 
73 /* Append information for a single cell. */
74 static int
75 layout_append(struct layout_cell *lc, char *buf, size_t len)
76 {
77 	struct layout_cell     *lcchild;
78 	char			tmp[64];
79 	size_t			tmplen;
80 	const char	       *brackets = "][";
81 
82 	if (len == 0)
83 		return (-1);
84 
85 	if (lc->wp != NULL) {
86 		tmplen = xsnprintf(tmp, sizeof tmp, "%ux%u,%u,%u,%u",
87 		    lc->sx, lc->sy, lc->xoff, lc->yoff, lc->wp->id);
88 	} else {
89 		tmplen = xsnprintf(tmp, sizeof tmp, "%ux%u,%u,%u",
90 		    lc->sx, lc->sy, lc->xoff, lc->yoff);
91 	}
92 	if (tmplen > (sizeof tmp) - 1)
93 		return (-1);
94 	if (strlcat(buf, tmp, len) >= len)
95 		return (-1);
96 
97 	switch (lc->type) {
98 	case LAYOUT_LEFTRIGHT:
99 		brackets = "}{";
100 		/* FALLTHROUGH */
101 	case LAYOUT_TOPBOTTOM:
102 		if (strlcat(buf, &brackets[1], len) >= len)
103 			return (-1);
104 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
105 			if (layout_append(lcchild, buf, len) != 0)
106 				return (-1);
107 			if (strlcat(buf, ",", len) >= len)
108 				return (-1);
109 		}
110 		buf[strlen(buf) - 1] = brackets[0];
111 		break;
112 	case LAYOUT_WINDOWPANE:
113 		break;
114 	}
115 
116 	return (0);
117 }
118 
119 /* Check layout sizes fit. */
120 static int
121 layout_check(struct layout_cell *lc)
122 {
123 	struct layout_cell	*lcchild;
124 	u_int			 n = 0;
125 
126 	switch (lc->type) {
127 	case LAYOUT_WINDOWPANE:
128 		break;
129 	case LAYOUT_LEFTRIGHT:
130 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
131 			if (lcchild->sy != lc->sy)
132 				return (0);
133 			if (!layout_check(lcchild))
134 				return (0);
135 			n += lcchild->sx + 1;
136 		}
137 		if (n - 1 != lc->sx)
138 			return (0);
139 		break;
140 	case LAYOUT_TOPBOTTOM:
141 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
142 			if (lcchild->sx != lc->sx)
143 				return (0);
144 			if (!layout_check(lcchild))
145 				return (0);
146 			n += lcchild->sy + 1;
147 		}
148 		if (n - 1 != lc->sy)
149 			return (0);
150 		break;
151 	}
152 	return (1);
153 }
154 
155 /* Parse a layout string and arrange window as layout. */
156 int
157 layout_parse(struct window *w, const char *layout, char **cause)
158 {
159 	struct layout_cell	*lc, *lcchild;
160 	struct window_pane	*wp;
161 	u_int			 npanes, ncells, sx = 0, sy = 0;
162 	u_short			 csum;
163 
164 	/* Check validity. */
165 	if (sscanf(layout, "%hx,", &csum) != 1) {
166 		*cause = xstrdup("invalid layout");
167 		return (-1);
168 	}
169 	layout += 5;
170 	if (csum != layout_checksum(layout)) {
171 		*cause = xstrdup("invalid layout");
172 		return (-1);
173 	}
174 
175 	/* Build the layout. */
176 	lc = layout_construct(NULL, &layout);
177 	if (lc == NULL) {
178 		*cause = xstrdup("invalid layout");
179 		return (-1);
180 	}
181 	if (*layout != '\0') {
182 		*cause = xstrdup("invalid layout");
183 		goto fail;
184 	}
185 
186 	/* Check this window will fit into the layout. */
187 	for (;;) {
188 		npanes = window_count_panes(w);
189 		ncells = layout_count_cells(lc);
190 		if (npanes > ncells) {
191 			xasprintf(cause, "have %u panes but need %u", npanes,
192 			    ncells);
193 			goto fail;
194 		}
195 		if (npanes == ncells)
196 			break;
197 
198 		/* Fewer panes than cells - close the bottom right. */
199 		lcchild = layout_find_bottomright(lc);
200 		layout_destroy_cell(w, lcchild, &lc);
201 	}
202 
203 	/*
204 	 * It appears older versions of tmux were able to generate layouts with
205 	 * an incorrect top cell size - if it is larger than the top child then
206 	 * correct that (if this is still wrong the check code will catch it).
