xref: /openbsd-src/usr.bin/tmux/layout-custom.c (revision 78fec973f57e9fc9edd564490c79661460ad807b)
1 /* $OpenBSD: layout-custom.c,v 1.21 2022/05/30 12:52:02 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 		return (-1);
167 	layout += 5;
168 	if (csum != layout_checksum(layout)) {
169 		*cause = xstrdup("invalid layout");
170 		return (-1);
171 	}
172 
173 	/* Build the layout. */
174 	lc = layout_construct(NULL, &layout);
175 	if (lc == NULL) {
176 		*cause = xstrdup("invalid layout");
177 		return (-1);
178 	}
179 	if (*layout != '\0') {
180 		*cause = xstrdup("invalid layout");
181 		goto fail;
182 	}
183 
184 	/* Check this window will fit into the layout. */
185 	for (;;) {
186 		npanes = window_count_panes(w);
187 		ncells = layout_count_cells(lc);
188 		if (npanes > ncells) {
189 			xasprintf(cause, "have %u panes but need %u", npanes,
190 			    ncells);
191 			goto fail;
192 		}
193 		if (npanes == ncells)
194 			break;
195 
196 		/* Fewer panes than cells - close the bottom right. */
197 		lcchild = layout_find_bottomright(lc);
198 		layout_destroy_cell(w, lcchild, &lc);
199 	}
200 
201 	/*
202 	 * It appears older versions of tmux were able to generate layouts with
203 	 * an incorrect top cell size - if it is larger than the top child then
204 	 * correct that (if this is still wrong the check code will catch it).
205 	 */
206 	switch (lc->type) {
207 	case LAYOUT_WINDOWPANE:
208 		break;
209 	case LAYOUT_LEFTRIGHT:
210 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
211 			sy = lcchild->sy + 1;
212 			sx += lcchild->sx + 1;
213 		}
214 		break;
215 	case LAYOUT_TOPBOTTOM:
216 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
217 			sx = lcchild->sx + 1;
218 			sy += lcchild->sy + 1;
219 		}
220 		break;
221 	}
222 	if (lc->type != LAYOUT_WINDOWPANE && (lc->sx != sx || lc->sy != sy)) {
223 		log_debug("fix layout %u,%u to %u,%u", lc->sx, lc->sy, sx,sy);
224 		layout_print_cell(lc, __func__, 0);
225 		lc->sx = sx - 1; lc->sy = sy - 1;
226 	}
227 
228 	/* Check the new layout. */
229 	if (!layout_check(lc)) {
230 		*cause = xstrdup("size mismatch after applying layout");
231 		return (-1);
232 	}
233 
234 	/* Resize to the layout size. */
235 	window_resize(w, lc->sx, lc->sy, -1, -1);
236 
237 	/* Destroy the old layout and swap to the new. */
238 	layout_free_cell(w->layout_root);
239 	w->layout_root = lc;
240 
241 	/* Assign the panes into the cells. */
242 	wp = TAILQ_FIRST(&w->panes);
243 	layout_assign(&wp, lc);
244 
245 	/* Update pane offsets and sizes. */
246 	layout_fix_offsets(w);
247 	layout_fix_panes(w, NULL);
248 	recalculate_sizes();
249 
250 	layout_print_cell(lc, __func__, 0);
251 
252 	notify_window("window-layout-changed", w);
253 
254 	return (0);
255 
256 fail:
257 	layout_free_cell(lc);
258 	return (-1);
259 }
260 
261 /* Assign panes into cells. */
262 static void
263 layout_assign(struct window_pane **wp, struct layout_cell *lc)
264 {
265 	struct layout_cell	*lcchild;
266 
267 	switch (lc->type) {
268 	case LAYOUT_WINDOWPANE:
269 		layout_make_leaf(lc, *wp);
270 		*wp = TAILQ_NEXT(*wp, entry);
271 		return;
272 	case LAYOUT_LEFTRIGHT:
273 	case LAYOUT_TOPBOTTOM:
274 		TAILQ_FOREACH(lcchild, &lc->cells, entry)
275 			layout_assign(wp, lcchild);
276 		return;
277 	}
278 }
279 
280 /* Construct a cell from all or part of a layout tree. */
281 static struct layout_cell *
282 layout_construct(struct layout_cell *lcparent, const char **layout)
283 {
284 	struct layout_cell     *lc, *lcchild;
285 	u_int			sx, sy, xoff, yoff;
286 	const char	       *saved;
287 
288 	if (!isdigit((u_char) **layout))
289 		return (NULL);
290 	if (sscanf(*layout, "%ux%u,%u,%u", &sx, &sy, &xoff, &yoff) != 4)
291 		return (NULL);
292 
293 	while (isdigit((u_char) **layout))
294 		(*layout)++;
295 	if (**layout != 'x')
296 		return (NULL);
297 	(*layout)++;
298 	while (isdigit((u_char) **layout))
299 		(*layout)++;
300 	if (**layout != ',')
301 		return (NULL);
302 	(*layout)++;
303 	while (isdigit((u_char) **layout))
304 		(*layout)++;
305 	if (**layout != ',')
306 		return (NULL);
307 	(*layout)++;
308 	while (isdigit((u_char) **layout))
309 		(*layout)++;
310 	if (**layout == ',') {
311 		saved = *layout;
312 		(*layout)++;
313 		while (isdigit((u_char) **layout))
314 			(*layout)++;
315 		if (**layout == 'x')
316 			*layout = saved;
317 	}
318 
319 	lc = layout_create_cell(lcparent);
320 	lc->sx = sx;
321 	lc->sy = sy;
322 	lc->xoff = xoff;
323 	lc->yoff = yoff;
324 
325 	switch (**layout) {
326 	case ',':
327 	case '}':
328 	case ']':
329 	case '\0':
330 		return (lc);
331 	case '{':
332 		lc->type = LAYOUT_LEFTRIGHT;
333 		break;
334 	case '[':
335 		lc->type = LAYOUT_TOPBOTTOM;
336 		break;
337 	default:
338 		goto fail;
339 	}
340 
341 	do {
342 		(*layout)++;
343 		lcchild = layout_construct(lc, layout);
344 		if (lcchild == NULL)
345 			goto fail;
346 		TAILQ_INSERT_TAIL(&lc->cells, lcchild, entry);
347 	} while (**layout == ',');
348 
349 	switch (lc->type) {
350 	case LAYOUT_LEFTRIGHT:
351 		if (**layout != '}')
352 			goto fail;
353 		break;
354 	case LAYOUT_TOPBOTTOM:
355 		if (**layout != ']')
356 			goto fail;
357 		break;
358 	default:
359 		goto fail;
360 	}
361 	(*layout)++;
362 
363 	return (lc);
364 
365 fail:
366 	layout_free_cell(lc);
367 	return (NULL);
368 }
369