207 	 */
208 	switch (lc->type) {
209 	case LAYOUT_WINDOWPANE:
210 		break;
211 	case LAYOUT_LEFTRIGHT:
212 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
213 			sy = lcchild->sy + 1;
214 			sx += lcchild->sx + 1;
215 		}
216 		break;
217 	case LAYOUT_TOPBOTTOM:
218 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
219 			sx = lcchild->sx + 1;
220 			sy += lcchild->sy + 1;
221 		}
222 		break;
223 	}
224 	if (lc->type != LAYOUT_WINDOWPANE && (lc->sx != sx || lc->sy != sy)) {
225 		log_debug("fix layout %u,%u to %u,%u", lc->sx, lc->sy, sx,sy);
226 		layout_print_cell(lc, __func__, 0);
227 		lc->sx = sx - 1; lc->sy = sy - 1;
228 	}
229 
230 	/* Check the new layout. */
231 	if (!layout_check(lc)) {
232 		*cause = xstrdup("size mismatch after applying layout");
233 		return (-1);
234 	}
235 
236 	/* Resize to the layout size. */
237 	window_resize(w, lc->sx, lc->sy, -1, -1);
238 
239 	/* Destroy the old layout and swap to the new. */
240 	layout_free_cell(w->layout_root);
241 	w->layout_root = lc;
242 
243 	/* Assign the panes into the cells. */
244 	wp = TAILQ_FIRST(&w->panes);
245 	layout_assign(&wp, lc);
246 
247 	/* Update pane offsets and sizes. */
248 	layout_fix_offsets(w);
249 	layout_fix_panes(w, NULL);
250 	recalculate_sizes();
251 
252 	layout_print_cell(lc, __func__, 0);
253 
254 	notify_window("window-layout-changed", w);
255 
256 	return (0);
257 
258 fail:
259 	layout_free_cell(lc);
260 	return (-1);
261 }
262 
263 /* Assign panes into cells. */
264 static void
265 layout_assign(struct window_pane **wp, struct layout_cell *lc)
266 {
267 	struct layout_cell	*lcchild;
268 
269 	switch (lc->type) {
270 	case LAYOUT_WINDOWPANE:
271 		layout_make_leaf(lc, *wp);
272 		*wp = TAILQ_NEXT(*wp, entry);
273 		return;
274 	case LAYOUT_LEFTRIGHT:
275 	case LAYOUT_TOPBOTTOM:
276 		TAILQ_FOREACH(lcchild, &lc->cells, entry)
277 			layout_assign(wp, lcchild);
278 		return;
279 	}
280 }
281 
282 /* Construct a cell from all or part of a layout tree. */
283 static struct layout_cell *
284 layout_construct(struct layout_cell *lcparent, const char **layout)
285 {
286 	struct layout_cell     *lc, *lcchild;
287 	u_int			sx, sy, xoff, yoff;
288 	const char	       *saved;
289 
290 	if (!isdigit((u_char) **layout))
291 		return (NULL);
292 	if (sscanf(*layout, "%ux%u,%u,%u", &sx, &sy, &xoff, &yoff) != 4)
293 		return (NULL);
294 
295 	while (isdigit((u_char) **layout))
296 		(*layout)++;
297 	if (**layout != 'x')
298 		return (NULL);
299 	(*layout)++;
300 	while (isdigit((u_char) **layout))
301 		(*layout)++;
302 	if (**layout != ',')
303 		return (NULL);
304 	(*layout)++;
305 	while (isdigit((u_char) **layout))
306 		(*layout)++;
307 	if (**layout != ',')
308 		return (NULL);
309 	(*layout)++;
310 	while (isdigit((u_char) **layout))
311 		(*layout)++;
312 	if (**layout == ',') {
313 		saved = *layout;
314 		(*layout)++;
315 		while (isdigit((u_char) **layout))
316 			(*layout)++;
317 		if (**layout == 'x')
318 			*layout = saved;
319 	}
320 
321 	lc = layout_create_cell(lcparent);
322 	lc->sx = sx;
323 	lc->sy = sy;
324 	lc->xoff = xoff;
325 	lc->yoff = yoff;
326 
327 	switch (**layout) {
328 	case ',':
329 	case '}':
330 	case ']':
331 	case '\0':
332 		return (lc);
333 	case '{':
334 		lc->type = LAYOUT_LEFTRIGHT;
335 		break;
336 	case '[':
337 		lc->type = LAYOUT_TOPBOTTOM;
338 		break;
339 	default:
340 		goto fail;
341 	}
342 
343 	do {
344 		(*layout)++;
345 		lcchild = layout_construct(lc, layout);
346 		if (lcchild == NULL)
347 			goto fail;
348 		TAILQ_INSERT_TAIL(&lc->cells, lcchild, entry);
349 	} while (**layout == ',');
350 
351 	switch (lc->type) {
352 	case LAYOUT_LEFTRIGHT:
353 		if (**layout != '}')
354 			goto fail;
355 		break;
356 	case LAYOUT_TOPBOTTOM:
357 		if (**layout != ']')
358 			goto fail;
359 		break;
360 	default:
361 		goto fail;
362 	}
363 	(*layout)++;
364 
365 	return (lc);
366 
367 fail:
368 	layout_free_cell(lc);
369 	return (NULL);
370 }
371